Action to Support Practices Implement Research Evidence (ASPIRE): protocol for a cluster-randomised evaluation of adaptable implementation packages targeting 'high impact' clinical practice recommendations in general practice.

PubMed

Willis, Thomas A; Hartley, Suzanne; Glidewell, Liz; Farrin, Amanda J; Lawton, Rebecca; McEachan, Rosemary R C; Ingleson, Emma; Heudtlass, Peter; Collinson, Michelle; Clamp, Susan; Hunter, Cheryl; Ward, Vicky; Hulme, Claire; Meads, David; Bregantini, Daniele; Carder, Paul; Foy, Robbie

2016-02-29

There are recognised gaps between evidence and practice in general practice, a setting which provides particular challenges for implementation. We earlier screened clinical guideline recommendations to derive a set of 'high impact' indicators based upon criteria including potential for significant patient benefit, scope for improved practice and amenability to measurement using routinely collected data. We aim to evaluate the effectiveness and cost-effectiveness of a multifaceted, adaptable intervention package to implement four targeted, high impact recommendations in general practice. The research programme Action to Support Practice Implement Research Evidence (ASPIRE) includes a pair of pragmatic cluster-randomised trials which use a balanced incomplete block design. Clusters are general practices in West Yorkshire, United Kingdom (UK), recruited using an 'opt-out' recruitment process. The intervention package adapted to each recommendation includes combinations of audit and feedback, educational outreach visits and computerised prompts with embedded behaviour change techniques selected on the basis of identified needs and barriers to change. In trial 1, practices are randomised to adapted interventions targeting either diabetes control or risky prescribing and those in trial 2 to adapted interventions targeting either blood pressure control in patients at risk of cardiovascular events or anticoagulation in atrial fibrillation. The respective primary endpoints comprise achievement of all recommended target levels of haemoglobin A1c (HbA1c), blood pressure and cholesterol in patients with type 2 diabetes, a composite indicator of risky prescribing, achievement of recommended blood pressure targets for specific patient groups and anticoagulation prescribing in patients with atrial fibrillation. We are also randomising practices to a fifth, non-intervention control group to further assess Hawthorne effects. Outcomes will be assessed using routinely collected data extracted 1 year after randomisation. Economic modelling will estimate intervention cost-effectiveness. A process evaluation involving eight non-trial practices will examine intervention delivery, mechanisms of action and unintended consequences. ASPIRE will provide 'real-world' evidence about the effects, cost-effectiveness and delivery of adapted intervention packages targeting high impact recommendations. By implementing our adaptable intervention package across four distinct clinical topics, and using 'opt-out' recruitment, our findings will provide evidence of wider generalisability. ISRCTN91989345.

Colonoscopy screening for colorectal cancer: the outcomes of two recruitment methods.

PubMed

Corbett, Mike; Chambers, Sharon L; Shadbolt, Bruce; Hillman, Lybus C; Taupin, Doug

2004-10-18

To determine the response to colorectal cancer (CRC) screening by colonoscopy, through direct invitation or through invitation by general practitioners. Two-way comparison of randomised population sampling versus cluster sampling of a representative general practice population in the Australian Capital Territory, May 2002 to January 2004. Invitation to screen, assessment for eligibility, interview, and colonoscopy. 881 subjects aged 55-74 years were invited to screen: 520 from the electoral roll (ER) sample and 361 from the general practice (GP) cluster sample. Response rate, participation rate, and rate of adenomatous polyps in the screened group. Participation was similar in the ER arm (35.1%; 95% CI, 30.2%-40.3%) and the GP arm (40.1%; 95% CI, 29.2%-51.0%) after correcting for ineligibility, which was higher in the ER arm. Superior eligibility in the GP arm was offset by the labour of manual record review. Response rates after two invitations were similar for the two groups (ER arm: 78.8%; 95% CI, 75.1%-82.1%; GP arm: 81.7%; 95% CI, 73.8%-89.6%). Overall, 53.4% ineligibility arose from having a colonoscopy in the past 10 years (ER arm, 98/178; GP arm, 42/84). Of 231 colonoscopies performed, 229 were complete, with 32% of subjects screened having adenomatous polyps. Colonoscopy-based CRC screening yields similar response and participation rates with either random population sampling or general practice cluster sampling, with population sampling through the electoral roll providing greater ease of recruitment.

Shape characteristics of equilibrium and non-equilibrium fractal clusters.

PubMed

Mansfield, Marc L; Douglas, Jack F

2013-07-28

It is often difficult in practice to discriminate between equilibrium and non-equilibrium nanoparticle or colloidal-particle clusters that form through aggregation in gas or solution phases. Scattering studies often permit the determination of an apparent fractal dimension, but both equilibrium and non-equilibrium clusters in three dimensions frequently have fractal dimensions near 2, so that it is often not possible to discriminate on the basis of this geometrical property. A survey of the anisotropy of a wide variety of polymeric structures (linear and ring random and self-avoiding random walks, percolation clusters, lattice animals, diffusion-limited aggregates, and Eden clusters) based on the principal components of both the radius of gyration and electric polarizability tensor indicates, perhaps counter-intuitively, that self-similar equilibrium clusters tend to be intrinsically anisotropic at all sizes, while non-equilibrium processes such as diffusion-limited aggregation or Eden growth tend to be isotropic in the large-mass limit, providing a potential means of discriminating these clusters experimentally if anisotropy could be determined along with the fractal dimension. Equilibrium polymer structures, such as flexible polymer chains, are normally self-similar due to the existence of only a single relevant length scale, and are thus anisotropic at all length scales, while non-equilibrium polymer structures that grow irreversibly in time eventually become isotropic if there is no difference in the average growth rates in different directions. There is apparently no proof of these general trends and little theoretical insight into what controls the universal anisotropy in equilibrium polymer structures of various kinds. This is an obvious topic of theoretical investigation, as well as a matter of practical interest. To address this general problem, we consider two experimentally accessible ratios, one between the hydrodynamic and gyration radii, the other between the viscosity and hydrodynamic radii, as potential measures of shape anisotropy. We also find a strong correlation between anisotropy and effective fractal dimension. These observations should provide new practical methods for quantifying the nature of particle clustering in diverse contexts.

Implementation of immunochemical faecal occult blood test in general practice: a study protocol using a cluster-randomised stepped-wedge design.

PubMed

Juul, Jakob Søgaard; Bro, Flemming; Hornung, Nete; Andersen, Berit Sanne; Laurberg, Søren; Olesen, Frede; Vedsted, Peter

2016-07-11

Colorectal cancer is a common malignancy and a leading cause of cancer-related death. Half of patients with colorectal cancer initially present with non-specific or vague symptoms. In the need for a safe low-cost test, the immunochemical faecal occult blood test (iFOBT) may be part of the evaluation of such patients in primary care. Currently, Danish general practitioners have limited access to this test. The aim of this article is to describe a study that will assess the uptake and clinical use of iFOBT in general practice. Furthermore, it will investigate the diagnostic value and the clinical implications of using iFOBT in general practice on patients presenting with non-alarm symptoms of colorectal cancer. The study uses a cluster-randomised stepped-wedge design and is conducted in the Central Denmark Region among 836 GPs in 381 general practices. The municipalities of the Region and their appertaining general practitioners will be included sequentially in the study during the first 7 months of the 1-year study period. The following intervention has been developed for the study: a mandatory intervention providing all general practitioners with a starting package of 10 iFOBTs, a clinical instruction on iFOBT use in general practice and online information material from the date of inclusion, and an optional intervention consisting of a continuous medical education on colorectal cancer diagnostics and use of iFOBT. This study is among the first and largest trials to investigate the diagnostic use and the clinical value of iFOBT on patients presenting with non-alarm symptoms of colorectal cancer. The findings will be of national and international importance for the future planning of colorectal cancer diagnostics, particularly for 'low-risk-but-not-no-risk' patients with non-alarm symptoms of colorectal cancer. A Trial of the Implementation of iFOBT in General Practice NCT02308384 . Date of registration: 26 November 2014.

Evaluation of a practice team-supported exposure training for patients with panic disorder with or without agoraphobia in primary care - study protocol of a cluster randomised controlled superiority trial.

PubMed

Gensichen, Jochen; Hiller, Thomas S; Breitbart, Jörg; Teismann, Tobias; Brettschneider, Christian; Schumacher, Ulrike; Piwtorak, Alexander; König, Hans-Helmut; Hoyer, Heike; Schneider, Nico; Schelle, Mercedes; Blank, Wolfgang; Thiel, Paul; Wensing, Michel; Margraf, Jürgen

2014-04-06

Panic disorder and agoraphobia are debilitating and frequently comorbid anxiety disorders. A large number of patients with these conditions are treated by general practitioners in primary care. Cognitive behavioural exposure exercises have been shown to be effective in reducing anxiety symptoms. Practice team-based case management can improve clinical outcomes for patients with chronic diseases in primary care. The present study compares a practice team-supported, self-managed exposure programme for patients with panic disorder with or without agoraphobia in small general practices to usual care in terms of clinical efficacy and cost-effectiveness. This is a cluster randomised controlled superiority trial with a two-arm parallel group design. General practices represent the units of randomisation. General practitioners recruit adult patients with panic disorder with or without agoraphobia according to the International Classification of Diseases, version 10 (ICD-10). In the intervention group, patients receive cognitive behaviour therapy-oriented psychoeducation and instructions to self-managed exposure exercises in four manual-based appointments with the general practitioner. A trained health care assistant from the practice team delivers case management and is continuously monitoring symptoms and treatment progress in ten protocol-based telephone contacts with patients. In the control group, patients receive usual care from general practitioners. Outcomes are measured at baseline (T0), at follow-up after six months (T1), and at follow-up after twelve months (T2). The primary outcome is clinical severity of anxiety of patients as measured by the Beck Anxiety Inventory (BAI). To detect a standardised effect size of 0.35 at T1, 222 patients from 37 general practices are included in each group. Secondary outcomes include anxiety-related clinical parameters and health-economic costs. Current Controlled Trials [http://ISCRTN64669297].

Evaluation of a practice team-supported exposure training for patients with panic disorder with or without agoraphobia in primary care - study protocol of a cluster randomised controlled superiority trial

PubMed Central

2014-01-01

Background Panic disorder and agoraphobia are debilitating and frequently comorbid anxiety disorders. A large number of patients with these conditions are treated by general practitioners in primary care. Cognitive behavioural exposure exercises have been shown to be effective in reducing anxiety symptoms. Practice team-based case management can improve clinical outcomes for patients with chronic diseases in primary care. The present study compares a practice team-supported, self-managed exposure programme for patients with panic disorder with or without agoraphobia in small general practices to usual care in terms of clinical efficacy and cost-effectiveness. Methods/Design This is a cluster randomised controlled superiority trial with a two-arm parallel group design. General practices represent the units of randomisation. General practitioners recruit adult patients with panic disorder with or without agoraphobia according to the International Classification of Diseases, version 10 (ICD-10). In the intervention group, patients receive cognitive behaviour therapy-oriented psychoeducation and instructions to self-managed exposure exercises in four manual-based appointments with the general practitioner. A trained health care assistant from the practice team delivers case management and is continuously monitoring symptoms and treatment progress in ten protocol-based telephone contacts with patients. In the control group, patients receive usual care from general practitioners. Outcomes are measured at baseline (T0), at follow-up after six months (T1), and at follow-up after twelve months (T2). The primary outcome is clinical severity of anxiety of patients as measured by the Beck Anxiety Inventory (BAI). To detect a standardised effect size of 0.35 at T1, 222 patients from 37 general practices are included in each group. Secondary outcomes include anxiety-related clinical parameters and health-economic costs. Trial registration Current Controlled Trials [http://ISCRTN64669297] PMID:24708672

Improved Cardiovascular Prevention Using Best CME Practices: A Randomized Trial

ERIC Educational Resources Information Center

Laprise, Rejean; Thivierge, Robert; Gosselin, Gilbert; Bujas-Bobanovic, Maja; Vandal, Sylvie; Paquette, Daniel; Luneau, Micheline; Julien, Pierre; Goulet, Serge; Desaulniers, Jean; Maltais, Paule

2009-01-01

Introduction: It was hypothesized that after a continuing medical education (CME) event, practice enablers and reinforcers addressing main clinical barriers to preventive care would be more effective in improving general practitioners' (GPs) adherence to cardiovascular guidelines than a CME event only. Methods: A cluster-randomized trial was…

Health-risk behaviour in Croatia.

PubMed

Bécue-Bertaut, Mónica; Kern, Josipa; Hernández-Maldonado, Maria-Luisa; Juresa, Vesna; Vuletic, Silvije

2008-02-01

To identify the health-risk behaviour of various homogeneous clusters of individuals. The study was conducted in 13 of the 20 Croatian counties and in Zagreb, the Croatian capital. In the first stage, general practices were selected in each county. The second-stage sample was created by drawing a random subsample of 10% of the patients registered at each selected general practice. The sample was divided into seven homogenous clusters using statistical methodology, combining multiple factor analysis with a hybrid clustering method. Seven homogeneous clusters were identified, three composed of males and four composed of females, based on statistically significant differences between selected characteristics (P<0.001). Although, in general, self-assessed health declined with age, significant variations were observed within specific age intervals. Higher levels of self-assessed health were associated with higher levels of education and/or socio-economic status. Many individuals, especially females, who self-reported poor health were heavy consumers of sleeping pills. Males and females reported different health-risk behaviours related to lifestyle, diet and use of the healthcare system. Heavy alcohol and tobacco use, unhealthy diet, risky physical activity and non-use of the healthcare system influenced self-assessed health in males. Females were slightly less satisfied with their health than males of the same age and educational level. Even highly educated females who took preventive healthcare tests and ate a healthy diet reported a less satisfactory self-assessed level of health than expected. Sociodemographic characteristics, life style, self-assessed health and use of the healthcare system were used in the identification of seven homogeneous population clusters. A comprehensive analysis of these clusters suggests health-related prevention and intervention efforts geared towards specific populations.

A pragmatic cluster randomized controlled trial of early intervention for chronic obstructive pulmonary disease by practice nurse-general practitioner teams: Study Protocol

PubMed Central

2012-01-01

Background Chronic Obstructive Pulmonary Disease (COPD) is a leading cause of disability, hospitalization, and premature mortality. General practice is well placed to diagnose and manage COPD, but there is a significant gap between evidence and current practice, with a low level of awareness and implementation of clinical practice guidelines. Under-diagnosis of COPD is a world-wide problem, limiting the benefit that could potentially be achieved through early intervention strategies such as smoking cessation, dietary advice, and exercise. General practice is moving towards more structured chronic disease management, and the increasing involvement of practice nurses in delivering chronic care. Design A pragmatic cluster randomised trial will test the hypothesis that intervention by a practice nurse-general practitioner (GP) team leads to improved health-related quality of life and greater adherence with clinical practice guidelines for patients with newly-diagnosed COPD, compared with usual care. Forty general practices in greater metropolitan Sydney Australia will be recruited to identify patients at risk of COPD and invite them to attend a case finding appointment. Practices will be randomised to deliver either practice nurse-GP partnership care, or usual care, to patients newly-diagnosed with COPD. The active intervention will involve the practice nurse and GP working in partnership with the patient in developing and implementing a care plan involving (as appropriate), smoking cessation, immunisation, pulmonary rehabilitation, medication review, assessment and correction of inhaler technique, nutritional advice, management of psycho-social issues, patient education, and management of co-morbidities. The primary outcome measure is health-related quality of life, assessed with the St George’s Respiratory Questionnaire 12 months after diagnosis. Secondary outcome measures include validated disease-specific and general health related quality of life measures, smoking and immunisation status, medications, inhaler technique, and lung function. Outcomes will be assessed by project officers blinded to patients’ randomization groups. Discussion This study will use proven case-finding methods to identify patients with undiagnosed COPD in general practice, where improved care has the potential for substantial benefit in health and healthcare utilization. The study provides the capacity to trial a new model of team-based assessment and management of newly diagnosed COPD in Australian primary care. Trial registration ACTRN12610000592044\\ PMID:22958678

Multicomponent Program to Reduce Functional Decline in Frail Elderly People: A Cluster Controlled Trial.

PubMed

Ruikes, Franca G H; Zuidema, Sytse U; Akkermans, Reinier P; Assendelft, Willem J J; Schers, Henk J; Koopmans, Raymond T C M

2016-01-01

The increasing number of community-dwelling frail elderly people poses a challenge to general practice. We evaluated the effectiveness of a general practitioner-led extensive, multicomponent program integrating cure, care, and welfare for the prevention of functional decline. We performed a cluster controlled trial in 12 general practices in Nijmegen, the Netherlands. Community-dwelling frail elderly people aged ≥70 years were identified with the EASY-Care two-step older persons screening instrument. In 6 general practices, 287 frail elderly received care according to the CareWell primary care program. This consisted of proactive care planning, case management, medication reviews, and multidisciplinary team meetings with a general practitioner, practice and/or community nurse, elderly care physician, and social worker. In another 6 general practices, 249 participants received care as usual. The primary outcome was independence in functioning during (instrumental) activities of daily living (Katz-15 index). Secondary outcomes were quality of life [EuroQol (EQ5D+C) instrument], mental health and health-related social functioning (36-item RAND Short Form survey instrument), institutionalization, hospitalization, and mortality. Outcomes were assessed at baseline and at 12 months, and were analyzed with linear mixed-model analyses. A total of 204 participants (71.1%) in the intervention group and 165 participants (66.3%) in the control group completed the study. No differences between groups regarding independence in functioning and secondary outcomes were found. We found no evidence for the effectiveness of a multifaceted integrated care program in the prevention of adverse outcomes in community-dwelling frail elderly people. Large-scale implementation of this program is not advocated. © Copyright 2016 by the American Board of Family Medicine.

All Different or All the Same? Exploring the Diversity of Professional Practices in Portuguese School Psychology

ERIC Educational Resources Information Center

Mendes, Sofia A.; Lasser, Jon; Abreu-Lima, Isabel M.; Almeida, Leandro S.

2017-01-01

Studies have generally characterized school psychologists as a relative homogenous population. Understanding the differences in professional practices and related variables is important for the development of the profession. Using a sample of 446 Portuguese school psychologists, this study used cluster analysis to identify distinct profiles of…

Analysis of basic clustering algorithms for numerical estimation of statistical averages in biomolecules.

PubMed

Anandakrishnan, Ramu; Onufriev, Alexey

2008-03-01

In statistical mechanics, the equilibrium properties of a physical system of particles can be calculated as the statistical average over accessible microstates of the system. In general, these calculations are computationally intractable since they involve summations over an exponentially large number of microstates. Clustering algorithms are one of the methods used to numerically approximate these sums. The most basic clustering algorithms first sub-divide the system into a set of smaller subsets (clusters). Then, interactions between particles within each cluster are treated exactly, while all interactions between different clusters are ignored. These smaller clusters have far fewer microstates, making the summation over these microstates, tractable. These algorithms have been previously used for biomolecular computations, but remain relatively unexplored in this context. Presented here, is a theoretical analysis of the error and computational complexity for the two most basic clustering algorithms that were previously applied in the context of biomolecular electrostatics. We derive a tight, computationally inexpensive, error bound for the equilibrium state of a particle computed via these clustering algorithms. For some practical applications, it is the root mean square error, which can be significantly lower than the error bound, that may be more important. We how that there is a strong empirical relationship between error bound and root mean square error, suggesting that the error bound could be used as a computationally inexpensive metric for predicting the accuracy of clustering algorithms for practical applications. An example of error analysis for such an application-computation of average charge of ionizable amino-acids in proteins-is given, demonstrating that the clustering algorithm can be accurate enough for practical purposes.

Electronically delivered, multicomponent intervention to reduce unnecessary antibiotic prescribing for respiratory infections in primary care: a cluster randomised trial using electronic health records—REDUCE Trial study original protocol

PubMed Central

Juszczyk, Dorota; Charlton, Judith; McDermott, Lisa; Soames, Jamie; Sultana, Kirin; Ashworth, Mark; Fox, Robin; Hay, Alastair D; Little, Paul; Moore, Michael V; Yardley, Lucy; Prevost, A Toby; Gulliford, Martin C

2016-01-01

Introduction Respiratory tract infections (RTIs) account for about 60% of antibiotics prescribed in primary care. This study aims to test the effectiveness, in a cluster randomised controlled trial, of electronically delivered, multicomponent interventions to reduce unnecessary antibiotic prescribing when patients consult for RTIs in primary care. The research will specifically evaluate the effectiveness of feeding back electronic health records (EHRs) data to general practices. Methods and analysis 2-arm cluster randomised trial using the EHRs of the Clinical Practice Research Datalink (CPRD). General practices in England, Scotland, Wales and Northern Ireland are being recruited and the general population of all ages represents the target population. Control trial arm practices will continue with usual care. Practices in the intervention arm will receive complex multicomponent interventions, delivered remotely to information systems, including (1) feedback of each practice's antibiotic prescribing through monthly antibiotic prescribing reports estimated from CPRD data; (2) delivery of educational and decision support tools; (3) a webinar to explain and promote effective usage of the intervention. The intervention will continue for 12 months. Outcomes will be evaluated from CPRD EHRs. The primary outcome will be the number of antibiotic prescriptions for RTIs per 1000 patient years. Secondary outcomes will be: the RTI consultation rate; the proportion of consultations for RTI with an antibiotic prescribed; subgroups of age; different categories of RTI and quartiles of intervention usage. There will be more than 80% power to detect an absolute reduction in antibiotic prescription for RTI of 12 per 1000 registered patient years. Total healthcare usage will be estimated from CPRD data and compared between trial arms. Ethics and dissemination Trial protocol was approved by the National Research Ethics Service Committee (14/LO/1730). The pragmatic design of the trial will enable subsequent translation of effective interventions at scale in order to achieve population impact. Trial registration number ISRCTN95232781; Pre-results. PMID:27491663

Evidence-based care of older people with suspected cognitive impairment in general practice: protocol for the IRIS cluster randomised trial.

PubMed

McKenzie, Joanne E; French, Simon D; O'Connor, Denise A; Mortimer, Duncan S; Browning, Colette J; Russell, Grant M; Grimshaw, Jeremy M; Eccles, Martin P; Francis, Jill J; Michie, Susan; Murphy, Kerry; Kossenas, Fiona; Green, Sally E

2013-08-19

Dementia is a common and complex condition. Evidence-based guidelines for the management of people with dementia in general practice exist; however, detection, diagnosis and disclosure of dementia have been identified as potential evidence-practice gaps. Interventions to implement guidelines into practice have had varying success. The use of theory in designing implementation interventions has been limited, but is advocated because of its potential to yield more effective interventions and aid understanding of factors modifying the magnitude of intervention effects across trials. This protocol describes methods of a randomised trial that tests a theory-informed implementation intervention that, if effective, may provide benefits for patients with dementia and their carers. This trial aims to estimate the effectiveness of a theory-informed intervention to increase GPs' (in Victoria, Australia) adherence to a clinical guideline for the detection, diagnosis, and management of dementia in general practice, compared with providing GPs with a printed copy of the guideline. Primary objectives include testing if the intervention is effective in increasing the percentage of patients with suspected cognitive impairment who receive care consistent with two key guideline recommendations: receipt of a i) formal cognitive assessment, and ii) depression assessment using a validated scale (primary outcomes for the trial). The design is a parallel cluster randomised trial, with clusters being general practices. We aim to recruit 60 practices per group. Practices will be randomised to the intervention and control groups using restricted randomisation. Patients meeting the inclusion criteria, and GPs' detection and diagnosis behaviours directed toward these patients, will be identified and measured via an electronic search of the medical records nine months after the start of the intervention. Practitioners in the control group will receive a printed copy of the guideline. In addition to receipt of the printed guideline, practitioners in the intervention group will be invited to participate in an interactive, opinion leader-led, educational face-to-face workshop. The theory-informed intervention aims to address identified barriers to and enablers of implementation of recommendations. Researchers responsible for identifying the cohort of patients with suspected cognitive impairment, and their detection and diagnosis outcomes, will be blind to group allocation. Australian New Zealand Clinical Trials Registry: ACTRN12611001032943 (date registered 28 September, 2011).

The variety of primary healthcare organisations in Australia: a taxonomy.

PubMed

Rodwell, John; Gulyas, Andre

2013-04-08

Healthcare policy appears to treat healthcare organisations as being homogenous, despite evidence that they vary considerably. This study develops a taxonomy of primary health care practices using characteristics associated with the job satisfaction of general medical practitioners (GPs) and the practices. The study used data from 3,662 survey respondents who were GPs in the 2009 wave of the MABEL survey. Cluster analyses were used to determine natural groups of medical practices based on multidimensional characteristics. Seven configurations of primary health care practices emerged from multivariate cluster analyses: optimised team, independent craft, reactive, winding down, classic, practitioner flexible, and scale efficiency. This taxonomy of configurations moves beyond simplistic categorisations such as geographic location and highlights the complexity of primary health care organisations in Australia. Health policy, workforce and procedure interventions informed by taxonomies can engage the diversity of primary health care practices.

Patient Engagement and Coaching for Health: The PEACH study--a cluster randomised controlled trial using the telephone to coach people with type 2 diabetes to engage with their GPs to improve diabetes care: a study protocol.

PubMed

Young, Doris; Furler, John; Vale, Margarite; Walker, Christine; Segal, Leonie; Dunning, Patricia; Best, James; Blackberry, Irene; Audehm, Ralph; Sulaiman, Nabil; Dunbar, James; Chondros, Patty

2007-04-11

The PEACH study is based on an innovative 'telephone coaching' program that has been used effectively in a post cardiac event trial. This intervention will be tested in a General Practice setting in a pragmatic trial using existing Practice Nurses (PN) as coaches for people with type 2 diabetes (T2D). Actual clinical care often fails to achieve standards, that are based on evidence that self-management interventions (educational and psychological) and intensive pharmacotherapy improve diabetes control. Telephone coaching in our study focuses on both. This paper describes our study protocol, which aims to test whether goal focused telephone coaching in T2D can improve diabetes control and reduce the treatment gap between guideline based standards and actual clinical practice. In a cluster randomised controlled trial, general practices employing Practice Nurses (PNs) are randomly allocated to an intervention or control group. We aim to recruit 546 patients with poorly controlled T2D (HbA1c >7.5%) from 42 General Practices that employ PNs in Melbourne, Australia. PNs from General Practices allocated to the intervention group will be trained in diabetes telephone coaching focusing on biochemical targets addressing both patient self-management and engaging patients to work with their General Practitioners (GPs) to intensify pharmacological treatment according to the study clinical protocol. Patients of intervention group practices will receive 8 telephone coaching sessions and one face-to-face coaching session from existing PNs over 18 months plus usual care and outcomes will be compared to the control group, who will only receive only usual care from their GPs. The primary outcome is HbA1c levels and secondary outcomes include cardiovascular disease risk factors, behavioral risk factors and process of care measures. Understanding how to achieve comprehensive treatment of T2D in a General Practice setting is the focus of the PEACH study. This study explores the potential role for PNs to help reduce the treatment and outcomes gap in people with T2D by using telephone coaching. The intervention, if found to be effective, has potential to be sustained and embedded within real world General Practice.

Clustering of diet, physical activity and smoking and a general willingness to change.

PubMed

de Vries, Hein; Kremers, Stef; Smeets, Tamara; Reubsaet, Astrid

2008-01-01

Addressing multiple health behaviours are important in preventing disease and mortality. The present study investigated the clustering of health behaviours, cognitive determinants and stages of change in 2827 adults for the lifestyle factors of physical activity, fruit, vegetable and fat consumption and smoking. The results showed that only 3% of the total population met recommended guidelines for all of the five behaviours. Behaviours were found to be weakly associated. Behaviour-specific cognitions and stages of change for the behaviours clustered more strongly, however. With respect to diet and physical activity, respondents in the preparation stage for one behaviour were likely also to be preparing to change another behaviour. Possible mechanisms for the apparent general willingness to change multiple behaviours are discussed, as well as potential implications for health promotion practice.

Spatial analysis of pulmonary tuberculosis in Antananarivo Madagascar: tuberculosis-related knowledge, attitude and practice.

PubMed

Rakotosamimanana, Sitraka; Mandrosovololona, Vatsiharizandry; Rakotonirina, Julio; Ramamonjisoa, Joselyne; Ranjalahy, Justin Rasolofomanana; Randremanana, Rindra Vatosoa; Rakotomanana, Fanjasoa

2014-01-01

Tuberculosis infection may remain latent, but the disease is nevertheless a serious public health issue. Various epidemiological studies on pulmonary tuberculosis have considered the spatial component and taken it into account, revealing the tendency of this disease to cluster in particular locations. The aim was to assess the contribution of Knowledge Attitude and Practice (KAP) to the distribution of tuberculosis and to provide information for the improvement of the National Tuberculosis Program. We investigated the role of KAP to distribution patterns of pulmonary tuberculosis in Antananarivo. First, we performed spatial scanning of tuberculosis aggregation among permanent cases resident in Antananarivo Urban Township using the Kulldorff method, and then we carried out a quantitative study on KAP, involving TB patients. The KAP study in the population was based on qualitative methods with focus groups. The disease still clusters in the same districts identified in the previous study. The principal cluster covered 22 neighborhoods. Most of them are part of the first district. A secondary cluster was found, involving 18 neighborhoods in the sixth district and two neighborhoods in the fifth. The relative risk was respectively 1.7 (p<10-6) in the principal cluster and 1.6 (p<10-3) in the secondary cluster. Our study showed that more was known about TB symptoms than about the duration of the disease or free treatment. Knowledge about TB was limited to that acquired at school or from relatives with TB. The attitude and practices of patients and the population in general indicated that there is still a stigma attached to tuberculosis. This type of survey can be conducted in remote zones where the tuberculosis-related KAP of the TB patients and the general population is less known or not documented; the findings could be used to adapt control measures to the local particularities.

Clinical effectiveness of a patient decision aid to improve decision quality and glycaemic control in people with diabetes making treatment choices: a cluster randomised controlled trial (PANDAs) in general practice

PubMed Central

Mathers, Nigel; Ng, Chirk Jenn; Campbell, Michael Joseph; Colwell, Brigitte; Brown, Ian; Bradley, Alastair

2012-01-01

Objective To determine the effectiveness of a patient decision aid (PDA) to improve decision quality and glycaemic control in people with diabetes making treatment choices using a cluster randomised controlled trial (RCT). Design A cluster RCT. Setting 49 general practices in UK randomised into intervention (n=25) and control (n=24). Participants General practices Inclusion criteria: >4 medical partners; list size >7000; and a diabetes register with >1% of practice population. 191 practices assessed for eligibility, and 49 practices randomised and completed the study. Patients People with type 2 diabetes mellitus (T2DM) taking at least two oral glucose-lowering drugs with maximum tolerated dose with a glycosolated haemoglobin (HbA1c) greater than 7.4% (IFCC HbA1c >57 mmol/mol) or advised in the preceeding 6 months to add or consider changing to insulin therapy. Exclusion criteria: currently using insulin therapy; difficulty reading or understanding English; difficulty in understanding the purpose of the study; visual or cognitive impairment or mentally ill. A total of 182 assessed for eligibility, 175 randomised to 95 intervention and 80 controls, and 167 completion and analysis. Intervention Brief training of clinicians and use of PDA with patients in single consultation. Primary outcomes Decision quality (Decisional Conflict Scores, knowledge, realistic expectations and autonomy) and glycaemic control (glycosolated haemoglobin, HbA1c). Secondary outcomes Knowledge and realistic expectations of the risks and benefits of insulin therapy and diabetic complications. Results Intervention group: lower total Decisional Conflict Scores (17.4 vs 25.2, p<0.001); better knowledge (51.6% vs 28.8%, p<0.001); realistic expectations (risk of ‘hypo’, ‘weight gain’, ‘complications’; 81.0% vs 5.2%, 70.5% vs 5.3%, 26.3% vs 5.0% respectively, p<0.001); and were more autonomous in decision-making (64.1% vs 42.9%, p=0.012). No significant difference in the glycaemic control between the two groups. Conclusions Use of the PANDAs decision aid reduces decisional conflict, improves knowledge, promotes realistic expectations and autonomy in people with diabetes making treatment choices in general practice. ISRCTN Trials Register Number 14842077. PMID:23129571

Text messaging reminders for influenza vaccine in primary care: protocol for a cluster randomised controlled trial (TXT4FLUJAB).

PubMed

Herrett, Emily; van Staa, Tjeerd; Free, Caroline; Smeeth, Liam

2014-05-02

The UK government recommends that at least 75% of people aged under 64 with certain conditions receive an annual influenza vaccination. Primary care practices often fall short of this target and strategies to increase vaccine uptake are required. Text messaging reminders are already used in 30% of practices to remind patients about vaccination, but there has been no trial addressing their effectiveness in increasing influenza vaccine uptake in the UK. The aims of the study are (1) to develop the methodology for conducting cluster randomised trials of text messaging interventions utilising routine electronic health records and (2) to assess the effectiveness of using a text messaging influenza vaccine reminder in achieving an increase in influenza vaccine uptake in patients aged 18-64 with chronic conditions, compared with standard care. This cluster randomised trial will recruit general practices across three settings in English primary care (Clinical Practice Research Datalink, ResearchOne and London iPLATO text messaging software users) and randomise them to either standard care or a text messaging campaign to eligible patients. Flu vaccine uptake will be ascertained using routinely collected, anonymised electronic patient records. This protocol outlines the proposed study design and analysis methods. This study will determine the effectiveness of text messaging vaccine reminders in primary care in increasing influenza vaccine uptake, and will strengthen the methodology for using electronic health records in cluster randomised trials of text messaging interventions. This trial was approved by the Surrey Borders Ethics Committee (13/LO/0872). The trial results will be disseminated at national conferences and published in a peer-reviewed medical journal. The results will also be distributed to the Primary Care Research Network and to all participating general practices. This study is registered at controlled-trials.com ISRCTN48840025, July 2013.

Finding reproducible cluster partitions for the k-means algorithm

PubMed Central

2013-01-01

K-means clustering is widely used for exploratory data analysis. While its dependence on initialisation is well-known, it is common practice to assume that the partition with lowest sum-of-squares (SSQ) total i.e. within cluster variance, is both reproducible under repeated initialisations and also the closest that k-means can provide to true structure, when applied to synthetic data. We show that this is generally the case for small numbers of clusters, but for values of k that are still of theoretical and practical interest, similar values of SSQ can correspond to markedly different cluster partitions. This paper extends stability measures previously presented in the context of finding optimal values of cluster number, into a component of a 2-d map of the local minima found by the k-means algorithm, from which not only can values of k be identified for further analysis but, more importantly, it is made clear whether the best SSQ is a suitable solution or whether obtaining a consistently good partition requires further application of the stability index. The proposed method is illustrated by application to five synthetic datasets replicating a real world breast cancer dataset with varying data density, and a large bioinformatics dataset. PMID:23369085

Finding reproducible cluster partitions for the k-means algorithm.

PubMed

Lisboa, Paulo J G; Etchells, Terence A; Jarman, Ian H; Chambers, Simon J

2013-01-01

K-means clustering is widely used for exploratory data analysis. While its dependence on initialisation is well-known, it is common practice to assume that the partition with lowest sum-of-squares (SSQ) total i.e. within cluster variance, is both reproducible under repeated initialisations and also the closest that k-means can provide to true structure, when applied to synthetic data. We show that this is generally the case for small numbers of clusters, but for values of k that are still of theoretical and practical interest, similar values of SSQ can correspond to markedly different cluster partitions. This paper extends stability measures previously presented in the context of finding optimal values of cluster number, into a component of a 2-d map of the local minima found by the k-means algorithm, from which not only can values of k be identified for further analysis but, more importantly, it is made clear whether the best SSQ is a suitable solution or whether obtaining a consistently good partition requires further application of the stability index. The proposed method is illustrated by application to five synthetic datasets replicating a real world breast cancer dataset with varying data density, and a large bioinformatics dataset.

Effects of patient safety culture interventions on incident reporting in general practice: a cluster randomised trial.

PubMed

Verbakel, Natasha J; Langelaan, Maaike; Verheij, Theo J M; Wagner, Cordula; Zwart, Dorien L M

2015-05-01

A constructive safety culture is essential for the successful implementation of patient safety improvements. To assess the effect of two patient safety culture interventions on incident reporting as a proxy of safety culture. A three-arm cluster randomised trial was conducted in a mixed method study, studying the effect of administering a patient safety culture questionnaire (intervention I), the questionnaire complemented with a practice-based workshop (intervention II) and no intervention (control) in 30 general practices in the Netherlands. The primary outcome, the number of reported incidents, was measured with a questionnaire at baseline and a year after. Analysis was performed using a negative binomial model. Secondary outcomes were quality and safety indicators and safety culture. Mixed effects linear regression was used to analyse the culture questionnaires. The number of incidents increased in both intervention groups, to 82 and 224 in intervention I and II respectively. Adjusted for baseline number of incidents, practice size and accreditation status, the study showed that practices that additionally participated in the workshop reported 42 (95% confidence interval [CI] = 9.81 to 177.50) times more incidents compared to the control group. Practices that only completed the questionnaire reported 5 (95% CI = 1.17 to 25.49) times more incidents. There were no statistically significant differences in staff perception of patient safety culture at follow-up between the three study groups. Educating staff and facilitating discussion about patient safety culture in their own practice leads to increased reporting of incidents. It is beneficial to invest in a team-wise effort to improve patient safety. © British Journal of General Practice 2015.

Improving the management of multimorbidity in general practice: protocol of a cluster randomised controlled trial (The 3D Study).

PubMed

Man, Mei-See; Chaplin, Katherine; Mann, Cindy; Bower, Peter; Brookes, Sara; Fitzpatrick, Bridie; Guthrie, Bruce; Shaw, Alison; Hollinghurst, Sandra; Mercer, Stewart; Rafi, Imran; Thorn, Joanna; Salisbury, Chris

2016-04-25

An increasing number of people are living with multimorbidity. The evidence base for how best to manage these patients is weak. Current clinical guidelines generally focus on single conditions, which may not reflect the needs of patients with multimorbidity. The aim of the 3D study is to develop, implement and evaluate an intervention to improve the management of patients with multimorbidity in general practice. This is a pragmatic two-arm cluster randomised controlled trial. 32 general practices around Bristol, Greater Manchester and Glasgow will be randomised to receive either the '3D intervention' or usual care. 3D is a complex intervention including components affecting practice organisation, the conduct of patient reviews, integration with secondary care and measures to promote change in practice organisation. Changes include improving continuity of care and replacing reviews of each disease with patient-centred reviews with a focus on patients' quality of life, mental health and polypharmacy. We aim to recruit 1383 patients who have 3 or more chronic conditions. This provides 90% power at 5% significance level to detect an effect size of 0.27 SDs in the primary outcome, which is health-related quality of life at 15 months using the EQ-5D-5L. Secondary outcome measures assess patient centredness, illness burden and treatment burden. The primary analysis will be a multilevel regression model adjusted for baseline, stratification/minimisation, clustering and important co-variables. Nested process evaluation will assess implementation, mechanisms of effectiveness and interaction of the intervention with local context. Economic analysis of cost-consequences and cost-effectiveness will be based on quality-adjusted life years. This study has approval from South-West (Frenchay) National Health Service (NHS) Research Ethics Committee (14/SW/0011). Findings will be disseminated via final report, peer-reviewed publications and guidance to healthcare professionals, commissioners and policymakers. ISRCTN06180958; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Dental care resistance prevention and antibiotic prescribing modification—the cluster-randomised controlled DREAM trial

PubMed Central

2014-01-01

Background Bacterial resistance development is one of the most urgent problems in healthcare worldwide. In Europe, dentistry accounts for a comparatively high amount of antibiotic prescriptions. In light of increasing levels of bacterial resistance, this development is alarming. So far, very few interventional studies have been performed, and further research is urgently needed. By means of a complex educational intervention, the DREAM trial aims at optimising antibiotic prescribing behaviour of general dentists in Germany. Method This is a cluster-randomised controlled trial, where each cluster consists of one dental practice and all of its patients in a defined period. Participants are general dentists practicing in the German region of Mecklenburg-Western Pomerania. Randomisation takes place after baseline data collection (6 months) and will be stratified by the antibiotic prescribing rates of the participating dental practices. Dentists randomised into the intervention group will participate in a complex small group educational seminar that aims at: increasing knowledge on bacterial resistance, pharmacology, and prophylaxis of infectious endocarditis; increasing awareness of dentist-patient communication using video-taped vignettes of dentist-patient communication on antibiotic treatment; improving collaboration between general dentists, general practitioners, and practice-based cardiologists on the necessity of antibiotic prophylaxis; enhancing awareness of the dentists’ own prescribing habits by providing antibiotic prescribing feedback; and increasing patient knowledge on antibiotic treatment by providing patient-centred information material on antibiotic prophylaxis of endocarditis. The dentists randomised into the control group will not receive any educational programme and provide care as usual. Primary outcome is the overall antibiotic prescribing rate measured at T1 (period of six months after intervention). In a subgroup of adult patients affected by odontogenic infections, microbiological analyses for antibiotic resistance of oral streptococci are performed. Discussion Major aim of the study is to improve the process of decision making with regard to antibiotic prescribing. The approach is simple to implement and might be used rapidly in graduate and post-graduate medical education. We expect the results of this trial to have a major impact on antibiotic prescription strategies and practices in Germany. Trial registration Current Controlled Trials ISRCTN09576376 PMID:24559212

Dental care resistance prevention and antibiotic prescribing modification-the cluster-randomised controlled DREAM trial.

PubMed

Löffler, Christin; Böhmer, Femke; Hornung, Anne; Lang, Hermann; Burmeister, Ulrike; Podbielski, Andreas; Wollny, Anja; Kundt, Günther; Altiner, Attila

2014-02-22

Bacterial resistance development is one of the most urgent problems in healthcare worldwide. In Europe, dentistry accounts for a comparatively high amount of antibiotic prescriptions. In light of increasing levels of bacterial resistance, this development is alarming. So far, very few interventional studies have been performed, and further research is urgently needed. By means of a complex educational intervention, the DREAM trial aims at optimising antibiotic prescribing behaviour of general dentists in Germany. This is a cluster-randomised controlled trial, where each cluster consists of one dental practice and all of its patients in a defined period. Participants are general dentists practicing in the German region of Mecklenburg-Western Pomerania. Randomisation takes place after baseline data collection (6 months) and will be stratified by the antibiotic prescribing rates of the participating dental practices. Dentists randomised into the intervention group will participate in a complex small group educational seminar that aims at: increasing knowledge on bacterial resistance, pharmacology, and prophylaxis of infectious endocarditis; increasing awareness of dentist-patient communication using video-taped vignettes of dentist-patient communication on antibiotic treatment; improving collaboration between general dentists, general practitioners, and practice-based cardiologists on the necessity of antibiotic prophylaxis; enhancing awareness of the dentists' own prescribing habits by providing antibiotic prescribing feedback; and increasing patient knowledge on antibiotic treatment by providing patient-centred information material on antibiotic prophylaxis of endocarditis. The dentists randomised into the control group will not receive any educational programme and provide care as usual. Primary outcome is the overall antibiotic prescribing rate measured at T1 (period of six months after intervention). In a subgroup of adult patients affected by odontogenic infections, microbiological analyses for antibiotic resistance of oral streptococci are performed. Major aim of the study is to improve the process of decision making with regard to antibiotic prescribing. The approach is simple to implement and might be used rapidly in graduate and post-graduate medical education. We expect the results of this trial to have a major impact on antibiotic prescription strategies and practices in Germany. Current Controlled Trials ISRCTN09576376.

Knowledge transfer for the management of dementia: a cluster-randomised trial of blended learning in general practice

PubMed Central

2010-01-01

Background The implementation of new medical knowledge into general practice is a complex process. Blended learning may offer an effective and efficient educational intervention to reduce the knowledge-to-practice gap. The aim of this study was to compare knowledge acquisition about dementia management between a blended learning approach using online modules in addition to quality circles (QCs) and QCs alone. Methods In this cluster-randomised trial with QCs as clusters and general practitioners (GPs) as participants, 389 GPs from 26 QCs in the western part of Germany were invited to participate. Data on the GPs' knowledge were obtained at three points in time by means of a questionnaire survey. Primary outcome was the knowledge gain before and after the interventions. A subgroup analysis of the users of the online modules was performed. Results 166 GPs were available for analysis and filled out a knowledge test at least two times. A significant increase of knowledge was found in both groups that indicated positive learning effects of both approaches. However, there was no significant difference between the groups. A subgroup analysis of the GPs who self-reported that they had actually used the online modules showed that they had a significant increase in their knowledge scores. Conclusion A blended learning approach was not superior to a QCs approach for improving knowledge about dementia management. However, a subgroup of GPs who were motivated to actually use the online modules had a gain in knowledge. Trial registration Current Controlled Trials ISRCTN36550981. PMID:20047652

Cluster and propensity based approximation of a network

PubMed Central

2013-01-01

Background The models in this article generalize current models for both correlation networks and multigraph networks. Correlation networks are widely applied in genomics research. In contrast to general networks, it is straightforward to test the statistical significance of an edge in a correlation network. It is also easy to decompose the underlying correlation matrix and generate informative network statistics such as the module eigenvector. However, correlation networks only capture the connections between numeric variables. An open question is whether one can find suitable decompositions of the similarity measures employed in constructing general networks. Multigraph networks are attractive because they support likelihood based inference. Unfortunately, it is unclear how to adjust current statistical methods to detect the clusters inherent in many data sets. Results Here we present an intuitive and parsimonious parametrization of a general similarity measure such as a network adjacency matrix. The cluster and propensity based approximation (CPBA) of a network not only generalizes correlation network methods but also multigraph methods. In particular, it gives rise to a novel and more realistic multigraph model that accounts for clustering and provides likelihood based tests for assessing the significance of an edge after controlling for clustering. We present a novel Majorization-Minimization (MM) algorithm for estimating the parameters of the CPBA. To illustrate the practical utility of the CPBA of a network, we apply it to gene expression data and to a bi-partite network model for diseases and disease genes from the Online Mendelian Inheritance in Man (OMIM). Conclusions The CPBA of a network is theoretically appealing since a) it generalizes correlation and multigraph network methods, b) it improves likelihood based significance tests for edge counts, c) it directly models higher-order relationships between clusters, and d) it suggests novel clustering algorithms. The CPBA of a network is implemented in Fortran 95 and bundled in the freely available R package PropClust. PMID:23497424

Application of the AMPLE cluster-and-truncate approach to NMR structures for molecular replacement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bibby, Jaclyn; Keegan, Ronan M.; Mayans, Olga

2013-11-01

Processing of NMR structures for molecular replacement by AMPLE works well. AMPLE is a program developed for clustering and truncating ab initio protein structure predictions into search models for molecular replacement. Here, it is shown that its core cluster-and-truncate methods also work well for processing NMR ensembles into search models. Rosetta remodelling helps to extend success to NMR structures bearing low sequence identity or high structural divergence from the target protein. Potential future routes to improved performance are considered and practical, general guidelines on using AMPLE are provided.

Increasing chlamydia screening tests in general practice: a modified Zelen prospective Cluster Randomised Controlled Trial evaluating a complex intervention based on the Theory of Planned Behaviour.

PubMed

McNulty, Cliodna A M; Hogan, Angela H; Ricketts, Ellie J; Wallace, Louise; Oliver, Isabel; Campbell, Rona; Kalwij, Sebastian; O'Connell, Elaine; Charlett, Andre

2014-05-01

To determine if a structured complex intervention increases opportunistic chlamydia screening testing of patients aged 15-24 years attending English general practitioner (GP) practices. A prospective, Cluster Randomised Controlled Trial with a modified Zelen design involving 160 practices in South West England in 2010. The intervention was based on the Theory of Planned Behaviour (TPB). It comprised of practice-based education with up to two additional contacts to increase the importance of screening to GP staff and their confidence to offer tests through skill development (including videos). Practical resources (targets, posters, invitation cards, computer reminders, newsletters including feedback) aimed to actively influence social cognitions of staff, increasing their testing intention. Data from 76 intervention and 81 control practices were analysed. In intervention practices, chlamydia screening test rates were 2.43/100 15-24-year-olds registered preintervention, 4.34 during intervention and 3.46 postintervention; controls testing rates were 2.61/100 registered patients prior intervention, 3.0 during intervention and 2.82 postintervention. During the intervention period, testing in intervention practices was 1.76 times as great (CI 1.24 to 2.48) as controls; this persisted for 9 months postintervention (1.57 times as great, CI 1.27 to 2.30). Chlamydia infections detected increased in intervention practices from 2.1/1000 registered 15-24-year-olds prior intervention to 2.5 during the intervention compared with 2.0 and 2.3/1000 in controls (Estimated Rate Ratio intervention versus controls 1.4 (CI 1.01 to 1.93). This complex intervention doubled chlamydia screening tests in fully engaged practices. The modified Zelen design gave realistic measures of practice full engagement (63%) and efficacy of this educational intervention in general practice; it should be used more often. The trial was registered on the UK Clinical Research Network Study Portfolio database. UKCRN number 9722.

Potentially Inappropriate Prescribing to Older Patients: Criteria, Prevalence and an Intervention to Reduce it: The Prescription Peer Academic Detailing (Rx-PAD) Study - A Cluster-Randomized, Educational Intervention in Norwegian General Practice.

PubMed

Rognstad, Sture; Brekke, Mette; Gjelstad, Svein; Straand, Jørund; Fetveit, Arne

2018-05-12

Potentially Inappropriate Prescriptions (PIP) is drug treatment, which in general, at the group level for a median/mean patient, can be considered unfavorable meaning that the risks commonly may outweigh the benefits. This MiniReview reports and discusses the main findings in a large cluster-randomized educational intervention in Norwegian general practice, aimed at reducing the prevalence of PIPs to patients ≥ 70 years (The Rx-PAD study). Targets for the intervention were general practitioners (GPs) in continuing medical education (CME) groups receiving educational outreach visits (i.e., peer academic detailing). A Delphi consensus process, with a panel of medical experts was undertaken to elaborate a list of explicit criteria defining PIPs for patients ≥ 70 years in general practice. Agreement was achieved for 36 explicit PIP criteria, the so-called Norwegian General Practice (NorGeP) criteria. Using a selection (n = 24) of these criteria during a one-year baseline period on the prescribing practice of 454 GPs (i.e., those enrolled to participate in the intervention trial), we found a prevalence rate of 24.7 PIPs per 100 patients ≥70 years per year. In the Rx-PAD study, 449 GPs completed an educational intervention (96.6% of the included GPs), 250 in the intervention group and 199 in the control arm. Following the intervention, PIPs were reduced by 13% (95% CI 8.6 - 17.3), and the number of patients who were no longer exposed to one or more PIPs was reduced by 1173 (8.1%). The GPs who responded most strongly to the educational intervention were the oldest GPs (57-68 years) and these were the GPs with the highest prevalence of PIPs at baseline before the intervention. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

[Time for cluster C personality disorders: state of the art].

PubMed

Hutsebaut, J; Willemsen, E M C; Van, H L

Compared to cluster B personality disorders, the assessment and treatment of people with obsessive-compulsive, dependent, and avoidant personality disorders (cluster C) is given little attention in the field of research and clinical practice. Presenting the current state of affairs in regard to cluster C personality disorders. A systematic literature search was conducted using the main data bases. Cluster C personality disorders are present in approximately 3-9% of the general population. In about half of the cases of mood, anxiety, and eating disorders, there is co-morbid cluster C pathology. This has a major influence on the progression of symptoms, treatment effectiveness and potential relapse. There are barely any well conducted randomized studies on the treatment of cluster-C in existence. Open cohort studies, however, show strong, lasting treatment effects. Given the frequent occurrence of cluster C personality disorders, the burden of disease, associated societal costs and the prognostic implications in case of a co-morbid cluster C personality disorder, early detection and treatment of these disorders is warranted.

Evaluation of a tailored implementation strategy to improve the management of patients with chronic obstructive pulmonary disease in primary care: a study protocol of a cluster randomized trial.

PubMed

Godycki-Cwirko, Maciek; Zakowska, Izabela; Kosiek, Katarzyna; Wensing, Michel; Krawczyk, Jaroslaw; Kowalczyk, Anna

2014-04-04

Chronic obstructive pulmonary disease (COPD) remains a major health problem, strongly related to smoking. Despite the publication of practice guidelines on prevention and treatment, not all patients with the disease receive the recommended healthcare, particularly with regard to smoking cessation advice where applicable. We have developed a tailored implementation strategy for enhancing general practitioners' adherence to the disease management guidelines. The primary aim of the study is to evaluate the effects of this tailored implementation intervention on general practitioners' adherence to guidelines. A pragmatic two-arm cluster randomized trial has been planned to compare care following the implementation of tailored interventions of four recommendations in COPD patients against usual care. The study will involve 18 general practices (9 in the intervention group and 9 in the control group) in Poland, each with at least 80 identified (at the baseline) patients with diagnosed COPD. The nine control practices will provide usual care without any interventions. Tailored interventions to implement four recommendations will be delivered in the remaining nine practices. At follow-up after nine months, data will be collected for all 18 general practices. The primary outcome measure is physicians' adherence to all four recommendations: brief anti-smoking advice, dyspnea assessment, care checklist utilization and demonstration to patients of correct inhaler use. This measurement will be based on data extracted from identified patients' records. Additionally, we will survey and interview patients with chronic obstructive pulmonary disease about the process of care. The results of this trial will be directly applicable to primary care in Poland and add to the growing body of evidence on interventions to improve chronic illness care. This trial has been registered with Clinical Trials Protocol Registration System. NCT01893476.

Structured functional assessments in general practice increased the use of part-time sick leave: a cluster randomised controlled trial.

PubMed

Osterås, Nina; Gulbrandsen, Pål; Kann, Inger Cathrine; Brage, Søren

2010-03-01

A method for structured functional assessments of persons with long-term sick leave was implemented in a cluster randomised controlled trial in general practice. The aim was to analyse intervention effects on general practitioner (GP) sick-listing practice and patient sick leave. 57 GPs were randomly assigned to an intervention or a control group. The intervention group GPs learned the method at a 1-day workshop including teamwork and role-playing. The control group GPs were requested to assess functional ability as usual during the 8 months intervention period in 2005. Outcome measures included duration of patient sick leave episodes, GP prescription of part-time sick leave, active sick leave, and vocational rehabilitation. This data was extracted from a national register. The GPs in the intervention group prescribed part-time sick leave more often (p < 0.01) and active sick leave less often (p = 0.04) than the control group GPs during the intervention period. There was no intervention effect on duration of patient sick leave episodes or on GP prescription of vocational rehabilitation. Implementing structured functional assessments in general practice made the GPs capable to assess functional ability of persons with long-term sick leave in a standardised and explicit manner. The intervention GPs' sick-listing practice was changed as they prescribed more part-time and less active sick leave compared to the control group GPs. As a result, more intervention GP patients returned to part-time work compared to control GP patients. No intervention effect was seen on duration of patient sick leave episodes or on prescription of vocational rehabilitation.

Segmenting a general practitioner market to improve recruitment outcomes.

PubMed

Hemphill, Elizabeth; Kulik, Carol T

2011-05-01

Recruitment is an ongoing challenge in the health industry with general practitioner (GP) shortages in many areas beyond rural and Indigenous communities. This paper suggests a marketing solution that identifies different segments of the GP market for recruitment strategy development. In February 2008, 96 GPs in Australia responded to a mail questionnaire (of which 85 questionnaires were useable). A total of 350 GPs were sent the questionnaire. Respondents considered small sets of attributes in the decision to accept a new job at a general practice and selected the most and least important attribute from each set. We identified latent class clusters (cohorts) of GPs from the most-least important data. Three cohorts were found in the GP market, distinguishing practitioners who emphasised job, family or practice attributes in their decision to join a practice. Few significant demographic differences exist between the cohorts. A segmented GP market suggests two alternative recruitment strategies. One option is for general practices to target members of a single cohort (family-, job-, or practice-focussed GPs). The other option is for general practices to diversify their recruitment strategies to target all three cohorts (family-, job- and practice-focussed GPs). A single brand (practice) can have multiple advertising strategies with each strategy involving advertising activities targeting a particular consumer segment.

The economics of patient-centered care.

PubMed

David, Guy; Saynisch, Philip A; Smith-McLallen, Aaron

2018-05-01

The Patient-Centered Medical Home (PCMH) is a widely-implemented model for improving primary care, emphasizing care coordination, information technology, and process improvements. However, its treatment as an undifferentiated intervention in policy evaluation obscures meaningful variation in implementation. This heterogeneity leads to contracting inefficiencies between insurers and practices and may account for mixed evidence on its success. Using a novel dataset we group practices into meaningful implementation clusters and then link these clusters with detailed patient claims data. We find implementation choice affects performance, suggesting that generally-unobserved features of primary care reorganization influence patient outcomes. Reporting these features may be valuable to insurers and their members. Copyright © 2018 Elsevier B.V. All rights reserved.

An integrated general practice and pharmacy-based intervention to promote the use of appropriate preventive medications among individuals at high cardiovascular disease risk: protocol for a cluster randomized controlled trial.

PubMed

Hayek, Adina; Joshi, Rohina; Usherwood, Tim; Webster, Ruth; Kaur, Baldeep; Saini, Bandana; Armour, Carol; Krass, Ines; Laba, Tracey-Lea; Reid, Christopher; Shiel, Louise; Hespe, Charlotte; Hersch, Fred; Jan, Stephen; Lo, Serigne; Peiris, David; Rodgers, Anthony; Patel, Anushka

2016-09-23

Cardiovascular diseases (CVD) are responsible for significant morbidity, premature mortality, and economic burden. Despite established evidence that supports the use of preventive medications among patients at high CVD risk, treatment gaps remain. Building on prior evidence and a theoretical framework, a complex intervention has been designed to address these gaps among high-risk, under-treated patients in the Australian primary care setting. This intervention comprises a general practice quality improvement tool incorporating clinical decision support and audit/feedback capabilities; availability of a range of CVD polypills (fixed-dose combinations of two blood pressure lowering agents, a statin ± aspirin) for prescription when appropriate; and access to a pharmacy-based program to support long-term medication adherence and lifestyle modification. Following a systematic development process, the intervention will be evaluated in a pragmatic cluster randomized controlled trial including 70 general practices for a median period of 18 months. The 35 general practices in the intervention group will work with a nominated partner pharmacy, whereas those in the control group will provide usual care without access to the intervention tools. The primary outcome is the proportion of patients at high CVD risk who were inadequately treated at baseline who achieve target blood pressure (BP) and low-density lipoprotein cholesterol (LDL-C) levels at the study end. The outcomes will be analyzed using data from electronic medical records, utilizing a validated extraction tool. Detailed process and economic evaluations will also be performed. The study intends to establish evidence about an intervention that combines technological innovation with team collaboration between patients, pharmacists, and general practitioners (GPs) for CVD prevention. Australian New Zealand Clinical Trials Registry ACTRN12616000233426.

Update in outpatient general internal medicine: practice-changing evidence published in 2014.

PubMed

Sundsted, Karna K; Wieland, Mark L; Szostek, Jason H; Post, Jason A; Mauck, Karen F

2015-10-01

The practice of outpatient general internal medicine requires a diverse and evolving knowledge base. General internists must identify practice-changing shifts in the literature and reflect on their impact. Accordingly, we conducted a review of practice-changing articles published in outpatient general internal medicine in 2014. To identify high-quality, clinically relevant publications, we reviewed all titles and abstracts published in the following primary data sources in 2014: New England Journal of Medicine, Journal of the American Medical Association (JAMA), Annals of Internal Medicine, JAMA Internal Medicine, and the Cochrane Database of Systematic Reviews. All 2014 primary data summaries from Journal Watch-General Internal Medicine and ACP JournalWise also were reviewed. The authors used a modified Delphi method to reach consensus on inclusion of 8 articles using the following criteria: clinical relevance to outpatient internal medicine, potential for practice change, and strength of evidence. Clusters of important articles around one clinical question were considered as a single-candidate series. The article merits were debated until consensus was reached on the final 8, spanning a variety of topics commonly encountered in outpatient general internal medicine. Copyright © 2015 Elsevier Inc. All rights reserved.

How do Australian patients rate their general practitioner? A descriptive study using the General Practice Assessment Questionnaire.

PubMed

Potiriadis, Maria; Chondros, Patty; Gilchrist, Gail; Hegarty, Kelsey; Blashki, Grant; Gunn, Jane M

2008-08-18

To report patient responses to the General Practice Assessment Questionnaire (GPAQ) as a measure of satisfaction with health care received from Australian general practitioners. A clustered cross-sectional study involving general practice patients from 30 randomly selected general practices in Victoria. Between January and December 2005, a screening survey, including a postal version of the GPAQ, was mailed to 17 780 eligible patients. Scores on the six GPAQ items. We analysed data from 7130 patients who completed the screening survey and fulfilled our eligibility criteria. Levels of patient satisfaction with general practice care were generally high: mean GPAQ scores ranged from 68.6 (95% CI, 66.1-71.0) for satisfaction with access to the practice to 84.0 (95% CI, 82.2-85.4) for satisfaction with communication. Intracluster correlations for the GPAQ items ranged from 0.016 for overall satisfaction with the practice to 0.163 for satisfaction with access to the practice. Compared with national benchmarks in the United Kingdom, the GPs and practices participating in our study were rated higher on all six GPAQ items. Multivariable mixed effects linear regression showed that patients who were older, rated their health more highly, visited their GP more frequently and saw the same GP each time tended to express greater satisfaction with their care. Generally patients reported high levels of satisfaction with GP care. Greater satisfaction with care was associated with older patients, good health, more frequent contact with the GP, and seeing the one GP consistently.

STEMS pilot trial: a pilot cluster randomised controlled trial to investigate the addition of patient direct access to physiotherapy to usual GP-led primary care for adults with musculoskeletal pain

PubMed Central

Ogollah, Reuben O; Jowett, Sue; Kigozi, Jesse; Tooth, Stephanie; Protheroe, Joanne; Hay, Elaine M; Salisbury, Chris; Foster, Nadine E

2017-01-01

Introduction Around 17% of general practitioner (GP) consultations are for musculoskeletal conditions, which will rise as the population ages. Patient direct access to physiotherapy provides one solution, yet adoption in the National Health Service (NHS) has been slow. Setting A pilot, pragmatic, non-inferiority, cluster randomised controlled trial (RCT) in general practice and physiotherapy services in the UK. Objectives Investigate feasibility of a main RCT. Participants Adult patients registered in participating practices and consulting with a musculoskeletal problem. Interventions 4 general practices (clusters) randomised to provide GP-led care as usual or the addition of a patient direct access to physiotherapy pathway. Outcomes Process outcomes and exploratory analyses of clinical and cost outcomes. Data collection Participant-level data were collected via questionnaires at identification, 2, 6 and 12 months and through medical records. Blinding The study statistician and research nurses were blinded to practice allocation. Results Of 2696 patients invited to complete study questionnaires, 978 participated (intervention group n=425, control arm n=553) and were analysed. Participant recruitment was completed in 6 months. Follow-up rates were 78% (6 months) and 71% (12 months). No evidence of selection bias was observed. The direct access pathway was used by 90% of patients in intervention practices needing physiotherapy. Some increase in referrals to physiotherapy occurred from one practice, although waiting times for physiotherapy did not increase (28 days before, 26 days after introduction of direct access). No safety issues were identified. Clinical and cost outcomes were similar in both groups. Exploratory estimates of between group effect (using 36-item Short Form Health Survey (SF-36) Physical Component Summary (PCS)) at 6 months was −0.28 (95% CI −1.35 to 0.79) and at 12 months 0.12 (95% CI −1.27 to 1.51). Conclusions A full RCT is feasible and will provide trial evidence about the clinical and cost-effectiveness of patient direct access to physiotherapy. Trial registration number ISRCTN23378642. PMID:28286331

Electronically delivered, multicomponent intervention to reduce unnecessary antibiotic prescribing for respiratory infections in primary care: a cluster randomised trial using electronic health records-REDUCE Trial study original protocol.

PubMed

Juszczyk, Dorota; Charlton, Judith; McDermott, Lisa; Soames, Jamie; Sultana, Kirin; Ashworth, Mark; Fox, Robin; Hay, Alastair D; Little, Paul; Moore, Michael V; Yardley, Lucy; Prevost, A Toby; Gulliford, Martin C

2016-08-04

Respiratory tract infections (RTIs) account for about 60% of antibiotics prescribed in primary care. This study aims to test the effectiveness, in a cluster randomised controlled trial, of electronically delivered, multicomponent interventions to reduce unnecessary antibiotic prescribing when patients consult for RTIs in primary care. The research will specifically evaluate the effectiveness of feeding back electronic health records (EHRs) data to general practices. 2-arm cluster randomised trial using the EHRs of the Clinical Practice Research Datalink (CPRD). General practices in England, Scotland, Wales and Northern Ireland are being recruited and the general population of all ages represents the target population. Control trial arm practices will continue with usual care. Practices in the intervention arm will receive complex multicomponent interventions, delivered remotely to information systems, including (1) feedback of each practice's antibiotic prescribing through monthly antibiotic prescribing reports estimated from CPRD data; (2) delivery of educational and decision support tools; (3) a webinar to explain and promote effective usage of the intervention. The intervention will continue for 12 months. Outcomes will be evaluated from CPRD EHRs. The primary outcome will be the number of antibiotic prescriptions for RTIs per 1000 patient years. Secondary outcomes will be: the RTI consultation rate; the proportion of consultations for RTI with an antibiotic prescribed; subgroups of age; different categories of RTI and quartiles of intervention usage. There will be more than 80% power to detect an absolute reduction in antibiotic prescription for RTI of 12 per 1000 registered patient years. Total healthcare usage will be estimated from CPRD data and compared between trial arms. Trial protocol was approved by the National Research Ethics Service Committee (14/LO/1730). The pragmatic design of the trial will enable subsequent translation of effective interventions at scale in order to achieve population impact. ISRCTN95232781; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Effectiveness and cost-effectiveness of a proactive, goal-oriented, integrated care model in general practice for older people. A cluster randomised controlled trial: Integrated Systematic Care for older People--the ISCOPE study.

PubMed

Blom, Jeanet; den Elzen, Wendy; van Houwelingen, Anne H; Heijmans, Margot; Stijnen, Theo; Van den Hout, Wilbert; Gussekloo, Jacobijn

2016-01-01

older people often experience complex problems. Because of multiple problems, care for older people in general practice needs to shift from a 'problem-based, disease-oriented' care aiming at improvement of outcomes per disease to a 'goal-oriented care', aiming at improvement of functioning and personal quality of life, integrating all healthcare providers. Feasibility and cost-effectiveness of this proactive and integrated way of working are not yet established. cluster randomised trial. all persons aged ≥75 in 59 general practices (30 intervention, 29 control), with a combination of problems, as identified with a structured postal questionnaire with 21 questions on four health domains. for participants with problems on ≥3 domains, general practitioners (GPs) made an integrated care plan using a functional geriatric approach. Control practices: care as usual. (i) quality of life (QoL), (ii) activities of daily living, (iii) satisfaction with delivered health care and (iv) cost-effectiveness of the intervention at 1-year follow-up. Netherlands trial register, NTR1946. of the 11,476 registered eligible older persons, 7,285 (63%) participated in the screening. One thousand nine hundred and twenty-one (26%) had problems on ≥3 health domains. For 225 randomly chosen persons, a care plan was made. No beneficial effects were found on QoL, patients' functioning or healthcare use/costs. GPs experienced better overview of the care and stability, e.g. less unexpected demands, in the care. GPs prefer proactive integrated care. 'Horizontal' care using care plans for older people with complex problems can be a valuable tool in general practice. However, no direct beneficial effect was found for older persons. © The Author 2016. Published by Oxford University Press on behalf of the British Geriatrics Society.

Primary care Identification and Referral to Improve Safety of women experiencing domestic violence (IRIS): protocol for a pragmatic cluster randomised controlled trial

PubMed Central

2010-01-01

Background Domestic violence, which may be psychological, physical, sexual, financial or emotional, is a major public health problem due to the long-term health consequences for women who have experienced it and for their children who witness it. In populations of women attending general practice, the prevalence of physical or sexual abuse in the past year from a partner or ex-partner ranges from 6 to 23%, and lifetime prevalence from 21 to 55%. Domestic violence is particularly important in general practice because women have many contacts with primary care clinicians and because women experiencing abuse identify doctors and nurses as professionals from whom they would like to get support. Yet health professionals rarely ask about domestic violence and have little or no training in how to respond to disclosure of abuse. Methods/Design This protocol describes IRIS, a pragmatic cluster randomised controlled trial with the general practice as unit of randomisation. Our trial tests the effectiveness and cost-effectiveness of a training and support programme targeted at general practice teams. The primary outcome is referral of women to specialist domestic violence agencies. Forty-eight practices in two UK cities (Bristol and London) are randomly allocated, using minimisation, into intervention and control groups. The intervention, based on an adult learning model in an educational outreach framework, has been designed to address barriers to asking women about domestic violence and to encourage appropriate responses to disclosure and referral to specialist domestic violence agencies. Multidisciplinary training sessions are held with clinicians and administrative staff in each of the intervention practices, with periodic feedback of identification and referral data to practice teams. Intervention practices have a prompt to ask about abuse integrated in the electronic medical record system. Other components of the intervention include an IRIS champion in each practice and a direct referral pathway to a named domestic violence advocate. Discussion This is the first European randomised controlled trial of an intervention to improve the health care response to domestic violence. The findings will have the potential to inform training and service provision. Trial registration ISRCTN74012786 PMID:20122266

The prevention access and risk taking in young people (PARTY) project protocol: a cluster randomised controlled trial of health risk screening and motivational interviewing for young people presenting to general practice.

PubMed

Sanci, Lena; Grabsch, Brenda; Chondros, Patty; Shiell, Alan; Pirkis, Jane; Sawyer, Susan; Hegarty, Kelsey; Patterson, Elizabeth; Cahill, Helen; Ozer, Elizabeth; Seymour, Janelle; Patton, George

2012-06-06

There are growing worldwide concerns about the ability of primary health care systems to manage the major burden of illness in young people. Over two thirds of premature adult deaths result from risks that manifest in adolescence, including injury, neuropsychiatric problems and consequences of risky behaviours. One policy response is to better reorientate primary health services towards prevention and early intervention. Currently, however, there is insufficient evidence to support this recommendation for young people. This paper describes the design and implementation of a trial testing an intervention to promote psychosocial risk screening of all young people attending general practice and to respond to identified risks using motivational interviewing. clinicians' detection of risk-taking and emotional distress, young people's intention to change and reduction of risk taking. pathways to care, trust in the clinician and likelihood of returning for future visits. The design of the economic and process evaluation are not detailed in this protocol. PARTY is a cluster randomised trial recruiting 42 general practices in Victoria, Australia. Baseline measures include: youth friendly practice characteristics; practice staff's self-perceived competency in young people's care and clinicians' detection and response to risk taking behaviours and emotional distress in 14-24 year olds, attending the practice. Practices are then stratified by a social disadvantage index and billing methods and randomised. Intervention practices receive: nine hours of training and tools; feedback of their baseline data and two practice visits over six weeks. Comparison practices receive a three hour seminar in youth friendly practice only. Six weeks post-intervention, 30 consecutive young people are interviewed post-consultation from each practice and followed-up for self-reported risk taking behaviour and emotional distress three and 12 months post consultation. The PARTY trial is the first to examine the effectiveness and efficiency of a psychosocial risk screening and counselling intervention for young people attending primary care. It will provide important data on health risk profiles of young people attending general practice and on the effects of the intervention on engagement with primary care and health outcomes over 12 months. ISRCTN16059206.

The prevention access and risk taking in young people (PARTY) project protocol: A cluster randomised controlled trial of health risk screening and motivational interviewing for young people presenting to general practice

PubMed Central

2012-01-01

Background There are growing worldwide concerns about the ability of primary health care systems to manage the major burden of illness in young people. Over two thirds of premature adult deaths result from risks that manifest in adolescence, including injury, neuropsychiatric problems and consequences of risky behaviours. One policy response is to better reorientate primary health services towards prevention and early intervention. Currently, however, there is insufficient evidence to support this recommendation for young people. This paper describes the design and implementation of a trial testing an intervention to promote psychosocial risk screening of all young people attending general practice and to respond to identified risks using motivational interviewing. Main outcomes: clinicians’ detection of risk-taking and emotional distress, young people’s intention to change and reduction of risk taking. Secondary outcomes: pathways to care, trust in the clinician and likelihood of returning for future visits. The design of the economic and process evaluation are not detailed in this protocol. Methods PARTY is a cluster randomised trial recruiting 42 general practices in Victoria, Australia. Baseline measures include: youth friendly practice characteristics; practice staff’s self-perceived competency in young people’s care and clinicians’ detection and response to risk taking behaviours and emotional distress in 14–24 year olds, attending the practice. Practices are then stratified by a social disadvantage index and billing methods and randomised. Intervention practices receive: nine hours of training and tools; feedback of their baseline data and two practice visits over six weeks. Comparison practices receive a three hour seminar in youth friendly practice only. Six weeks post-intervention, 30 consecutive young people are interviewed post-consultation from each practice and followed-up for self-reported risk taking behaviour and emotional distress three and 12 months post consultation. Discussion The PARTY trial is the first to examine the effectiveness and efficiency of a psychosocial risk screening and counselling intervention for young people attending primary care. It will provide important data on health risk profiles of young people attending general practice and on the effects of the intervention on engagement with primary care and health outcomes over 12 months. Trial registration ISRCTN16059206 PMID:22672481

Relative efficiency of unequal versus equal cluster sizes in cluster randomized trials using generalized estimating equation models.

PubMed

Liu, Jingxia; Colditz, Graham A

2018-05-01

There is growing interest in conducting cluster randomized trials (CRTs). For simplicity in sample size calculation, the cluster sizes are assumed to be identical across all clusters. However, equal cluster sizes are not guaranteed in practice. Therefore, the relative efficiency (RE) of unequal versus equal cluster sizes has been investigated when testing the treatment effect. One of the most important approaches to analyze a set of correlated data is the generalized estimating equation (GEE) proposed by Liang and Zeger, in which the "working correlation structure" is introduced and the association pattern depends on a vector of association parameters denoted by ρ. In this paper, we utilize GEE models to test the treatment effect in a two-group comparison for continuous, binary, or count data in CRTs. The variances of the estimator of the treatment effect are derived for the different types of outcome. RE is defined as the ratio of variance of the estimator of the treatment effect for equal to unequal cluster sizes. We discuss a commonly used structure in CRTs-exchangeable, and derive the simpler formula of RE with continuous, binary, and count outcomes. Finally, REs are investigated for several scenarios of cluster size distributions through simulation studies. We propose an adjusted sample size due to efficiency loss. Additionally, we also propose an optimal sample size estimation based on the GEE models under a fixed budget for known and unknown association parameter (ρ) in the working correlation structure within the cluster. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

General Practice Clinical Data Help Identify Dementia Hotspots: A Novel Geospatial Analysis Approach.

PubMed

Bagheri, Nasser; Wangdi, Kinley; Cherbuin, Nicolas; Anstey, Kaarin J

2018-01-01

We have a poor understanding of whether dementia clusters geographically, how this occurs, and how dementia may relate to socio-demographic factors. To shed light on these important questions, this study aimed to compute a dementia risk score for individuals to assess spatial variation of dementia risk, identify significant clusters (hotspots), and explore their association with socioeconomic status. We used clinical records from 16 general practices (468 Statistical Area level 1 s, N = 14,746) from the city of west Adelaide, Australia for the duration of 1 January 2012 to 31 December 2014. Dementia risk was estimated using The Australian National University-Alzheimer's Disease Risk Index. Hotspot analyses were applied to examine potential clusters in dementia risk at small area level. Significant hotspots were observed in eastern and southern areas while coldspots were observed in the western area within the study perimeter. Additionally, significant hotspots were observed in low socio-economic communities. We found dementia risk scores increased with age, sex (female), high cholesterol, no physical activity, living alone (widow, divorced, separated, or never married), and co-morbidities such as diabetes and depression. Similarly, smoking was associated with a lower dementia risk score. The identification of dementia risk clusters may provide insight into possible geographical variations in risk factors for dementia and quantify these risks at the community level. As such, this research may enable policy makers to tailor early prevention strategies to the correct individuals within their precise locations.

Can preventive care activities in general practice be sustained when financial incentives and external audit plus feedback are removed? ACCEPt-able: a cluster randomised controlled trial protocol.

PubMed

Hocking, Jane S; Temple-Smith, Meredith; van Driel, Mieke; Law, Matthew; Guy, Rebecca; Bulfone, Liliana; Wood, Anna; Low, Nicola; Donovan, Basil; Fairley, Christopher K; Kaldor, John; Gunn, Jane

2016-09-13

Financial incentives and audit plus feedback on performance are two strategies commonly used by governments to motivate general practitioners (GP) to undertake specific healthcare activities. However, in recent years, governments have reduced or removed incentive payments without evidence of the potential impact on GP behaviour and patient outcomes. This trial (known as ACCEPt-able) aims to determine whether preventive care activities in general practice are sustained when financial incentives and/or external audit plus feedback on preventive care activities are removed. The activity investigated is annual chlamydia testing for 16- to 29-year-old adults, a key preventive health strategy within this age group. ACCEPt-able builds on a large cluster randomised controlled trial (RCT) that evaluated a 3-year chlamydia testing intervention in general practice. GPs were provided with a support package to facilitate annual chlamydia testing of all sexually active 16- to 29-year-old patients. This package included financial incentive payments to the GP for each chlamydia test conducted and external audit plus feedback on each GP's chlamydia testing rates. ACCEPt-able is a factorial cluster RCT in which general practices are randomised to one of four groups: (i) removal of audit plus feedback-continue to receive financial incentive payments for each chlamydia test; (ii) removal of financial incentive payments-continue to receive audit plus feedback; (iii) removal of financial incentive payments and audit plus feedback; and (iv) continue financial incentive payments and audit plus feedback. The primary outcome is chlamydia testing rate measured as the proportion of sexually active 16- to 29-year-olds who have a GP consultation within a 12-month period and at least one chlamydia test. This will be the first RCT to examine the impact of removal of financial incentive payments and audit plus feedback on the chlamydia testing behaviour of GPs. This trial is particularly timely and will increase our understanding about the impact of financial incentives and audit plus feedback on GP behaviour when governments are looking for opportunities to control healthcare budgets and maximise clinical outcomes for money spent. The results of this trial will have implications for supporting preventive health measures beyond the content area of chlamydia. The trial has been registered on the Australian and New Zealand Clinical Trials Registry ( ACTRN12614000595617 ).

Developing a typology of African Americans with limited literacy based on preventive health practice orientation: implications for colorectal cancer screening strategies.

PubMed

Gordon, Thomas F; Bass, Sarah Bauerle; Ruzek, Sheryl B; Wolak, Caitlin; Rovito, Michael J; Ruggieri, Dominique G; Ward, Stephanie; Paranjape, Anuradha; Greener, Judith

2014-01-01

Preventive health messages are often tailored to reach broad sociodemographic groups. However, within groups, there may be considerable variation in perceptions of preventive health practices, such as colorectal cancer screening. Segmentation analysis provides a tool for crafting messages that are tailored more closely to the mental models of targeted individuals or subgroups. This study used cluster analysis, a psychosocial marketing segmentation technique, to develop a typology of colorectal cancer screening orientation among 102 African American clinic patients between the ages of 50 and 74 years with limited literacy. Patients were from a general internal medicine clinic in a large urban teaching hospital, a subpopulation known to have high rates of colorectal cancer and low rates of screening. Preventive screening orientation variables included the patients' responses to questions involving personal attitudes and preferences toward preventive screening and general prevention practices. A k-means cluster analysis yielded three clusters of patients on the basis of their screening orientation: ready screeners (50.0%), cautious screeners (30.4%), and fearful avoiders (19.6%). The resulting typology clearly defines important subgroups on the basis of their preventive health practice perceptions. The authors propose that the development of a validated typology of patients on the basis of their preventive health perceptions could be applicable to a variety of health concerns. Such a typology would serve to standardize how populations are characterized and would provide a more accurate view of their preventive health-related attitudes, values, concerns, preferences, and behaviors. Used with standardized assessment tools, it would provide an empirical basis for tailoring health messages and improving medical communication.

Efficacy of communication skills training on colorectal cancer screening by GPs: a cluster randomised controlled trial.

PubMed

Aubin-Auger, I; Laouénan, C; Le Bel, J; Mercier, A; Baruch, D; Lebeau, J P; Youssefian, A; Le Trung, T; Peremans, L; Van Royen, P

2016-01-01

Colorectal cancer (CRC) mass screening has been implemented in France since 2008. Participation rates remain too low. The objective of this study was to test if the implementation of a training course focused on communication skills among general practitioners (GP) would increase the delivery of gaiac faecal occult blood test and CRC screening participation among the target population of each participating GP. A cluster randomised controlled trial was conducted with GP's practice as a cluster unit. GPs from practices in the control group were asked to continue their usual care. GPs of the intervention group received a 4-h educational training, built with previous qualitative data on CRC screening focusing on doctor-patient communication with a follow-up of 7 months for both groups. The primary outcome measure was the patients' participation rate in the target population for each GP. Seventeen GPs (16 practices) in intervention group and 28 GPs (19 practices) in control group participated. The patients' participation rate in the intervention group were 36.7% vs. 24.5% in the control group (P = 0.03). Doctor-patient communication should be developed and appear to be one of the possible targets of improvement patients adherence and participation rate in the target population for CRC mass screening. © 2015 John Wiley & Sons Ltd.

Versatile Method for the Site-Specific Modification of DNA with Boron Clusters: Anti-Epidermal Growth Factor Receptor (EGFR) Antisense Oligonucleotide Case.

PubMed

Ebenryter-Olbińska, Katarzyna; Kaniowski, Damian; Sobczak, Milena; Wojtczak, Błażej A; Janczak, Sławomir; Wielgus, Ewelina; Nawrot, Barbara; Leśnikowski, Zbigniew J

2017-11-21

A general and convenient approach for the incorporation of different types of boron clusters into specific locations of the DNA-oligonucleotide chain based on the automated phosphoramidite method of oligonucleotide synthesis and post-synthetic "click chemistry" modification has been developed. Pronounced effects of boron-cluster modification on the physico- and biochemical properties of the antisense oligonucleotides were observed. The silencing activity of antisense oligonucleotides bearing a single boron cluster modification in the middle of the oligonucleotide chain was substantially higher than that of unmodified oligonucleotides. This finding may be of importance for the design of therapeutic nucleic acids with improved properties. The proposed synthetic methodology broadens the availability of nucleic acid-boron cluster conjugates and opens up new avenues for their potential practical use. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Clustering of diet- and activity-related parenting practices: cross-sectional findings of the INPACT study

PubMed Central

2013-01-01

Background Various diet- and activity-related parenting practices are positive determinants of child dietary and activity behaviour, including home availability, parental modelling and parental policies. There is evidence that parenting practices cluster within the dietary domain and within the activity domain. This study explores whether diet- and activity-related parenting practices cluster across the dietary and activity domain. Also examined is whether the clusters are related to child and parental background characteristics. Finally, to indicate the relevance of the clusters in influencing child dietary and activity behaviour, we examined whether clusters of parenting practices are related to these behaviours. Methods Data were used from 1480 parent–child dyads participating in the Dutch IVO Nutrition and Physical Activity Child cohorT (INPACT). Parents of children aged 8–11 years completed questionnaires at home assessing their diet- and activity-related parenting practices, child and parental background characteristics, and child dietary and activity behaviours. Principal component analysis (PCA) was used to identify clusters of parenting practices. Backward regression analysis was used to examine the relationship between child and parental background characteristics with cluster scores, and partial correlations to examine associations between cluster scores and child dietary and activity behaviours. Results PCA revealed five clusters of parenting practices: 1) high visibility and accessibility of screens and unhealthy food, 2) diet- and activity-related rules, 3) low availability of unhealthy food, 4) diet- and activity-related positive modelling, and 5) positive modelling on sports and fruit. Low parental education was associated with unhealthy cluster 1, while high(er) education was associated with healthy clusters 2, 3 and 5. Separate clusters were related to both child dietary and activity behaviour in the hypothesized directions: healthy clusters were positively related to obesity-reducing behaviours and negatively to obesity-inducing behaviours. Conclusion Parenting practices cluster across the dietary and activity domain. Parental education can be seen as an indicator of a broader parental context in which clusters of parenting practices operate. Separate clusters are related to both child dietary and activity behaviour. Interventions that focus on clusters of parenting practices to assist parents (especially low-educated parents) in changing their child’s dietary and activity behaviour seems justified. PMID:23531232

Implicit Priors in Galaxy Cluster Mass and Scaling Relation Determinations

NASA Technical Reports Server (NTRS)

Mantz, A.; Allen, S. W.

2011-01-01

Deriving the total masses of galaxy clusters from observations of the intracluster medium (ICM) generally requires some prior information, in addition to the assumptions of hydrostatic equilibrium and spherical symmetry. Often, this information takes the form of particular parametrized functions used to describe the cluster gas density and temperature profiles. In this paper, we investigate the implicit priors on hydrostatic masses that result from this fully parametric approach, and the implications of such priors for scaling relations formed from those masses. We show that the application of such fully parametric models of the ICM naturally imposes a prior on the slopes of the derived scaling relations, favoring the self-similar model, and argue that this prior may be influential in practice. In contrast, this bias does not exist for techniques which adopt an explicit prior on the form of the mass profile but describe the ICM non-parametrically. Constraints on the slope of the cluster mass-temperature relation in the literature show a separation based the approach employed, with the results from fully parametric ICM modeling clustering nearer the self-similar value. Given that a primary goal of scaling relation analyses is to test the self-similar model, the application of methods subject to strong, implicit priors should be avoided. Alternative methods and best practices are discussed.

Longitudinal genomic surveillance of MRSA in the UK reveals transmission patterns in hospitals and the community.

PubMed

Coll, Francesc; Harrison, Ewan M; Toleman, Michelle S; Reuter, Sandra; Raven, Kathy E; Blane, Beth; Palmer, Beverley; Kappeler, A Ruth M; Brown, Nicholas M; Török, M Estée; Parkhill, Julian; Peacock, Sharon J

2017-10-25

Genome sequencing has provided snapshots of the transmission of methicillin-resistant Staphylococcus aureus (MRSA) during suspected outbreaks in isolated hospital wards. Scale-up to populations is now required to establish the full potential of this technology for surveillance. We prospectively identified all individuals over a 12-month period who had at least one MRSA-positive sample processed by a routine diagnostic microbiology laboratory in the East of England, which received samples from three hospitals and 75 general practitioner (GP) practices. We sequenced at least 1 MRSA isolate from 1465 individuals (2282 MRSA isolates) and recorded epidemiological data. An integrated epidemiological and phylogenetic analysis revealed 173 transmission clusters containing between 2 and 44 cases and involving 598 people (40.8%). Of these, 118 clusters (371 people) involved hospital contacts alone, 27 clusters (72 people) involved community contacts alone, and 28 clusters (157 people) had both types of contact. Community- and hospital-associated MRSA lineages were equally capable of transmission in the community, with instances of spread in households, long-term care facilities, and GP practices. Our study provides a comprehensive picture of MRSA transmission in a sampled population of 1465 people and suggests the need to review existing infection control policy and practice. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

STEMS pilot trial: a pilot cluster randomised controlled trial to investigate the addition of patient direct access to physiotherapy to usual GP-led primary care for adults with musculoskeletal pain.

PubMed

Bishop, Annette; Ogollah, Reuben O; Jowett, Sue; Kigozi, Jesse; Tooth, Stephanie; Protheroe, Joanne; Hay, Elaine M; Salisbury, Chris; Foster, Nadine E

2017-03-12

Around 17% of general practitioner (GP) consultations are for musculoskeletal conditions, which will rise as the population ages. Patient direct access to physiotherapy provides one solution, yet adoption in the National Health Service (NHS) has been slow. A pilot, pragmatic, non-inferiority, cluster randomised controlled trial (RCT) in general practice and physiotherapy services in the UK. Investigate feasibility of a main RCT. Adult patients registered in participating practices and consulting with a musculoskeletal problem. 4 general practices (clusters) randomised to provide GP-led care as usual or the addition of a patient direct access to physiotherapy pathway. Process outcomes and exploratory analyses of clinical and cost outcomes. Participant-level data were collected via questionnaires at identification, 2, 6 and 12 months and through medical records. The study statistician and research nurses were blinded to practice allocation. Of 2696 patients invited to complete study questionnaires, 978 participated (intervention group n=425, control arm n=553) and were analysed. Participant recruitment was completed in 6 months. Follow-up rates were 78% (6 months) and 71% (12 months). No evidence of selection bias was observed. The direct access pathway was used by 90% of patients in intervention practices needing physiotherapy. Some increase in referrals to physiotherapy occurred from one practice, although waiting times for physiotherapy did not increase (28 days before, 26 days after introduction of direct access). No safety issues were identified. Clinical and cost outcomes were similar in both groups. Exploratory estimates of between group effect (using 36-item Short Form Health Survey (SF-36) Physical Component Summary (PCS)) at 6 months was -0.28 (95% CI -1.35 to 0.79) and at 12 months 0.12 (95% CI -1.27 to 1.51). A full RCT is feasible and will provide trial evidence about the clinical and cost-effectiveness of patient direct access to physiotherapy. ISRCTN23378642. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Peer support for patients with type 2 diabetes: cluster randomised controlled trial.

PubMed

Smith, S M; Paul, G; Kelly, A; Whitford, D L; O'Shea, E; O'Dowd, T

2011-02-15

To test the effectiveness of peer support for patients with type 2 diabetes. Cluster randomised controlled. 20 general practices in the east of the Republic of Ireland. 395 patients (192 in intervention group, 203 in control group) and 29 peer supporters with type 2 diabetes. All practices introduced a standardised diabetes care system. The peer support intervention ran over a two year period and contained four elements: the recruitment and training of peer supporters, nine group meetings led by peer supporters in participant's own general practice, and a retention plan for the peer supporters. HbA(1c); cholesterol concentration; systolic blood pressure; and wellbeing score. There was no difference between intervention and control patients at baseline. All practices and 85% (337) of patients were followed up. At two year follow-up, there were no significant differences in HbA(1c) (mean difference -0.08%, 95% confidence interval -0.35% to 0.18%), systolic blood pressure (-3.9 mm Hg, -8.9 to 1.1 mm Hg), total cholesterol concentration (-0.03 mmol/L, -0.28 to 0.22 mmol/L), or wellbeing scores (-0.7, -2.3 to 0.8). While there was a trend towards decreases in the proportion of patients with poorly controlled risk factors at follow-up, particularly for systolic blood pressure (52% (87/166) >130 mm Hg in intervention v 61% (103/169) >130 mm Hg in control), these changes were not significant. The process evaluation indicated that the intervention was generally delivered as intended, though 18% (35) of patients in the intervention group never attended any group meetings. A group based peer support intervention is feasible in general practice settings, but the intervention was not effective when targeted at all patients with type 2 diabetes. While there was a trend towards improvements of clinical outcomes, the results do not support the widespread adoption of peer support. Trial registration Current Controlled Trials ISRCTN42541690.

Evaluation of a tailored implementation strategy to improve the management of patients with chronic obstructive pulmonary disease in primary care: a study protocol of a cluster randomized trial

PubMed Central

2014-01-01

Background Chronic obstructive pulmonary disease (COPD) remains a major health problem, strongly related to smoking. Despite the publication of practice guidelines on prevention and treatment, not all patients with the disease receive the recommended healthcare, particularly with regard to smoking cessation advice where applicable. We have developed a tailored implementation strategy for enhancing general practitioners’ adherence to the disease management guidelines. The primary aim of the study is to evaluate the effects of this tailored implementation intervention on general practitioners’ adherence to guidelines. Methods/Design A pragmatic two-arm cluster randomized trial has been planned to compare care following the implementation of tailored interventions of four recommendations in COPD patients against usual care. The study will involve 18 general practices (9 in the intervention group and 9 in the control group) in Poland, each with at least 80 identified (at the baseline) patients with diagnosed COPD. The nine control practices will provide usual care without any interventions. Tailored interventions to implement four recommendations will be delivered in the remaining nine practices. At follow-up after nine months, data will be collected for all 18 general practices. The primary outcome measure is physicians’ adherence to all four recommendations: brief anti-smoking advice, dyspnea assessment, care checklist utilization and demonstration to patients of correct inhaler use. This measurement will be based on data extracted from identified patients’ records. Additionally, we will survey and interview patients with chronic obstructive pulmonary disease about the process of care. Discussion The results of this trial will be directly applicable to primary care in Poland and add to the growing body of evidence on interventions to improve chronic illness care. Trial registration This trial has been registered with Clinical Trials Protocol Registration System. Trial number: NCT01893476. PMID:24708623

Promoting Mental Health and Preventing Mental Illness in General Practice.

PubMed

Thomas, Steve; Jenkins, Rachel; Burch, Tony; Calamos Nasir, Laura; Fisher, Brian; Giotaki, Gina; Gnani, Shamini; Hertel, Lise; Marks, Marina; Mathers, Nigel; Millington-Sanders, Catherine; Morris, David; Ruprah-Shah, Baljeet; Stange, Kurt; Thomas, Paul; White, Robert; Wright, Fiona

2016-01-01

This paper calls for the routine integration of mental health promotion and prevention into UK General Practice in order to reduce the burden of mental and physical disorders and the ensuing pressure on General Practice. The proposals & the resulting document (https://ethicscharity.files.wordpress.com/2015/09/rcgp_keymsg_150925_v5.pdf) arise from an expert 'Think Tank' convened by the London Journal of Primary Care, Educational Trust for Health Improvement through Cognitive Strategies (ETHICS Foundation) and the Royal College of General Practitioners. It makes 12 recommendations for General Practice: (1) Mental health promotion and prevention are too important to wait. (2) Work with your community to map risk factors, resources and assets. (3) Good health care, medicine and best practice are biopsychosocial rather than purely physical. (4) Integrate mental health promotion and prevention into your daily work. (5) Boost resilience in your community through approaches such as community development. (6) Identify people at increased risk of mental disorder for support and screening. (7) Support early intervention for people of all ages with signs of illness. (8) Maintain your biopsychosocial skills. (9) Ensure good communication, interdisciplinary team working and inter-sectoral working with other staff, teams and agencies. (10) Lead by example, taking action to promote the resilience of the general practice workforce. (11) Ensure mental health is appropriately included in the strategic agenda for your 'cluster' of General Practices, at the Clinical Commissioning Groups, and the Health and Wellbeing Board. (12) Be aware of national mental health strategies and localise them, including action to destigmatise mental illness within the context of community development.

Personality disorders: review and clinical application in daily practice.

PubMed

Angstman, Kurt B; Rasmussen, Norman H

2011-12-01

Personality disorders have been documented in approximately 9 percent of the general U.S. population. Psychotherapy, pharmacotherapy, and brief interventions designed for use by family physicians can improve the health of patients with these disorders. Personality disorders are classified into clusters A, B, and C. Cluster A includes schizoid, schizotypal, and paranoid personality disorders. Cluster B includes borderline, histrionic, antisocial, and narcissistic personality disorders. Cluster C disorders are more prevalent and include avoidant, dependent, and obsessive-compulsive personality disorders. Many patients with personality disorders can be treated by family physicians. Patients with borderline personality disorder may benefit from the use of omega-3 fatty acids, second-generation antipsychotics, and mood stabilizers. Patients with antisocial personality disorder may benefit from the use of mood stabilizers, antipsychotics, and antidepressants. Other therapeutic interventions include motivational interviewing and solution-based problem solving.

Metal-cluster ionization energy: A profile-insensitive exact expression for the size effect

NASA Astrophysics Data System (ADS)

Seidl, Michael; Perdew, John P.; Brajczewska, Marta; Fiolhais, Carlos

1997-05-01

The ionization energy of a large spherical metal cluster of radius R is I(R)=W+(+c)/R, where W is the bulk work function and c~-0.1 is a material-dependent quantum correction to the electrostatic size effect. We present 'Koopmans' and 'displaced-profile change-in-self-consistent-field' expressions for W and c within the ordinary and stabilized-jellium models. These expressions are shown to be exact and equivalent when the exact density profile of a large neutral cluster is employed; these equivalences generalize the Budd-Vannimenus theorem. With an approximate profile obtained from a restricted variational calculation, the 'displaced-profile' expressions are the more accurate ones. This profile insensitivity is important, because it is not practical to extract c from solutions of the Kohn-Sham equations for small metal clusters.

Effectiveness of integrated disease management for primary care chronic obstructive pulmonary disease patients: results of cluster randomised trial.

PubMed

Kruis, Annemarije L; Boland, Melinde R S; Assendelft, Willem J J; Gussekloo, Jacobijn; Tsiachristas, Apostolos; Stijnen, Theo; Blom, Coert; Sont, Jacob K; Rutten-van Mölken, Maureen P H M; Chavannes, Niels H

2014-09-10

To investigate the long term effectiveness of integrated disease management delivered in primary care on quality of life in patients with chronic obstructive pulmonary disease (COPD) compared with usual care. 24 month, multicentre, pragmatic cluster randomised controlled trial 40 general practices in the western part of the Netherlands Patients with COPD according to GOLD (Global Initiative for COPD) criteria. Exclusion criteria were terminal illness, cognitive impairment, alcohol or drug misuse, and inability to fill in Dutch questionnaires. Practices were included if they were willing to create a multidisciplinary COPD team. General practitioners, practice nurses, and specialised physiotherapists in the intervention group received a two day training course on incorporating integrated disease management in practice, including early recognition of exacerbations and self management, smoking cessation, physiotherapeutic reactivation, optimal diagnosis, and drug adherence. Additionally, the course served as a network platform and collaborating healthcare providers designed an individual practice plan to integrate integrated disease management into daily practice. The control group continued usual care (based on international guidelines). The primary outcome was difference in health status at 12 months, measured by the Clinical COPD Questionnaire (CCQ); quality of life, Medical Research Council dyspnoea, exacerbation related outcomes, self management, physical activity, and level of integrated care (PACIC) were also assessed as secondary outcomes. Of a total of 1086 patients from 40 clusters, 20 practices (554 patients) were randomly assigned to the intervention group and 20 clusters (532 patients) to the usual care group. No difference was seen between groups in the CCQ at 12 months (mean difference -0.01, 95% confidence interval -0.10 to 0.08; P=0.8). After 12 months, no differences were seen in secondary outcomes between groups, except for the PACIC domain "follow-up/coordination" (indicating improved integration of care) and proportion of physically active patients. Exacerbation rates as well as number of days in hospital did not differ between groups. After 24 months, no differences were seen in outcomes, except for the PACIC follow-up/coordination domain. In this pragmatic study, an integrated disease management approach delivered in primary care showed no additional benefit compared with usual care, except improved level of integrated care and a self reported higher degree of daily activities. The contradictory findings to earlier positive studies could be explained by differences between interventions (provider versus patient targeted), selective reporting of positive trials, or little room for improvement in the already well developed Dutch healthcare system. Netherlands Trial Register NTR2268. © Kruis et al 2014.

Effectiveness of a virtual intervention for primary healthcare professionals aimed at improving attitudes towards the empowerment of patients with chronic diseases: study protocol for a cluster randomized controlled trial (e-MPODERA project).

PubMed

González-González, Ana Isabel; Orrego, Carola; Perestelo-Perez, Lilisbeth; Bermejo-Caja, Carlos Jesús; Mora, Nuria; Koatz, Débora; Ballester, Marta; Del Pino, Tasmania; Pérez-Ramos, Jeannet; Toledo-Chavarri, Ana; Robles, Noemí; Pérez-Rivas, Francisco Javier; Ramírez-Puerta, Ana Belén; Canellas-Criado, Yolanda; Del Rey-Granado, Yolanda; Muñoz-Balsa, Marcos José; Becerril-Rojas, Beatriz; Rodríguez-Morales, David; Sánchez-Perruca, Luis; Vázquez, José Ramón; Aguirre, Armando

2017-10-30

Communities of practice are based on the idea that learning involves a group of people exchanging experiences and knowledge. The e-MPODERA project aims to assess the effectiveness of a virtual community of practice aimed at improving primary healthcare professional attitudes to the empowerment of patients with chronic diseases. This paper describes the protocol for a cluster randomized controlled trial. We will randomly assign 18 primary-care practices per participating region of Spain (Catalonia, Madrid and Canary Islands) to a virtual community of practice or to usual training. The primary-care practice will be the randomization unit and the primary healthcare professional will be the unit of analysis. We will need a sample of 270 primary healthcare professionals (general practitioners and nurses) and 1382 patients. We will perform randomization after professionals and patients are selected. We will ask the intervention group to participate for 12 months in a virtual community of practice based on a web 2.0 platform. We will measure the primary outcome using the Patient-Provider Orientation Scale questionnaire administered at baseline and after 12 months. Secondary outcomes will be the sociodemographic characteristics of health professionals, sociodemographic and clinical characteristics of patients, the Patient Activation Measure questionnaire for patient activation and outcomes regarding use of the virtual community of practice. We will calculate a linear mixed-effects regression to estimate the effect of participating in the virtual community of practice. This cluster randomized controlled trial will show whether a virtual intervention for primary healthcare professionals improves attitudes to the empowerment of patients with chronic diseases. ClicalTrials.gov, NCT02757781 . Registered on 25 April 2016. Protocol Version. PI15.01 22 January 2016.

Design and preliminary recruitment results of the Cluster randomised triAl of PSA testing for Prostate cancer (CAP).

PubMed

Turner, E L; Metcalfe, C; Donovan, J L; Noble, S; Sterne, J A C; Lane, J A; Avery, K N; Down, L; Walsh, E; Davis, M; Ben-Shlomo, Y; Oliver, S E; Evans, S; Brindle, P; Williams, N J; Hughes, L J; Hill, E M; Davies, C; Ng, S Y; Neal, D E; Hamdy, F C; Martin, R M

2014-06-10

Screening for prostate cancer continues to generate controversy because of concerns about over-diagnosis and unnecessary treatment. We describe the rationale, design and recruitment of the Cluster randomised triAl of PSA testing for Prostate cancer (CAP) trial, a UK-wide cluster randomised controlled trial investigating the effectiveness and cost-effectiveness of prostate-specific antigen (PSA) testing. Seven hundred and eighty-five general practitioner (GP) practices in England and Wales were randomised to a population-based PSA testing or standard care and then approached for consent to participate. In the intervention arm, men aged 50-69 years were invited to undergo PSA testing, and those diagnosed with localised prostate cancer were invited into a treatment trial. Control arm practices undertook standard UK management. All men were flagged with the Health and Social Care Information Centre for deaths and cancer registrations. The primary outcome is prostate cancer mortality at a median 10-year-follow-up. Among randomised practices, 271 (68%) in the intervention arm (198,114 men) and 302 (78%) in the control arm (221,929 men) consented to participate, meeting pre-specified power requirements. There was little evidence of differences between trial arms in measured baseline characteristics of the consenting GP practices (or men within those practices). The CAP trial successfully met its recruitment targets and will make an important contribution to international understanding of PSA-based prostate cancer screening.

Effects of patient safety culture interventions on incident reporting in general practice: a cluster randomised trial

PubMed Central

Verbakel, Natasha J; Langelaan, Maaike; Verheij, Theo JM; Wagner, Cordula; Zwart, Dorien LM

2015-01-01

Background A constructive safety culture is essential for the successful implementation of patient safety improvements. Aim To assess the effect of two patient safety culture interventions on incident reporting as a proxy of safety culture. Design and setting A three-arm cluster randomised trial was conducted in a mixed method study, studying the effect of administering a patient safety culture questionnaire (intervention I), the questionnaire complemented with a practice-based workshop (intervention II) and no intervention (control) in 30 general practices in the Netherlands. Method The primary outcome, the number of reported incidents, was measured with a questionnaire at baseline and a year after. Analysis was performed using a negative binomial model. Secondary outcomes were quality and safety indicators and safety culture. Mixed effects linear regression was used to analyse the culture questionnaires. Results The number of incidents increased in both intervention groups, to 82 and 224 in intervention I and II respectively. Adjusted for baseline number of incidents, practice size and accreditation status, the study showed that practices that additionally participated in the workshop reported 42 (95% confidence interval [CI] = 9.81 to 177.50) times more incidents compared to the control group. Practices that only completed the questionnaire reported 5 (95% CI = 1.17 to 25.49) times more incidents. There were no statistically significant differences in staff perception of patient safety culture at follow-up between the three study groups. Conclusion Educating staff and facilitating discussion about patient safety culture in their own practice leads to increased reporting of incidents. It is beneficial to invest in a team-wise effort to improve patient safety. PMID:25918337

Imputation of a true endpoint from a surrogate: application to a cluster randomized controlled trial with partial information on the true endpoint.

PubMed

Nixon, Richard M; Duffy, Stephen W; Fender, Guy R K

2003-09-24

The Anglia Menorrhagia Education Study (AMES) is a randomized controlled trial testing the effectiveness of an education package applied to general practices. Binary data are available from two sources; general practitioner reported referrals to hospital, and referrals to hospital determined by independent audit of the general practices. The former may be regarded as a surrogate for the latter, which is regarded as the true endpoint. Data are only available for the true end point on a sub set of the practices, but there are surrogate data for almost all of the audited practices and for most of the remaining practices. The aim of this paper was to estimate the treatment effect using data from every practice in the study. Where the true endpoint was not available, it was estimated by three approaches, a regression method, multiple imputation and a full likelihood model. Including the surrogate data in the analysis yielded an estimate of the treatment effect which was more precise than an estimate gained from using the true end point data alone. The full likelihood method provides a new imputation tool at the disposal of trials with surrogate data.

Evaluation of a theory-informed implementation intervention for the management of acute low back pain in general medical practice: the IMPLEMENT cluster randomised trial.

PubMed

French, Simon D; McKenzie, Joanne E; O'Connor, Denise A; Grimshaw, Jeremy M; Mortimer, Duncan; Francis, Jill J; Michie, Susan; Spike, Neil; Schattner, Peter; Kent, Peter; Buchbinder, Rachelle; Page, Matthew J; Green, Sally E

2013-01-01

This cluster randomised trial evaluated an intervention to decrease x-ray referrals and increase giving advice to stay active for people with acute low back pain (LBP) in general practice. General practices were randomised to either access to a guideline for acute LBP (control) or facilitated interactive workshops (intervention). We measured behavioural predictors (e.g. knowledge, attitudes and intentions) and fear avoidance beliefs. We were unable to recruit sufficient patients to measure our original primary outcomes so we introduced other outcomes measured at the general practitioner (GP) level: behavioural simulation (clinical decision about vignettes) and rates of x-ray and CT-scan (medical administrative data). All those not involved in the delivery of the intervention were blinded to allocation. 47 practices (53 GPs) were randomised to the control and 45 practices (59 GPs) to the intervention. The number of GPs available for analysis at 12 months varied by outcome due to missing confounder information; a minimum of 38 GPs were available from the intervention group, and a minimum of 40 GPs from the control group. For the behavioural constructs, although effect estimates were small, the intervention group GPs had greater intention of practising consistent with the guideline for the clinical behaviour of x-ray referral. For behavioural simulation, intervention group GPs were more likely to adhere to guideline recommendations about x-ray (OR 1.76, 95%CI 1.01, 3.05) and more likely to give advice to stay active (OR 4.49, 95%CI 1.90 to 10.60). Imaging referral was not statistically significantly different between groups and the potential importance of effects was unclear; rate ratio 0.87 (95%CI 0.68, 1.10) for x-ray or CT-scan. The intervention led to small changes in GP intention to practice in a manner that is consistent with an evidence-based guideline, but it did not result in statistically significant changes in actual behaviour. Australian New Zealand Clinical Trials Registry ACTRN012606000098538.

Evaluation of a Theory-Informed Implementation Intervention for the Management of Acute Low Back Pain in General Medical Practice: The IMPLEMENT Cluster Randomised Trial

PubMed Central

French, Simon D.; McKenzie, Joanne E.; O'Connor, Denise A.; Grimshaw, Jeremy M.; Mortimer, Duncan; Francis, Jill J.; Michie, Susan; Spike, Neil; Schattner, Peter; Kent, Peter; Buchbinder, Rachelle; Page, Matthew J.; Green, Sally E.

2013-01-01

Introduction This cluster randomised trial evaluated an intervention to decrease x-ray referrals and increase giving advice to stay active for people with acute low back pain (LBP) in general practice. Methods General practices were randomised to either access to a guideline for acute LBP (control) or facilitated interactive workshops (intervention). We measured behavioural predictors (e.g. knowledge, attitudes and intentions) and fear avoidance beliefs. We were unable to recruit sufficient patients to measure our original primary outcomes so we introduced other outcomes measured at the general practitioner (GP) level: behavioural simulation (clinical decision about vignettes) and rates of x-ray and CT-scan (medical administrative data). All those not involved in the delivery of the intervention were blinded to allocation. Results 47 practices (53 GPs) were randomised to the control and 45 practices (59 GPs) to the intervention. The number of GPs available for analysis at 12 months varied by outcome due to missing confounder information; a minimum of 38 GPs were available from the intervention group, and a minimum of 40 GPs from the control group. For the behavioural constructs, although effect estimates were small, the intervention group GPs had greater intention of practising consistent with the guideline for the clinical behaviour of x-ray referral. For behavioural simulation, intervention group GPs were more likely to adhere to guideline recommendations about x-ray (OR 1.76, 95%CI 1.01, 3.05) and more likely to give advice to stay active (OR 4.49, 95%CI 1.90 to 10.60). Imaging referral was not statistically significantly different between groups and the potential importance of effects was unclear; rate ratio 0.87 (95%CI 0.68, 1.10) for x-ray or CT-scan. Conclusions The intervention led to small changes in GP intention to practice in a manner that is consistent with an evidence-based guideline, but it did not result in statistically significant changes in actual behaviour. Trial Registration Australian New Zealand Clinical Trials Registry ACTRN012606000098538 PMID:23785427

The clustering of baryonic matter. I: a halo-model approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fedeli, C., E-mail: cosimo.fedeli@oabo.inaf.it

2014-04-01

In this paper I generalize the halo model for the clustering of dark matter in order to produce the power spectra of the two main baryonic matter components in the Universe: stars and hot gas. As a natural extension, this can be also used to describe the clustering of all mass. According to the design of the halo model, the large-scale power spectra of the various matter components are physically connected with the distribution of each component within bound structures and thus, ultimately, with the complete set of physical processes that drive the formation of galaxies and galaxy clusters. Besidesmore » being practical for cosmological and parametric studies, the semi-analytic model presented here has also other advantages. Most importantly, it allows one to understand on physical ground what is the relative contribution of each matter component to the total clustering of mass as a function of scale, and thus it opens an interesting new window to infer the distribution of baryons through high precision cosmic shear measurements. This is particularly relevant for future wide-field photometric surveys such as Euclid. In this work the concept of the model and its uncertainties are illustrated in detail, while in a companion paper we use a set of numerical hydrodynamic simulations to show a practical application and to investigate where the model itself needs to be improved.« less

A multifaceted intervention to narrow the evidence-based gap in the treatment of acute coronary syndromes: rationale and design of the Brazilian Intervention to Increase Evidence Usage in Acute Coronary Syndromes (BRIDGE-ACS) cluster-randomized trial.

PubMed

Berwanger, Otávio; Guimarães, Hélio P; Laranjeira, Ligia N; Cavalcanti, Alexandre B; Kodama, Alessandra; Zazula, Ana Denise; Santucci, Eliana; Victor, Elivane; Flato, Uri A; Tenuta, Marcos; Carvalho, Vitor; Mira, Vera Lucia; Pieper, Karen S; Mota, Luiz Henrique; Peterson, Eric D; Lopes, Renato D

2012-03-01

Translating evidence into clinical practice in the management of acute coronary syndromes (ACS) is challenging. Few ACS quality improvement interventions have been rigorously evaluated to determine their impact on patient care and clinical outcomes. We designed a pragmatic, 2-arm, cluster-randomized trial involving 34 clusters (Brazilian public hospitals). Clusters were randomized to receive a multifaceted quality improvement intervention (experimental group) or routine practice (control group). The 6-month educational intervention included reminders, care algorithms, a case manager, and distribution of educational materials to health care providers. The primary end point was a composite of evidence-based post-ACS therapies within 24 hours of admission, with the secondary measure of major cardiovascular clinical events (death, nonfatal myocardial infarction, nonfatal cardiac arrest, and nonfatal stroke). Prescription of evidence-based therapies at hospital discharge were also evaluated as part of the secondary outcomes. All analyses were performed by the intention-to-treat principle and took the cluster design into account using individual-level regression modeling (generalized estimating equations). If proven effective, this multifaceted intervention would have wide use as a means of promoting optimal use of evidence-based interventions for the management of ACS. Copyright © 2012 Mosby, Inc. All rights reserved.

A cluster randomised controlled trial evaluating the effectiveness of a structured pulmonary rehabilitation education programme for improving the health status of people with chronic obstructive pulmonary disease (COPD): The PRINCE Study protocol.

PubMed

Murphy, Kathy; Casey, Dympna; Devane, Declan; Cooney, Adeline; McCarthy, Bernard; Mee, Lorraine; Nichulain, Martina; Murphy, Andrew W; Newell, John; O' Shea, Eamon

2011-01-18

A key strategy in improving care for people with chronic obstructive pulmonary disease (COPD) is the provision of pulmonary rehabilitation programmes. Pulmonary rehabilitation programmes have been successful in improving patients' sense of dyspnoea and Health Related Quality of Life. However, the effectiveness of structured education pulmonary rehabilitation programmes delivered at the level of the general practice on the health status of people with COPD remains uncertain and there is a need for a robust and fair assessment of this. The PRINCE study will evaluate the effectiveness of a Structured Education Pulmonary Rehabilitation Programme (SEPRP), delivered at the level of the general practice, on the health status of people with COPD. The PRINCE Trial is a two-armed, single blind cluster randomised trial conducted in the primary care setting in Ireland. Randomisation to control and intervention is at the level of the General Practice. Participants in the intervention arm will receive a SEPRP and those allocated to the control arm will receive usual care. Delivery of the SEPRP will be by a practice nurse and physiotherapist in the General Practice (GP) site. The primary outcome measure of the study will be health status as measured by the Chronic Respiratory Questionnaire (CRQ). Blinded outcome assessment will be undertaken at baseline and at twelve-fourteen weeks after completion of the programme. A comparison of outcomes between the intervention and control sites will be made to examine if differences exist and, if so, to what extent between control and experimental groups. Sample size calculations estimate that 32 practices with a minimum of 10 participants per practice are required, in total, to be randomised to control and intervention arms for power of at least 80% with alpha levels of 0.05, to determine a clinically significant change of 0.5 units in the CRQ. A cost effectiveness analysis will also be conducted. The results of this trial are directly applicable to primary care settings in Ireland. Should a SEPRP delivered by practice nurses and physiotherapists in primary care be found to be effective in improving patients' sense of dyspnoea and HRQoL, then the findings would be applicable to many thousands of individuals in Ireland and beyond.

Effectiveness and cost-effectiveness of an educational intervention for practice teams to deliver problem focused therapy for insomnia: rationale and design of a pilot cluster randomised trial

PubMed Central

Siriwardena, A Niroshan; Apekey, Tanefa; Tilling, Michelle; Harrison, Andrew; Dyas, Jane V; Middleton, Hugh C; Ørner, Roderick; Sach, Tracey; Dewey, Michael; Qureshi, Zubair M

2009-01-01

Background Sleep problems are common, affecting over a third of adults in the United Kingdom and leading to reduced productivity and impaired health-related quality of life. Many of those whose lives are affected seek medical help from primary care. Drug treatment is ineffective long term. Psychological methods for managing sleep problems, including cognitive behavioural therapy for insomnia (CBTi) have been shown to be effective and cost effective but have not been widely implemented or evaluated in a general practice setting where they are most likely to be needed and most appropriately delivered. This paper outlines the protocol for a pilot study designed to evaluate the effectiveness and cost-effectiveness of an educational intervention for general practitioners, primary care nurses and other members of the primary care team to deliver problem focused therapy to adult patients presenting with sleep problems due to lifestyle causes, pain or mild to moderate depression or anxiety. Methods and design This will be a pilot cluster randomised controlled trial of a complex intervention. General practices will be randomised to an educational intervention for problem focused therapy which includes a consultation approach comprising careful assessment (using assessment of secondary causes, sleep diaries and severity) and use of modified CBTi for insomnia in the consultation compared with usual care (general advice on sleep hygiene and pharmacotherapy with hypnotic drugs). Clinicians randomised to the intervention will receive an educational intervention (2 × 2 hours) to implement a complex intervention of problem focused therapy. Clinicians randomised to the control group will receive reinforcement of usual care with sleep hygiene advice. Outcomes will be assessed via self-completion questionnaires and telephone interviews of patients and staff as well as clinical records for interventions and prescribing. Discussion Previous studies in adults have shown that psychological treatments for insomnia administered by specialist nurses to groups of patients can be effective within a primary care setting. This will be a pilot study to determine whether an educational intervention aimed at primary care teams to deliver problem focused therapy for insomnia can improve sleep management and outcomes for individual adult patients presenting to general practice. The study will also test procedures and collect information in preparation for a larger definitive cluster-randomised trial. The study is funded by The Health Foundation. Trial Registration ClinicalTrials.gov ID ISRCTN55001433 – PMID:19171070

Generalized vibrating potential model for collective excitations in spherical, deformed and superdeformed systems: (1) Atomic nuclei, (2) Metal clusters

NASA Astrophysics Data System (ADS)

Nesterenko, V. O.; Kleinig, W.

1995-01-01

The self-consistent vibrating potential model (VPM) is extended for description of Eλ collective excitations in atomic nuclei and metal clusters with practically any kind of static deformation. The model is convenient for a qualitative analysis and provides the RPA accuracy of numerical calculations. The VPM is applied to study Eλ giant resonances in spherical metal clusters and deformed and superdeformed nuclei. It is shown that the deformation splitting of superdeformed nuclei results in a very complicated ("jungle-like") structure of the resonances, which makes the experimental observation of E2 and E3 giant resonances in superdeformed nuclei quite problematic. Calculations of E1 giant resonances in spherical sodium clusters Na8, Na20 and Na40 are presented, as a test of the VPM in this field. The results are in qualitative agreement with the experimental data.

Palliative sedation in Dutch general practice from 2005 to 2011: a dynamic cohort study of trends and reasons

PubMed Central

Donker, Gé A; Slotman, Frank G; Spreeuwenberg, Peter; Francke, Anneke L

2013-01-01

Background Little is known about the quantity and reasons for use of palliative sedation in general practice. Aim To gain more insight into the trends of and reasons for palliative sedation in Dutch general practice. Design and setting Dynamic cohort study using registrations and questionnaire data of Dutch GPs. Method Data collected in the years from 2005 until 2011 in the Dutch Sentinel General Practice Network were analysed. Trends and reasons for use of palliative sedation were analysed using multilevel analyses to control for clustering of observations within general practices. Results From 2005–2011, 183 cases were reported from 56 general practices. The incidence of palliative sedation fluctuated between 33.7 per 100 000 patients in 2006 and 15.2 in 2011. No rise or decline during the period was observed. Palliative sedation was applied in 5.7% of all deaths and most frequently used in younger patients with cancer. The mean number of refractory symptoms was 2.6 (SD 1.2); pain (69.4%), dyspnoea (53.0%), and fear (39.3%). Patient involvement in decision making before the start of palliative sedation (87.4%) was less frequently present in patients suffering from cardiovascular or chronic obstructive pulmonary disease and in older patients compared to patients with cancer (P<0.05). Pending euthanasia requests were present in 20.8% of cases; the choice for palliative sedation in these cases was clearly motivated. Conclusion Palliative sedation is performed in a small proportion of dying patients in Dutch general practice, without a rise or decline observed from 2005 to 2011. Patients with non-cancer diseases are less frequently involved in decision making than patients with cancer, possibly related to sudden deterioration. PMID:24152481

Palliative sedation in Dutch general practice from 2005 to 2011: a dynamic cohort study of trends and reasons.

PubMed

Donker, Gé A; Slotman, Frank G; Spreeuwenberg, Peter; Francke, Anneke L

2013-10-01

Little is known about the quantity and reasons for use of palliative sedation in general practice. To gain more insight into the trends of and reasons for palliative sedation in Dutch general practice. Dynamic cohort study using registrations and questionnaire data of Dutch GPs. Method Data collected in the years from 2005 until 2011 in the Dutch Sentinel General Practice Network were analysed. Trends and reasons for use of palliative sedation were analysed using multilevel analyses to control for clustering of observations within general practices. From 2005-2011, 183 cases were reported from 56 general practices. The incidence of palliative sedation fluctuated between 33.7 per 100 000 patients in 2006 and 15.2 in 2011. No rise or decline during the period was observed. Palliative sedation was applied in 5.7% of all deaths and most frequently used in younger patients with cancer. The mean number of refractory symptoms was 2.6 (SD 1.2); pain (69.4%), dyspnoea (53.0%), and fear (39.3%). Patient involvement in decision making before the start of palliative sedation (87.4%) was less frequently present in patients suffering from cardiovascular or chronic obstructive pulmonary disease and in older patients compared to patients with cancer (P<0.05). Pending euthanasia requests were present in 20.8% of cases; the choice for palliative sedation in these cases was clearly motivated. Palliative sedation is performed in a small proportion of dying patients in Dutch general practice, without a rise or decline observed from 2005 to 2011. Patients with non-cancer diseases are less frequently involved in decision making than patients with cancer, possibly related to sudden deterioration.

Update in Outpatient General Internal Medicine: Practice-Changing Evidence Published in 2017.

PubMed

Wieland, Mark L; Szostek, Jason H; Wingo, Majken T; Post, Jason A; Mauck, Karen F

2018-02-26

Clinicians are challenged to identify new practice-changing articles in the medical literature. To identify the practice-changing articles published in 2017 most relevant to outpatient general internal medicine, 5 internists reviewed the following sources: 1) titles and abstracts from internal medicine journals with the 7 highest impact factors, including New England Journal of Medicine, Lancet, Journal of the American Medical Association, British Medical Journal, Public Library of Science Medicine, Annals of Internal Medicine, and JAMA Internal Medicine; 2) synopses and syntheses of individual studies, including collections in the American College of Physicians Journal Club, Journal Watch, and Evidence-Based Medicine; 3) databases of synthesis, including Evidence Updates and the Cochrane Library. Inclusion criteria were perceived clinical relevance to outpatient general medicine, potential for practice change, and strength of evidence. This process yielded 140 articles. Clusters of important articles around one topic were considered as a single-candidate series. A modified Delphi method was utilized by the 5 authors to reach consensus on 7 topics to highlight and appraise from the 2017 literature. Copyright © 2018 Elsevier Inc. All rights reserved.

Comparing Regression Coefficients between Nested Linear Models for Clustered Data with Generalized Estimating Equations

ERIC Educational Resources Information Center

Yan, Jun; Aseltine, Robert H., Jr.; Harel, Ofer

2013-01-01

Comparing regression coefficients between models when one model is nested within another is of great practical interest when two explanations of a given phenomenon are specified as linear models. The statistical problem is whether the coefficients associated with a given set of covariates change significantly when other covariates are added into…

Cluster: Metals. Course: Machine Shop. Research Project.

ERIC Educational Resources Information Center

Sanford - Lee County Schools, NC.

The set of 13 units is designed for use with an instructor in actual machine shop practice and is also keyed to audio visual and textual materials. Each unit contains a series of task packages which: specify prerequisites within the series (minimum is Unit 1); provide a narrative rationale for learning; list both general and specific objectives in…

The contribution of demographic and morbidity factors to self-reported visit frequency of patients: a cross-sectional study of general practice patients in Australia

PubMed Central

Knox, Stephanie A; Britt, Helena

2004-01-01

Background Understanding the factors that affect patients' utilisation of health services is important for health service provision and effective patient management. This study aimed to investigate the specific morbidity and demographic factors related to the frequency with which general practice patients visit a general practitioner/family physician (GP) in Australia. Methods A sub-study was undertaken as part of an ongoing national study of general practice activity in Australia. A cluster sample of 10,755 general practice patients were surveyed through a random sample of 379 general practitioners. The patient reported the number of times he/she had visited a general practitioner in the previous twelve months. The GP recorded all the patient's major health problems, including those managed at the current consultation. Results Patients reported an average of 8.8 visits to a general practitioner per year. After adjusting for other patient demographics and number of health problems, concession health care card holders made on average 2.6 more visits per year to a general practitioner than did non-card holders (p < .001). After adjustment, patients from remote/very remote locations made 2.3 fewer visits per year than patients from locations where services were highly accessible (p < .001). After adjustment for patient demographics, patients with diagnosed anxiety made on average 2.7 more visits per year (p = 0.003), those with diagnosed depression 2.2 more visits than average (p < .0001), and those with back problems 2.4 more visits (p = 0.009) than patients without the respective disorders. Conclusions Anxiety, back pain and depression are associated with greater patient demand for general practice services than other health problems. The effect of sociodemographic factors on patient utilisation of general practice services is complex. Equity of access to general practice services remains an issue for patients from remote areas, while concession health care card holders are attending general practice more frequently than other patients relative to their number of health problems. PMID:15318948

Protocol for the PINCER trial: a cluster randomised trial comparing the effectiveness of a pharmacist-led IT-based intervention with simple feedback in reducing rates of clinically important errors in medicines management in general practices

PubMed Central

Avery, Anthony J; Rodgers, Sarah; Cantrill, Judith A; Armstrong, Sarah; Elliott, Rachel; Howard, Rachel; Kendrick, Denise; Morris, Caroline J; Murray, Scott A; Prescott, Robin J; Cresswell, Kathrin; Sheikh, Aziz

2009-01-01

Background Medication errors are an important cause of morbidity and mortality in primary care. The aims of this study are to determine the effectiveness, cost effectiveness and acceptability of a pharmacist-led information-technology-based complex intervention compared with simple feedback in reducing proportions of patients at risk from potentially hazardous prescribing and medicines management in general (family) practice. Methods Research subject group: "At-risk" patients registered with computerised general practices in two geographical regions in England. Design: Parallel group pragmatic cluster randomised trial. Interventions: Practices will be randomised to either: (i) Computer-generated feedback; or (ii) Pharmacist-led intervention comprising of computer-generated feedback, educational outreach and dedicated support. Primary outcome measures: The proportion of patients in each practice at six and 12 months post intervention: - with a computer-recorded history of peptic ulcer being prescribed non-selective non-steroidal anti-inflammatory drugs - with a computer-recorded diagnosis of asthma being prescribed beta-blockers - aged 75 years and older receiving long-term prescriptions for angiotensin converting enzyme inhibitors or loop diuretics without a recorded assessment of renal function and electrolytes in the preceding 15 months. Secondary outcome measures; These relate to a number of other examples of potentially hazardous prescribing and medicines management. Economic analysis: An economic evaluation will be done of the cost per error avoided, from the perspective of the UK National Health Service (NHS), comparing the pharmacist-led intervention with simple feedback. Qualitative analysis: A qualitative study will be conducted to explore the views and experiences of health care professionals and NHS managers concerning the interventions, and investigate possible reasons why the interventions prove effective, or conversely prove ineffective. Sample size: 34 practices in each of the two treatment arms would provide at least 80% power (two-tailed alpha of 0.05) to demonstrate a 50% reduction in error rates for each of the three primary outcome measures in the pharmacist-led intervention arm compared with a 11% reduction in the simple feedback arm. Discussion At the time of submission of this article, 72 general practices have been recruited (36 in each arm of the trial) and the interventions have been delivered. Analysis has not yet been undertaken. Trial registration Current controlled trials ISRCTN21785299 PMID:19409095

Protocol for the PINCER trial: a cluster randomised trial comparing the effectiveness of a pharmacist-led IT-based intervention with simple feedback in reducing rates of clinically important errors in medicines management in general practices.

PubMed

Avery, Anthony J; Rodgers, Sarah; Cantrill, Judith A; Armstrong, Sarah; Elliott, Rachel; Howard, Rachel; Kendrick, Denise; Morris, Caroline J; Murray, Scott A; Prescott, Robin J; Cresswell, Kathrin; Sheikh, Aziz

2009-05-01

Medication errors are an important cause of morbidity and mortality in primary care. The aims of this study are to determine the effectiveness, cost effectiveness and acceptability of a pharmacist-led information-technology-based complex intervention compared with simple feedback in reducing proportions of patients at risk from potentially hazardous prescribing and medicines management in general (family) practice. RESEARCH SUBJECT GROUP: "At-risk" patients registered with computerised general practices in two geographical regions in England. Parallel group pragmatic cluster randomised trial. Practices will be randomised to either: (i) Computer-generated feedback; or (ii) Pharmacist-led intervention comprising of computer-generated feedback, educational outreach and dedicated support. The proportion of patients in each practice at six and 12 months post intervention: - with a computer-recorded history of peptic ulcer being prescribed non-selective non-steroidal anti-inflammatory drugs; - with a computer-recorded diagnosis of asthma being prescribed beta-blockers; - aged 75 years and older receiving long-term prescriptions for angiotensin converting enzyme inhibitors or loop diuretics without a recorded assessment of renal function and electrolytes in the preceding 15 months. SECONDARY OUTCOME MEASURES; These relate to a number of other examples of potentially hazardous prescribing and medicines management. An economic evaluation will be done of the cost per error avoided, from the perspective of the UK National Health Service (NHS), comparing the pharmacist-led intervention with simple feedback. QUALITATIVE ANALYSIS: A qualitative study will be conducted to explore the views and experiences of health care professionals and NHS managers concerning the interventions, and investigate possible reasons why the interventions prove effective, or conversely prove ineffective. 34 practices in each of the two treatment arms would provide at least 80% power (two-tailed alpha of 0.05) to demonstrate a 50% reduction in error rates for each of the three primary outcome measures in the pharmacist-led intervention arm compared with a 11% reduction in the simple feedback arm. At the time of submission of this article, 72 general practices have been recruited (36 in each arm of the trial) and the interventions have been delivered. Analysis has not yet been undertaken.

What is the role and authority of gatekeepers in cluster randomized trials in health research?

PubMed Central

2012-01-01

This article is part of a series of papers examining ethical issues in cluster randomized trials (CRTs) in health research. In the introductory paper in this series, we set out six areas of inquiry that must be addressed if the CRT is to be set on a firm ethical foundation. This paper addresses the sixth of the questions posed, namely, what is the role and authority of gatekeepers in CRTs in health research? ‘Gatekeepers’ are individuals or bodies that represent the interests of cluster members, clusters, or organizations. The need for gatekeepers arose in response to the difficulties in obtaining informed consent because of cluster randomization, cluster-level interventions, and cluster size. In this paper, we call for a more restrictive understanding of the role and authority of gatekeepers. Previous papers in this series have provided solutions to the challenges posed by informed consent in CRTs without the need to invoke gatekeepers. We considered that consent to randomization is not required when cluster members are approached for consent at the earliest opportunity and before any study interventions or data-collection procedures have started. Further, when cluster-level interventions or cluster size means that obtaining informed consent is not possible, a waiver of consent may be appropriate. In this paper, we suggest that the role of gatekeepers in protecting individual interests in CRTs should be limited. Generally, gatekeepers do not have the authority to provide proxy consent for cluster members. When a municipality or other community has a legitimate political authority that is empowered to make such decisions, cluster permission may be appropriate; however, gatekeepers may usefully protect cluster interests in other ways. Cluster consultation may ensure that the CRT addresses local health needs, and is conducted in accord with local values and customs. Gatekeepers may also play an important role in protecting the interests of organizations, such as hospitals, nursing homes, general practices, and schools. In these settings, permission to access the organization relies on resource implications and adherence to institutional policies. PMID:22834691

Applying clinical guidelines in general practice: a qualitative study of potential complications.

PubMed

Austad, Bjarne; Hetlevik, Irene; Mjølstad, Bente Prytz; Helvik, Anne-Sofie

2016-07-22

Clinical guidelines for single diseases often pose problems in general practice work with multimorbid patients. However, little research focuses on how general practice is affected by the demand to follow multiple guidelines. This study explored Norwegian general practitioners' (GPs') experiences with and reflections upon the consequences for general practice of applying multiple guidelines. Qualitative focus group study carried out in Mid-Norway. The study involved a purposeful sample of 25 Norwegian GPs from four pre-existing groups. Interviews were audio-recorded, transcribed and analyzed using systematic text condensation, i.e. applying a phenomenological approach. The GPs' responses clustered around two major topics: 1) Complications for the GPs of applying multiple guidelines; and, 2) Complications for their patients when GPs apply multiple guidelines. For the GPs, applying multiple guidelines created a highly problematic situation as they felt obliged to implement guidelines that were not suited to their patients: too often, the map and the terrain did not match. They also experienced greater insecurity regarding their own practice which, they admitted, resulted in an increased tendency to practice 'defensive medicine'. For their patients, the GPs experienced that applying multiple guidelines increased the risk of polypharmacy, excessive non-pharmacological recommendations, a tendency toward medicalization and, for some, a reduction in quality of life. The GPs experienced negative consequences when obliged to apply a variety of single disease guidelines to multimorbid patients, including increased risk of polypharmacy and overtreatment. We believe patient-centered care and the GPs' courage to non-comply when necessary may aid in reducing these risks. Health care authorities and guideline developers need to be aware of the potential negative effects of applying a single disease focus in general practice, where multimorbidity is highly prevalent.

A cluster randomised pragmatic trial applying Self-determination theory to type 2 diabetes care in general practice

PubMed Central

2011-01-01

Background Treatment recommendations for prevention of type 2 diabetes complications often require radical and life-long health behaviour changes. Observational studies based on Self-determination theory (SDT) propose substantial factors for the maintenance of behaviour changes and concomitant well-being, but experimental research is needed to develop and evaluate SDT-based interventions. The aims of this paper were to describe 1) the design of a trial assessing the effectiveness of a training course for practice-nurses in autonomy support on patient-perceived motivation, HbA1, cholesterol, and well-being among a diabetes population, 2) the actual intervention to a level of detail that allows its replication, and 3) the connection between SDT recommendations for health care-provider behaviour and the content of the training course. Methods/Design The study is a cluster-randomised pragmatic trial including 40 Danish general practices with nurse-led diabetes consultations, and the associated diabetes population. The diabetes population was identified by registers (n = 4034). The intervention was a 16-hour course with interactive training for practice nurses. The course was delivered over 4 afternoons at Aarhus University and one 1/2 hour visit to the practice by one of the course-teachers over a period of 10 months (0, 2, 5, 10 mths.). The intervention is depicted by a PaT Plot showing the timeline and the characteristics of the intervention components. Effectiveness of the intervention will be assessed on the diabetes populations with regard to well-being (PAID, SF-12), HbA1c- and cholesterol-levels, perceived autonomy support (HCCQ), type of motivation (TSRQ), and perceived competence for diabetes care (PCD) 15-21 months after the core course; the completion of the second course afternoon. Data will be retrieved from registers and by questionnaires. Discussion Challenges and advantages of the pragmatic design are discussed. In a real-world setting, this study will determine the impact on motivation, HbA1c, cholesterol, and well-being for people with diabetes by offering a training course in autonomy support to practice-nurses from general practices with nurse-led consultations. Trial registration ClinicalTrials.gov: NCT01187069 PMID:22111524

The relative clinical effectiveness and cost-effectiveness of three contrasting approaches to partner notification for curable sexually transmitted infections: a cluster randomised trial in primary care.

PubMed

Cassell, Jackie A; Dodds, Julie; Estcourt, Claudia; Llewellyn, Carrie; Lanza, Stefania; Richens, John; Smith, Helen; Symonds, Merle; Copas, Andrew; Roberts, Tracy; Walters, Kate; White, Peter; Lowndes, Catherine; Mistry, Hema; Rossello-Roig, Melcior; Smith, Hilary; Rait, Greta

2015-01-01

Partner notification is the process of providing support for, informing and treating sexual partners of individuals who have been diagnosed with sexually transmitted infections (STIs). It is traditionally undertaken by specialist sexual health services, and may involve informing a partner on a patient's behalf, with consent. With an increasing proportion of STIs diagnosed in general practice and other community settings, there is a growing need to understand the best way to provide partner notification for people diagnosed with a STI in this setting using a web-based referral system. We aimed to compare three different approaches to partner notification for people diagnosed with chlamydia within general practice. Cluster randomised controlled trial. General practices in England and, within these, patients tested for and diagnosed with genital chlamydia or other bacterial STIs in that setting using a web-based referral system. Three different approaches to partner notification: patient referral alone, or the additional offer of either provider referral or contract referral. (1) Number of main partners per index patient treated for chlamydia and/or gonorrhoea/non-specific urethritis/pelvic inflammatory disease; and (2) proportion of index patients testing negative for the relevant STI at 3 months. As testing rates for chlamydia were far lower than expected, we were unable to scale up the trial, which was concluded at pilot stage. We are not able to answer the original research question. We present the results of the work undertaken to improve recruitment to similar studies requiring opportunistic recruitment of young people in general practice. We were unable to standardise provider and contract referral separately; however, we also present results of qualitative work aimed at optimising these interventions. External recruitment may be required to facilitate the recruitment of young people to research in general practice, especially in sensitive areas, because of specific barriers experienced by general practice staff. Costs need to be taken into account together with feasibility considerations. Partner notification interventions for bacterial STIs may not be clearly separable into the three categories of patient, provider and contract referral. Future research is needed to operationalise the approaches of provider and contract partner notification if future trials are to provide generalisable information. Current Controlled Trials ISRCTN24160819. This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 5. See the NIHR Journals Library website for further project information.

Effectiveness of a complex intervention on Prioritising Multimedication in Multimorbidity (PRIMUM) in primary care: results of a pragmatic cluster randomised controlled trial.

PubMed

Muth, Christiane; Uhlmann, Lorenz; Haefeli, Walter E; Rochon, Justine; van den Akker, Marjan; Perera, Rafael; Güthlin, Corina; Beyer, Martin; Oswald, Frank; Valderas, Jose Maria; Knottnerus, J André; Gerlach, Ferdinand M; Harder, Sebastian

2018-02-24

Investigate the effectiveness of a complex intervention aimed at improving the appropriateness of medication in older patients with multimorbidity in general practice. Pragmatic, cluster randomised controlled trial with general practice as unit of randomisation. 72 general practices in Hesse, Germany. 505 randomly sampled, cognitively intact patients (≥60 years, ≥3 chronic conditions under pharmacological treatment, ≥5 long-term drug prescriptions with systemic effects); 465 patients and 71 practices completed the study. Intervention group (IG): The healthcare assistant conducted a checklist-based interview with patients on medication-related problems and reconciled their medications. Assisted by a computerised decision support system, the general practitioner optimised medication, discussed it with patients and adjusted it accordingly. The control group (CG) continued with usual care. The primary outcome was a modified Medication Appropriateness Index (MAI, excluding item 10 on cost-effectiveness), assessed in blinded medication reviews and calculated as the difference between baseline and after 6 months; secondary outcomes after 6 and 9 months' follow-up: quality of life, functioning, medication adherence, and so on. At baseline, a high proportion of patients had appropriate to mildly inappropriate prescriptions (MAI 0-5 points: n=350 patients). Randomisation revealed balanced groups (IG: 36 practices/252 patients; CG: 36/253). Intervention had no significant effect on primary outcome: mean MAI sum scores decreased by 0.3 points in IG and 0.8 points in CG, resulting in a non-significant adjusted mean difference of 0.7 (95% CI -0.2 to 1.6) points in favour of CG. Secondary outcomes showed non-significant changes (quality of life slightly improved in IG but continued to decline in CG) or remained stable (functioning, medication adherence). The intervention had no significant effects. Many patients already received appropriate prescriptions and enjoyed good quality of life and functional status. We can therefore conclude that in our study, there was not enough scope for improvement. ISRCTN99526053. NCT01171339; Results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Evaluating an audit and feedback intervention for reducing antibiotic prescribing behaviour in general dental practice (the RAPiD trial): a partial factorial cluster randomised trial protocol.

PubMed

Prior, Maria; Elouafkaoui, Paula; Elders, Andrew; Young, Linda; Duncan, Eilidh M; Newlands, Rumana; Clarkson, Jan E; Ramsay, Craig R

2014-04-24

Antibiotic prescribing in dentistry accounts for 9% of total antibiotic prescriptions in Scottish primary care. The Scottish Dental Clinical Effectiveness Programme (SDCEP) published guidance in April 2008 (2nd edition, August 2011) for Drug Prescribing in Dentistry, which aims to assist dentists to make evidence-based antibiotic prescribing decisions. However, wide variation in prescribing persists and the overall use of antibiotics is increasing. RAPiD is a 12-month partial factorial cluster randomised trial conducted in NHS General Dental Practices across Scotland. Its aim is to compare the effectiveness of individualised audit and feedback (A&F) strategies for the translation into practice of SDCEP recommendations on antibiotic prescribing. The trial uses routinely collected electronic healthcare data in five aspects of its design in order to: identify the study population; apply eligibility criteria; carry out stratified randomisation; generate the trial intervention; analyse trial outcomes. Eligibility was determined on contract status and a minimum level of recent NHS treatment provision. All eligible dental practices in Scotland were simultaneously randomised at baseline either to current audit practice or to an intervention group. Randomisation was stratified by single-handed/multi-handed practices. General dental practitioners (GDPs) working at intervention practices will receive individualised graphical representations of their antibiotic prescribing rate from the previous 14 months at baseline and an update at six months. GDPs could not be blinded to their practice allocation. Intervention practices were further randomised using a factorial design to receive feedback with or without: a health board comparator; a supplementary text-based intervention; additional feedback at nine months. The primary outcome is the total antibiotic prescribing rate per 100 courses of treatment over the year following delivery of the baseline intervention. A concurrent qualitative process evaluation will apply theory-based approaches using the Consolidated Framework for Implementation Research to explore the acceptability of the interventions and the Theoretical Domains Framework to identify barriers and enablers to evidence-based antibiotic prescribing behaviour by GDPs. RAPiD will provide a robust evaluation of A&F in dentistry in Scotland. It also demonstrates that linked administrative datasets have the potential to be used efficiently and effectively across all stages of an randomised controlled trial. Current Controlled Trials ISRCTN49204710.

Evaluating an audit and feedback intervention for reducing antibiotic prescribing behaviour in general dental practice (the RAPiD trial): a partial factorial cluster randomised trial protocol

PubMed Central

2014-01-01

Background Antibiotic prescribing in dentistry accounts for 9% of total antibiotic prescriptions in Scottish primary care. The Scottish Dental Clinical Effectiveness Programme (SDCEP) published guidance in April 2008 (2nd edition, August 2011) for Drug Prescribing in Dentistry, which aims to assist dentists to make evidence-based antibiotic prescribing decisions. However, wide variation in prescribing persists and the overall use of antibiotics is increasing. Methods RAPiD is a 12-month partial factorial cluster randomised trial conducted in NHS General Dental Practices across Scotland. Its aim is to compare the effectiveness of individualised audit and feedback (A&F) strategies for the translation into practice of SDCEP recommendations on antibiotic prescribing. The trial uses routinely collected electronic healthcare data in five aspects of its design in order to: identify the study population; apply eligibility criteria; carry out stratified randomisation; generate the trial intervention; analyse trial outcomes. Eligibility was determined on contract status and a minimum level of recent NHS treatment provision. All eligible dental practices in Scotland were simultaneously randomised at baseline either to current audit practice or to an intervention group. Randomisation was stratified by single-handed/multi-handed practices. General dental practitioners (GDPs) working at intervention practices will receive individualised graphical representations of their antibiotic prescribing rate from the previous 14 months at baseline and an update at six months. GDPs could not be blinded to their practice allocation. Intervention practices were further randomised using a factorial design to receive feedback with or without: a health board comparator; a supplementary text-based intervention; additional feedback at nine months. The primary outcome is the total antibiotic prescribing rate per 100 courses of treatment over the year following delivery of the baseline intervention. A concurrent qualitative process evaluation will apply theory-based approaches using the Consolidated Framework for Implementation Research to explore the acceptability of the interventions and the Theoretical Domains Framework to identify barriers and enablers to evidence-based antibiotic prescribing behaviour by GDPs. Discussion RAPiD will provide a robust evaluation of A&F in dentistry in Scotland. It also demonstrates that linked administrative datasets have the potential to be used efficiently and effectively across all stages of an randomised controlled trial. Trial registration Current Controlled Trials ISRCTN49204710 PMID:24758164

Epidemiology of Patient Harms in New Zealand: Protocol of a General Practice Records Review Study

PubMed Central

Leitch, Sharon; Wallis, Katharine A; Eggleton, Kyle S; Cunningham, Wayne K; Williamson, Martyn I; Lillis, Steven; McMenamin, Andrew W; Tilyard, Murray W; Reith, David M; Samaranayaka, Ari; Hall, Jason E

2017-01-01

Background Knowing where and why harm occurs in general practice will assist patients, doctors, and others in making informed decisions about the risks and benefits of treatment options. Research to date has been unable to verify the safety of primary health care and epidemiological research about patient harms in general practice is now a top priority for advancing health systems safety. Objective We aim to study the incidence, distribution, severity, and preventability of the harms patients experience due to their health care, from the whole-of-health-system lens afforded by electronic general practice patient records. Methods “Harm” is defined as disease, injury, disability, suffering, and death, arising from the health system. The study design is a stratified, 2-level cluster, retrospective records review study. Both general practices and patients will be randomly selected so that the study’s results will apply nationally, after weighting. Stratification by practice size and rurality will allow comparisons between 6 study groups (large, medium-sized, small; urban and rural practices). Records of equal numbers of patients from each study group will be included in the study because there may be systematic differences in patient harms in different types of practices. Eight general practitioner investigators will review 3 years of electronic general practice health records (consultation notes, prescriptions, investigations, referrals, and summaries of hospital care) from 9000 patients registered in 60 general practices. Double-blinded reviews will check the concordance of reviewers’ assessments. Study data will comprise demographic data of all 9000 patients and reviewers’ assessments of whether patients experienced harm arising from health care. Where patient harm is identified, their types, preventability, severity, and outcomes will be coded using the Medical Dictionary for Regulatory Activities (MedDRA) 18.0. Results We have recruited practices and collected electronic records from 9078 patients. Reviews of these records are under way. The study is expected to be completed in August 2017. Conclusions The design of this complex study is presented with discussion on data collection methods, sampling weights, power analysis, and statistical approach. This study will show the epidemiology of patient harms recorded in general practice records for all of New Zealand and will show whether this epidemiology differs by rural location and clinic size. PMID:28119276

Cluster-randomized Studies in Educational Research: Principles and Methodological Aspects

PubMed Central

Dreyhaupt, Jens; Mayer, Benjamin; Keis, Oliver; Öchsner, Wolfgang; Muche, Rainer

2017-01-01

An increasing number of studies are being performed in educational research to evaluate new teaching methods and approaches. These studies could be performed more efficiently and deliver more convincing results if they more strictly applied and complied with recognized standards of scientific studies. Such an approach could substantially increase the quality in particular of prospective, two-arm (intervention) studies that aim to compare two different teaching methods. A key standard in such studies is randomization, which can minimize systematic bias in study findings; such bias may result if the two study arms are not structurally equivalent. If possible, educational research studies should also achieve this standard, although this is not yet generally the case. Some difficulties and concerns exist, particularly regarding organizational and methodological aspects. An important point to consider in educational research studies is that usually individuals cannot be randomized, because of the teaching situation, and instead whole groups have to be randomized (so-called “cluster randomization”). Compared with studies with individual randomization, studies with cluster randomization normally require (significantly) larger sample sizes and more complex methods for calculating sample size. Furthermore, cluster-randomized studies require more complex methods for statistical analysis. The consequence of the above is that a competent expert with respective special knowledge needs to be involved in all phases of cluster-randomized studies. Studies to evaluate new teaching methods need to make greater use of randomization in order to achieve scientifically convincing results. Therefore, in this article we describe the general principles of cluster randomization and how to implement these principles, and we also outline practical aspects of using cluster randomization in prospective, two-arm comparative educational research studies. PMID:28584874

Cluster-randomized Studies in Educational Research: Principles and Methodological Aspects.

PubMed

Dreyhaupt, Jens; Mayer, Benjamin; Keis, Oliver; Öchsner, Wolfgang; Muche, Rainer

2017-01-01

An increasing number of studies are being performed in educational research to evaluate new teaching methods and approaches. These studies could be performed more efficiently and deliver more convincing results if they more strictly applied and complied with recognized standards of scientific studies. Such an approach could substantially increase the quality in particular of prospective, two-arm (intervention) studies that aim to compare two different teaching methods. A key standard in such studies is randomization, which can minimize systematic bias in study findings; such bias may result if the two study arms are not structurally equivalent. If possible, educational research studies should also achieve this standard, although this is not yet generally the case. Some difficulties and concerns exist, particularly regarding organizational and methodological aspects. An important point to consider in educational research studies is that usually individuals cannot be randomized, because of the teaching situation, and instead whole groups have to be randomized (so-called "cluster randomization"). Compared with studies with individual randomization, studies with cluster randomization normally require (significantly) larger sample sizes and more complex methods for calculating sample size. Furthermore, cluster-randomized studies require more complex methods for statistical analysis. The consequence of the above is that a competent expert with respective special knowledge needs to be involved in all phases of cluster-randomized studies. Studies to evaluate new teaching methods need to make greater use of randomization in order to achieve scientifically convincing results. Therefore, in this article we describe the general principles of cluster randomization and how to implement these principles, and we also outline practical aspects of using cluster randomization in prospective, two-arm comparative educational research studies.

Combinations of Personal Responsibility: Differences on Pre-service and Practicing Teachers’ Efficacy, Engagement, Classroom Goal Structures and Wellbeing

PubMed Central

Daniels, Lia M.; Radil, Amanda I.; Goegan, Lauren D.

2017-01-01

Pre-service and practicing teachers feel responsible for a range of educational activities. Four domains of personal responsibility emerging in the literature are: student achievement, student motivation, relationships with students, and responsibility for ones own teaching. To date, most research has used variable-centered approaches to examining responsibilities even though the domains appear related. In two separate samples we used cluster analysis to explore how pre-service (n = 130) and practicing (n = 105) teachers combined personal responsibilities and their impact on three professional cognitions and their wellbeing. Both groups had low and high responsibility clusters but the third cluster differed: Pre-service teachers combined responsibilities for relationships and their own teaching in a cluster we refer to as teacher-based responsibility; whereas, practicing teachers combined achievement and motivation in a cluster we refer to as student-outcome focused responsibility. These combinations affected outcomes for pre-service but not practicing teachers. Pre-service teachers in the low responsibility cluster reported less engagement, less mastery approaches to instruction, and more performance goal structures than the other two clusters. PMID:28620332

Combinations of Personal Responsibility: Differences on Pre-service and Practicing Teachers' Efficacy, Engagement, Classroom Goal Structures and Wellbeing.

PubMed

Daniels, Lia M; Radil, Amanda I; Goegan, Lauren D

2017-01-01

Pre-service and practicing teachers feel responsible for a range of educational activities. Four domains of personal responsibility emerging in the literature are: student achievement, student motivation, relationships with students, and responsibility for ones own teaching. To date, most research has used variable-centered approaches to examining responsibilities even though the domains appear related. In two separate samples we used cluster analysis to explore how pre-service ( n = 130) and practicing ( n = 105) teachers combined personal responsibilities and their impact on three professional cognitions and their wellbeing. Both groups had low and high responsibility clusters but the third cluster differed: Pre-service teachers combined responsibilities for relationships and their own teaching in a cluster we refer to as teacher-based responsibility; whereas, practicing teachers combined achievement and motivation in a cluster we refer to as student-outcome focused responsibility. These combinations affected outcomes for pre-service but not practicing teachers. Pre-service teachers in the low responsibility cluster reported less engagement, less mastery approaches to instruction, and more performance goal structures than the other two clusters.

Patient experience and the role of postgraduate GP training: a cross-sectional analysis of national Patient Survey data in England

PubMed Central

Ashworth, Mark; Schofield, Peter; Durbaba, Stevo; Ahluwalia, Sanjiv

2014-01-01

Background Quality indicators for primary care focus predominantly on the public health model and organisational measures. Patient experience is an important dimension of quality. Accreditation for GP training practices requires demonstration of a series of attributes including patient-centred care. Aim The national GP Patient Survey (GPPS) was used to determine the characteristics of general practices scoring highly in responses relating to the professional skills and characteristics of doctors. Specifically, to determine whether active participation in postgraduate GP training was associated with more positive experiences of care. Design and setting Retrospective cross-sectional study in general practices in England. Method Data were obtained from the national QOF dataset for England, 2011/12 (8164 general practices); the GPPS in 2012 (2.7 million questionnaires in England; response rate 36%); general practice and demographic characteristics. Sensitivity analyses included local data validated by practice inspections. Outcome measures: multilevel regression models adjusted for clustering. Results GP training practice status (29% of practices) was a significant predictor of positive GPPS responses to all questions in the ‘doctor care’ (n = 6) and ‘overall satisfaction’ (n = 2) domains but not to any of the ‘nurse care’ or ‘out-of-hours’ domain questions. The findings were supported by the sensitivity analyses. Other positive determinants were: smaller practice and individual GP list sizes, more older patients, lower social deprivation and fewer ethnic minority patients. Conclusion Based on GPPS responses, doctors in GP training practices appeared to offer more patient-centred care with patients reporting more positively on attributes of doctors such as ‘listening’ or ‘care and concern’. PMID:24567656

Implementing core NICE guidelines for osteoarthritis in primary care with a model consultation (MOSAICS): a cluster randomised controlled trial.

PubMed

Dziedzic, K S; Healey, E L; Porcheret, M; Afolabi, E K; Lewis, M; Morden, A; Jinks, C; McHugh, G A; Ryan, S; Finney, A; Main, C; Edwards, J J; Paskins, Z; Pushpa-Rajah, A; Hay, E M

2018-01-01

To determine the effectiveness of a model osteoarthritis consultation, compared with usual care, on physical function and uptake of National Institute for Health and Care Excellence (NICE) osteoarthritis recommendations, in adults ≥45 years consulting with peripheral joint pain in UK general practice. Two-arm cluster-randomised controlled trial with baseline health survey. Eight general practices in England. 525 adults ≥45 years consulting for peripheral joint pain, amongst 28,443 population survey recipients. Four intervention practices delivered the model osteoarthritis consultation to patients consulting with peripheral joint pain; four control practices continued usual care. The primary clinical outcome of the trial was the SF-12 physical component score (PCS) at 6 months; the main secondary outcome was uptake of NICE core recommendations by 6 months, measured by osteoarthritis quality indicators. A Linear Mixed Model was used to analyse clinical outcome data (SF-12 PCS). Differences in quality indicator outcomes were assessed using logistic regression. 525 eligible participants were enrolled (mean age 67.3 years, SD 10.5; 59.6% female): 288 from intervention and 237 from control practices. There were no statistically significant differences in SF-12 PCS: mean difference at the 6-month primary endpoint was -0.37 (95% CI -2.32, 1.57). Uptake of core NICE recommendations by 6 months was statistically significantly higher in the intervention arm compared with control: e.g., increased written exercise information, 20.5% (7.9, 28.3). Whilst uptake of core NICE recommendations was increased, there was no evidence of benefit of this intervention, as delivered in this pragmatic randomised trial, on the primary outcome of physical functioning at 6 months. ISRCTN06984617. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Primary healthcare solo practices: homogeneous or heterogeneous?

PubMed

Pineault, Raynald; Borgès Da Silva, Roxane; Provost, Sylvie; Beaulieu, Marie-Dominique; Boivin, Antoine; Couture, Audrey; Prud'homme, Alexandre

2014-01-01

Introduction. Solo practices have generally been viewed as forming a homogeneous group. However, they may differ on many characteristics. The objective of this paper is to identify different forms of solo practice and to determine the extent to which they are associated with patient experience of care. Methods. Two surveys were carried out in two regions of Quebec in 2010: a telephone survey of 9180 respondents from the general population and a postal survey of 606 primary healthcare (PHC) practices. Data from the two surveys were linked through the respondent's usual source of care. A taxonomy of solo practices was constructed (n = 213), using cluster analysis techniques. Bivariate and multilevel analyses were used to determine the relationship of the taxonomy with patient experience of care. Results. Four models were derived from the taxonomy. Practices in the "resourceful networked" model contrast with those of the "resourceless isolated" model to the extent that the experience of care reported by their patients is more favorable. Conclusion. Solo practice is not a homogeneous group. The four models identified have different organizational features and their patients' experience of care also differs. Some models seem to offer a better organizational potential in the context of current reforms.

Primary Healthcare Solo Practices: Homogeneous or Heterogeneous?

PubMed Central

Beaulieu, Marie-Dominique; Boivin, Antoine; Prud'homme, Alexandre

2014-01-01

Introduction. Solo practices have generally been viewed as forming a homogeneous group. However, they may differ on many characteristics. The objective of this paper is to identify different forms of solo practice and to determine the extent to which they are associated with patient experience of care. Methods. Two surveys were carried out in two regions of Quebec in 2010: a telephone survey of 9180 respondents from the general population and a postal survey of 606 primary healthcare (PHC) practices. Data from the two surveys were linked through the respondent's usual source of care. A taxonomy of solo practices was constructed (n = 213), using cluster analysis techniques. Bivariate and multilevel analyses were used to determine the relationship of the taxonomy with patient experience of care. Results. Four models were derived from the taxonomy. Practices in the “resourceful networked” model contrast with those of the “resourceless isolated” model to the extent that the experience of care reported by their patients is more favorable. Conclusion. Solo practice is not a homogeneous group. The four models identified have different organizational features and their patients' experience of care also differs. Some models seem to offer a better organizational potential in the context of current reforms. PMID:24523964

Description and typology of intensive Chios dairy sheep farms in Greece.

PubMed

Gelasakis, A I; Valergakis, G E; Arsenos, G; Banos, G

2012-06-01

The aim was to assess the intensified dairy sheep farming systems of the Chios breed in Greece, establishing a typology that may properly describe and characterize them. The study included the total of the 66 farms of the Chios sheep breeders' cooperative Macedonia. Data were collected using a structured direct questionnaire for in-depth interviews, including questions properly selected to obtain a general description of farm characteristics and overall management practices. A multivariate statistical analysis was used on the data to obtain the most appropriate typology. Initially, principal component analysis was used to produce uncorrelated variables (principal components), which would be used for the consecutive cluster analysis. The number of clusters was decided using hierarchical cluster analysis, whereas, the farms were allocated in 4 clusters using k-means cluster analysis. The identified clusters were described and afterward compared using one-way ANOVA or a chi-squared test. The main differences were evident on land availability and use, facility and equipment availability and type, expansion rates, and application of preventive flock health programs. In general, cluster 1 included newly established, intensive, well-equipped, specialized farms and cluster 2 included well-established farms with balanced sheep and feed/crop production. In cluster 3 were assigned small flock farms focusing more on arable crops than on sheep farming with a tendency to evolve toward cluster 2, whereas cluster 4 included farms representing a rather conservative form of Chios sheep breeding with low/intermediate inputs and choosing not to focus on feed/crop production. In the studied set of farms, 4 different farmer attitudes were evident: 1) farming disrupts sheep breeding; feed should be purchased and economies of scale will decrease costs (mainly cluster 1), 2) only exercise/pasture land is necessary; at least part of the feed (pasture) must be home-grown to decrease costs (clusters 1 and 4), 3) providing pasture to sheep is essential; on-farm feed production decreases costs (mainly cluster 3), and 4) large-scale farming (feed production and cash crops) does not disrupt sheep breeding; all feed must be produced on-farm to decrease costs (mainly cluster 3). Conducting a profitability analysis among different clusters, exploring and discovering the most beneficial levels of intensified management and capital investment should now be considered. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Pathological and non-pathological variants of restrictive eating behaviors in middle childhood: A latent class analysis.

PubMed

Schmidt, Ricarda; Vogel, Mandy; Hiemisch, Andreas; Kiess, Wieland; Hilbert, Anja

2018-08-01

Although restrictive eating behaviors are very common during early childhood, their precise nature and clinical correlates remain unclear. Especially, there is little evidence on restrictive eating behaviors in older children and their associations with children's shape concern. The present population-based study sought to delineate subgroups of restrictive eating patterns in N = 799 7-14 year old children. Using Latent Class Analysis, children were classified based on six restrictive eating behaviors (for example, picky eating, food neophobia, and eating-related anxiety) and shape concern, separately in three age groups. For cluster validation, sociodemographic and objective anthropometric data, parental feeding practices, and general and eating disorder psychopathology were used. The results showed a 3-cluster solution across all age groups: an asymptomatic class (Cluster 1), a class with restrictive eating behaviors without shape concern (Cluster 2), and a class showing restrictive eating behaviors with prominent shape concern (Cluster 3). The clusters differed in all variables used for validation. Particularly, the proportion of children with symptoms of avoidant/restrictive food intake disorder was greater in Cluster 2 than Clusters 1 and 3. The study underlined the importance of considering shape concern to distinguish between different phenotypes of children's restrictive eating patterns. Longitudinal data are needed to evaluate the clusters' predictive effects on children's growth and development of clinical eating disorders. Copyright © 2018 Elsevier Ltd. All rights reserved.

Training practitioners to deliver opportunistic multiple behaviour change counselling in primary care: a cluster randomised trial.

PubMed

Butler, Christopher C; Simpson, Sharon A; Hood, Kerenza; Cohen, David; Pickles, Tim; Spanou, Clio; McCambridge, Jim; Moore, Laurence; Randell, Elizabeth; Alam, M Fasihul; Kinnersley, Paul; Edwards, Adrian; Smith, Christine; Rollnick, Stephen

2013-03-19

To evaluate the effect of training primary care health professionals in behaviour change counselling on the proportion of patients self reporting change in four risk behaviours (smoking, alcohol use, exercise, and healthy eating). Cluster randomised trial with general practices as the unit of randomisation. General practices in Wales. 53 general practitioners and practice nurses from 27 general practices (one each at all but one practice) recruited 1827 patients who screened positive for at least one risky behaviour. Behaviour change counselling was developed from motivational interviewing to enable clinicians to enhance patients' motivation to change health related behaviour. Clinicians were trained using a blended learning programme called Talking Lifestyles. Proportion of patients who reported making beneficial changes in at least one of the four risky behaviours at three months. 1308 patients from 13 intervention and 1496 from 14 control practices were approached: 76% and 72% respectively agreed to participate, with 831 (84%) and 996 (92%) respectively screening eligible for an intervention. There was no effect on the primary outcome (beneficial change in behaviour) at three months (362 (44%) v 404 (41%), odds ratio 1.12 (95% CI 0.90 to 1.39)) or on biochemical or biometric measures at 12 months. More patients who had consulted with trained clinicians recalled consultation discussion about a health behaviour (724/795 (91%) v 531/966 (55%), odds ratio 12.44 (5.85 to 26.46)) and intended to change (599/831 (72%) v 491/996 (49%), odds ratio 2.88 (2.05 to 4.05)). More intervention practice patients reported making an attempt to change (328 (39%) v 317 (32%), odds ratio 1.40 (1.15 to 1.70)), a sustained behaviour change at three months (288 (35%) v 280 (28%), odds ratio 1.36 (1.11 to 1.65)), and reported slightly greater improvements in healthy eating at three and 12 months, plus improved activity at 12 months. Training cost £1597 per practice. Training primary care clinicians in behaviour change counselling using a brief blended learning programme did not increase patients reported beneficial behaviour change at three months or improve biometric and a biochemical measure at 12 months, but it did increase patients' recollection of discussing behaviour change with their clinicians, intentions to change, attempts to change, and perceptions of having made a lasting change at three months. Enduring behaviour change and improvements in biometric measures are unlikely after a single routine consultation with a clinician trained in behaviour change counselling without additional intervention. ISRCTN 22495456.

Preventing disease through opportunistic, rapid engagement by primary care teams using behaviour change counselling (PRE-EMPT): protocol for a general practice-based cluster randomised trial.

PubMed

Spanou, Clio; Simpson, Sharon A; Hood, Kerry; Edwards, Adrian; Cohen, David; Rollnick, Stephen; Carter, Ben; McCambridge, Jim; Moore, Laurence; Randell, Elizabeth; Pickles, Timothy; Smith, Christine; Lane, Claire; Wood, Fiona; Thornton, Hazel; Butler, Chris C

2010-09-21

Smoking, excessive alcohol consumption, lack of exercise and an unhealthy diet are the key modifiable factors contributing to premature morbidity and mortality in the developed world. Brief interventions in health care consultations can be effective in changing single health behaviours. General Practice holds considerable potential for primary prevention through modifying patients' multiple risk behaviours, but feasible, acceptable and effective interventions are poorly developed, and uptake by practitioners is low. Through a process of theoretical development, modeling and exploratory trials, we have developed an intervention called Behaviour Change Counselling (BCC) derived from Motivational Interviewing (MI). This paper describes the protocol for an evaluation of a training intervention (the Talking Lifestyles Programme) which will enable practitioners to routinely use BCC during consultations for the above four risk behaviours. This cluster randomised controlled efficacy trial (RCT) will evaluate the outcomes and costs of this training intervention for General Practitioners (GPs) and nurses. Training methods will include: a practice-based seminar, online self-directed learning, and reflecting on video recorded and simulated consultations. The intervention will be evaluated in 29 practices in Wales, UK; two clinicians will take part (one GP and one nurse) from each practice. In intervention practices both clinicians will receive training. The aim is to recruit 2000 patients into the study with an expected 30% drop out. The primary outcome will be the proportion of patients making changes in one or more of the four behaviours at three months. Results will be compared for patients seeing clinicians trained in BCC with patients seeing non-BCC trained clinicians. Economic and process evaluations will also be conducted. Opportunistic engagement by health professionals potentially represents a cost effective medical intervention. This study integrates an existing, innovative intervention method with an innovative training model to enable clinicians to routinely use BCC, providing them with new tools to encourage and support people to make healthier choices. This trial will evaluate effectiveness in primary care and determine costs of the intervention.

Preventing disease through opportunistic, rapid engagement by primary care teams using behaviour change counselling (PRE-EMPT): protocol for a general practice-based cluster randomised trial

PubMed Central

2010-01-01

Background Smoking, excessive alcohol consumption, lack of exercise and an unhealthy diet are the key modifiable factors contributing to premature morbidity and mortality in the developed world. Brief interventions in health care consultations can be effective in changing single health behaviours. General Practice holds considerable potential for primary prevention through modifying patients' multiple risk behaviours, but feasible, acceptable and effective interventions are poorly developed, and uptake by practitioners is low. Through a process of theoretical development, modeling and exploratory trials, we have developed an intervention called Behaviour Change Counselling (BCC) derived from Motivational Interviewing (MI). This paper describes the protocol for an evaluation of a training intervention (the Talking Lifestyles Programme) which will enable practitioners to routinely use BCC during consultations for the above four risk behaviours. Methods/Design This cluster randomised controlled efficacy trial (RCT) will evaluate the outcomes and costs of this training intervention for General Practitioners (GPs) and nurses. Training methods will include: a practice-based seminar, online self-directed learning, and reflecting on video recorded and simulated consultations. The intervention will be evaluated in 29 practices in Wales, UK; two clinicians will take part (one GP and one nurse) from each practice. In intervention practices both clinicians will receive training. The aim is to recruit 2000 patients into the study with an expected 30% drop out. The primary outcome will be the proportion of patients making changes in one or more of the four behaviours at three months. Results will be compared for patients seeing clinicians trained in BCC with patients seeing non-BCC trained clinicians. Economic and process evaluations will also be conducted. Discussion Opportunistic engagement by health professionals potentially represents a cost effective medical intervention. This study integrates an existing, innovative intervention method with an innovative training model to enable clinicians to routinely use BCC, providing them with new tools to encourage and support people to make healthier choices. This trial will evaluate effectiveness in primary care and determine costs of the intervention. Trial Registration ISRCTN22495456 PMID:20858273

The effects of implementing a point-of-care electronic template to prompt routine anxiety and depression screening in patients consulting for osteoarthritis (the Primary Care Osteoarthritis Trial): A cluster randomised trial in primary care.

PubMed

Mallen, Christian D; Nicholl, Barbara I; Lewis, Martyn; Bartlam, Bernadette; Green, Daniel; Jowett, Sue; Kigozi, Jesse; Belcher, John; Clarkson, Kris; Lingard, Zoe; Pope, Christopher; Chew-Graham, Carolyn A; Croft, Peter; Hay, Elaine M; Peat, George

2017-04-01

This study aimed to evaluate whether prompting general practitioners (GPs) to routinely assess and manage anxiety and depression in patients consulting with osteoarthritis (OA) improves pain outcomes. We conducted a cluster randomised controlled trial involving 45 English general practices. In intervention practices, patients aged ≥45 y consulting with OA received point-of-care anxiety and depression screening by the GP, prompted by an automated electronic template comprising five questions (a two-item Patient Health Questionnaire-2 for depression, a two-item Generalized Anxiety Disorder-2 questionnaire for anxiety, and a question about current pain intensity [0-10 numerical rating scale]). The template signposted GPs to follow National Institute for Health and Care Excellence clinical guidelines for anxiety, depression, and OA and was supported by a brief training package. The template in control practices prompted GPs to ask the pain intensity question only. The primary outcome was patient-reported current pain intensity post-consultation and at 3-, 6-, and 12-mo follow-up. Secondary outcomes included pain-related disability, anxiety, depression, and general health. During the trial period, 7,279 patients aged ≥45 y consulted with a relevant OA-related code, and 4,240 patients were deemed potentially eligible by participating GPs. Templates were completed for 2,042 patients (1,339 [31.6%] in the control arm and 703 [23.1%] in the intervention arm). Of these 2,042 patients, 1,412 returned questionnaires (501 [71.3%] from 20 intervention practices, 911 [68.0%] from 24 control practices). Follow-up rates were similar in both arms, totalling 1,093 (77.4%) at 3 mo, 1,064 (75.4%) at 6 mo, and 1,017 (72.0%) at 12 mo. For the primary endpoint, multilevel modelling yielded significantly higher average pain intensity across follow-up to 12 mo in the intervention group than the control group (adjusted mean difference 0.31; 95% CI 0.04, 0.59). Secondary outcomes were consistent with the primary outcome measure in reflecting better outcomes as a whole for the control group than the intervention group. Anxiety and depression scores did not reduce following the intervention. The main limitations of this study are two potential sources of bias: an imbalance in cluster size (mean practice size 7,397 [intervention] versus 5,850 [control]) and a difference in the proportion of patients for whom the GP deactivated the template (33.6% [intervention] versus 27.8% [control]). In this study, we observed no beneficial effect on pain outcomes of prompting GPs to routinely screen for and manage comorbid anxiety and depression in patients presenting with symptoms due to OA, with those in the intervention group reporting statistically significantly higher average pain scores over the four follow-up time points than those in the control group. ISRCTN registry ISRCTN40721988.

Sustainability of Evidence-Based Acute Pain Management Practices for Hospitalized Older Adults.

PubMed

Shuman, Clayton J; Xie, Xian-Jin; Herr, Keela A; Titler, Marita G

2017-11-01

Little is known regarding sustainability of evidence-based practices (EBPs) following implementation. This article reports sustainability of evidence-based acute pain management practices in hospitalized older adults following testing of a multifaceted Translating Research Into Practice (TRIP) implementation intervention. A cluster randomized trial with follow-up period was conducted in 12 Midwest U.S. hospitals (six experimental, six comparison). Use of evidence-based acute pain management practices and mean pain intensity were analyzed using generalized estimating equations across two time points (following implementation and 18 months later) to determine sustainability of TRIP intervention effects. Summative Index scores and six of seven practices were sustained. Experimental and comparison group differences for mean pain intensity over 72 hours following admission were sustained. Results revealed most evidence-based acute pain management practices were sustained for 18 months following implementation. Further work is needed to identify factors affecting sustainability of EBPs to guide development and testing of sustainability strategies.

A multifaceted implementation strategy versus passive implementation of low back pain guidelines in general practice: a cluster randomised controlled trial.

PubMed

Riis, Allan; Jensen, Cathrine Elgaard; Bro, Flemming; Maindal, Helle Terkildsen; Petersen, Karin Dam; Bendtsen, Mette Dahl; Jensen, Martin Bach

2016-10-21

Guidelines are often slowly adapted into clinical practice. However, actively supporting healthcare professionals in evidence-based treatment may speed up guideline implementation. Danish low back pain (LBP) guidelines focus on primary care treatment of LBP, to reduce referrals from primary care to secondary care. The primary aim of this project was to reduce secondary care referral within 12 weeks by a multifaceted implementation strategy (MuIS). In a cluster randomised design, 189 general practices from the North Denmark Region were invited to participate. Practices were randomised (1:1) and stratified by practice size to MuIS (28 practices) or a passive implementation strategy (PaIS; 32 practices). Included were patients with LBP aged 18 to 65 years who were able to complete questionnaires, had no serious underlying pathology, and were not pregnant. We developed a MuIS including outreach visits, quality reports, and the STarT Back Tool for subgrouping patients with LBP. Both groups were offered the usual dissemination of guidelines, guideline-concordant structuring of the medical record, and a new referral opportunity for patients with psycho-social problems. In an intention-to-treat analysis, the primary and secondary outcomes pertained to the patient, and a cost-effectiveness analysis was performed from a healthcare sector perspective. Patients and the assessment of outcomes were blinded. Practices and caregivers delivering the interventions were not blinded. Between January 2013 and July 2014, 60 practices were included, of which 54 practices (28 MuIS, 26 PaIS) included 1101 patients (539 MuIS, 562 PaIS). Follow-up data for the primary outcome were available on 100 % of these patients. Twenty-seven patients (5.0 %) in the MuIS group were referred to secondary care vs. 59 patients (10.5 %) in the PaIS group. The adjusted odds ratio (AOR) was 0.52 [95 % CI 0.30 to 0.90; p = 0.020]. The MuIS was cost-saving £-93.20 (£406.51 vs. £499.71 per patient) after 12 weeks. Conversely, the MuIS resulted in less satisfied patients after 52 weeks (AOR 0.50 [95 % CI 0.31 to 0.81; p = 0.004]). Using a MuIS changed general practice referral behaviour and was cost effective, but patients in the MuIS group were less satisfied. This study supports the application of a MuIS when implementing guidelines. ClinicalTrials.gov, NCT01699256.

Study protocol of an economic evaluation of an extended implementation strategy for the treatment of low back pain in general practice: a cluster randomised controlled trial.

PubMed

Jensen, Cathrine Elgaard; Riis, Allan; Pedersen, Kjeld Møller; Jensen, Martin Bach; Petersen, Karin Dam

2014-10-08

In Denmark, guidelines on low back pain management are currently being implemented; in association with this, a clinical trial is conducted. A health economic evaluation is carried out alongside the clinical trial to assess the cost-effectiveness of an extended implementation strategy to increase the general practitioners' adherence to the guidelines. In addition to usual dissemination, the extended implementation strategy is composed of visits from a guideline facilitator, stratification tools, and feedback on guideline adherence. The aim of this paper is to provide the considerations on the design of the health economic evaluation. The economic evaluation is carried out alongside a cluster randomised controlled trial consisting of 60 general practices in the North Denmark Region. An expected 1,200 patients between the age of 18 and 65 years with a low back pain diagnosis will be enrolled. The economic evaluation comprises both a cost-effectiveness analyses and a cost-utility analysis. Effectiveness measures include referral to secondary care, health-related quality of life measured by EQ-5D-5L, and disability measured by the Roland Morris disability questionnaire. Cost measures include all relevant additional costs of the extended implementation strategy compared to usual implementation. The economic evaluation will be performed from both a societal perspective and a health sector perspective with a 12-month time horizon. It is expected that the extended implementation strategy will reduce the number of patients referred to secondary care. It is hypothesised that the additional upfront cost of extended implementation will be counterbalanced by improvements in clinical practice and patient-related outcomes, thereby rendering the extended implementation strategy cost-effective. ClinicalTrials.gov: NCT01699256.

Specific collaborative group intervention for patients with medically unexplained symptoms in general practice: a cluster randomized controlled trial.

PubMed

Schaefert, R; Kaufmann, C; Wild, B; Schellberg, D; Boelter, R; Faber, R; Szecsenyi, J; Sauer, N; Guthrie, E; Herzog, W

2013-01-01

Patients with medically unexplained symptoms (MUS) are frequent in primary care and substantially impaired in their quality of life (QoL). Specific training of general practitioners (GPs) alone did not demonstrate sustained improvement at later follow-up in current reviews. We evaluated a collaborative group intervention. We conducted a cluster randomized controlled trial. Thirty-five GPs recruited 304 MUS patients (intervention group: 170; control group: 134). All GPs were trained in diagnosis and management of MUS (control condition). Eighteen randomly selected intervention GPs participated in training for a specific collaborative group intervention. They conducted 10 weekly group sessions and 2 booster meetings in their practices, together with a psychosomatic specialist. Six and 12 months after baseline, QoL was assessed with the Short-Form 36. The primary outcome was the physical composite score (PCS), and the secondary outcome was the mental composite score (MCS). At 12 months, intention-to-treat analyses showed a significant between-group effect for the MCS (p = 0.023) but not for the PCS (p = 0.674). This effect was preceded by a significant reduction of somatic symptom severity (15-item somatic symptom severity scale of the Patient Health Questionnaire, PHQ-15) at 6 months (p = 0.008) that lacked significance at 12 months (p = 0.078). As additional between-group effects at 12 months, per-protocol analyses showed less health anxiety (Whiteley-7; p = 0.038) and less psychosocial distress (PHQ; p = 0.024); GP visits were significantly (p = 0.042) reduced in the intervention group. Compared to pure GP training, collaborative group intervention achieved a progressive, clinically meaningful improvement in mental but not physical QoL. It could bridge gaps between general practice and mental health care. Copyright © 2012 S. Karger AG, Basel.

Effect of telecare on use of health and social care services: findings from the Whole Systems Demonstrator cluster randomised trial

PubMed Central

Steventon, Adam; Bardsley, Martin; Billings, John; Dixon, Jennifer; Doll, Helen; Beynon, Michelle; Hirani, Shashi; Cartwright, Martin; Rixon, Lorna; Knapp, Martin; Henderson, Catherine; Rogers, Anne; Hendy, Jane; Fitzpatrick, Ray; Newman, Stanton

2013-01-01

Objective: to assess the impact of telecare on the use of social and health care. Part of the evaluation of the Whole Systems Demonstrator trial. Participants and setting: a total of 2,600 people with social care needs were recruited from 217 general practices in three areas in England. Design: a cluster randomised trial comparing telecare with usual care, general practice being the unit of randomisation. Participants were followed up for 12 months and analyses were conducted as intention-to-treat. Data sources: trial data were linked at the person level to administrative data sets on care funded at least in part by local authorities or the National Health Service. Main outcome measures: the proportion of people admitted to hospital within 12 months. Secondary endpoints included mortality, rates of secondary care use (seven different metrics), contacts with general practitioners and practice nurses, proportion of people admitted to permanent residential or nursing care, weeks in domiciliary social care and notional costs. Results: 46.8% of intervention participants were admitted to hospital, compared with 49.2% of controls. Unadjusted differences were not statistically significant (odds ratio: 0.90, 95% CI: 0.75–1.07, P = 0.211). They reached statistical significance after adjusting for baseline covariates, but this was not replicated when adjusting for the predictive risk score. Secondary metrics including impacts on social care use were not statistically significant. Conclusions: telecare as implemented in the Whole Systems Demonstrator trial did not lead to significant reductions in service use, at least in terms of results assessed over 12 months. International Standard Randomised Controlled Trial Number Register ISRCTN43002091. PMID:23443509

Web-based consultation between general practitioners and nephrologists: a cluster randomized controlled trial.

PubMed

van Gelder, Vincent A; Scherpbier-de Haan, Nynke D; van Berkel, Saskia; Akkermans, Reinier P; de Grauw, Inge S; Adang, Eddy M; Assendelft, Pim J; de Grauw, Wim J C; Biermans, Marion C J; Wetzels, Jack F M

2017-08-01

Consultation of a nephrologist is important in aligning care for patients with chronic kidney disease (CKD) at the primary-secondary care interface. However, current consultation methods come with practical difficulties that can lead to postponed consultation or patient referral instead. This study aimed to investigate whether a web-based consultation platform, telenephrology, led to a lower referral rate of indicated patients. Furthermore, we assessed consultation rate, quality of care, costs and general practitioner (GPs') experiences with telenephrology. Cluster randomized controlled trial with 47 general practices in the Netherlands was randomized to access to telenephrology or to enhanced usual care. A total of 3004 CKD patients aged 18 years or older who were under primary care were included (intervention group n = 1277, control group n = 1727) and 2693 completed the trial. All practices participated in a CKD management course and were given an overview of their CKD patients. The referral rates amounted to 2.3% (n = 29) in the intervention group and 3.0% (n = 52) in the control group, which was a non-significant difference, OR 0.61; 95% CI 0.31 to 1.23. The intervention group's consultation rate was 6.3% (n = 81) against 5.0% (n = 87) (OR 2.00; 95% CI 0.75-5.33). We found no difference in quality of care or costs. The majority of GPs had a positive opinion about telenephrology. The data in our study do not allow for conclusions on the effect of telenephrology on the rate of patient referrals and provider-to-provider consultations, compared to conventional methods. It was positively evaluated by GPs and was non-inferior in terms of quality of care and costs. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The search for person-related information in general practice: a qualitative study.

PubMed

Schrans, Diego; Avonts, Dirk; Christiaens, Thierry; Willems, Sara; de Smet, Kaat; van Boven, Kees; Boeckxstaens, Pauline; Kühlein, Thomas

2016-02-01

General practice is person-focused. Contextual information influences the clinical decision-making process in primary care. Currently, person-related information (PeRI) is neither recorded in a systematic way nor coded in the electronic medical record (EMR), and therefore not usable for scientific use. To search for classes of PeRI influencing the process of care. GPs, from nine countries worldwide, were asked to write down narrative case histories where personal factors played a role in decision-making. In an inductive process, the case histories were consecutively coded according to classes of PeRI. The classes found were deductively applied to the following cases and refined, until saturation was reached. Then, the classes were grouped into code-families and further clustered into domains. The inductive analysis of 32 case histories resulted in 33 defined PeRI codes, classifying all personal-related information in the cases. The 33 codes were grouped in the following seven mutually exclusive code-families: 'aspects between patient and formal care provider', 'social environment and family', 'functioning/behaviour', 'life history/non-medical experiences', 'personal medical information', 'socio-demographics' and 'work-/employment-related information'. The code-families were clustered into four domains: 'social environment and extended family', 'medicine', 'individual' and 'work and employment'. As PeRI is used in the process of decision-making, it should be part of the EMR. The PeRI classes we identified might form the basis of a new contextual classification mainly for research purposes. This might help to create evidence of the person-centredness of general practice. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Knowledge translation on dementia: a cluster randomized trial to compare a blended learning approach with a "classical" advanced training in GP quality circles.

PubMed

Vollmar, Horst C; Butzlaff, Martin E; Lefering, Rolf; Rieger, Monika A

2007-06-22

Thus far important findings regarding the dementia syndrome have been implemented into patients' medical care only inadequately. A professional training accounting for both, general practitioners' (GP) needs and learning preferences as well as care-relevant aspects could be a major step towards improving medical care. In the WIDA-study, entitled "Knowledge translation on dementia in general practice" two different training concepts are developed, implemented and evaluated. Both concepts are building on an evidence-based, GP-related dementia guideline and communicate the guideline's essential insights. Both development and implementation emphasize a procedure that is well-accepted in practice and, thus, can achieve a high degree of external validity. This is particularly guaranteed through the preparation of training material and the fact that general practitioners' quality circles (QC) are addressed. The evaluation of the two training concepts is carried out by comparing two groups of GPs to which several quality circles have been randomly assigned. The primary outcome is the GPs' knowledge gain. Secondary outcomes are designed to indicate the training's potential effects on the GPs' practical actions. In the first training concept (study arm A) GPs participate in a structured case discussion prepared for by internet-based learning material ("blended-learning" approach). The second training concept (study arm B) relies on frontal medical training in the form of a slide presentation and follow-up discussion ("classical" approach). This paper presents the outline of a cluster-randomized trial which has been peer reviewed and support by a national funding organization--Federal Ministry of Education and Research (BMBF)--and is approved by an ethics commission. The data collection has started in August 2006 and the results will be published independently of the study's outcome. Current Controlled Trials [ISRCTN36550981].

Review of methods for handling confounding by cluster and informative cluster size in clustered data

PubMed Central

Seaman, Shaun; Pavlou, Menelaos; Copas, Andrew

2014-01-01

Clustered data are common in medical research. Typically, one is interested in a regression model for the association between an outcome and covariates. Two complications that can arise when analysing clustered data are informative cluster size (ICS) and confounding by cluster (CBC). ICS and CBC mean that the outcome of a member given its covariates is associated with, respectively, the number of members in the cluster and the covariate values of other members in the cluster. Standard generalised linear mixed models for cluster-specific inference and standard generalised estimating equations for population-average inference assume, in general, the absence of ICS and CBC. Modifications of these approaches have been proposed to account for CBC or ICS. This article is a review of these methods. We express their assumptions in a common format, thus providing greater clarity about the assumptions that methods proposed for handling CBC make about ICS and vice versa, and about when different methods can be used in practice. We report relative efficiencies of methods where available, describe how methods are related, identify a previously unreported equivalence between two key methods, and propose some simple additional methods. Unnecessarily using a method that allows for ICS/CBC has an efficiency cost when ICS and CBC are absent. We review tools for identifying ICS/CBC. A strategy for analysis when CBC and ICS are suspected is demonstrated by examining the association between socio-economic deprivation and preterm neonatal death in Scotland. PMID:25087978

How do components of evidence-based psychological treatment cluster in practice? A survey and cluster analysis.

PubMed

Gifford, Elizabeth V; Tavakoli, Sara; Weingardt, Kenneth R; Finney, John W; Pierson, Heather M; Rosen, Craig S; Hagedorn, Hildi J; Cook, Joan M; Curran, Geoff M

2012-01-01

Evidence-based psychological treatments (EBPTs) are clusters of interventions, but it is unclear how providers actually implement these clusters in practice. A disaggregated measure of EBPTs was developed to characterize clinicians' component-level evidence-based practices and to examine relationships among these practices. Survey items captured components of evidence-based treatments based on treatment integrity measures. The Web-based survey was conducted with 75 U.S. Department of Veterans Affairs (VA) substance use disorder (SUD) practitioners and 149 non-VA community-based SUD practitioners. Clinician's self-designated treatment orientations were positively related to their endorsement of those EBPT components; however, clinicians used components from a variety of EBPTs. Hierarchical cluster analysis indicated that clinicians combined and organized interventions from cognitive-behavioral therapy, the community reinforcement approach, motivational interviewing, structured family and couples therapy, 12-step facilitation, and contingency management into clusters including empathy and support, treatment engagement and activation, abstinence initiation, and recovery maintenance. Understanding how clinicians use EBPT components may lead to improved evidence-based practice dissemination and implementation. Published by Elsevier Inc.

A cluster randomized trial of strategies to increase uptake amongst young women invited for their first cervical screen: The STRATEGIC trial.

PubMed

Kitchener, H; Gittins, M; Cruickshank, M; Moseley, C; Fletcher, S; Albrow, R; Gray, A; Brabin, L; Torgerson, D; Crosbie, E J; Sargent, A; Roberts, C

2018-06-01

Objectives To measure the feasibility and effectiveness of interventions to increase cervical screening uptake amongst young women. Methods A two-phase cluster randomized trial conducted in general practices in the NHS Cervical Screening Programme. In Phase 1, women in practices randomized to intervention due for their first invitation to cervical screening received a pre-invitation leaflet and, separately, access to online booking. In Phase 2, non-attenders at six months were randomized to one of: vaginal self-sample kits sent unrequested or offered; timed appointments; nurse navigator; or the choice between nurse navigator or self-sample kits. Primary outcome was uplift in intervention vs. control practices, at 3 and 12 months post invitation. Results Phase 1 randomized 20,879 women. Neither pre-invitation leaflet nor online booking increased screening uptake by three months (18.8% pre-invitation leaflet vs. 19.2% control and 17.8% online booking vs. 17.2% control). Uptake was higher amongst human papillomavirus vaccinees at three months (OR 2.07, 95% CI 1.69-2.53, p < 0.001). Phase 2 randomized 10,126 non-attenders, with 32-34 clusters for each intervention and 100 clusters as controls. Sending self-sample kits increased uptake at 12 months (OR 1.51, 95% CI 1.20-1.91, p = 0.001), as did timed appointments (OR 1.41, 95% CI 1.14-1.74, p = 0.001). The offer of a nurse navigator, a self-sample kits on request, and choice between timed appointments and nurse navigator were ineffective. Conclusions Amongst non-attenders, self-sample kits sent and timed appointments achieved an uplift in screening over the short term; longer term impact is less certain. Prior human papillomavirus vaccination was associated with increased screening uptake.

Flemish palliative-care nurses' attitudes to palliative sedation: a quantitative study.

PubMed

Gielen, Joris; Van den Branden, Stef; Van Iersel, Trudie; Broeckaert, Bert

2012-09-01

Palliative sedation is an option of last resort to control refractory suffering. In order to better understand palliative-care nurses' attitudes to palliative sedation, an anonymous questionnaire was sent to all nurses (589) employed in palliative care in Flanders (Belgium). In all, 70.5% of the nurses (n = 415) responded. A large majority did not agree that euthanasia is preferable to palliative sedation, were against non-voluntary euthanasia in the case of a deeply and continuously sedated patient and considered it generally better not to administer artificial floods or fluids to such a patient. Two clusters were found: 58.5% belonged to the cluster of advocates of deep and continuous sedation and 41.5% belonged to the cluster of nurses restricting the application of deep and continuous sedation. These differences notwithstanding, overall the attitudes of the nurses are in accordance with the practice and policy of palliative sedation in Flemish palliative-care units.

Assessing the feasibility of screening and providing brief advice for alcohol misuse in general dental practice: a clustered randomised control trial protocol for the DART study

PubMed Central

Ntouva, Antiopi; Porter, Jessie; Crawford, Mike J; Britton, Annie; Gratus, Christine; Newton, Tim; Tsakos, Georgios; Heilmann, Anja; Pikhart, Hynek; Watt, Richard G

2015-01-01

Introduction Alcohol misuse is a significant public health problem with major health, social and economic consequences. Systematic reviews have reported that brief advice interventions delivered in various health service settings can reduce harmful drinking. Although the links between alcohol and oral health are well established and dentists come into contact with large numbers of otherwise healthy patients regularly, no studies have been conducted in the UK to test the feasibility of delivering brief advice about alcohol in general dental settings. Methods and analysis The Dental Alcohol Reduction Trial (DART) aims to assess the feasibility and acceptability of screening for alcohol misuse and delivering brief advice in patients attending National Health Service (NHS) general dental practices in North London. DART is a cluster randomised control feasibility trial and uses a mixed methods approach throughout the development, design, delivery and evaluation of the intervention. It will be conducted in 12 NHS general dental practices across North London and will include dental patients who drink above the recommended guidance, as measured by the Alcohol Use Disorders Identification Test (AUDIT-C) screening tool. The intervention involves 5 min of tailored brief advice delivered by dental practitioners during the patient's appointment. Feasibility and acceptability measures as well as suitability of proposed primary outcomes of alcohol consumption will be assessed. Initial economic evaluation will be undertaken. Recruitment and retention rates as well as acceptability of the study procedures from screening to follow-up will be measured. Ethics and dissemination Ethical approval was obtained from the Camden and Islington Research Ethics Committee. Study outputs will be disseminated via scientific publications, newsletters, reports and conference presentations to a range of professional and patient groups and stakeholders. Based on the results of the trial, recommendations will be made on the conduct of a definitive randomised controlled trial. Trial registration number ISRCTN81193263. PMID:26443659

A nurse-led clinic for patients consulting with osteoarthritis in general practice: development and impact of training in a cluster randomised controlled trial.

PubMed

Healey, Emma L; Main, Chris J; Ryan, Sarah; McHugh, Gretl A; Porcheret, Mark; Finney, Andrew G; Morden, Andrew; Dziedzic, Krysia S

2016-12-21

Despite a lack of service provision for people with osteoarthritis (OA), each year 1 in 5 of the general population consults a GP about a musculoskeletal condition such as OA. Consequently this may provide an opportunity for practice nurses to take an active role in helping patients manage their condition. A nurse led clinic for supporting patients with OA was developed for the MOSAICS study investigating how to implement the NICE 2014 OA Guideline core recommendations. This paper has two main objectives, firstly to provide an overview of the nurse-led OA clinic, and secondly to describe the development, key learning objectives, content and impact of the training to support its delivery. A training programme was developed and delivered to provide practice nurses with the knowledge and skill set needed to run the nurse-led OA clinic. The impact of the training programme on knowledge, confidence and OA management was evaluated using case report forms and pre and post training questionnaires. The pre-training questionnaire identified a gap between what practice nurses feel they can do and what they should be doing in line with NICE OA guidelines. Evaluation of the training suggests that it enabled practice nurses to feel more knowledgeable and confident in supporting patients to manage their OA and this was reflected in the clinical management patients received in the nurse-led OA clinics. A significant gap between what is recommended and what practice nurses feel they can currently provide in terms of OA management was evident. The development of a nurse training programme goes some way to develop a system in primary care for delivering the core recommendations by NICE. The cluster trial linked to this training was conducted from May 2012 through February 2014 by the Arthritis Research UK Primary Care Centre, Keele University, UK (Trial registration number ISRCTN06984617 ).

A note on the kappa statistic for clustered dichotomous data.

PubMed

Zhou, Ming; Yang, Zhao

2014-06-30

The kappa statistic is widely used to assess the agreement between two raters. Motivated by a simulation-based cluster bootstrap method to calculate the variance of the kappa statistic for clustered physician-patients dichotomous data, we investigate its special correlation structure and develop a new simple and efficient data generation algorithm. For the clustered physician-patients dichotomous data, based on the delta method and its special covariance structure, we propose a semi-parametric variance estimator for the kappa statistic. An extensive Monte Carlo simulation study is performed to evaluate the performance of the new proposal and five existing methods with respect to the empirical coverage probability, root-mean-square error, and average width of the 95% confidence interval for the kappa statistic. The variance estimator ignoring the dependence within a cluster is generally inappropriate, and the variance estimators from the new proposal, bootstrap-based methods, and the sampling-based delta method perform reasonably well for at least a moderately large number of clusters (e.g., the number of clusters K ⩾50). The new proposal and sampling-based delta method provide convenient tools for efficient computations and non-simulation-based alternatives to the existing bootstrap-based methods. Moreover, the new proposal has acceptable performance even when the number of clusters is as small as K = 25. To illustrate the practical application of all the methods, one psychiatric research data and two simulated clustered physician-patients dichotomous data are analyzed. Copyright © 2014 John Wiley & Sons, Ltd.

A Rasch Model Analysis of Evidence-Based Treatment Practices Used in the Criminal Justice System

PubMed Central

Henderson, Craig E.; Taxman, Faye S.; Young, Douglas W.

2008-01-01

This study used item response theory (IRT) to examine the extent to which criminal justice facilities and community-based agencies are using evidence-based substance abuse treatment practices (EBPs), which EBPs are most commonly used, and how EBPs cluster together. The study used data collected from wardens, justice administrators, and treatment directors as part of the National Criminal Justice Treatment Practices survey (NCJTP; Taxman et al., 2007a), and includes both adult criminal and juvenile justice samples. Results of Rasch modeling demonstrated that a reliable measure can be formed to gauge the extent to which juvenile and adult correctional facilities, and community treatment agencies serving offenders, have adopted various treatment practices supported by research. We also demonstrated the concurrent validity of the measure by showing that features of the facilities’ organizational contexts were associated with the extent to which facilities were using EBPs, and which EBPs they were using. Researchers, clinicians, and program administrators may find these results interesting not only because they show the program factors most strongly related to EBP use, but the results also suggest that certain treatment practices are generally clustered together, which may help stakeholders plan and prioritize the adoption of new EBPs in their facilities. The study has implications for future research focused on understanding the adoption and implementation of EBPs in correctional environments. PMID:18029116

When is informed consent required in cluster randomized trials in health research?

PubMed Central

2011-01-01

This article is part of a series of papers examining ethical issues in cluster randomized trials (CRTs) in health research. In the introductory paper in this series, we set out six areas of inquiry that must be addressed if the cluster trial is to be set on a firm ethical foundation. This paper addresses the second of the questions posed, namely, from whom, when, and how must informed consent be obtained in CRTs in health research? The ethical principle of respect for persons implies that researchers are generally obligated to obtain the informed consent of research subjects. Aspects of CRT design, including cluster randomization, cluster level interventions, and cluster size, present challenges to obtaining informed consent. Here we address five questions related to consent and CRTs: How can a study proceed if informed consent is not possible? Is consent to randomization always required? What information must be disclosed to potential subjects if their cluster has already been randomized? Is passive consent a valid substitute for informed consent? Do health professionals have a moral obligation to participate as subjects in CRTs designed to improve professional practice? We set out a framework based on the moral foundations of informed consent and international regulatory provisions to address each of these questions. First, when informed consent is not possible, a study may proceed if a research ethics committee is satisfied that conditions for a waiver of consent are satisfied. Second, informed consent to randomization may not be required if it is not possible to approach subjects at the time of randomization. Third, when potential subjects are approached after cluster randomization, they must be provided with a detailed description of the interventions in the trial arm to which their cluster has been randomized; detailed information on interventions in other trial arms need not be provided. Fourth, while passive consent may serve a variety of practical ends, it is not a substitute for valid informed consent. Fifth, while health professionals may have a moral obligation to participate as subjects in research, this does not diminish the necessity of informed consent to study participation. PMID:21906277

Reducing Medical Admissions into Hospital through Optimising Medicines (REMAIN HOME) Study: protocol for a stepped-wedge, cluster-randomised trial

PubMed Central

Foot, Holly; Freeman, Christopher; Hemming, Karla; Scott, Ian; Coombes, Ian D; Williams, Ian D; Connelly, Luke; Whitty, Jennifer A; Sturman, Nancy; Kirsa, Sue; Nicholson, Caroline; Russell, Grant; Kirkpatrick, Carl; Cottrell, Neil

2017-01-01

Introduction A model of general practitioner (GP) and pharmacist collaboration in primary care may be an effective strategy to reduce medication-related problems and provide better support to patients after discharge. The aim of this study is to investigate whether a model of structured pharmacist and GP care reduces hospital readmissions in high-risk patients. Methods and analysis This protocol details a stepped-wedge, cluster-randomised trial that will recruit participants over 9 months with a 12-month follow-up. There will be 14 clusters each representing a different general practice medical centre. A total of 2240 participants will be recruited from hospital who attend an enrolled medical centre, take five or more long-term medicines or whose reason for admission was related to heart failure or chronic obstructive pulmonary disease. The intervention is a multifaceted service, involving a pharmacist integrated into a medical centre to assist patients after hospitalisation. Participants will meet with the practice pharmacist and their GP after discharge to review and reconcile their medicines and discuss changes made in hospital. The pharmacist will follow-up with the participant and liaise with other health professionals involved in the participant’s care. The control will be usual care, which usually involves a patient self-organising a visit to their GP after hospital discharge. The primary outcome is the rate of unplanned, all-cause hospital readmissions over 12 months, which will be analysed using a mixed effects Poisson regression model with a random effect for cluster and a fixed effect to account for any temporal trend. A cost analysis will be undertaken to compare the healthcare costs associated with the intervention to those of usual care. Ethics and dissemination The study has received ethical approval (HREC/16/QRBW/410). The study findings will be disseminated through peer-reviewed publications, conferences and reports to key stakeholders. Trial registration number ACTRN12616001627448 PMID:28408545

Tailored educational intervention for primary care to improve the management of dementia: the EVIDEM-ED cluster randomized controlled trial.

PubMed

Wilcock, Jane; Iliffe, Steve; Griffin, Mark; Jain, Priya; Thuné-Boyle, Ingela; Lefford, Frances; Rapp, David

2013-11-20

Early diagnosis of dementia is important because this allows those with dementia and their families to engage support and plan ahead. However, dementia remains underdetected and suboptimally managed in general practice. Our objective was to test the effect of a workplace-based tailored educational intervention developed for general practice on the clinical management of people with dementia. The tailored educational intervention was tested in an unblinded cluster randomized controlled trial with a pre/post-intervention design, with two arms: usual/normal care control versus educational intervention. The primary outcome measure was an increase in the proportion of patients with dementia who received at least two documented dementia-specific management reviews per year. Case identification was a secondary outcome measure. 23 practices in South-East England participated. A total of 1,072 patients with dementia (intervention: 512, control: 560) had information in their medical records showing the number of reviews within 12 months (or a proportion of) before intervention or randomization and within 12 months (or a proportion of) after. The mean total number of dementia management reviews after the educational intervention for people with dementia was 0.89 (SD 1.09; minimum 0; median 1; maximum 8) compared with 0.89 (SD 0.92; minimum 0; median 1; maximum 4) before intervention. In the control group prior to randomization the mean total number of dementia management reviews was 1.66 (SD 1.87; minimum 0; median 1; maximum 12) and in the period after randomization it was 1.56 (SD 1.79; minimum 0; median 1; maximum 11). Case detection rates were unaffected. The estimated incidence rate ratio for intervention versus control group was 1.03 (P = 0.927, 95% CI 0.57 to 1.86). The trial was timely, coinciding with financial incentives for dementia management in general practice (through the Quality Outcomes Framework); legal imperatives (in the form of the Mental Capacity Act 2005); policy pressure (The National Dementia Strategy 2009); and new resources (such as dementia advisors) that increased the salience of dementia for general practitioners. Despite this the intervention did not alter the documentation of clinical management of patients with dementia in volunteer practices, nor did it increase case identification. NCT00866099/Clinical Trials.

Nurse-led motivational interviewing to change the lifestyle of patients with type 2 diabetes (MILD-project): protocol for a cluster, randomized, controlled trial on implementing lifestyle recommendations

PubMed Central

Jansink, Renate; Braspenning, Jozé; van der Weijden, Trudy; Niessen, Louis; Elwyn, Glyn; Grol, Richard

2009-01-01

Background The diabetes of many patients is managed in general practice; healthcare providers aim to promote healthful behaviors, such as healthful diet, adequate physical activity, and smoking cessation. These measures may decrease insulin resistance, improve glycemic control, lipid abnormalities, and hypertension. They may also prevent cardiovascular disease and complications of diabetes. However, professionals do not adhere optimally to guidelines for lifestyle counseling. Motivational interviewing to change the lifestyle of patients with type 2 diabetes is intended to improve diabetes care in accordance with the national guidelines for lifestyle counseling. Primary care nurses will be trained in motivational interviewing embedded in structured care in general practice. The aim of this paper is to describe the design and methods of a study evaluating the effects of the nurses' training on patient outcomes. Methods/Design A cluster, randomized, controlled trial involving 70 general practices (35 practices in the intervention arm and 35 in the control arm) starting in March 2007. A total of 700 patients with type 2 diabetes will be recruited. The patients in the intervention arm will receive care from the primary care nurse, who will receive training in an implementation strategy with motivational interviewing as the core component. Other components of this strategy will be adaptation of the diabetes protocol to local circumstances, introduction of a social map for lifestyle support, and educational and supportive tools for sustaining motivational interviewing. The control arm will be encouraged to maintain usual care. The effect measures will be the care process, metabolic parameters (glycosylated hemoglobin, blood pressure and lipids), lifestyle (diet, physical activity, smoking, and alcohol), health-related quality of life, and patients' willingness to change behaviors. The measurements will take place at baseline and after 14 months. Discussion Applying motivational interviewing for patients with diabetes in primary care has been studied, but to our knowledge, no other study has yet evaluated the implementation and sustainability of motivating and involving patients in day-to-day diabetes care in general practice. If this intervention proves to be effective and cost-effective, large-scale implementation of this nurse-oriented intervention will be considered and anticipated. Trial registration Current Controlled Trials ISRCTN68707773. PMID:19183462

Update in Outpatient General Internal Medicine: Practice-Changing Evidence Published in 2015.

PubMed

Szostek, Jason H; Wieland, Mark L; Post, Jason A; Sundsted, Karna K; Mauck, Karen F

2016-08-01

Identifying new practice-changing articles is challenging. To determine the 2015 practice-changing articles most relevant to outpatient general internal medicine, 3 internists independently reviewed the titles and abstracts of original articles, synopses of single studies and syntheses, and databases of syntheses. For original articles, internal medicine journals with the 7 highest impact factors were reviewed: New England Journal of Medicine, Lancet, Journal of the American Medical Association (JAMA), British Medical Journal, Public Library of Science Medicine, Annals of Internal Medicine, and JAMA Internal Medicine. For synopses of single studies and syntheses, collections in American College of Physicians Journal Club, Journal Watch, and Evidence-Based Medicine were reviewed. For databases of synthesis, Evidence Updates and the Cochrane Library were reviewed. More than 100 articles were identified. Criteria for inclusion were as follows: clinical relevance, potential for practice change, and strength of evidence. Clusters of important articles around one topic were considered as a single-candidate series. The 5 authors used a modified Delphi method to reach consensus on inclusion of 7 topics for in-depth appraisal. Copyright © 2016 Elsevier Inc. All rights reserved.

A Cluster-Randomized Trial of Restorative Practices: An Illustration to Spur High-Quality Research and Evaluation

ERIC Educational Resources Information Center

Acosta, Joie D.; Chinman, Matthew; Ebener, Patricia; Phillips, Andrea; Xenakis, Lea; Malone, Patrick S.

2016-01-01

Restorative practices in schools lack rigorous evaluation studies. As an example of rigorous school-based research, this article describes the first randomized control trial of restorative practices to date, the Study of Restorative Practices. It is a 5-year, cluster-randomized controlled trial (RCT) of the Restorative Practices Intervention (RPI)…

Conformation-dependent restraints for polynucleotides: I. Clustering of the geometry of the phosphodiester group

PubMed Central

Kowiel, Marcin; Brzezinski, Dariusz; Jaskolski, Mariusz

2016-01-01

The refinement of macromolecular structures is usually aided by prior stereochemical knowledge in the form of geometrical restraints. Such restraints are also used for the flexible sugar-phosphate backbones of nucleic acids. However, recent highly accurate structural studies of DNA suggest that the phosphate bond angles may have inadequate description in the existing stereochemical dictionaries. In this paper, we analyze the bonding deformations of the phosphodiester groups in the Cambridge Structural Database, cluster the studied fragments into six conformation-related categories and propose a revised set of restraints for the O-P-O bond angles and distances. The proposed restraints have been positively validated against data from the Nucleic Acid Database and an ultrahigh-resolution Z-DNA structure in the Protein Data Bank. Additionally, the manual classification of PO4 geometry is compared with geometrical clusters automatically discovered by machine learning methods. The machine learning cluster analysis provides useful insights and a practical example for general applications of clustering algorithms for automatic discovery of hidden patterns of molecular geometry. Finally, we describe the implementation and application of a public-domain web server for automatic generation of the proposed restraints. PMID:27521371

On the Analysis of Case-Control Studies in Cluster-correlated Data Settings.

PubMed

Haneuse, Sebastien; Rivera-Rodriguez, Claudia

2018-01-01

In resource-limited settings, long-term evaluation of national antiretroviral treatment (ART) programs often relies on aggregated data, the analysis of which may be subject to ecological bias. As researchers and policy makers consider evaluating individual-level outcomes such as treatment adherence or mortality, the well-known case-control design is appealing in that it provides efficiency gains over random sampling. In the context that motivates this article, valid estimation and inference requires acknowledging any clustering, although, to our knowledge, no statistical methods have been published for the analysis of case-control data for which the underlying population exhibits clustering. Furthermore, in the specific context of an ongoing collaboration in Malawi, rather than performing case-control sampling across all clinics, case-control sampling within clinics has been suggested as a more practical strategy. To our knowledge, although similar outcome-dependent sampling schemes have been described in the literature, a case-control design specific to correlated data settings is new. In this article, we describe this design, discuss balanced versus unbalanced sampling techniques, and provide a general approach to analyzing case-control studies in cluster-correlated settings based on inverse probability-weighted generalized estimating equations. Inference is based on a robust sandwich estimator with correlation parameters estimated to ensure appropriate accounting of the outcome-dependent sampling scheme. We conduct comprehensive simulations, based in part on real data on a sample of N = 78,155 program registrants in Malawi between 2005 and 2007, to evaluate small-sample operating characteristics and potential trade-offs associated with standard case-control sampling or when case-control sampling is performed within clusters.

Why does it run in families? Explaining family similarity in help-seeking behaviour by shared circumstances, socialisation and selection.

PubMed

Cardol, Mieke; Groenewegen, Peter P; Spreeuwenberg, Peter; Van Dijk, Liset; Van Den Bosch, Wil J H M; De Bakker, Dinny H

2006-08-01

Why do contact frequencies with general practice of family members resemble each other? Many aspects related to the clustering of health-care utilisation within families have been studied, but the underlying mechanisms have not been addressed. This article considers whether family similarity in contact frequency with general practice can be explained as (a) a result of shared circumstances, (b) through socialisation, and (c) through homogeneity of background characteristics. Data from the second Dutch national survey of general practice were used to test these mechanisms empirically. This survey recorded all consultations in 2001 for 104 general practices in the Netherlands, serving 385,461 patients. Information about socio-demographic characteristics was collected by means of a patient survey. In a random sample, an extended health interview took place (n=12,699). Overall, we were able to show that having determinants in common through socialisation and shared circumstances can explain similarity in contact frequencies within families, but not all hypotheses could be confirmed. In specific terms, this study shows that resemblances in contact frequencies within families can be best explained by spending more time together (socialisation) and parents and children consulting a general practitioner simultaneously (circumstances of the moment). For general practitioners, the mechanisms identified can serve as a framework for a family case history. The importance of the mechanism of socialisation in explaining similarities in help-seeking behaviour between family members points to the significance of knowledge and health beliefs underlying consultation behaviour. An integrated framework including these aspects can help to better explain health behaviour.

Effect of an Education Programme for South Asians with Asthma and Their Clinicians: A Cluster Randomised Controlled Trial (OEDIPUS)

PubMed Central

Griffiths, Chris; Bremner, Stephen; Islam, Kamrul; Sohanpal, Ratna; Vidal, Debi-Lee; Dawson, Carolyn; Foster, Gillian; Ramsay, Jean; Feder, Gene; Taylor, Stephanie; Barnes, Neil; Choudhury, Aklak; Packe, Geoff; Bayliss, Elizabeth; Trathen, Duncan; Moss, Philip; Cook, Viv; Livingstone, Anna Eleri; Eldridge, Sandra

2016-01-01

Background People with asthma from ethnic minority groups experience significant morbidity. Culturally-specific interventions to reduce asthma morbidity are rare. We tested the hypothesis that a culturally-specific education programme, adapted from promising theory-based interventions developed in the USA, would reduce unscheduled care for South Asians with asthma in the UK. Methods A cluster randomised controlled trial, set in two east London boroughs. 105 of 107 eligible general practices were randomised to usual care or the education programme. Participants were south Asians with asthma aged 3 years and older with recent unscheduled care. The programme had two components: the Physician Asthma Care Education (PACE) programme and the Chronic Disease Self Management Programme (CDSMP), targeted at clinicians and patients with asthma respectively. Both were culturally adapted for south Asians with asthma. Specialist nurses, and primary care teams from intervention practices were trained using the PACE programme. South Asian participants attended an outpatient appointment; those registered with intervention practices received self-management training from PACE-trained specialist nurses, a follow-up appointment with PACE-trained primary care practices, and an invitation to attend the CDSMP. Patients from control practices received usual care. Primary outcome was unscheduled care. Findings 375 south Asians with asthma from 84 general practices took part, 183 registered with intervention practices and 192 with control practices. Primary outcome data were available for 358/375 (95.5%) of participants. The intervention had no effect on time to first unscheduled attendance for asthma (Adjusted Hazard Ratio AHR = 1.19 95% CI 0.92 to 1.53). Time to first review in primary care was reduced (AHR = 2.22, (1.67 to 2.95). Asthma-related quality of life and self-efficacy were improved at 3 months (adjusted mean difference -2.56, (-3.89 to -1.24); 0.44, (0.05 to 0.82) respectively. Conclusions A multi-component education programme adapted for south Asians with asthma did not reduce unscheduled care but did improve follow-up in primary care, self-efficacy and quality of life. More effective interventions are needed for south Asians with asthma. PMID:28030569

The QICKD study protocol: a cluster randomised trial to compare quality improvement interventions to lower systolic BP in chronic kidney disease (CKD) in primary care

PubMed Central

de Lusignan, Simon; Gallagher, Hugh; Chan, Tom; Thomas, Nicki; van Vlymen, Jeremy; Nation, Michael; Jain, Neerja; Tahir, Aumran; du Bois, Elizabeth; Crinson, Iain; Hague, Nigel; Reid, Fiona; Harris, Kevin

2009-01-01

Background Chronic kidney disease (CKD) is a relatively newly recognised but common long-term condition affecting 5 to 10% of the population. Effective management of CKD, with emphasis on strict blood pressure (BP) control, reduces cardiovascular risk and slows the progression of CKD. There is currently an unprecedented rise in referral to specialist renal services, which are often located in tertiary centres, inconvenient for patients, and wasteful of resources. National and international CKD guidelines include quality targets for primary care. However, there have been no rigorous evaluations of strategies to implement these guidelines. This study aims to test whether quality improvement interventions improve primary care management of elevated BP in CKD, reduce cardiovascular risk, and slow renal disease progression Design Cluster randomised controlled trial (CRT) Methods This three-armed CRT compares two well-established quality improvement interventions with usual practice. The two interventions comprise: provision of clinical practice guidelines with prompts and audit-based education. The study population will be all individuals with CKD from general practices in eight localities across England. Randomisation will take place at the level of the general practices. The intended sample (three arms of 25 practices) powers the study to detect a 3 mmHg difference in systolic BP between the different quality improvement interventions. An additional 10 practices per arm will receive a questionnaire to measure any change in confidence in managing CKD. Follow up will take place over two years. Outcomes will be measured using anonymised routinely collected data extracted from practice computer systems. Our primary outcome measure will be reduction of systolic BP in people with CKD and hypertension at two years. Secondary outcomes will include biomedical outcomes and markers of quality, including practitioner confidence in managing CKD. A small group of practices (n = 4) will take part in an in-depth process evaluation. We will use time series data to examine the natural history of CKD in the community. Finally, we will conduct an economic evaluation based on a comparison of the cost effectiveness of each intervention. Clinical Trials Registration ISRCTN56023731. ClinicalTrials.gov identifier. PMID:19602233

What do we do? Practices and learning strategies of medical education leaders.

PubMed

Lieff, Susan; Albert, Mathieu

2012-01-01

Continuous changes in undergraduate and postgraduate medical education require faculty to assume a variety of new leadership roles. While numerous faculty development programmes have been developed, there is little evidence about the specific practices of medical education leaders or their learning strategies to help inform their design. This study aimed to explore what medical education leaders' actually do, their learning strategies and recommendations for faculty development. A total of 16 medical education leaders from a variety of contexts within the faculty of medicine of a large North American medical school participated in semi-structured interviews to explore the nature of their work and the learning strategies they employ. Using thematic analysis, interview transcripts were coded inductively and then clustered into emergent themes. Findings clustered into four key themes of practice: (1) intrapersonal (e.g., self-awareness), (2) interpersonal (e.g., fostering informal networks), (3) organizational (e.g., creating a shared vision) and (4) systemic (e.g. strategic navigation). Learning strategies employed included learning from experience and example, reflective practice, strategic mentoring or advanced training. Our findings illuminate a four-domain framework for understanding medical education leader practices and their learning preferences. While some of these findings are not unknown in the general leadership literature, our understanding of their application in medical education is unique. These practices and preferences have a potential utility for conceptualizing a coherent and relevant approach to the design of faculty development strategies for medical education leadership.

Microbial biodiversity in arable soils is affected by agricultural practices

NASA Astrophysics Data System (ADS)

Wolińska, Agnieszka; Górniak, Dorota; Zielenkiewicz, Urszula; Goryluk-Salmonowicz, Agata; Kuźniar, Agnieszka; Stępniewska, Zofia; Błaszczyk, Mieczysław

2017-04-01

The aim of the study was to examine the differences in microbial community structure as a result of agricultural practices. Sixteen samples of cultivated and the same number of non-cultivated soils were selected. Gel bands were identified using the GelCompar software to create the presence-absence matrix, where each band represented a bacterial operational taxonomic unit. The data were used for principal-component analysis and additionally, the Shannon- Weaver index of general diversity, Simpson index of dominance and Simpson index of diversity were calculated. Denaturing gradient gel electrophoresis profiles clearly indicated differentiation of tested samples into two clusters: cultivated and non-cultivated soils. Greater numbers of dominant operational taxonomic units (65) in non-cultivated soils were noted compared to cultivated soils (47 operational taxonomic units). This implies that there was a reduction of dominant bacterial operational taxonomic units by nearly 30% in cultivated soils. Simpson dominance index expressing the number of species weighted by their abundance amounted to 1.22 in cultivated soils, whereas a 3-fold higher value (3.38) was observed in non-cultivated soils. Land-use practices seemed to be a important factors affected on biodiversity, because more than soil type determined the clustering into groups.

Training practitioners to deliver opportunistic multiple behaviour change counselling in primary care: a cluster randomised trial

PubMed Central

Simpson, Sharon A; Hood, Kerenza; Cohen, David; Pickles, Tim; Spanou, Clio; McCambridge, Jim; Moore, Laurence; Randell, Elizabeth; Alam, M Fasihul; Kinnersley, Paul; Edwards, Adrian; Smith, Christine; Rollnick, Stephen

2013-01-01

Objectives To evaluate the effect of training primary care health professionals in behaviour change counselling on the proportion of patients self reporting change in four risk behaviours (smoking, alcohol use, exercise, and healthy eating). Design Cluster randomised trial with general practices as the unit of randomisation. Setting General practices in Wales. Participants 53 general practitioners and practice nurses from 27 general practices (one each at all but one practice) recruited 1827 patients who screened positive for at least one risky behaviour. Intervention Behaviour change counselling was developed from motivational interviewing to enable clinicians to enhance patients’ motivation to change health related behaviour. Clinicians were trained using a blended learning programme called Talking Lifestyles. Main outcome measures Proportion of patients who reported making beneficial changes in at least one of the four risky behaviours at three months. Results 1308 patients from 13 intervention and 1496 from 14 control practices were approached: 76% and 72% respectively agreed to participate, with 831 (84%) and 996 (92%) respectively screening eligible for an intervention. There was no effect on the primary outcome (beneficial change in behaviour) at three months (362 (44%) v 404 (41%), odds ratio 1.12 (95% CI 0.90 to 1.39)) or on biochemical or biometric measures at 12 months. More patients who had consulted with trained clinicians recalled consultation discussion about a health behaviour (724/795 (91%) v 531/966 (55%), odds ratio 12.44 (5.85 to 26.46)) and intended to change (599/831 (72%) v 491/996 (49%), odds ratio 2.88 (2.05 to 4.05)). More intervention practice patients reported making an attempt to change (328 (39%) v 317 (32%), odds ratio 1.40 (1.15 to 1.70)), a sustained behaviour change at three months (288 (35%) v 280 (28%), odds ratio 1.36 (1.11 to 1.65)), and reported slightly greater improvements in healthy eating at three and 12 months, plus improved activity at 12 months. Training cost £1597 per practice. Discussion Training primary care clinicians in behaviour change counselling using a brief blended learning programme did not increase patients reported beneficial behaviour change at three months or improve biometric and a biochemical measure at 12 months, but it did increase patients’ recollection of discussing behaviour change with their clinicians, intentions to change, attempts to change, and perceptions of having made a lasting change at three months. Enduring behaviour change and improvements in biometric measures are unlikely after a single routine consultation with a clinician trained in behaviour change counselling without additional intervention. Trial registration ISRCTN 22495456 PMID:23512758

A workplace exercise versus health promotion intervention to prevent and reduce the economic and personal burden of non-specific neck pain in office personnel: protocol of a cluster-randomised controlled trial.

PubMed

Johnston, V; O'Leary, S; Comans, T; Straker, L; Melloh, M; Khan, A; Sjøgaard, G

2014-12-01

Non-specific neck pain is a major burden to industry, yet the impact of introducing a workplace ergonomics and exercise intervention on work productivity and severity of neck pain in a population of office personnel is unknown. Does a combined workplace-based best practice ergonomic and neck exercise program reduce productivity losses and risk of developing neck pain in asymptomatic workers, or decrease severity of neck pain in symptomatic workers, compared to a best practice ergonomic and general health promotion program? Prospective cluster randomised controlled trial. Office personnel aged over 18 years, and who work>30 hours/week. Individualised best practice ergonomic intervention plus 3×20 minute weekly, progressive neck/shoulder girdle exercise group sessions for 12 weeks. Individualised best practice ergonomic intervention plus 1-hour weekly health information sessions for 12 weeks. Primary (productivity loss) and secondary (neck pain and disability, muscle performance, and quality of life) outcome measures will be collected using validated scales at baseline, immediate post-intervention and 12 months after commencement. 640 volunteering office personnel will be randomly allocated to either an intervention or control arm in work group clusters. Analysis will be on an 'intent-to-treat' basis and per protocol. Multilevel, generalised linear models will be used to examine the effect of the intervention on reducing the productivity loss in dollar units (AUD), and severity of neck pain and disability. The findings of this study will have a direct impact on policies that underpin the prevention and management of neck pain in office personnel. Copyright © 2014 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

Nurse-Facilitated Health Checks for Persons With Severe Mental Illness: A Cluster-Randomized Controlled Trial.

PubMed

White, Jacquie; Lucas, Joanne; Swift, Louise; Barton, Garry R; Johnson, Harriet; Irvine, Lisa; Abotsie, Gabriel; Jones, Martin; Gray, Richard J

2018-05-01

This study tested the effectiveness of a nurse-delivered health check with the Health Improvement Profile (HIP), which takes approximately 1.5 hours to complete and code, for persons with severe mental illness. A single-blind, cluster-randomized controlled trial was conducted in England to test whether health checks improved the general medical well-being of persons with severe mental illness at 12-month follow-up. Sixty nurses were randomly assigned to the HIP group or the treatment-as-usual group. From their case lists, 173 patients agreed to participate. HIP group nurses completed health checks for 38 of their 90 patients (42%) at baseline and 22 (24%) at follow-up. No significant between-group differences were noted in patients' general medical well-being at follow-up. Nurses who had volunteered for a clinical trial administered health checks only to a minority of participating patients, suggesting that it may not be feasible to undertake such lengthy structured health checks in routine practice.

Spatiotemporal modeling of node temperatures in supercomputers

DOE PAGES

Storlie, Curtis Byron; Reich, Brian James; Rust, William Newton; ...

2016-06-10

Los Alamos National Laboratory (LANL) is home to many large supercomputing clusters. These clusters require an enormous amount of power (~500-2000 kW each), and most of this energy is converted into heat. Thus, cooling the components of the supercomputer becomes a critical and expensive endeavor. Recently a project was initiated to investigate the effect that changes to the cooling system in a machine room had on three large machines that were housed there. Coupled with this goal was the aim to develop a general good-practice for characterizing the effect of cooling changes and monitoring machine node temperatures in this andmore » other machine rooms. This paper focuses on the statistical approach used to quantify the effect that several cooling changes to the room had on the temperatures of the individual nodes of the computers. The largest cluster in the room has 1,600 nodes that run a variety of jobs during general use. Since extremes temperatures are important, a Normal distribution plus generalized Pareto distribution for the upper tail is used to model the marginal distribution, along with a Gaussian process copula to account for spatio-temporal dependence. A Gaussian Markov random field (GMRF) model is used to model the spatial effects on the node temperatures as the cooling changes take place. This model is then used to assess the condition of the node temperatures after each change to the room. The analysis approach was used to uncover the cause of a problematic episode of overheating nodes on one of the supercomputing clusters. Lastly, this same approach can easily be applied to monitor and investigate cooling systems at other data centers, as well.« less

Entrapment of metal clusters in metal-organic framework channels by extended hooks anchored at open metal sites.

PubMed

Zheng, Shou-Tian; Zhao, Xiang; Lau, Samuel; Fuhr, Addis; Feng, Pingyun; Bu, Xianhui

2013-07-17

Reported here are the new concept of utilizing open metal sites (OMSs) for architectural pore design and its practical implementation. Specifically, it is shown here that OMSs can be used to run extended hooks (isonicotinates in this work) from the framework walls to the channel centers to effect the capture of single metal ions or clusters, with the concurrent partitioning of the large channel spaces into multiple domains, alteration of the host-guest charge relationship and associated guest-exchange properties, and transfer of OMSs from the walls to the channel centers. The concept of the extended hook, demonstrated here in the multicomponent dual-metal and dual-ligand system, should be generally applicable to a range of framework types.

Patterns of Food Parenting Practices and Children's Intake of Energy-Dense Snack Foods.

PubMed

Gevers, Dorus W M; Kremers, Stef P J; de Vries, Nanne K; van Assema, Patricia

2015-05-27

Most previous studies of parental influences on children's diets included just a single or a few types of food parenting practices, while parents actually employ multiple types of practices. Our objective was to investigate the clustering of parents regarding food parenting practices and to characterize the clusters in terms of background characteristics and children's intake of energy-dense snack foods. A sample of Dutch parents of children aged 4-12 was recruited by a research agency to fill out an online questionnaire. A hierarchical cluster analysis (n = 888) was performed, followed by k-means clustering. ANOVAs, ANCOVAs and chi-square tests were used to investigate associations between cluster membership, parental and child background characteristics, as well as children's intake of energy-dense snack foods. Four distinct patterns were discovered: "high covert control and rewarding", "low covert control and non-rewarding", "high involvement and supportive" and "low involvement and indulgent". The "high involvement and supportive" cluster was found to be most favorable in terms of children's intake. Several background factors characterized cluster membership. This study expands the current knowledge about parental influences on children's diets. Interventions should focus on increasing parental involvement in food parenting.

Walking Away from Type 2 diabetes: a cluster randomized controlled trial.

PubMed

Yates, T; Edwardson, C L; Henson, J; Gray, L J; Ashra, N B; Troughton, J; Khunti, K; Davies, M J

2017-05-01

This study aimed to investigate whether an established behavioural intervention, Walking Away from Type 2 Diabetes, is effective at promoting and sustaining increased walking activity when delivered within primary care. Cluster randomized controlled trial involving 10 general practices recruited from Leicestershire, UK, in 2009-2010. Eight hundred and eight (36% female) individuals with a high risk of Type 2 diabetes mellitus, identified through a validated risk score, were included. Participants in five practices were randomized to Walking Away from Type 2 Diabetes, a pragmatic 3-h group-based structured education programme incorporating pedometer use with annual follow-on refresher sessions. The primary outcome was accelerometer assessed ambulatory activity (steps/day) at 12 months. Longer term maintenance was assessed at 24 and 36 months. Results were analysed using generalized estimating equation models, accounting for clustering. Complete accelerometer data for the primary outcome were available for 571 (71%) participants. Increases in ambulatory activity of 411 steps/day [95% confidence interval (CI): 117, 704] and self-reported vigorous-intensity physical activity of 218 metabolic equivalent min/week (95% CI: 6, 425) at 12 months were observed in the intervention group compared with control; differences between groups were not sustained at 36 months. No differences between groups were observed for markers of cardiometabolic health. Replacing missing data with multiple imputation did not affect the results. A pragmatic low-resource group-based structured education programme with pedometer use resulted in modest increases in ambulatory activity compared with control conditions after 12 months when implemented within a primary care setting to those at high risk of Type 2 diabetes mellitus; however, the results were not maintained over 36 months. © 2016 Diabetes UK.

Are general practice characteristics predictors of good glycaemic control in patients with diabetes? A cross-sectional study.

PubMed

Esterman, Adrian J; Fountaine, Tim; McDermott, Robyn

2016-01-18

To determine whether certain characteristics of general practices are associated with good glycaemic control in patients with diabetes and with completing an annual cycle of care (ACC). Our cross-sectional analysis used baseline data from the Australian Diabetes Care Project conducted between 2011 and 2014. Practice characteristics were self-reported. Characteristics of the patients that were assessed included glycaemic control (HbA1c level ≤ 53 mmol/mol), age, sex, duration of diabetes, socio-economic disadvantage (SEIFA) score, the complexity of the patient's condition, and whether the patient had completed an ACC for diabetes in the past 18 months. Clustered logistic regression was used to establish predictors of glycaemic control and a completed ACC. Data were available from 147 general practices and 5455 patients with established type 1 or type 2 diabetes in three Australian states. After adjustment for other patient characteristics, only the patient completing an ACC was statistically significant as a predictor of glycaemic control (P = 0.011). In a multivariate model, the practice having a chronic disease-focused practice nurse (P = 0.036) and running educational events for patients with diabetes (P = 0.004) were statistically significant predictors of the patient having complete an ACC. Patient characteristics are moderately good predictors of whether the patient is in glycaemic control, whereas practice characteristics appear to predict only the likelihood of patients completing an ACC. The ACC is an established indicator of good diabetes management. This is the first study to report a positive association between having completed an ACC and the patient being in glycaemic control.

Economic evaluation of an implementation strategy for the management of low back pain in general practice.

PubMed

Jensen, Cathrine Elgaard; Riis, Allan; Petersen, Karin Dam; Jensen, Martin Bach; Pedersen, Kjeld Møller

2017-05-01

In connection with the publication of a clinical practice guideline on the management of low back pain (LBP) in general practice in Denmark, a cluster randomised controlled trial was conducted. In this trial, a multifaceted guideline implementation strategy to improve general practitioners' treatment of patients with LBP was compared with a usual implementation strategy. The aim was to determine whether the multifaceted strategy was cost effective, as compared with the usual implementation strategy. The economic evaluation was conducted as a cost-utility analysis where cost collected from a societal perspective and quality-adjusted life years were used as outcome measures. The analysis was conducted as a within-trial analysis with a 12-month time horizon consistent with the follow-up period of the clinical trial. To adjust for a priori selected covariates, generalised linear models with a gamma family were used to estimate incremental costs and quality-adjusted life years. Furthermore, both deterministic and probabilistic sensitivity analyses were conducted. Results showed that costs associated with primary health care were higher, whereas secondary health care costs were lower for the intervention group when compared with the control group. When adjusting for covariates, the intervention was less costly, and there was no significant difference in effect between the 2 groups. Sensitivity analyses showed that results were sensitive to uncertainty. In conclusion, the multifaceted implementation strategy was cost saving when compared with the usual strategy for implementing LBP clinical practice guidelines in general practice. Furthermore, there was no significant difference in effect, and the estimate was sensitive to uncertainty.

Bayesian analysis of volcanic eruptions

NASA Astrophysics Data System (ADS)

Ho, Chih-Hsiang

1990-10-01

The simple Poisson model generally gives a good fit to many volcanoes for volcanic eruption forecasting. Nonetheless, empirical evidence suggests that volcanic activity in successive equal time-periods tends to be more variable than a simple Poisson with constant eruptive rate. An alternative model is therefore examined in which eruptive rate(λ) for a given volcano or cluster(s) of volcanoes is described by a gamma distribution (prior) rather than treated as a constant value as in the assumptions of a simple Poisson model. Bayesian analysis is performed to link two distributions together to give the aggregate behavior of the volcanic activity. When the Poisson process is expanded to accomodate a gamma mixing distribution on λ, a consequence of this mixed (or compound) Poisson model is that the frequency distribution of eruptions in any given time-period of equal length follows the negative binomial distribution (NBD). Applications of the proposed model and comparisons between the generalized model and simple Poisson model are discussed based on the historical eruptive count data of volcanoes Mauna Loa (Hawaii) and Etna (Italy). Several relevant facts lead to the conclusion that the generalized model is preferable for practical use both in space and time.

Parental Influences on Adolescent Adjustment: Parenting Styles Versus Parenting Practices

ERIC Educational Resources Information Center

Lee, Sang Min; Daniels, M. Harry; Kissinger, Daniel B.

2006-01-01

The study identified distinct patterns of parental practices that differentially influence adolescent behavior using the National Educational Longitudinal Survey (NELS:88) database. Following Brenner and Fox's research model (1999), the cluster analysis was used to classify the four types of parental practices. The clusters of parenting practices…

Clinicians' Perspectives on Managing Symptom Clusters in Advanced Cancer: A Semistructured Interview Study.

PubMed

Dong, Skye T; Butow, Phyllis N; Agar, Meera; Lovell, Melanie R; Boyle, Frances; Stockler, Martin; Forster, Benjamin C; Tong, Allison

2016-04-01

Managing symptom clusters or multiple concurrent symptoms in patients with advanced cancer remains a clinical challenge. The optimal processes constituting effective management of symptom clusters remain uncertain. To describe the attitudes and strategies of clinicians in managing multiple co-occurring symptoms in patients with advanced cancer. Semistructured interviews were conducted with 48 clinicians (palliative care physicians [n = 10], oncologists [n = 6], general practitioners [n = 6], nurses [n = 12], and allied health providers [n = 14]), purposively recruited from two acute hospitals, two palliative care centers, and four community general practices in Sydney, Australia. Transcripts were analyzed using thematic analysis and adapted grounded theory. Six themes were identified: uncertainty in decision making (inadequacy of scientific evidence, relying on experiential knowledge, and pressure to optimize care); attunement to patient and family (sensitivity to multiple cues, prioritizing individual preferences, addressing psychosocial and physical interactions, and opening Pandora's box); deciphering cause to guide intervention (disaggregating symptoms and interactions, flexibility in assessment, and curtailing investigative intrusiveness); balancing complexities in medical management (trading off side effects, minimizing mismatched goals, and urgency in resolving severe symptoms); fostering hope and empowerment (allaying fear of the unknown, encouraging meaning making, championing patient empowerment, and truth telling); and depending on multidisciplinary expertise (maximizing knowledge exchange, sharing management responsibility, contending with hierarchical tensions, and isolation and discontinuity of care). Management of symptom clusters, as both an art and a science, is currently fraught with uncertainty in decision making. Strengthening multidisciplinary collaboration, continuity of care, more pragmatic planning of clinical trials to address more than one symptom, and training in symptom cluster management are required. Copyright © 2016 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Deletion Diagnostics for Alternating Logistic Regressions

PubMed Central

Preisser, John S.; By, Kunthel; Perin, Jamie; Qaqish, Bahjat F.

2013-01-01

Deletion diagnostics are introduced for the regression analysis of clustered binary outcomes estimated with alternating logistic regressions, an implementation of generalized estimating equations (GEE) that estimates regression coefficients in a marginal mean model and in a model for the intracluster association given by the log odds ratio. The diagnostics are developed within an estimating equations framework that recasts the estimating functions for association parameters based upon conditional residuals into equivalent functions based upon marginal residuals. Extensions of earlier work on GEE diagnostics follow directly, including computational formulae for one-step deletion diagnostics that measure the influence of a cluster of observations on the estimated regression parameters and on the overall marginal mean or association model fit. The diagnostic formulae are evaluated with simulations studies and with an application concerning an assessment of factors associated with health maintenance visits in primary care medical practices. The application and the simulations demonstrate that the proposed cluster-deletion diagnostics for alternating logistic regressions are good approximations of their exact fully iterated counterparts. PMID:22777960

Parenting practices are associated with fruit and vegetable consumption in pre-school children

PubMed Central

O’Connor, Teresia M; Hughes, Sheryl O; Watson, Kathy B; Baranowski, Tom; Nicklas, Theresa A; Fisher, Jennie O; Beltran, Alicia; Baranowski, Janice C; Qu, Haiyan; Shewchuk, Richard M

2009-01-01

Objective Parents may influence children’s fruit and vegetable (F&V) consumption in many ways, but research has focused primarily on counterproductive parenting practices, such as restriction and pressure to eat. The present study aimed to assess the association of diverse parenting practices to promote F&V and its consumption among pre-school children. Design An exploratory analysis was performed on cross-sectional data from 755 Head Start pre-school children and their parents collected in 2004–5. Data included parent practices to facilitate child F&V consumption (grouped into five categories); parent-reported dietary intake of their child over 3 d; and a number of potential correlates. K-means cluster analysis assigned parents to groups with similar use of the food parenting practice categories. Stepwise linear regression analyses investigated the association of parent clusters with children’s consumption of F&V, after controlling for potential confounding factors. Results A three-cluster solution provided the best fit (R2 = 0 62), with substantial differences in the use of parenting practices. The clusters were labelled Indiscriminate Food Parenting, Non-directive Food Parenting and Low-involved Food Parenting. Non-directive parents extensively used enhanced availability and teachable moments’ practices, but less firm discipline practices than the other clusters, and were significantly associated with child F&V intake (standardized β = 0·09, P < 0·1; final model R2 = 0·17) after controlling for confounders, including parental feeding styles. Conclusions Parents use a variety of parenting practices, beyond pressuring to eat and restrictive practices, to promote F&V intake in their young child. Evaluating the use of combinations of practices may provide a better understanding of parental influences on children’s F&V intake. PMID:19490734

The impact of a point-of-care testing device on CVD risk assessment completion in New Zealand primary-care practice: A cluster randomised controlled trial and qualitative investigation.

PubMed

Wells, Sue; Rafter, Natasha; Kenealy, Timothy; Herd, Geoff; Eggleton, Kyle; Lightfoot, Rose; Arcus, Kim; Wadham, Angela; Jiang, Yannan; Bullen, Chris

2017-01-01

To assess the effect of a point of care (POC) device for testing lipids and HbA1c in addition to testing by community laboratory facilities (usual practice) on the completion of cardiovascular disease (CVD) risk assessments in general practice. We conducted a pragmatic, cluster randomised controlled trial in 20 New Zealand general practices stratified by size and rurality and randomised to POC device plus usual practice or usual practice alone (controls). Patients aged 35-79 years were eligible if they met national guideline criteria for CVD risk assessment. Data on CVD risk assessments were aggregated using a web-based decision support programme common to each practice. Data entered into the on-line CVD risk assessment form could be saved pending blood test results. The primary outcome was the proportion of completed CVD risk assessments. Qualitative data on practice processes for CVD risk assessment and feasibility of POC testing were collected at the end of the study by interviews and questionnaire. The POC testing was supported by a comprehensive quality assurance programme. A CVD risk assessment entry was recorded for 7421 patients in 10 POC practices and 6217 patients in 10 control practices; 99.5% of CVD risk assessments had complete data in both groups (adjusted odds ratio 1.02 [95%CI 0.61-1.69]). There were major external influences that affected the trial: including a national performance target for CVD risk assessment and changes to CVD guidelines. All practices had invested in systems and dedicated staff time to identify and follow up patients to completion. However, the POC device was viewed by most as an additional tool rather than as an opportunity to review practice work flow and leverage the immediate test results for patient education and CVD risk management discussions. Shortly after commencement, the trial was halted due to a change in the HbA1c test assay performance. The trial restarted after the manufacturing issue was rectified but this affected the end use of the device. Performance incentives and external influences were more powerful modifiers of practice behaviours than the POC device in relation to CVD risk assessment completion. The promise of combining risk assessment, communication and management within one consultation was not realised. With shifts in policy focus, the utility of POC devices for patient engagement in CVD preventive care may be demonstrated if fully integrated into the clinical setting. Australian New Zealand Clinical Trials Registry ACTRN12613000607774.

A general framework to test gravity using galaxy clusters - I. Modelling the dynamical mass of haloes in f(R) gravity

NASA Astrophysics Data System (ADS)

Mitchell, Myles A.; He, Jian-hua; Arnold, Christian; Li, Baojiu

2018-06-01

We propose a new framework for testing gravity using cluster observations, which aims to provide an unbiased constraint on modified gravity models from Sunyaev-Zel'dovich (SZ) and X-ray cluster counts and the cluster gas fraction, among other possible observables. Focusing on a popular f(R) model of gravity, we propose a novel procedure to recalibrate mass scaling relations from Λ cold dark matter (ΛCDM) to f(R) gravity for SZ and X-ray cluster observables. We find that the complicated modified gravity effects can be simply modelled as a dependence on a combination of the background scalar field and redshift, fR(z)/(1 + z), regardless of the f(R) model parameter. By employing a large suite of N-body simulations, we demonstrate that a theoretically derived tanh fitting formula is in excellent agreement with the dynamical mass enhancement of dark matter haloes for a large range of background field parameters and redshifts. Our framework is sufficiently flexible to allow for tests of other models and inclusion of further observables, and the one-parameter description of the dynamical mass enhancement can have important implications on the theoretical modelling of observables and on practical tests of gravity.

Physician styles of decision-making for a complex condition: Type 2 diabetes with co-morbid mental illness.

PubMed

Trachtenberg, Felicia L; Pober, David M; Welch, Lisa C; McKinlay, John B

Variation in physician decisions may reflect personal styles of decision-making, as opposed to singular clinical actions and these styles may be applied differently depending on patient complexity. The objective of this study is to examine clusters of physician decision-making for type 2 diabetes, overall and in the presence of a mental health co-morbidity. This randomized balanced factorial experiment presented video vignettes of a "patient" with diagnosed, but uncontrolled type 2 diabetes. "Patients" were systematically varied by age, sex, race and co-morbidity (depression, schizophrenia with normal or bizarre affect, eczema as control). Two hundred and fifty-six primary care physicians, balanced by gender and experience level, completed a structured interview about clinical management. Cluster analysis identified 3 styles of diabetes management. "Minimalists" (n=84) performed fewer exams or tests compared to "middle of the road" physicians (n=84). "Interventionists" (n=88) suggested more medications and referrals. A second cluster analysis, without control for co-morbidities, identified an additional cluster of "information seekers" (n=15) who requested more additional information and referrals. Physicians ranking schizophrenia higher than diabetes on their problem list were more likely "minimalists" and none were "interventionists" or "information seekers". Variations in clinical management encompass multiple clinical actions and physicians subtly shift these decision-making styles depending on patient co-morbidities. Physicians' practice styles may help explain persistent differences in patient care. Training and continuing education efforts to encourage physicians to implement evidence-based clinical practice should account for general styles of decision-making and for how physicians process complicating comorbidities.

Knowledge translation on dementia: a cluster randomized trial to compare a blended learning approach with a "classical" advanced training in GP quality circles

PubMed Central

Vollmar, Horst C; Butzlaff, Martin E; Lefering, Rolf; Rieger, Monika A

2007-01-01

Background Thus far important findings regarding the dementia syndrome have been implemented into patients' medical care only inadequately. A professional training accounting for both, general practitioners' (GP) needs and learning preferences as well as care-relevant aspects could be a major step towards improving medical care. In the WIDA-study, entitled "Knowledge translation on dementia in general practice" two different training concepts are developed, implemented and evaluated. Both concepts are building on an evidence-based, GP-related dementia guideline and communicate the guideline's essential insights. Methods/Design Both development and implementation emphasize a procedure that is well-accepted in practice and, thus, can achieve a high degree of external validity. This is particularly guaranteed through the preparation of training material and the fact that general practitioners' quality circles (QC) are addressed. The evaluation of the two training concepts is carried out by comparing two groups of GPs to which several quality circles have been randomly assigned. The primary outcome is the GPs' knowledge gain. Secondary outcomes are designed to indicate the training's potential effects on the GPs' practical actions. In the first training concept (study arm A) GPs participate in a structured case discussion prepared for by internet-based learning material ("blended-learning" approach). The second training concept (study arm B) relies on frontal medical training in the form of a slide presentation and follow-up discussion ("classical" approach). Discussion This paper presents the outline of a cluster-randomized trial which has been peer reviewed and support by a national funding organization – Federal Ministry of Education and Research (BMBF) – and is approved by an ethics commission. The data collection has started in August 2006 and the results will be published independently of the study's outcome. Trial Registration Current Controlled Trials [ISRCTN36550981] PMID:17587452

Rationale, design and methods of the Study of Work and Pain (SWAP): a cluster randomised controlled trial testing the addition of a vocational advice service to best current primary care for patients with musculoskeletal pain (ISRCTN 52269669)

PubMed Central

2014-01-01

Background Musculoskeletal pain is a major contributor to short and long term work absence. Patients seek care from their general practitioner (GP) and yet GPs often feel ill-equipped to deal with work issues. Providing a vocational case management service in primary care, to support patients with musculoskeletal problems to remain at or return to work, is one potential solution but requires robust evaluation to test clinical and cost-effectiveness. Methods/Design This protocol describes a cluster randomised controlled trial, with linked qualitative interviews, to investigate the effect of introducing a vocational advice service into general practice, to provide a structured approach to managing work related issues in primary care patients with musculoskeletal pain who are absent from work or struggling to remain in work. General practices (n = 6) will be randomised to offer best current care or best current care plus a vocational advice service. Adults of working age who are absent from or struggling to remain in work due to a musculoskeletal pain problem will be invited to participate and 330 participants will be recruited. Data collection will be through patient completed questionnaires at baseline, 4 and 12 months. The primary outcome is self-reported work absence at 4 months. Incremental cost-utility analysis will be undertaken to calculate the cost per additional QALY gained and incremental net benefits. A linked interview study will explore the experiences of the vocational advice service from the perspectives of GPs, nurse practitioners (NPs), patients and vocational advisors. Discussion This paper presents the rationale, design, and methods of the Study of Work And Pain (SWAP) trial. The results of this trial will provide evidence to inform primary care practice and guide the development of services to provide support for musculoskeletal pain patients with work-related issues. Trial registration Current Controlled Trials ISRCTN52269669. PMID:25012813

Rationale, design and methods of the Study of Work and Pain (SWAP): a cluster randomised controlled trial testing the addition of a vocational advice service to best current primary care for patients with musculoskeletal pain (ISRCTN 52269669).

PubMed

Bishop, Annette; Wynne-Jones, Gwenllian; Lawton, Sarah A; van der Windt, Danielle; Main, Chris; Sowden, Gail; Burton, A Kim; Lewis, Martyn; Jowett, Sue; Sanders, Tom; Hay, Elaine M; Foster, Nadine E

2014-07-10

Musculoskeletal pain is a major contributor to short and long term work absence. Patients seek care from their general practitioner (GP) and yet GPs often feel ill-equipped to deal with work issues. Providing a vocational case management service in primary care, to support patients with musculoskeletal problems to remain at or return to work, is one potential solution but requires robust evaluation to test clinical and cost-effectiveness. This protocol describes a cluster randomised controlled trial, with linked qualitative interviews, to investigate the effect of introducing a vocational advice service into general practice, to provide a structured approach to managing work related issues in primary care patients with musculoskeletal pain who are absent from work or struggling to remain in work. General practices (n = 6) will be randomised to offer best current care or best current care plus a vocational advice service. Adults of working age who are absent from or struggling to remain in work due to a musculoskeletal pain problem will be invited to participate and 330 participants will be recruited. Data collection will be through patient completed questionnaires at baseline, 4 and 12 months. The primary outcome is self-reported work absence at 4 months. Incremental cost-utility analysis will be undertaken to calculate the cost per additional QALY gained and incremental net benefits. A linked interview study will explore the experiences of the vocational advice service from the perspectives of GPs, nurse practitioners (NPs), patients and vocational advisors. This paper presents the rationale, design, and methods of the Study of Work And Pain (SWAP) trial. The results of this trial will provide evidence to inform primary care practice and guide the development of services to provide support for musculoskeletal pain patients with work-related issues. Current Controlled Trials ISRCTN52269669.

A pragmatic cluster randomised controlled trial to evaluate the safety, clinical effectiveness, cost effectiveness and satisfaction with point of care testing in a general practice setting - rationale, design and baseline characteristics.

PubMed

Laurence, Caroline; Gialamas, Angela; Yelland, Lisa; Bubner, Tanya; Ryan, Philip; Willson, Kristyn; Glastonbury, Briony; Gill, Janice; Shephard, Mark; Beilby, Justin

2008-08-06

Point of care testing (PoCT) may be a useful adjunct in the management of chronic conditions in general practice (GP). The provision of pathology test results at the time of the consultation could lead to enhanced clinical management, better health outcomes, greater convenience and satisfaction for patients and general practitioners (GPs), and savings in costs and time. It could also result in inappropriate testing, increased consultations and poor health outcomes resulting from inaccurate results. Currently there are very few randomised controlled trials (RCTs) in GP that have investigated these aspects of PoCT. The Point of Care Testing in General Practice Trial (PoCT Trial) was an Australian Government funded multi-centre, cluster randomised controlled trial to determine the safety, clinical effectiveness, cost effectiveness and satisfaction of PoCT in a GP setting.The PoCT Trial covered an 18 month period with the intervention consisting of the use of PoCT for seven tests used in the management of patients with diabetes, hyperlipidaemia and patients on anticoagulant therapy. The primary outcome measure was the proportion of patients within target range, a measure of therapeutic control. In addition, the PoCT Trial investigated the safety of PoCT, impact of PoCT on patient compliance to medication, stakeholder satisfaction, cost effectiveness of PoCT versus laboratory testing, and influence of geographic location. The paper provides an overview of the Trial Design, the rationale for the research methodology chosen and how the Trial was implemented in a GP environment. The evaluation protocol and data collection processes took into account the large number of patients, the broad range of practice types distributed over a large geographic area, and the inclusion of pathology test results from multiple pathology laboratories.The evaluation protocol developed reflects the complexity of the Trial setting, the Trial Design and the approach taken within the funding provided. The PoCT Trial is regarded as a pragmatic RCT, evaluating the effectiveness of implementing PoCT in GP and every effort was made to ensure that, in these circumstances, internal and external validity was maintained. 12612605000272695.

Generalized quantum kinetic expansion: Higher-order corrections to multichromophoric Förster theory

NASA Astrophysics Data System (ADS)

Wu, Jianlan; Gong, Zhihao; Tang, Zhoufei

2015-08-01

For a general two-cluster energy transfer network, a new methodology of the generalized quantum kinetic expansion (GQKE) method is developed, which predicts an exact time-convolution equation for the cluster population evolution under the initial condition of the local cluster equilibrium state. The cluster-to-cluster rate kernel is expanded over the inter-cluster couplings. The lowest second-order GQKE rate recovers the multichromophoric Förster theory (MCFT) rate. The higher-order corrections to the MCFT rate are systematically included using the continued fraction resummation form, resulting in the resummed GQKE method. The reliability of the GQKE methodology is verified in two model systems, revealing the relevance of higher-order corrections.

Security practices and regulatory compliance in the healthcare industry.

PubMed

Kwon, Juhee; Johnson, M Eric

2013-01-01

Securing protected health information is a critical responsibility of every healthcare organization. We explore information security practices and identify practice patterns that are associated with improved regulatory compliance. We employed Ward's cluster analysis using minimum variance based on the adoption of security practices. Variance between organizations was measured using dichotomous data indicating the presence or absence of each security practice. Using t tests, we identified the relationships between the clusters of security practices and their regulatory compliance. We utilized the results from the Kroll/Healthcare Information and Management Systems Society telephone-based survey of 250 US healthcare organizations including adoption status of security practices, breach incidents, and perceived compliance levels on Health Information Technology for Economic and Clinical Health, Health Insurance Portability and Accountability Act, Red Flags rules, Centers for Medicare and Medicaid Services, and state laws governing patient information security. Our analysis identified three clusters (which we call leaders, followers, and laggers) based on the variance of security practice patterns. The clusters have significant differences among non-technical practices rather than technical practices, and the highest level of compliance was associated with hospitals that employed a balanced approach between technical and non-technical practices (or between one-off and cultural practices). Hospitals in the highest level of compliance were significantly managing third parties' breaches and training. Audit practices were important to those who scored in the middle of the pack on compliance. Our results provide security practice benchmarks for healthcare administrators and can help policy makers in developing strategic and practical guidelines for practice adoption.

Security practices and regulatory compliance in the healthcare industry

PubMed Central

Kwon, Juhee; Johnson, M Eric

2013-01-01

Objective Securing protected health information is a critical responsibility of every healthcare organization. We explore information security practices and identify practice patterns that are associated with improved regulatory compliance. Design We employed Ward's cluster analysis using minimum variance based on the adoption of security practices. Variance between organizations was measured using dichotomous data indicating the presence or absence of each security practice. Using t tests, we identified the relationships between the clusters of security practices and their regulatory compliance. Measurement We utilized the results from the Kroll/Healthcare Information and Management Systems Society telephone-based survey of 250 US healthcare organizations including adoption status of security practices, breach incidents, and perceived compliance levels on Health Information Technology for Economic and Clinical Health, Health Insurance Portability and Accountability Act, Red Flags rules, Centers for Medicare and Medicaid Services, and state laws governing patient information security. Results Our analysis identified three clusters (which we call leaders, followers, and laggers) based on the variance of security practice patterns. The clusters have significant differences among non-technical practices rather than technical practices, and the highest level of compliance was associated with hospitals that employed a balanced approach between technical and non-technical practices (or between one-off and cultural practices). Conclusions Hospitals in the highest level of compliance were significantly managing third parties’ breaches and training. Audit practices were important to those who scored in the middle of the pack on compliance. Our results provide security practice benchmarks for healthcare administrators and can help policy makers in developing strategic and practical guidelines for practice adoption. PMID:22955497

An improved initialization center k-means clustering algorithm based on distance and density

NASA Astrophysics Data System (ADS)

Duan, Yanling; Liu, Qun; Xia, Shuyin

2018-04-01

Aiming at the problem of the random initial clustering center of k means algorithm that the clustering results are influenced by outlier data sample and are unstable in multiple clustering, a method of central point initialization method based on larger distance and higher density is proposed. The reciprocal of the weighted average of distance is used to represent the sample density, and the data sample with the larger distance and the higher density are selected as the initial clustering centers to optimize the clustering results. Then, a clustering evaluation method based on distance and density is designed to verify the feasibility of the algorithm and the practicality, the experimental results on UCI data sets show that the algorithm has a certain stability and practicality.

A pharmacist-led information technology intervention for medication errors (PINCER): a multicentre, cluster randomised, controlled trial and cost-effectiveness analysis

PubMed Central

Avery, Anthony J; Rodgers, Sarah; Cantrill, Judith A; Armstrong, Sarah; Cresswell, Kathrin; Eden, Martin; Elliott, Rachel A; Howard, Rachel; Kendrick, Denise; Morris, Caroline J; Prescott, Robin J; Swanwick, Glen; Franklin, Matthew; Putman, Koen; Boyd, Matthew; Sheikh, Aziz

2012-01-01

Summary Background Medication errors are common in primary care and are associated with considerable risk of patient harm. We tested whether a pharmacist-led, information technology-based intervention was more effective than simple feedback in reducing the number of patients at risk of measures related to hazardous prescribing and inadequate blood-test monitoring of medicines 6 months after the intervention. Methods In this pragmatic, cluster randomised trial general practices in the UK were stratified by research site and list size, and randomly assigned by a web-based randomisation service in block sizes of two or four to one of two groups. The practices were allocated to either computer-generated simple feedback for at-risk patients (control) or a pharmacist-led information technology intervention (PINCER), composed of feedback, educational outreach, and dedicated support. The allocation was masked to general practices, patients, pharmacists, researchers, and statisticians. Primary outcomes were the proportions of patients at 6 months after the intervention who had had any of three clinically important errors: non-selective non-steroidal anti-inflammatory drugs (NSAIDs) prescribed to those with a history of peptic ulcer without co-prescription of a proton-pump inhibitor; β blockers prescribed to those with a history of asthma; long-term prescription of angiotensin converting enzyme (ACE) inhibitor or loop diuretics to those 75 years or older without assessment of urea and electrolytes in the preceding 15 months. The cost per error avoided was estimated by incremental cost-effectiveness analysis. This study is registered with Controlled-Trials.com, number ISRCTN21785299. Findings 72 general practices with a combined list size of 480 942 patients were randomised. At 6 months' follow-up, patients in the PINCER group were significantly less likely to have been prescribed a non-selective NSAID if they had a history of peptic ulcer without gastroprotection (OR 0·58, 95% CI 0·38–0·89); a β blocker if they had asthma (0·73, 0·58–0·91); or an ACE inhibitor or loop diuretic without appropriate monitoring (0·51, 0·34–0·78). PINCER has a 95% probability of being cost effective if the decision-maker's ceiling willingness to pay reaches £75 per error avoided at 6 months. Interpretation The PINCER intervention is an effective method for reducing a range of medication errors in general practices with computerised clinical records. Funding Patient Safety Research Portfolio, Department of Health, England. PMID:22357106

Merging K-means with hierarchical clustering for identifying general-shaped groups.

PubMed

Peterson, Anna D; Ghosh, Arka P; Maitra, Ranjan

2018-01-01

Clustering partitions a dataset such that observations placed together in a group are similar but different from those in other groups. Hierarchical and K -means clustering are two approaches but have different strengths and weaknesses. For instance, hierarchical clustering identifies groups in a tree-like structure but suffers from computational complexity in large datasets while K -means clustering is efficient but designed to identify homogeneous spherically-shaped clusters. We present a hybrid non-parametric clustering approach that amalgamates the two methods to identify general-shaped clusters and that can be applied to larger datasets. Specifically, we first partition the dataset into spherical groups using K -means. We next merge these groups using hierarchical methods with a data-driven distance measure as a stopping criterion. Our proposal has the potential to reveal groups with general shapes and structure in a dataset. We demonstrate good performance on several simulated and real datasets.

1986 Survey of Aviation Business Operators: Their Views of FAA (Federal Aviation Administration) Airworthiness Inspectors.

DTIC Science & Technology

1987-03-01

the Central Region (ACE) had the most positive responses, followed by a clustering of the Eastern (AEA), Southern (ASO), and Southwest (ASW) Regions...OPM 41-83/WO 41-182, 1985 Washington, D.C. 2. Andreasen AR and Beat A. Consumers Complain--Does Business Respond?, Narvgrd 6ULLDM Reviw , M:98-1O1...by a bureaucracy that is more Intent on being legally correct than they are on addressing problems In practical terms." K . GENERAL NEGATIVE

Evaluation of different recruitment and randomisation methods in a trial of general practitioner-led interventions to increase physical activity: a randomised controlled feasibility study with factorial design

PubMed Central

2014-01-01

Background Interventions promoting physical activity by General Practitioners (GPs) lack a strong evidence base. Recruiting participants to trials in primary care is challenging. We investigated the feasibility of (i) delivering three interventions to promote physical activity in inactive participants and (ii) different methods of participant recruitment and randomised allocation. Methods We recruited general practices from Devon, Bristol and Coventry. We used a 2-by-2 factorial design for participant recruitment and randomisation. Recruitment strategies were either opportunistic (approaching patients attending their GP surgery) or systematic (selecting patients from practice lists and approaching them by letter). Randomisation strategies were either individual or by practice cluster. Feasibility outcomes included time taken to recruit the target number of participants within each practice. Participants were randomly allocated to one of three interventions: (i) written advice (control); (ii) brief GP advice (written advice plus GP advice on physical activity), and (iii) brief GP advice plus a pedometer to self-monitor physical activity during the trial. Participants allocated to written advice or brief advice each received a sealed pedometer to record their physical activity, and were instructed not to unseal the pedometer before the scheduled day of data collection. Participant level outcomes were reported descriptively and included the mean number of pedometer steps over a 7-day period, and European Quality of Life (EuroQoL)-5 dimensions (EQ-5D) scores, recorded at 12 weeks’ follow-up. Results We recruited 24 practices (12 using each recruitment method; 18 randomising by cluster, 6 randomising by individual participant), encompassing 131 participants. Opportunistic recruitment was associated with less time to target recruitment compared with systematic (mean difference (days) -54.9, 95% confidence interval (CI) -103.6; -6.2) but with greater loss to follow up (28.8% versus. 6.9%; mean difference 21.9% (95% CI 9.6%; 34.1%)). There were differences in the socio-demographic characteristics of participants according to recruitment method. There was no clear pattern of change in participant level outcomes from baseline to 12 weeks across the three arms. Conclusions Delivering and trialling GP-led interventions to promote physical activity is feasible, but trial design influences time to participant recruitment, participant withdrawal, and possibly, the socio-demographic characteristics of participants. Trial registration number ISRCTN73725618. PMID:24746263

A pharmacist-led information technology intervention for medication errors (PINCER): a multicentre, cluster randomised, controlled trial and cost-effectiveness analysis.

PubMed

Avery, Anthony J; Rodgers, Sarah; Cantrill, Judith A; Armstrong, Sarah; Cresswell, Kathrin; Eden, Martin; Elliott, Rachel A; Howard, Rachel; Kendrick, Denise; Morris, Caroline J; Prescott, Robin J; Swanwick, Glen; Franklin, Matthew; Putman, Koen; Boyd, Matthew; Sheikh, Aziz

2012-04-07

Medication errors are common in primary care and are associated with considerable risk of patient harm. We tested whether a pharmacist-led, information technology-based intervention was more effective than simple feedback in reducing the number of patients at risk of measures related to hazardous prescribing and inadequate blood-test monitoring of medicines 6 months after the intervention. In this pragmatic, cluster randomised trial general practices in the UK were stratified by research site and list size, and randomly assigned by a web-based randomisation service in block sizes of two or four to one of two groups. The practices were allocated to either computer-generated simple feedback for at-risk patients (control) or a pharmacist-led information technology intervention (PINCER), composed of feedback, educational outreach, and dedicated support. The allocation was masked to researchers and statisticians involved in processing and analysing the data. The allocation was not masked to general practices, pharmacists, patients, or researchers who visited practices to extract data. [corrected]. Primary outcomes were the proportions of patients at 6 months after the intervention who had had any of three clinically important errors: non-selective non-steroidal anti-inflammatory drugs (NSAIDs) prescribed to those with a history of peptic ulcer without co-prescription of a proton-pump inhibitor; β blockers prescribed to those with a history of asthma; long-term prescription of angiotensin converting enzyme (ACE) inhibitor or loop diuretics to those 75 years or older without assessment of urea and electrolytes in the preceding 15 months. The cost per error avoided was estimated by incremental cost-effectiveness analysis. This study is registered with Controlled-Trials.com, number ISRCTN21785299. 72 general practices with a combined list size of 480,942 patients were randomised. At 6 months' follow-up, patients in the PINCER group were significantly less likely to have been prescribed a non-selective NSAID if they had a history of peptic ulcer without gastroprotection (OR 0·58, 95% CI 0·38-0·89); a β blocker if they had asthma (0·73, 0·58-0·91); or an ACE inhibitor or loop diuretic without appropriate monitoring (0·51, 0·34-0·78). PINCER has a 95% probability of being cost effective if the decision-maker's ceiling willingness to pay reaches £75 per error avoided at 6 months. The PINCER intervention is an effective method for reducing a range of medication errors in general practices with computerised clinical records. Patient Safety Research Portfolio, Department of Health, England. Copyright © 2012 Elsevier Ltd. All rights reserved.

Customized recommendations for production management clusters of North American automatic milking systems.

PubMed

Tremblay, Marlène; Hess, Justin P; Christenson, Brock M; McIntyre, Kolby K; Smink, Ben; van der Kamp, Arjen J; de Jong, Lisanne G; Döpfer, Dörte

2016-07-01

Automatic milking systems (AMS) are implemented in a variety of situations and environments. Consequently, there is a need to characterize individual farming practices and regional challenges to streamline management advice and objectives for producers. Benchmarking is often used in the dairy industry to compare farms by computing percentile ranks of the production values of groups of farms. Grouping for conventional benchmarking is commonly limited to the use of a few factors such as farms' geographic region or breed of cattle. We hypothesized that herds' production data and management information could be clustered in a meaningful way using cluster analysis and that this clustering approach would yield better peer groups of farms than benchmarking methods based on criteria such as country, region, breed, or breed and region. By applying mixed latent-class model-based cluster analysis to 529 North American AMS dairy farms with respect to 18 significant risk factors, 6 clusters were identified. Each cluster (i.e., peer group) represented unique management styles, challenges, and production patterns. When compared with peer groups based on criteria similar to the conventional benchmarking standards, the 6 clusters better predicted milk produced (kilograms) per robot per day. Each cluster represented a unique management and production pattern that requires specialized advice. For example, cluster 1 farms were those that recently installed AMS robots, whereas cluster 3 farms (the most northern farms) fed high amounts of concentrates through the robot to compensate for low-energy feed in the bunk. In addition to general recommendations for farms within a cluster, individual farms can generate their own specific goals by comparing themselves to farms within their cluster. This is very comparable to benchmarking but adds the specific characteristics of the peer group, resulting in better farm management advice. The improvement that cluster analysis allows for is characterized by the multivariable approach and the fact that comparisons between production units can be accomplished within a cluster and between clusters as a choice. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Low attendance at structured education for people with newly diagnosed type 2 diabetes: General practice characteristics and individual patient factors predict uptake.

PubMed

Winkley, Kirsty; Stahl, Daniel; Chamley, Mark; Stopford, Rosanna; Boughdady, Monica; Thomas, Stephen; Amiel, Stephanie A; Forbes, Angus; Ismail, Khalida

2016-01-01

The aims were to determine the association between individual and neighbourhood factors and attendance at structured education amongst people with newly diagnosed type 2 diabetes (T2DM). Multi-level analysis of questionnaire data from a prospective cohort of adults newly diagnosed T2DM. Setting was primary care, London, UK. Main outcome was attendance at structured education within 2 years. Of 1790 people recruited, attendance data were available for 1626 (91%). Only 22.4% (n=365/1626) attended education. Attendance was independently associated with female gender (OR 1.28, 95% CI 1.05-1.46), lower HbA1c (OR 0.98 mmol/mol 95% CI 0.97-0.99) and non-smoker status (OR 1.36, 95% CI 1.07-1.55). General practice covariates, achievement of primary care targets for glycaemic control (OR 1.05, 95% C.I. 1.01-1.08) and recording of retinal screening (OR 0.96, 95% C.I. 0.93-0.99) were independently associated with attendance but unexplained general practice clustering accounted for 17% of the variance. Education uptake is low amongst people with new onset T2DM. Attenders are more likely to be female, non-smokers with better HbA1c. General practices achieving glycaemic targets are more likely to have patients who attend education. Strategies are needed to improve attendance at structured diabetes education particularly amongst hard to reach groups. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Finite-sample corrected generalized estimating equation of population average treatment effects in stepped wedge cluster randomized trials.

PubMed

Scott, JoAnna M; deCamp, Allan; Juraska, Michal; Fay, Michael P; Gilbert, Peter B

2017-04-01

Stepped wedge designs are increasingly commonplace and advantageous for cluster randomized trials when it is both unethical to assign placebo, and it is logistically difficult to allocate an intervention simultaneously to many clusters. We study marginal mean models fit with generalized estimating equations for assessing treatment effectiveness in stepped wedge cluster randomized trials. This approach has advantages over the more commonly used mixed models that (1) the population-average parameters have an important interpretation for public health applications and (2) they avoid untestable assumptions on latent variable distributions and avoid parametric assumptions about error distributions, therefore, providing more robust evidence on treatment effects. However, cluster randomized trials typically have a small number of clusters, rendering the standard generalized estimating equation sandwich variance estimator biased and highly variable and hence yielding incorrect inferences. We study the usual asymptotic generalized estimating equation inferences (i.e., using sandwich variance estimators and asymptotic normality) and four small-sample corrections to generalized estimating equation for stepped wedge cluster randomized trials and for parallel cluster randomized trials as a comparison. We show by simulation that the small-sample corrections provide improvement, with one correction appearing to provide at least nominal coverage even with only 10 clusters per group. These results demonstrate the viability of the marginal mean approach for both stepped wedge and parallel cluster randomized trials. We also study the comparative performance of the corrected methods for stepped wedge and parallel designs, and describe how the methods can accommodate interval censoring of individual failure times and incorporate semiparametric efficient estimators.

Mental workload and motor performance dynamics during practice of reaching movements under various levels of task difficulty.

PubMed

Shuggi, Isabelle M; Oh, Hyuk; Shewokis, Patricia A; Gentili, Rodolphe J

2017-09-30

The assessment of mental workload can inform attentional resource allocation during task performance that is essential for understanding the underlying principles of human cognitive-motor behavior. While many studies have focused on mental workload in relation to human performance, a modest body of work has examined it in a motor practice/learning context without considering individual variability. Thus, this work aimed to examine mental workload by employing the NASA TLX as well as the changes in motor performance resulting from the practice of a novel reaching task. Two groups of participants practiced a reaching task at a high and low nominal difficulty during which a group-level analysis assessed the mental workload, motor performance and motor improvement dynamics. A secondary cluster analysis was also conducted to identify specific individual patterns of cognitive-motor responses. Overall, both group- and cluster-level analyses revealed that: (i) all participants improved their performance throughout motor practice, and (ii) an increase in mental workload was associated with a reduction of the quality of motor performance along with a slower rate of motor improvement. The results are discussed in the context of the optimal challenge point framework and in particular it is proposed that under the experimental conditions employed here, functional task difficulty: (i) would possibly depend on an individuals' information processing capabilities, and (ii) could be indexed by the level of mental workload which, when excessively heightened can decrease the quality of performance and more generally result in delayed motor improvements. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Efficient algorithms for accurate hierarchical clustering of huge datasets: tackling the entire protein space.

PubMed

Loewenstein, Yaniv; Portugaly, Elon; Fromer, Menachem; Linial, Michal

2008-07-01

UPGMA (average linking) is probably the most popular algorithm for hierarchical data clustering, especially in computational biology. However, UPGMA requires the entire dissimilarity matrix in memory. Due to this prohibitive requirement, UPGMA is not scalable to very large datasets. We present a novel class of memory-constrained UPGMA (MC-UPGMA) algorithms. Given any practical memory size constraint, this framework guarantees the correct clustering solution without explicitly requiring all dissimilarities in memory. The algorithms are general and are applicable to any dataset. We present a data-dependent characterization of hardness and clustering efficiency. The presented concepts are applicable to any agglomerative clustering formulation. We apply our algorithm to the entire collection of protein sequences, to automatically build a comprehensive evolutionary-driven hierarchy of proteins from sequence alone. The newly created tree captures protein families better than state-of-the-art large-scale methods such as CluSTr, ProtoNet4 or single-linkage clustering. We demonstrate that leveraging the entire mass embodied in all sequence similarities allows to significantly improve on current protein family clusterings which are unable to directly tackle the sheer mass of this data. Furthermore, we argue that non-metric constraints are an inherent complexity of the sequence space and should not be overlooked. The robustness of UPGMA allows significant improvement, especially for multidomain proteins, and for large or divergent families. A comprehensive tree built from all UniProt sequence similarities, together with navigation and classification tools will be made available as part of the ProtoNet service. A C++ implementation of the algorithm is available on request.

An efficient and scalable graph modeling approach for capturing information at different levels in next generation sequencing reads

PubMed Central

2013-01-01

Background Next generation sequencing technologies have greatly advanced many research areas of the biomedical sciences through their capability to generate massive amounts of genetic information at unprecedented rates. The advent of next generation sequencing has led to the development of numerous computational tools to analyze and assemble the millions to billions of short sequencing reads produced by these technologies. While these tools filled an important gap, current approaches for storing, processing, and analyzing short read datasets generally have remained simple and lack the complexity needed to efficiently model the produced reads and assemble them correctly. Results Previously, we presented an overlap graph coarsening scheme for modeling read overlap relationships on multiple levels. Most current read assembly and analysis approaches use a single graph or set of clusters to represent the relationships among a read dataset. Instead, we use a series of graphs to represent the reads and their overlap relationships across a spectrum of information granularity. At each information level our algorithm is capable of generating clusters of reads from the reduced graph, forming an integrated graph modeling and clustering approach for read analysis and assembly. Previously we applied our algorithm to simulated and real 454 datasets to assess its ability to efficiently model and cluster next generation sequencing data. In this paper we extend our algorithm to large simulated and real Illumina datasets to demonstrate that our algorithm is practical for both sequencing technologies. Conclusions Our overlap graph theoretic algorithm is able to model next generation sequencing reads at various levels of granularity through the process of graph coarsening. Additionally, our model allows for efficient representation of the read overlap relationships, is scalable for large datasets, and is practical for both Illumina and 454 sequencing technologies. PMID:24564333

The Ontario printed educational message (OPEM) trial to narrow the evidence-practice gap with respect to prescribing practices of general and family physicians: a cluster randomized controlled trial, targeting the care of individuals with diabetes and hypertension in Ontario, Canada

PubMed Central

Zwarenstein, Merrick; Hux, Janet E; Kelsall, Diane; Paterson, Michael; Grimshaw, Jeremy; Davis, Dave; Laupacis, Andreas; Evans, Michael; Austin, Peter C; Slaughter, Pamela M; Shiller, Susan K; Croxford, Ruth; Tu, Karen

2007-01-01

Background There are gaps between what family practitioners do in clinical practice and the evidence-based ideal. The most commonly used strategy to narrow these gaps is the printed educational message (PEM); however, the attributes of successful printed educational messages and their overall effectiveness in changing physician practice are not clear. The current endeavor aims to determine whether such messages change prescribing quality in primary care practice, and whether these effects differ with the format of the message. Methods/design The design is a large, simple, factorial, unblinded cluster-randomized controlled trial. PEMs will be distributed with informed, a quarterly evidence-based synopsis of current clinical information produced by the Institute for Clinical Evaluative Sciences, Toronto, Canada, and will be sent to all eligible general and family practitioners in Ontario. There will be three replicates of the trial, with three different educational messages, each aimed at narrowing a specific evidence-practice gap as follows: 1) angiotensin-converting enzyme inhibitors, hypertension treatment, and cholesterol lowering agents for diabetes; 2) retinal screening for diabetes; and 3) diuretics for hypertension. For each of the three replicates there will be three intervention groups. The first group will receive informed with an attached postcard-sized, short, directive "outsert." The second intervention group will receive informed with a two-page explanatory "insert" on the same topic. The third intervention group will receive informed, with both the above-mentioned outsert and insert. The control group will receive informed only, without either an outsert or insert. Routinely collected physician billing, prescription, and hospital data found in Ontario's administrative databases will be used to monitor pre-defined prescribing changes relevant and specific to each replicate, following delivery of the educational messages. Multi-level modeling will be used to study patterns in physician-prescribing quality over four quarters, before and after each of the three interventions. Subgroup analyses will be performed to assess the association between the characteristics of the physician's place of practice and target behaviours. A further analysis of the immediate and delayed impacts of the PEMs will be performed using time-series analysis and interventional, auto-regressive, integrated moving average modeling. Trial registration number Current controlled trial ISRCTN72772651. PMID:18039361

Using Cluster Bootstrapping to Analyze Nested Data with a Few Clusters

ERIC Educational Resources Information Center

Huang, Francis L.

2018-01-01

Cluster randomized trials involving participants nested within intact treatment and control groups are commonly performed in various educational, psychological, and biomedical studies. However, recruiting and retaining intact groups present various practical, financial, and logistical challenges to evaluators and often, cluster randomized trials…

The Diabetes Care Project: an Australian multicentre, cluster randomised controlled trial [study protocol].

PubMed

Leach, Matthew J; Segal, Leonie; Esterman, Adrian; Armour, Caroline; McDermott, Robyn; Fountaine, Tim

2013-12-20

Diabetes mellitus is an increasingly prevalent metabolic disorder that is associated with substantial disease burden. Australia has an opportunity to improve ways of caring for the growing number of people with diabetes, but this may require changes to the way care is funded, organised and delivered. To inform how best to care for people with diabetes, and to identify the extent of change that is required to achieve this, the Diabetes Care Project (DCP) will evaluate the impact of two different, evidence-based models of care (compared to usual care) on clinical quality, patient and provider experience, and cost. The DCP uses a pragmatic, cluster randomised controlled trial design. Accredited general practices that are situated within any of the seven Australian Medicare Locals/Divisions of General Practice that have agreed to take part in the study were invited to participate. Consenting practices will be randomly assigned to one of three treatment groups for approximately 18 to 22 months: (a) control group (usual care); (b) Intervention 1 (which tests improvements that could be made within the current funding model, facilitated through the use of an online chronic disease management network); or (c) Intervention 2 (which includes the same components as Intervention 1, as well as altered funding to support voluntary patient registration with their practice, incentive payments and a care facilitator). Adult patients who attend the enrolled practices and have established (≥12 month's duration) type 1 diabetes mellitus or newly diagnosed or established type 2 diabetes mellitus are invited to participate. Multiple outcomes will be studied, including changes in glycosylated haemoglobin (primary outcome), changes in other biochemical and clinical metrics, incidence of diabetes-related complications, quality of life, clinical depression, success of tailored care, patient and practitioner satisfaction, and budget sustainability. This project responds to a need for robust evidence of the clinical and economic effectiveness of coordinated care for the management of diabetes in the Australian primary care setting. The outcomes of the study will have implications not only for diabetes management, but also for the management of other chronic diseases, both in Australia and overseas. Australian New Zealand Clinical Trials Registry (ACTRN12612000363886); World Health Organisation (U1111-1128-0481).

Predictive risk stratification model: a progressive cluster-randomised trial in chronic conditions management (PRISMATIC) research protocol

PubMed Central

2013-01-01

Background An ageing population increases demand on health and social care. New approaches are needed to shift care from hospital to community and general practice. A predictive risk stratification tool (Prism) has been developed for general practice that estimates risk of an emergency hospital admission in the following year. We present a protocol for the evaluation of Prism. Methods/Design We will undertake a mixed methods progressive cluster-randomised trial. Practices begin as controls, delivering usual care without Prism. Practices will receive Prism and training randomly, and thereafter be able to use Prism with clinical and technical support. We will compare costs, processes of care, satisfaction and patient outcomes at baseline, 6 and 18 months, using routine data and postal questionnaires. We will assess technical performance by comparing predicted against actual emergency admissions. Focus groups and interviews will be undertaken to understand how Prism is perceived and adopted by practitioners and policy makers. We will model data using generalised linear models and survival analysis techniques to determine whether any differences exist between intervention and control groups. We will take account of covariates and explanatory factors. In the economic evaluation we will carry out a cost-effectiveness analysis to examine incremental cost per emergency admission to hospital avoided and will examine costs versus changes in primary and secondary outcomes in a cost-consequence analysis. We will also examine changes in quality of life of patients across the risk spectrum. We will record and transcribe focus groups and interviews and analyse them thematically. We have received full ethical and R&D approvals for the study and Information Governance Review Panel (IGRP) permission for the use of routine data. We will comply with the CONSORT guidelines and will disseminate the findings at national and international conferences and in peer-reviewed journals. Discussion The proposed study will provide information on costs and effects of Prism; how it is used in practice, barriers and facilitators to its implementation; and its perceived value in supporting the management of patients with and at risk of developing chronic conditions. Trial registration Controlled Clinical Trials ISRCTN no. ISRCTN55538212. PMID:24330749

The Psychology of Yoga Practitioners: A Cluster Analysis.

PubMed

Genovese, Jeremy E C; Fondran, Kristine M

2017-11-01

Yoga practitioners (N = 261) completed the revised Expression of Spirituality Inventory (ESI) and the Multidimensional Body-Self Relations Questionnaire. Cluster analysis revealed three clusters: Cluster A scored high on all four spiritual constructs. They had high positive evaluations of their appearance, but a lower orientation towards their appearance. They tended to have a high evaluation of their fitness and health, and higher body satisfaction. Cluster B showed lower scores on the spiritual constructs. Like Cluster A, members of Cluster B tended to show high positive evaluations of appearance and fitness. They also had higher body satisfaction. Members of Cluster B had a higher fitness orientation and a higher appearance orientation than members of Cluster A. Members of Cluster C had low scores for all spiritual constructs. They had a low evaluation of, and unhappiness with, their appearance. They were unhappy with the size and appearance of their bodies. They tended to see themselves as overweight. There was a significant difference in years of practice between the three groups (Kruskall -Wallis, p = .0041). Members of Cluster A have the most years of yoga experience and members of Cluster B have more yoga experience than members of Cluster C. These results suggest the possible existence of a developmental trajectory for yoga practitioners. Such a developmental sequence may have important implications for yoga practice and instruction.

The Psychology of Yoga Practitioners: A Cluster Analysis.

PubMed

Genovese, Jeremy E C; Fondran, Kristine M

2017-03-30

Yoga practitioners (N = 261) completed the revised Expression of Spirituality Inventory (ESI) and the Multidimensional Body-Self Relations Questionnaire. Cluster analysis revealed three clusters: Cluster A scored high on all four spiritual constructs. They had high positive evaluations of their appearance, but a lower orientation towards their appearance. They tended to have a high evaluation of their fitness and health, and higher body satisfaction. Cluster B showed lower scores on the spiritual constructs. Like Cluster A, members of Cluster B tended to show high positive evaluations of appearance and fitness. They also had higher body satisfaction. Members of Cluster B had a higher fitness orientation and a higher appearance orientation than members of Cluster A. Members of Cluster C had low scores for all spiritual constructs. They had a low evaluation of, and unhappiness with, their appearance. They were unhappy with the size and appearance of their bodies. They tended to see themselves as overweight. There was a significant difference in years of practice between the three groups (Kruskall-Wallis, p = .0041). Members of Cluster A have the most years of yoga experience and members of Cluster B have more yoga experience than members of Cluster C. These results suggest the possible existence of a developmental trajectory for yoga practitioners. Such a developmental sequence may have important implications for yoga practice and instruction.

Description and process evaluation of pharmacists' interventions in a pharmacist-led information technology-enabled multicentre cluster randomised controlled trial for reducing medication errors in general practice (PINCER trial).

PubMed

Howard, Rachel; Rodgers, Sarah; Avery, Anthony J; Sheikh, Aziz

2014-02-01

To undertake a process evaluation of pharmacists' recommendations arising in the context of a complex IT-enabled pharmacist-delivered randomised controlled trial (PINCER trial) to reduce the risk of hazardous medicines management in general practices. PINCER pharmacists manually recorded patients' demographics, details of interventions recommended, actions undertaken by practice staff and time taken to manage individual cases of hazardous medicines management. Data were coded, double-entered into SPSS version 15 and then summarised using percentages for categorical data (with 95% confidence interval (CI)) and, as appropriate, means (± standard deviation) or medians (interquartile range) for continuous data. Pharmacists spent a median of 20 min (interquartile range 10, 30) reviewing medical records, recommending interventions and completing actions in each case of hazardous medicines management. Pharmacists judged 72% (95% CI 70, 74; 1463/2026) of cases of hazardous medicines management to be clinically relevant. Pharmacists recommended 2105 interventions in 74% (95% CI 73, 76; 1516/2038) of cases and 1685 actions were taken in 61% (95% CI 59, 63; 1246/2038) of cases; 66% (95% CI 64, 68; 1383/2105) of interventions recommended by pharmacists were completed and 5% (95% CI 4, 6; 104/2105) of recommendations were accepted by general practitioners (GPs), but not completed at the end of the pharmacists' placement; the remaining recommendations were rejected or considered not relevant by GPs. The outcome measures were used to target pharmacist activity in general practice towards patients at risk from hazardous medicines management. Recommendations from trained PINCER pharmacists were found to be broadly acceptable to GPs and led to ameliorative action in the majority of cases. It seems likely that the approach used by the PINCER pharmacists could be employed by other practice pharmacists following appropriate training. © 2013 The Authors. International Journal of Pharmacy Practice published by John Wiley & Sons Ltd on behalf of Royal Pharmaceutical Society.

Dietary patterns in middle-aged Irish men and women defined by cluster analysis.

PubMed

Villegas, R; Salim, A; Collins, M M; Flynn, A; Perry, I J

2004-12-01

To identify and characterise dietary patterns in a middle-aged Irish population sample and study associations between these patterns, sociodemographic and anthropometric variables and major risk factors for cardiovascular disease. A cross-sectional study. A group of 1473 men and women were sampled from 17 general practice lists in the South of Ireland. A total of 1018 attended for screening, with a response rate of 69%. Participants completed a detailed health and lifestyle questionnaire and provided a fasting blood sample for glucose, lipids and homocysteine. Dietary intake was assessed using a standard food-frequency questionnaire adapted for use in the Irish population. The food-frequency questionnaire was a modification of that used in the UK arm of the European Prospective Investigation into Cancer study, which was based on that used in the US Nurses' Health Study. Dietary patterns were assessed primarily by K-means cluster analysis, following initial principal components analysis to identify the seeds. Three dietary patterns were identified. These clusters corresponded to a traditional Irish diet, a prudent diet and a diet characterised by high consumption of alcoholic drinks and convenience foods. Cluster 1 (Traditional Diet) had the highest intakes of saturated fat (SFA), monounsaturated fat (MUFA) and percentage of total energy from fat, and the lowest polyunsaturated fat (PUFA) intake and ratio of polyunsaturated to saturated fat (P:S). Cluster 2 (Prudent Diet) was characterised by significantly higher intakes of fibre, PUFA, P:S ratio and antioxidant vitamins (vitamins C and E), and lower intakes of total fat, MUFA, SFA and cholesterol. Cluster 3 (Alcohol & Convenience Foods) had the highest intakes of alcohol, protein, cholesterol, vitamin B(12), vitamin B(6), folate, iron, phosphorus, selenium and zinc, and the lowest intakes of PUFA, vitamin A and antioxidant vitamins (vitamins C and E). There were significant differences between clusters in gender distribution, smoking status, physical activity, body mass index, waist circumference and serum homocysteine concentrations. In this general population sample, cluster analysis methods yielded two major dietary patterns: prudent and traditional. The prudent dietary pattern is associated with other health-seeking behaviours. Study of dietary patterns will help elucidate links between diet and disease and contribute to the development of healthy eating guidelines for health promotion.

Predicting declines in perceived relationship continuity using practice deprivation scores: a longitudinal study in primary care.

PubMed

Levene, Louis S; Baker, Richard; Walker, Nicola; Williams, Christopher; Wilson, Andrew; Bankart, John

2018-06-01

Increased relationship continuity in primary care is associated with better health outcomes, greater patient satisfaction, and fewer hospital admissions. Greater socioeconomic deprivation is associated with lower levels of continuity, as well as poorer health outcomes. To investigate whether deprivation scores predicted variations in the decline over time of patient-perceived relationship continuity of care, after adjustment for practice organisational and population factors. An observational study in 6243 primary care practices with more than one GP, in England, using a longitudinal multilevel linear model, 2012-2017 inclusive. Patient-perceived relationship continuity was calculated using two questions from the GP Patient Survey. The effect of deprivation on the linear slope of continuity over time was modelled, adjusting for nine confounding variables (practice population and organisational factors). Clustering of measurements within general practices was adjusted for by using a random intercepts and random slopes model. Descriptive statistics and univariable analyses were also undertaken. Relationship continuity declined by 27.5% between 2012 and 2017, and at all deprivation levels. Deprivation scores from 2012 did not predict variations in the decline of relationship continuity at practice level, after accounting for the effects of organisational and population confounding variables, which themselves did not predict, or weakly predicted with very small effect sizes, the decline of continuity. Cross-sectionally, continuity and deprivation were negatively correlated within each year. The decline in relationship continuity of care has been marked and widespread. Measures to maximise continuity will need to be feasible for individual practices with diverse population and organisational characteristics. © British Journal of General Practice 2018.

Multiconstrained gene clustering based on generalized projections

PubMed Central

2010-01-01

Background Gene clustering for annotating gene functions is one of the fundamental issues in bioinformatics. The best clustering solution is often regularized by multiple constraints such as gene expressions, Gene Ontology (GO) annotations and gene network structures. How to integrate multiple pieces of constraints for an optimal clustering solution still remains an unsolved problem. Results We propose a novel multiconstrained gene clustering (MGC) method within the generalized projection onto convex sets (POCS) framework used widely in image reconstruction. Each constraint is formulated as a corresponding set. The generalized projector iteratively projects the clustering solution onto these sets in order to find a consistent solution included in the intersection set that satisfies all constraints. Compared with previous MGC methods, POCS can integrate multiple constraints from different nature without distorting the original constraints. To evaluate the clustering solution, we also propose a new performance measure referred to as Gene Log Likelihood (GLL) that considers genes having more than one function and hence in more than one cluster. Comparative experimental results show that our POCS-based gene clustering method outperforms current state-of-the-art MGC methods. Conclusions The POCS-based MGC method can successfully combine multiple constraints from different nature for gene clustering. Also, the proposed GLL is an effective performance measure for the soft clustering solutions. PMID:20356386

Five task clusters that enable efficient and effective digitization of biological collections

PubMed Central

Nelson, Gil; Paul, Deborah; Riccardi, Gregory; Mast, Austin R.

2012-01-01

Abstract This paper describes and illustrates five major clusters of related tasks (herein referred to as task clusters) that are common to efficient and effective practices in the digitization of biological specimen data and media. Examples of these clusters come from the observation of diverse digitization processes. The staff of iDigBio (The U.S. National Science Foundation’s National Resource for Advancing Digitization of Biological Collections) visited active biological and paleontological collections digitization programs for the purpose of documenting and assessing current digitization practices and tools. These observations identified five task clusters that comprise the digitization process leading up to data publication: (1) pre-digitization curation and staging, (2) specimen image capture, (3) specimen image processing, (4) electronic data capture, and (5) georeferencing locality descriptions. While not all institutions are completing each of these task clusters for each specimen, these clusters describe a composite picture of digitization of biological and paleontological specimens across the programs that were observed. We describe these clusters, three workflow patterns that dominate the implemention of these clusters, and offer a set of workflow recommendations for digitization programs. PMID:22859876

Implementation of a guideline for low back pain management in primary care: a cost-effectiveness analysis.

PubMed

Becker, Annette; Held, Heiko; Redaelli, Marcus; Chenot, Jean F; Leonhardt, Corinna; Keller, Stefan; Baum, Erika; Pfingsten, Michael; Hildebrandt, Jan; Basler, Heinz-Dieter; Kochen, Michael M; Donner-Banzhoff, Norbert; Strauch, Konstantin

2012-04-15

Cost-effectiveness analysis alongside a cluster randomized controlled trial. To study the cost-effectiveness of 2 low back pain guideline implementation (GI) strategies. Several evidence-based guidelines on management of low back pain have been published. However, there is still no consensus on the effective implementation strategy. Especially studies on the economic impact of different implementation strategies are lacking. This analysis was performed alongside a cluster randomized controlled trial on the effectiveness of 2 GI strategies (physician education alone [GI] or physician education in combination with motivational counseling [MC] by practice nurses)--both compared with the postal dissemination of the guideline (control group, C). Sociodemographic data, pain characteristics, and cost data were collected by interview at baseline and after 6 and 12 months. low back pain-related health care costs were valued for 2004 from the societal perspective. For the cost analysis, 1322 patients from 126 general practices were included. Both interventions showed lower direct and indirect costs as well as better patient outcomes during follow-up compared with controls. In addition, both intervention arms showed superiority of cost-effectiveness to C. The effects attenuated when adjusting for differences of health care utilization prior to patient recruitment and for clustering of data. Trends in cost-effectiveness are visible but need to be confirmed in future studies. Researchers performing cost-evaluation studies should test for baseline imbalances of health care utilization data instead of judging on the randomization success by reviewing non-cost parameters like clinical data alone.

A generalized analysis of hydrophobic and loop clusters within globular protein sequences

PubMed Central

Eudes, Richard; Le Tuan, Khanh; Delettré, Jean; Mornon, Jean-Paul; Callebaut, Isabelle

2007-01-01

Background Hydrophobic Cluster Analysis (HCA) is an efficient way to compare highly divergent sequences through the implicit secondary structure information directly derived from hydrophobic clusters. However, its efficiency and application are currently limited by the need of user expertise. In order to help the analysis of HCA plots, we report here the structural preferences of hydrophobic cluster species, which are frequently encountered in globular domains of proteins. These species are characterized only by their hydrophobic/non-hydrophobic dichotomy. This analysis has been extended to loop-forming clusters, using an appropriate loop alphabet. Results The structural behavior of hydrophobic cluster species, which are typical of protein globular domains, was investigated within banks of experimental structures, considered at different levels of sequence redundancy. The 294 more frequent hydrophobic cluster species were analyzed with regard to their association with the different secondary structures (frequencies of association with secondary structures and secondary structure propensities). Hydrophobic cluster species are predominantly associated with regular secondary structures, and a large part (60 %) reveals preferences for α-helices or β-strands. Moreover, the analysis of the hydrophobic cluster amino acid composition generally allows for finer prediction of the regular secondary structure associated with the considered cluster within a cluster species. We also investigated the behavior of loop forming clusters, using a "PGDNS" alphabet. These loop clusters do not overlap with hydrophobic clusters and are highly associated with coils. Finally, the structural information contained in the hydrophobic structural words, as deduced from experimental structures, was compared to the PSI-PRED predictions, revealing that β-strands and especially α-helices are generally over-predicted within the limits of typical β and α hydrophobic clusters. Conclusion The dictionary of hydrophobic clusters described here can help the HCA user to interpret and compare the HCA plots of globular protein sequences, as well as provides an original fundamental insight into the structural bricks of protein folds. Moreover, the novel loop cluster analysis brings additional information for secondary structure prediction on the whole sequence through a generalized cluster analysis (GCA), and not only on regular secondary structures. Such information lays the foundations for developing a new and original tool for secondary structure prediction. PMID:17210072

Spatial distribution of clinical computer systems in primary care in England in 2016 and implications for primary care electronic medical record databases: a cross-sectional population study.

PubMed

Kontopantelis, Evangelos; Stevens, Richard John; Helms, Peter J; Edwards, Duncan; Doran, Tim; Ashcroft, Darren M

2018-02-28

UK primary care databases (PCDs) are used by researchers worldwide to inform clinical practice. These databases have been primarily tied to single clinical computer systems, but little is known about the adoption of these systems by primary care practices or their geographical representativeness. We explore the spatial distribution of clinical computing systems and discuss the implications for the longevity and regional representativeness of these resources. Cross-sectional study. English primary care clinical computer systems. 7526 general practices in August 2016. Spatial mapping of family practices in England in 2016 by clinical computer system at two geographical levels, the lower Clinical Commissioning Group (CCG, 209 units) and the higher National Health Service regions (14 units). Data for practices included numbers of doctors, nurses and patients, and area deprivation. Of 7526 practices, Egton Medical Information Systems (EMIS) was used in 4199 (56%), SystmOne in 2552 (34%) and Vision in 636 (9%). Great regional variability was observed for all systems, with EMIS having a stronger presence in the West of England, London and the South; SystmOne in the East and some regions in the South; and Vision in London, the South, Greater Manchester and Birmingham. PCDs based on single clinical computer systems are geographically clustered in England. For example, Clinical Practice Research Datalink and The Health Improvement Network, the most popular primary care databases in terms of research outputs, are based on the Vision clinical computer system, used by <10% of practices and heavily concentrated in three major conurbations and the South. Researchers need to be aware of the analytical challenges posed by clustering, and barriers to accessing alternative PCDs need to be removed. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Preventing chronic disease in patients with low health literacy using eHealth and teamwork in primary healthcare: protocol for a cluster randomised controlled trial

PubMed Central

Parker, Sharon M; Stocks, Nigel; Nutbeam, Don; Thomas, Louise; Denney-Wilson, Elizabeth; Zwar, Nicholas; Karnon, Jon; Lloyd, Jane; Noakes, Manny; Lau, Annie; Osborne, Richard

2018-01-01

Introduction Adults with lower levels of health literacy are less likely to engage in health-promoting behaviours. Our trial evaluates the impacts and outcomes of a mobile health-enhanced preventive intervention in primary care for people who are overweight or obese. Methods and analysis A two-arm pragmatic practice-level cluster randomised trial will be conducted in 40 practices in low socioeconomic areas in Sydney and Adelaide, Australia. Forty patients aged 40–70 years with a body mass index ≥28 kg/m2 will be enrolled per practice. The HeLP-general practitioner (GP) intervention includes a practice-level quality improvement intervention (medical record audit and feedback, staff training and practice facilitation visits) to support practices to implement the clinical intervention for patients. The clinical intervention involves a health check visit with a practice nurse based on the 5As framework (assess, advise, agree, assist and arrange), the use of a purpose-built patient-facing app, my snapp, and referral for telephone coaching. The primary outcomes are change in health literacy, lifestyle behaviours, weight, waist circumference and blood pressure. The study will also evaluate changes in quality of life and health service use to determine the cost-effectiveness of the intervention and examine the experiences of practices in implementing the programme. Ethics and dissemination The study has been approved by the University of New South Wales (UNSW) Human Research Ethics Committee (HC17474) and ratified by the University of Adelaide Human Research Ethics committee. There are no restrictions on publication, and findings of the study will be made available to the public via the Centre for Primary Health Care and Equity website and through conference presentations and research publications. Deidentified data and meta-data will be stored in a repository at UNSW and made available subject to ethics committee approval. Trial Registration number ACTRN12617001508369; Pre-results. PMID:29866737

Robust root clustering for linear uncertain systems using generalized Lyapunov theory

NASA Technical Reports Server (NTRS)

Yedavalli, R. K.

1993-01-01

Consideration is given to the problem of matrix root clustering in subregions of a complex plane for linear state space models with real parameter uncertainty. The nominal matrix root clustering theory of Gutman & Jury (1981) using the generalized Liapunov equation is extended to the perturbed matrix case, and bounds are derived on the perturbation to maintain root clustering inside a given region. The theory makes it possible to obtain an explicit relationship between the parameters of the root clustering region and the uncertainty range of the parameter space.

A General Class of Signed Rank Tests for Clustered Data when the Cluster Size is Potentially Informative

PubMed Central

Datta, Somnath; Nevalainen, Jaakko; Oja, Hannu

2012-01-01

SUMMARY Rank based tests are alternatives to likelihood based tests popularized by their relative robustness and underlying elegant mathematical theory. There has been a serge in research activities in this area in recent years since a number of researchers are working to develop and extend rank based procedures to clustered dependent data which include situations with known correlation structures (e.g., as in mixed effects models) as well as more general form of dependence. The purpose of this paper is to test the symmetry of a marginal distribution under clustered data. However, unlike most other papers in the area, we consider the possibility that the cluster size is a random variable whose distribution is dependent on the distribution of the variable of interest within a cluster. This situation typically arises when the clusters are defined in a natural way (e.g., not controlled by the experimenter or statistician) and in which the size of the cluster may carry information about the distribution of data values within a cluster. Under the scenario of an informative cluster size, attempts to use some form of variance adjusted sign or signed rank tests would fail since they would not maintain the correct size under the distribution of marginal symmetry. To overcome this difficulty Datta and Satten (2008; Biometrics, 64, 501–507) proposed a Wilcoxon type signed rank test based on the principle of within cluster resampling. In this paper we study this problem in more generality by introducing a class of valid tests employing a general score function. Asymptotic null distribution of these tests is obtained. A simulation study shows that a more general choice of the score function can sometimes result in greater power than the Datta and Satten test; furthermore, this development offers the user a wider choice. We illustrate our tests using a real data example on spinal cord injury patients. PMID:23074359

A General Class of Signed Rank Tests for Clustered Data when the Cluster Size is Potentially Informative.

PubMed

Datta, Somnath; Nevalainen, Jaakko; Oja, Hannu

2012-09-01

Rank based tests are alternatives to likelihood based tests popularized by their relative robustness and underlying elegant mathematical theory. There has been a serge in research activities in this area in recent years since a number of researchers are working to develop and extend rank based procedures to clustered dependent data which include situations with known correlation structures (e.g., as in mixed effects models) as well as more general form of dependence.The purpose of this paper is to test the symmetry of a marginal distribution under clustered data. However, unlike most other papers in the area, we consider the possibility that the cluster size is a random variable whose distribution is dependent on the distribution of the variable of interest within a cluster. This situation typically arises when the clusters are defined in a natural way (e.g., not controlled by the experimenter or statistician) and in which the size of the cluster may carry information about the distribution of data values within a cluster.Under the scenario of an informative cluster size, attempts to use some form of variance adjusted sign or signed rank tests would fail since they would not maintain the correct size under the distribution of marginal symmetry. To overcome this difficulty Datta and Satten (2008; Biometrics, 64, 501-507) proposed a Wilcoxon type signed rank test based on the principle of within cluster resampling. In this paper we study this problem in more generality by introducing a class of valid tests employing a general score function. Asymptotic null distribution of these tests is obtained. A simulation study shows that a more general choice of the score function can sometimes result in greater power than the Datta and Satten test; furthermore, this development offers the user a wider choice. We illustrate our tests using a real data example on spinal cord injury patients.

Analysis of partially observed clustered data using generalized estimating equations and multiple imputation

PubMed Central

Aloisio, Kathryn M.; Swanson, Sonja A.; Micali, Nadia; Field, Alison; Horton, Nicholas J.

2015-01-01

Clustered data arise in many settings, particularly within the social and biomedical sciences. As an example, multiple–source reports are commonly collected in child and adolescent psychiatric epidemiologic studies where researchers use various informants (e.g. parent and adolescent) to provide a holistic view of a subject’s symptomatology. Fitzmaurice et al. (1995) have described estimation of multiple source models using a standard generalized estimating equation (GEE) framework. However, these studies often have missing data due to additional stages of consent and assent required. The usual GEE is unbiased when missingness is Missing Completely at Random (MCAR) in the sense of Little and Rubin (2002). This is a strong assumption that may not be tenable. Other options such as weighted generalized estimating equations (WEEs) are computationally challenging when missingness is non–monotone. Multiple imputation is an attractive method to fit incomplete data models while only requiring the less restrictive Missing at Random (MAR) assumption. Previously estimation of partially observed clustered data was computationally challenging however recent developments in Stata have facilitated their use in practice. We demonstrate how to utilize multiple imputation in conjunction with a GEE to investigate the prevalence of disordered eating symptoms in adolescents reported by parents and adolescents as well as factors associated with concordance and prevalence. The methods are motivated by the Avon Longitudinal Study of Parents and their Children (ALSPAC), a cohort study that enrolled more than 14,000 pregnant mothers in 1991–92 and has followed the health and development of their children at regular intervals. While point estimates were fairly similar to the GEE under MCAR, the MAR model had smaller standard errors, while requiring less stringent assumptions regarding missingness. PMID:25642154

Identifying At-Risk Students in General Chemistry via Cluster Analysis of Affective Characteristics

ERIC Educational Resources Information Center

Chan, Julia Y. K.; Bauer, Christopher F.

2014-01-01

The purpose of this study is to identify academically at-risk students in first-semester general chemistry using affective characteristics via cluster analysis. Through the clustering of six preselected affective variables, three distinct affective groups were identified: low (at-risk), medium, and high. Students in the low affective group…

Evaluation of a program to strengthen general practice care for patients with chronic disease in Germany.

PubMed

Wensing, Michel; Szecsenyi, Joachim; Stock, Christian; Kaufmann Kolle, Petra; Laux, Gunter

2017-01-21

A program to strengthen general practice care for patients with chronic disease was offered in Germany. Enrollment was a free individual choice for both patients and physicians. This study aimed to examine the long-term impact of this program. Two comparative evaluations were done, at 4 and 5 years (T1 and T2) after start of the program. In each year, patients in the program were compared with patients in usual care. Measures were based on routinely collected data and concerned 11 aspects of primary care and hospital care. Study groups were compared, using regression analysis adjusted for confounders and clustering. Data on 1.187.597 and 1.591.017 eligible patients were available for the analysis for T1 and T2, respectively. Compared to usual care, the program was associated with more visits to the GP per patient (adjusted difference at T2: +1.98), more drugs prescribed per patient (+0.071), lower percentage of drugs that should be avoided (-0.699), and lower yearly medication costs per patient (-85.39 euro). The number of referrals to ambulatory specialists, either with or without referral from GP, was reduced at T2. In hospital care, the program was associated with fewer hospital admissions per patient per year (-0.017) and fewer avoidable hospital admissions of all admissions (-1.165%). Total hospital costs were slightly higher in T1, but lower in T2. Days in hospital and number of readmissions were lower at T2 only. The program has increased the role of general practice in healthcare for patients who chose to be included in the program of intensified general practice care.

Ordering blood tests for patients with unexplained fatigue in general practice: what does it yield? Results of the VAMPIRE trial.

PubMed

Koch, Hèlen; van Bokhoven, Marloes A; ter Riet, Gerben; van Alphen-Jager, Jm Tineke; van der Weijden, Trudy; Dinant, Geert-Jan; Bindels, Patrick J E

2009-04-01

Unexplained fatigue is frequently encountered in general practice. Because of the low prior probability of underlying somatic pathology, the positive predictive value of abnormal (blood) test results is limited in such patients. The study objectives were to investigate the relationship between established diagnoses and the occurrence of abnormal blood test results among patients with unexplained fatigue; to survey the effects of the postponement of test ordering on this relationship; and to explore consultation-related determinants of abnormal test results. Cluster randomised trial. General practices of 91 GPs in the Netherlands. GPs were randomised to immediate or postponed blood-test ordering. Patients with new unexplained fatigue were included. Limited and expanded sets of blood tests were ordered either immediately or after 4 weeks. Diagnoses during the 1-year follow-up period were extracted from medical records. Two-by-two tables were generated. To establish independent determinants of abnormal test results, a multivariate logistic regression model was used. Data of 325 patients were analysed (71% women; mean age 41 years). Eight per cent of patients had a somatic illness that was detectable by blood-test ordering. The number of false-positive test results increased in particular in the expanded test set. Patients rarely re-consulted after 4 weeks. Test postponement did not affect the distribution of patients over the two-by-two tables. No independent consultation-related determinants of abnormal test results were found. Results support restricting the number of tests ordered because of the increased risk of false-positive test results from expanded test sets. Although the number of re-consulting patients was small, the data do not refute the advice to postpone blood-test ordering for medical reasons in patients with unexplained fatigue in general practice.

Minimal improvement of nurses' motivational interviewing skills in routine diabetes care one year after training: a cluster randomized trial.

PubMed

Jansink, Renate; Braspenning, Jozé; Laurant, Miranda; Keizer, Ellen; Elwyn, Glyn; Weijden, Trudy van der; Grol, Richard

2013-03-28

The effectiveness of nurse-led motivational interviewing (MI) in routine diabetes care in general practice is inconclusive. Knowledge about the extent to which nurses apply MI skills and the factors that affect the usage can help to understand the black box of this intervention. The current study compared MI skills of trained versus non-trained general practice nurses in diabetes consultations. The nurses participated in a cluster randomized trial in which a comprehensive program (including MI training) was tested on improving clinical parameters, lifestyle, patients' readiness to change lifestyle, and quality of life. Fifty-eight general practices were randomly assigned to usual care (35 nurses) or the intervention (30 nurses). The ratings of applying 24 MI skills (primary outcome) were based on five consultation recordings per nurse at baseline and 14 months later. Two judges evaluated independently the MI skills and the consultation characteristics time, amount of nurse communication, amount of lifestyle discussion and patients' readiness to change. The effect of the training on the MI skills was analysed with a multilevel linear regression by comparing baseline and the one-year follow-up between the interventions with usual care group. The overall effect of the consultation characteristics on the MI skills was studied in a multilevel regression analyses. At one year follow up, it was demonstrated that the nurses improved on 2 of the 24 MI skills, namely, "inviting the patient to talk about behaviour change" (mean difference=0.39, p=0.009), and "assessing patient's confidence in changing their lifestyle" (mean difference=0.28, p=0.037). Consultation time and the amount of lifestyle discussion as well as the patients' readiness to change health behaviour was associated positively with applying MI skills. The maintenance of the MI skills one year after the training program was minimal. The question is whether the success of MI to change unhealthy behaviour must be doubted, whether the technique is less suitable for patients with a complex chronic disease, such as diabetes mellitus, or that nurses have problems with the acquisition and maintenance of MI skills in daily practice. Overall, performing MI skills during consultation increases, if there is more time, more lifestyle discussion, and the patients show more readiness to change. Current Controlled Trials ISRCTN68707773.

Minimal improvement of nurses’ motivational interviewing skills in routine diabetes care one year after training: a cluster randomized trial

PubMed Central

2013-01-01

Background The effectiveness of nurse-led motivational interviewing (MI) in routine diabetes care in general practice is inconclusive. Knowledge about the extent to which nurses apply MI skills and the factors that affect the usage can help to understand the black box of this intervention. The current study compared MI skills of trained versus non-trained general practice nurses in diabetes consultations. The nurses participated in a cluster randomized trial in which a comprehensive program (including MI training) was tested on improving clinical parameters, lifestyle, patients’ readiness to change lifestyle, and quality of life. Methods Fifty-eight general practices were randomly assigned to usual care (35 nurses) or the intervention (30 nurses). The ratings of applying 24 MI skills (primary outcome) were based on five consultation recordings per nurse at baseline and 14 months later. Two judges evaluated independently the MI skills and the consultation characteristics time, amount of nurse communication, amount of lifestyle discussion and patients’ readiness to change. The effect of the training on the MI skills was analysed with a multilevel linear regression by comparing baseline and the one-year follow-up between the interventions with usual care group. The overall effect of the consultation characteristics on the MI skills was studied in a multilevel regression analyses. Results At one year follow up, it was demonstrated that the nurses improved on 2 of the 24 MI skills, namely, “inviting the patient to talk about behaviour change” (mean difference=0.39, p=0.009), and “assessing patient’s confidence in changing their lifestyle” (mean difference=0.28, p=0.037). Consultation time and the amount of lifestyle discussion as well as the patients’ readiness to change health behaviour was associated positively with applying MI skills. Conclusions The maintenance of the MI skills one year after the training program was minimal. The question is whether the success of MI to change unhealthy behaviour must be doubted, whether the technique is less suitable for patients with a complex chronic disease, such as diabetes mellitus, or that nurses have problems with the acquisition and maintenance of MI skills in daily practice. Overall, performing MI skills during consultation increases, if there is more time, more lifestyle discussion, and the patients show more readiness to change. Trial registration Current Controlled Trials ISRCTN68707773 PMID:23537327

Impact of general practice endorsement on the social gradient in uptake in bowel cancer screening

PubMed Central

Raine, Rosalind; Duffy, Stephen W; Wardle, Jane; Solmi, Francesca; Morris, Stephen; Howe, Rosemary; Kralj-Hans, Ines; Snowball, Julia; Counsell, Nicholas; Moss, Sue; Hackshaw, Allan; von Wagner, Christian; Vart, Gemma; McGregor, Lesley M; Smith, Samuel G; Halloran, Stephen; Handley, Graham; Logan, Richard F; Rainbow, Sandra; Smith, Steve; Thomas, Mary C; Atkin, Wendy

2016-01-01

Background: There is a socioeconomic gradient in the uptake of screening in the English NHS Bowel Cancer Screening Programme (BCSP), potentially leading to inequalities in outcomes. We tested whether endorsement of bowel cancer screening by an individual's general practice (GP endorsement; GPE) reduced this gradient. Methods: A cluster-randomised controlled trial. Over 20 days, individuals eligible for screening in England from 6480 participating general practices were randomly allocated to receive a GP-endorsed or the standard invitation letter. The primary outcome was the proportion of people adequately screened and its variation by quintile of Index of Multiple Deprivation. Results: We enrolled 265 434 individuals. Uptake was 58.2% in the intervention arm and 57.5% in the control arm. After adjusting for age, sex, hub and screening episode, GPE increased the overall odds of uptake (OR=1.07, 95% CI 1.04–1.10), but did not affect its socioeconomic gradient. We estimated that implementing GPE could result in up to 165 more people with high or intermediate risk colorectal adenomas and 61 cancers detected, and a small one-off cost to modify the standard invitation (£78 000). Conclusions: Although GPE did not improve its socioeconomic gradient, it offers a low-cost approach to enhancing overall screening uptake within the NHS BCSP. PMID:26742011

Efficient algorithms for accurate hierarchical clustering of huge datasets: tackling the entire protein space

PubMed Central

Loewenstein, Yaniv; Portugaly, Elon; Fromer, Menachem; Linial, Michal

2008-01-01

Motivation: UPGMA (average linking) is probably the most popular algorithm for hierarchical data clustering, especially in computational biology. However, UPGMA requires the entire dissimilarity matrix in memory. Due to this prohibitive requirement, UPGMA is not scalable to very large datasets. Application: We present a novel class of memory-constrained UPGMA (MC-UPGMA) algorithms. Given any practical memory size constraint, this framework guarantees the correct clustering solution without explicitly requiring all dissimilarities in memory. The algorithms are general and are applicable to any dataset. We present a data-dependent characterization of hardness and clustering efficiency. The presented concepts are applicable to any agglomerative clustering formulation. Results: We apply our algorithm to the entire collection of protein sequences, to automatically build a comprehensive evolutionary-driven hierarchy of proteins from sequence alone. The newly created tree captures protein families better than state-of-the-art large-scale methods such as CluSTr, ProtoNet4 or single-linkage clustering. We demonstrate that leveraging the entire mass embodied in all sequence similarities allows to significantly improve on current protein family clusterings which are unable to directly tackle the sheer mass of this data. Furthermore, we argue that non-metric constraints are an inherent complexity of the sequence space and should not be overlooked. The robustness of UPGMA allows significant improvement, especially for multidomain proteins, and for large or divergent families. Availability: A comprehensive tree built from all UniProt sequence similarities, together with navigation and classification tools will be made available as part of the ProtoNet service. A C++ implementation of the algorithm is available on request. Contact: lonshy@cs.huji.ac.il PMID:18586742

The Complexities of Implementing Cluster Supply Chain - Case Study of JCH

NASA Astrophysics Data System (ADS)

Xue, Xiao; Zhang, Jibiao; Wang, Yang

As a new type of management pattern, "cluster supply chain" (CSC) can help SMEs to face the global challenges through all kinds of collaboration. However, a major challenge in implementing CSC is the gap between theory and practice in the field. In an effort to provide a better understanding of this emerging phenomenon, this paper presents the implementation process of CSC in the context of JingCheng Mechanical & Electrical Holding co., ltd.(JCH) as a case study. The cast study of JCH suggests that the key problems in the practice of cluster supply chain: How do small firms use cluster supply chain? Only after we clarify the problem, the actual construction and operation of cluster supply chain does show successful results as it should be.

Clustering of food and activity preferences in primary school children.

PubMed

Rodenburg, Gerda; Oenema, Anke; Pasma, Marleen; Kremers, Stef P J; van de Mheen, Dike

2013-01-01

This study examined clustering of food and activity preferences in Dutch primary school children. It also explored whether the preference clusters are associated with child and parental background characteristics and with parenting practices. Data were used from 1480 parent-child dyads participating in the IVO Nutrition and Physical Activity Child cohort (INPACT). Children aged 8-11years reported their preferences for food (e.g. fruit and sweet snacks) and activities (e.g. biking and watching television) at school with a newly-developed, visual instrument designed for primary school children. Parents completed a questionnaire at home. Principal component analysis was used to identify preference clusters. Backward regression analyses were used to examine the relationship between child and parental characteristics with cluster scores. We found (1) a clustering of preferences for unhealthy foods and unhealthy drinks, (2) a clustering of preferences for various physical activity behaviours, and (3) a clustering of preferences for unhealthy drinks and sedentary behaviour. Boys had a higher cluster score than girls on all three preference clusters. In addition, physical activity-related parenting practices were negatively related to unhealthy preference clusters and positively to the physical-activity-preference cluster. The next step is to relate our preference clusters to child dietary and activity behaviours, with special attention to gender differences. This may help in the development of interventions aimed at improving children's food and activity preferences. Copyright © 2012 Elsevier Ltd. All rights reserved.

QMRA for Drinking Water: 2. The Effect of Pathogen Clustering in Single-Hit Dose-Response Models.

PubMed

Nilsen, Vegard; Wyller, John

2016-01-01

Spatial and/or temporal clustering of pathogens will invalidate the commonly used assumption of Poisson-distributed pathogen counts (doses) in quantitative microbial risk assessment. In this work, the theoretically predicted effect of spatial clustering in conventional "single-hit" dose-response models is investigated by employing the stuttering Poisson distribution, a very general family of count distributions that naturally models pathogen clustering and contains the Poisson and negative binomial distributions as special cases. The analysis is facilitated by formulating the dose-response models in terms of probability generating functions. It is shown formally that the theoretical single-hit risk obtained with a stuttering Poisson distribution is lower than that obtained with a Poisson distribution, assuming identical mean doses. A similar result holds for mixed Poisson distributions. Numerical examples indicate that the theoretical single-hit risk is fairly insensitive to moderate clustering, though the effect tends to be more pronounced for low mean doses. Furthermore, using Jensen's inequality, an upper bound on risk is derived that tends to better approximate the exact theoretical single-hit risk for highly overdispersed dose distributions. The bound holds with any dose distribution (characterized by its mean and zero inflation index) and any conditional dose-response model that is concave in the dose variable. Its application is exemplified with published data from Norovirus feeding trials, for which some of the administered doses were prepared from an inoculum of aggregated viruses. The potential implications of clustering for dose-response assessment as well as practical risk characterization are discussed. © 2016 Society for Risk Analysis.

An Empirical Comparison of Variable Standardization Methods in Cluster Analysis.

ERIC Educational Resources Information Center

Schaffer, Catherine M.; Green, Paul E.

1996-01-01

The common marketing research practice of standardizing the columns of a persons-by-variables data matrix prior to clustering the entities corresponding to the rows was evaluated with 10 large-scale data sets. Results indicate that the column standardization practice may be problematic for some kinds of data that marketing researchers used for…

Shared decision-making in antihypertensive therapy: a cluster randomised controlled trial

PubMed Central

2013-01-01

Background Hypertension is one of the key factors causing cardiovascular diseases. A substantial proportion of treated hypertensive patients do not reach recommended target blood pressure values. Shared decision making (SDM) is to enhance the active role of patients. As until now there exists little information on the effects of SDM training in antihypertensive therapy, we tested the effect of an SDM training programme for general practitioners (GPs). Our hypotheses are that this SDM training (1) enhances the participation of patients and (2) leads to an enhanced decrease in blood pressure (BP) values, compared to patients receiving usual care without prior SDM training for GPs. Methods The study was conducted as a cluster randomised controlled trial (cRCT) with GP practices in Southwest Germany. Each GP practice included patients with treated but uncontrolled hypertension and/or with relevant comorbidity. After baseline assessment (T0) GP practices were randomly allocated into an intervention and a control arm. GPs of the intervention group took part in the SDM training. GPs of the control group treated their patients as usual. The intervention was blinded to the patients. Primary endpoints on patient level were (1) change of patients’ perceived participation (SDM-Q-9) and (2) change of systolic BP (24h-mean). Secondary endpoints were changes of (1) diastolic BP (24h-mean), (2) patients’ knowledge about hypertension, (3) adherence (MARS-D), and (4) cardiovascular risk score (CVR). Results In total 1357 patients from 36 general practices were screened for blood pressure control by ambulatory blood pressure monitoring (ABPM). Thereof 1120 patients remained in the study because of uncontrolled (but treated) hypertension and/or a relevant comorbidity. At T0 the intervention group involved 17 GP practices with 552 patients and the control group 19 GP practices with 568 patients. The effectiveness analysis could not demonstrate a significant or relevant effect of the SDM training on any of the endpoints. Conclusion The study hypothesis that the SDM training enhanced patients’ perceived participation and lowered their BP could not be confirmed. Further research is needed to examine the impact of patient participation on the treatment of hypertension in primary care. Trial registration German Clinical Trials Register (DRKS): DRKS00000125 PMID:24024587

[Typologies of Madrid's citizens (Spain) at the end-of-life: cluster analysis].

PubMed

Ortiz-Gonçalves, Belén; Perea-Pérez, Bernardo; Labajo González, Elena; Albarrán Juan, Elena; Santiago-Sáez, Andrés

2018-03-06

To establish typologies within Madrid's citizens (Spain) with regard to end-of-life by cluster analysis. The SPAD 8 programme was implemented in a sample from a health care centre in the autonomous region of Madrid (Spain). A multiple correspondence analysis technique was used, followed by a cluster analysis to create a dendrogram. A cross-sectional study was made beforehand with the results of the questionnaire. Five clusters stand out. Cluster 1: a group who preferred not to answer numerous questions (5%). Cluster 2: in favour of receiving palliative care and euthanasia (40%). Cluster 3: would oppose assisted suicide and would not ask for spiritual assistance (15%). Cluster 4: would like to receive palliative care and assisted suicide (16%). Cluster 5: would oppose assisted suicide and would ask for spiritual assistance (24%). The following four clusters stood out. Clusters 2 and 4 would like to receive palliative care, euthanasia (2) and assisted suicide (4). Clusters 4 and 5 regularly practiced their faith and their family members did not receive palliative care. Clusters 3 and 5 would be opposed to euthanasia and assisted suicide in particular. Clusters 2, 4 and 5 had not completed an advance directive document (2, 4 and 5). Clusters 2 and 3 seldom practiced their faith. This study could be taken into consideration to improve the quality of end-of-life care choices. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Deciding who gets treatment for depression and anxiety: a study of consecutive GP attenders

PubMed Central

Hyde, Julia; Evans, Jonathan; Sharp, Debbie; Croudace, Tim; Harrison, Glynn; Lewis, Glyn; Araya, Ricardo

2005-01-01

Background Most research has focused on recognition by GPs of the common mental disorders: depression and anxiety. However, less is known about the factors that determine whether patients with those disorders that are recognised receive any active treatment. Aim To investigate factors associated with receiving active treatment among consecutive attenders identified by GPs as having a common mental disorder. Setting Data were collected as part of a cluster randomised controlled trial in 30 general practices in the south of Bristol, UK, on the impact of mental health guidelines in primary care. Method We studied 439 consecutive general practice attenders aged 16–64 years who were given a diagnosis of depression, anxiety, or chronic mixed anxiety and depression by their GP. The main outcome measure was the provision of any active treatment, whether pharmacological or psychological, for these disorders. Patient, GP, and practice level data, including sociodemographic, clinical, and administrative data were explored as predictors in a logistic regression model. Huber White variance estimates were used to account for hierarchical clustering. Results Of those patients identified as having a common mental disorder by the GP, 54% were offered active treatment. Higher symptom score, as measured by the General Health Questionnaire (GHQ) (odds ratio [OR] = 1.09; 95% confidence interval [CI] = 1.06 to 1.13; P<0.001) and being male (OR = 1.54; 95% CI = 1.13 to 2.09; P = 0.006), were both associated with an increased likelihood of being offered active treatment. Patients with anxiety (OR = 0.24; 95% = CI 0.14 to 0.41; P<0.001), or chronic mixed anxiety/depression (OR = 0.41; 95% CI = 0.23 to 0.73; P = 0.003) were less likely to be offered active treatment than those considered to have depression. Conclusion When deciding to offer active treatment for common mental disorders, GPs appear to be influenced by the severity of symptoms rather than their ‘understandability’ in relation to recent life stresses or the social context of distress. Further research is needed to investigate why men are more likely and those with an anxiety disorder less likely, to be offered active treatment. PMID:16282000

Explaining use of food parenting practices: the importance of predisposing factors and parental cognitions.

PubMed

Gevers, Dorus Wm; van Assema, Patricia; de Vries, Nanne K; Kremers, Stef Pj

2017-09-01

The high energy intake from energy-dense foods among children in developed countries is undesirable. Improving food parenting practices has the potential to lower snack intakes among children. To inform the development of interventions, we aimed to predict food parenting practice patterns around snacking (i.e. 'high covert control and rewarding', 'low covert control and non-rewarding', 'high involvement and supportive' and 'low involvement and indulgent'). A cross-sectional survey was conducted. To predict the patterns of food parenting practices, multinomial logistic regression analyses were run with 888 parents. Predictors included predisposing factors (i.e. parents' and children's demographics and BMI, parents' personality, general parenting, and parenting practices used by their own parents) and parents' cognitions (i.e. perceived behaviour of other parents, subjective norms, attitudes, self-efficacy and outcome expectations). The Netherlands (October-November 2014). Dutch parents of children aged 4-12 years old. After backward elimination, nineteen factors had a statistically significant contribution to the model (Nagelkerke R 2=0·63). Overall, self-efficacy and outcome expectations were among the strongest explanatory factors. Considering the predisposing factors only, the general parenting factor nurturance most strongly predicted the food parenting clusters. Nurturance particularly distinguished highly involved parents from parents employing a pattern of low involvement. Parental cognitions and nurturance are important factors to explain the use of food parenting practices around snacking. The results suggest that intervention developers should attempt to increase self-efficacy and educate parents about what constitute effective and ineffective parenting practices. Promoting nurturance might be a prerequisite to achieve prolonged change.

Crystallization of glass-forming liquids: Specific surface energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmelzer, Jürn W. P., E-mail: juern-w.schmelzer@uni-rostock.de; Abyzov, Alexander S.

2016-08-14

A generalization of the Stefan-Skapski-Turnbull relation for the melt-crystal specific interfacial energy is developed in terms of the generalized Gibbs approach extending its standard formulation to thermodynamic non-equilibrium states. With respect to crystal nucleation, this relation is required in order to determine the parameters of the critical crystal clusters being a prerequisite for the computation of the work of critical cluster formation. As one of its consequences, a relation for the dependence of the specific surface energy of critical clusters on temperature and pressure is derived applicable for small and moderate deviations from liquid-crystal macroscopic equilibrium states. Employing the Stefan-Skapski-Turnbullmore » relation, general expressions for the size and the work of formation of critical crystal clusters are formulated. The resulting expressions are much more complex as compared to the respective relations obtained via the classical Gibbs theory. Latter relations are retained as limiting cases of these more general expressions for moderate undercoolings. By this reason, the formulated, here, general relations for the specification of the critical cluster size and the work of critical cluster formation give a key for an appropriate interpretation of a variety of crystallization phenomena occurring at large undercoolings which cannot be understood in terms of the Gibbs’ classical treatment.« less

Effect of tailored practice and patient care plans on secondary prevention of heart disease in general practice: cluster randomised controlled trial.

PubMed

Murphy, A W; Cupples, M E; Smith, S M; Byrne, M; Byrne, M C; Newell, J

2009-10-29

To test the effectiveness of a complex intervention designed, within a theoretical framework, to improve outcomes for patients with coronary heart disease. Cluster randomised controlled multicentre trial. General practices in Northern Ireland and the Republic of Ireland, regions with different healthcare systems. 903 patients with established coronary heart disease registered with one of 48 practices. Tailored care plans for practices (practice based training in prescribing and behaviour change, administrative support, quarterly newsletter), and tailored care plans for patients (motivational interviewing, goal identification, and target setting for lifestyle change) with reviews every four months at the practices. Control practices provided usual care. The proportion of patients at 18 month follow-up above target levels for blood pressure and total cholesterol concentration, and those admitted to hospital, and changes in physical and mental health status (SF-12). At baseline the numbers (proportions) of patients above the recommended limits were: systolic blood pressure greater than 140 mm Hg (305/899; 33.9%, 95% confidence interval 30.8% to 33.9%), diastolic blood pressure greater than 90 mm Hg (111/901; 12.3%, 10.2% to 14.5%), and total cholesterol concentration greater than 5 mmol/l (188/860; 20.8%, 19.1% to 24.6%). At the 18 month follow-up there were no significant differences between intervention and control groups in the numbers (proportions) of patients above the recommended limits: systolic blood pressure, intervention 98/360 (27.2%) v control, 133/405 (32.8%), odds ratio 1.51 (95% confidence interval 0.99 to 2.30; P=0.06); diastolic blood pressure, intervention 32/360 (8.9%) v control, 40/405 (9.9%), 1.40 (0.75 to 2.64; P=0.29); and total cholesterol concentration, intervention 52/342 (15.2%) v control, 64/391 (16.4%), 1.13 (0.63 to 2.03; P=0.65). The number of patients admitted to hospital over the 18 month study period significantly decreased in the intervention group compared with the control group: 107/415 (25.8%) v 148/435 (34.0%), 1.56 (1.53 to 2.60; P=0.03). Admissions to hospital were significantly reduced after an intensive 18 month intervention to improve outcomes for patients with coronary heart disease, but no other clinical benefits were shown, possibly because of a ceiling effect related to improved management of the disease. Current Controlled Trials ISRCTN24081411.

The Computation of Orthogonal Independent Cluster Solutions and Their Oblique Analogs in Factor Analysis.

ERIC Educational Resources Information Center

Hofmann, Richard J.

A very general model for the computation of independent cluster solutions in factor analysis is presented. The model is discussed as being either orthogonal or oblique. Furthermore, it is demonstrated that for every orthogonal independent cluster solution there is an oblique analog. Using three illustrative examples, certain generalities are made…

Cluster-state quantum computing enhanced by high-fidelity generalized measurements.

PubMed

Biggerstaff, D N; Kaltenbaek, R; Hamel, D R; Weihs, G; Rudolph, T; Resch, K J

2009-12-11

We introduce and implement a technique to extend the quantum computational power of cluster states by replacing some projective measurements with generalized quantum measurements (POVMs). As an experimental demonstration we fully realize an arbitrary three-qubit cluster computation by implementing a tunable linear-optical POVM, as well as fast active feedforward, on a two-qubit photonic cluster state. Over 206 different computations, the average output fidelity is 0.9832+/-0.0002; furthermore the error contribution from our POVM device and feedforward is only of O(10(-3)), less than some recent thresholds for fault-tolerant cluster computing.

Joint inversion of multiple geophysical and petrophysical data using generalized fuzzy clustering algorithms

NASA Astrophysics Data System (ADS)

Sun, Jiajia; Li, Yaoguo

2017-02-01

Joint inversion that simultaneously inverts multiple geophysical data sets to recover a common Earth model is increasingly being applied to exploration problems. Petrophysical data can serve as an effective constraint to link different physical property models in such inversions. There are two challenges, among others, associated with the petrophysical approach to joint inversion. One is related to the multimodality of petrophysical data because there often exist more than one relationship between different physical properties in a region of study. The other challenge arises from the fact that petrophysical relationships have different characteristics and can exhibit point, linear, quadratic, or exponential forms in a crossplot. The fuzzy c-means (FCM) clustering technique is effective in tackling the first challenge and has been applied successfully. We focus on the second challenge in this paper and develop a joint inversion method based on variations of the FCM clustering technique. To account for the specific shapes of petrophysical relationships, we introduce several different fuzzy clustering algorithms that are capable of handling different shapes of petrophysical relationships. We present two synthetic and one field data examples and demonstrate that, by choosing appropriate distance measures for the clustering component in the joint inversion algorithm, the proposed joint inversion method provides an effective means of handling common petrophysical situations we encounter in practice. The jointly inverted models have both enhanced structural similarity and increased petrophysical correlation, and better represent the subsurface in the spatial domain and the parameter domain of physical properties.

Prevalence of acute repetitive seizures (ARS) in the United Kingdom.

PubMed

Martinez, Carlos; Sullivan, Tim; Hauser, W Allen

2009-12-01

"Acute repetitive seizures" (ARS) is a term to describe a condition manifest by multiple seizures occurring over a relatively brief period of time -generally 24 hours- in patients with epilepsy. There is limited information regarding the epidemiology of ARS in the general population. We performed a historical cohort study using data from the United Kingdom General Practice Research Database (GPRD) to identify all incident and prevalent cases of active epilepsy in 2005. From among this group, we identified individuals at risk for ARS. This included those with "catastrophic epilepsy syndromes of childhood" (CE), and those with a history of seizure clustering in the context of other epilepsy syndromes. We identified 21,010 people with active epilepsy in the GPRD in 2005; prevalence 7.2/1000; age adjusted to the European Standard Population, 6.7; incidence 50/100,000 per year, age-adjusted 48/100,000. We identified 665 people at risk for ARS. The prevalence of CE in the general population was 1.2/10,000 and that of cluster seizures was 1.1/10,000. We estimated the crude prevalence of ARS in the general population to be 2.3/10,000; age adjusted 2.5 (CI, 2.3-2.7. The prevalence of ARS was highest in those 0-4 years of age (5.9/10,000) and fell with advancing age to 0.5/10,000 in those age 70 and older). This is the first population-based study to provide information on the prevalence of ARS. ARS affects about 3% of the population with epilepsy and 0.02% of the general population. More studies are needed to further evaluate this serious epilepsy phenomenon.

Two generalizations of Kohonen clustering

NASA Technical Reports Server (NTRS)

Bezdek, James C.; Pal, Nikhil R.; Tsao, Eric C. K.

1993-01-01

The relationship between the sequential hard c-means (SHCM), learning vector quantization (LVQ), and fuzzy c-means (FCM) clustering algorithms is discussed. LVQ and SHCM suffer from several major problems. For example, they depend heavily on initialization. If the initial values of the cluster centers are outside the convex hull of the input data, such algorithms, even if they terminate, may not produce meaningful results in terms of prototypes for cluster representation. This is due in part to the fact that they update only the winning prototype for every input vector. The impact and interaction of these two families with Kohonen's self-organizing feature mapping (SOFM), which is not a clustering method, but which often leads ideas to clustering algorithms is discussed. Then two generalizations of LVQ that are explicitly designed as clustering algorithms are presented; these algorithms are referred to as generalized LVQ = GLVQ; and fuzzy LVQ = FLVQ. Learning rules are derived to optimize an objective function whose goal is to produce 'good clusters'. GLVQ/FLVQ (may) update every node in the clustering net for each input vector. Neither GLVQ nor FLVQ depends upon a choice for the update neighborhood or learning rate distribution - these are taken care of automatically. Segmentation of a gray tone image is used as a typical application of these algorithms to illustrate the performance of GLVQ/FLVQ.

Spatial-temporal clustering of companion animal enteric syndrome: detection and investigation through the use of electronic medical records from participating private practices.

PubMed

Anholt, R M; Berezowski, J; Robertson, C; Stephen, C

2015-09-01

There is interest in the potential of companion animal surveillance to provide data to improve pet health and to provide early warning of environmental hazards to people. We implemented a companion animal surveillance system in Calgary, Alberta and the surrounding communities. Informatics technologies automatically extracted electronic medical records from participating veterinary practices and identified cases of enteric syndrome in the warehoused records. The data were analysed using time-series analyses and a retrospective space-time permutation scan statistic. We identified a seasonal pattern of reports of occurrences of enteric syndromes in companion animals and four statistically significant clusters of enteric syndrome cases. The cases within each cluster were examined and information about the animals involved (species, age, sex), their vaccination history, possible exposure or risk behaviour history, information about disease severity, and the aetiological diagnosis was collected. We then assessed whether the cases within the cluster were unusual and if they represented an animal or public health threat. There was often insufficient information recorded in the medical record to characterize the clusters by aetiology or exposures. Space-time analysis of companion animal enteric syndrome cases found evidence of clustering. Collection of more epidemiologically relevant data would enhance the utility of practice-based companion animal surveillance.

The Effects of Cluster-Based Mentoring Programme on Classroom Teaching Practices: Lessons from Pakistan

ERIC Educational Resources Information Center

Rizvi, Meher; Nagy, Philip

2016-01-01

This paper presents and evaluates a teacher training approach called the cluster-based mentoring programme (CBMP) for the professional development of government primary school teachers in Pakistan. The study sought to find differences in the teaching practices between districts where the CBMP was used (intervention) and control districts where it…

Proactive Parenting Practices during Early Adolescence: A Cluster Approach

ERIC Educational Resources Information Center

Padilla-Walker, Laura M.; Christensen, Katherine J.; Day, Randal D.

2011-01-01

The purpose of the current study was to explore clusters of proactive parenting practices, and how they might vary as a function of parental demographics, the quality of the parent-child relationship, and the traits and behaviors of the adolescent child. Data were taken from the "Flourishing Families Project", which includes 500 families with an…

Cluster Supervision Practices in Primary School of Jimma Zone

ERIC Educational Resources Information Center

Afework, E. A.; Frew, A. T.; Abeya, G. G.

2017-01-01

The main objective of this study was to assess the supervisory practice of cluster resource centre (CRC) supervisors in Jimma Zone primary schools. To achieve this purpose, the descriptive survey design was employed. Data were collected from 238 randomly selected teachers, and 60 school principals with a response rate of 98.6%. Moreover, 12 CRC…

A new model to understand the career choice and practice location decisions of medical graduates.

PubMed

Stagg, P; Greenhill, J; Worley, P S

2009-01-01

Australian medical education is increasingly influenced by rural workforce policy. Therefore, understanding the influences on medical graduates' practice location and specialty choice is crucial for medical educators and medical workforce planners. The South Australian Flinders University Parallel Rural Community Curriculum (PRCC) was funded by the Australian Government to help address the rural doctor workforce shortage. The PRCC was the first community based medical education program in Australia to teach a full academic year of medicine in South Australian rural general practices. The aim of this research was to identify what factors influence the career choices of PRCC graduates. A retrospective survey of all contactable graduates of the PRCC was undertaken. Quantitative data were analysed using SPSS 14.0 for Windows. Qualitative data were entered into NVIVO 7 software for coding, and analysed using content analysis. Usable data were collected from 46 of the 86 contactable graduates (53%). More than half of the respondents (54%) reported being on a rural career path. A significant relationship exists between being on a rural career pathway and making the decision prior to or during medical school (p = 0.027), and between graduates in vocational training who are on an urban career path and making a decision on career specialty after graduation from medical school (p = .004). Graduates in a general practice vocational training program are more likely to be on a rural career pathway than graduates in a specialty other than general practice (p = .003). A key influence on graduates' practice location is geographic location prior to entering medical school. Key influences on graduates choosing a rural career pathway are: having a spouse/partner with a rural background; clinical teachers and mentors; the extended rural based undergraduate learning experience; and a specialty preference for general practice. A lack of rural based internships and specialist training places is influencing both urban- and rural-origin graduates to practise in urban locations. Further analysis of graduates' career pathway choices (rural or urban) and geographic background (rural or urban) was conducted. This resulted in the development of a new model, 'The Four Qs Model'. This model consists of four quadrants derived from the variables career pathway choice (rural or urban) and geographic background (rural or urban). Clustering of consistent demographic and qualitative trends unique to each quadrant was demonstrated. The distinctive clustering that emerged from the data resulted in the quadrants being renamed 'The True Believers', 'The Convertibles' 'The Frustrated' and 'The Metro Docs'. The PRCC is influencing graduates to choose a rural career path. The PRCC program affirms the career preferences of rural origin students while graduates with little rural exposure prior to the PRCC report being positively influenced to pursue a rural career path. The Four Qs Model is a useful model in that it demonstrates consistent themes in the characteristics of PRCC graduates and assists understanding of why they choose a rural medical career. This could be relevant to the selection of medical students into rural medical education programs and in the construction of rural curricula. The model also offers a useful framework for further research in this field.

Responding to Young People's Health Risks in Primary Care: A Cluster Randomised Trial of Training Clinicians in Screening and Motivational Interviewing.

PubMed

Sanci, Lena; Chondros, Patty; Sawyer, Susan; Pirkis, Jane; Ozer, Elizabeth; Hegarty, Kelsey; Yang, Fan; Grabsch, Brenda; Shiell, Alan; Cahill, Helen; Ambresin, Anne-Emmanuelle; Patterson, Elizabeth; Patton, George

2015-01-01

To evaluate the effectiveness of a complex intervention implementing best practice guidelines recommending clinicians screen and counsel young people across multiple psychosocial risk factors, on clinicians' detection of health risks and patients' risk taking behaviour, compared to a didactic seminar on young people's health. Pragmatic cluster randomised trial where volunteer general practices were stratified by postcode advantage or disadvantage score and billing type (private, free national health, community health centre), then randomised into either intervention or comparison arms using a computer generated random sequence. Three months post-intervention, patients were recruited from all practices post-consultation for a Computer Assisted Telephone Interview and followed up three and 12 months later. Researchers recruiting, consenting and interviewing patients and patients themselves were masked to allocation status; clinicians were not. General practices in metropolitan and rural Victoria, Australia. General practices with at least one interested clinician (general practitioner or nurse) and their 14-24 year old patients. This complex intervention was designed using evidence based practice in learning and change in clinician behaviour and general practice systems, and included best practice approaches to motivating change in adolescent risk taking behaviours. The intervention involved training clinicians (nine hours) in health risk screening, use of a screening tool and motivational interviewing; training all practice staff (receptionists and clinicians) in engaging youth; provision of feedback to clinicians of patients' risk data; and two practice visits to support new screening and referral resources. Comparison clinicians received one didactic educational seminar (three hours) on engaging youth and health risk screening. Primary outcomes were patient report of (1) clinician detection of at least one of six health risk behaviours (tobacco, alcohol and illicit drug use, risks for sexually transmitted infection, STI, unplanned pregnancy, and road risks); and (2) change in one or more of the six health risk behaviours, at three months or at 12 months. Secondary outcomes were likelihood of future visits, trust in the clinician after exit interview, clinician detection of emotional distress and fear and abuse in relationships, and emotional distress at three and 12 months. Patient acceptability of the screening tool was also described for the intervention arm. Analyses were adjusted for practice location and billing type, patients' sex, age, and recruitment method, and past health risks, where appropriate. An intention to treat analysis approach was used, which included multilevel multiple imputation for missing outcome data. 42 practices were randomly allocated to intervention or comparison arms. Two intervention practices withdrew post allocation, prior to training, leaving 19 intervention (53 clinicians, 377 patients) and 21 comparison (79 clinicians, 524 patients) practices. 69% of patients in both intervention (260) and comparison (360) arms completed the 12 month follow-up. Intervention clinicians discussed more health risks per patient (59.7%) than comparison clinicians (52.7%) and thus were more likely to detect a higher proportion of young people with at least one of the six health risk behaviours (38.4% vs 26.7%, risk difference [RD] 11.6%, Confidence Interval [CI] 2.93% to 20.3%; adjusted odds ratio [OR] 1.7, CI 1.1 to 2.5). Patients reported less illicit drug use (RD -6.0, CI -11 to -1.2; OR 0.52, CI 0.28 to 0.96), and less risk for STI (RD -5.4, CI -11 to 0.2; OR 0.66, CI 0.46 to 0.96) at three months in the intervention relative to the comparison arm, and for unplanned pregnancy at 12 months (RD -4.4; CI -8.7 to -0.1; OR 0.40, CI 0.20 to 0.80). No differences were detected between arms on other health risks. There were no differences on secondary outcomes, apart from a greater detection of abuse (OR 13.8, CI 1.71 to 111). There were no reports of harmful events and intervention arm youth had high acceptance of the screening tool. A complex intervention, compared to a simple educational seminar for practices, improved detection of health risk behaviours in young people. Impact on health outcomes was inconclusive. Technology enabling more efficient, systematic health-risk screening may allow providers to target counselling toward higher risk individuals. Further trials require more power to confirm health benefits. ISRCTN.com ISRCTN16059206.

Teenage suicide cluster formation and contagion: implications for primary care

PubMed Central

Johansson, Lars; Lindqvist, Per; Eriksson, Anders

2006-01-01

Background We have previously studied unintentional as well as intentional injury deaths among teenagers living in the four northernmost counties, forming approximately 55% of Sweden with 908,000 inhabitants in 1991. During this work, we found what we suspected to be a suicide cluster among teenagers and we also suspected contagion since there were links between these cases. In this present study, we investigate the occurrence of suicide clustering among teenagers, analyze cluster definitions, and suggest preventive measures. Methods A retrospective study of teenager suicides autopsied at the Department of Forensic Medicine in Umeå, Sweden, during 1981 through 2000. Police reports, autopsy protocols, and medical records were studied in all cases, and the police officers that conducted the investigation at the scene were interviewed in all cluster cases. Parents of the suicide victims of the first cluster were also interviewed. Two aggregations of teenager suicides were detected and evaluated as possible suicide clusters using the US Centers for Disease Control definition of a suicide cluster. Results Two clusters including six teenagers were confirmed, and contagion was established within each cluster. Conclusion The general practitioner is identified as a key person in the aftermath of a teenage suicide since the general practitioner often meet the family, friends of the deceased, and other acquaintances early in the process after a suicide. This makes the general practitioner suitable to initiate contacts with others involved in the well-being of the young, in order to prevent suicide cluster formation and para-suicidal activities. PMID:16707009

General view looking toward the roulette farm cluster from south ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view looking toward the roulette farm cluster from south to north; note the present-day field was an orchard at the time of the battle - Roulette Farm, House, Sharpsburg, Washington County, MD

Implementation of effective practices in health facilities: a systematic review of cluster randomised trials.

PubMed

Allanson, Emma R; Tunçalp, Özge; Vogel, Joshua P; Khan, Dina N; Oladapo, Olufemi T; Long, Qian; Gülmezoglu, Ahmet Metin

2017-01-01

The capacity for health systems to support the translation of research in to clinical practice may be limited. The cluster randomised controlled trial (cluster RCT) design is often employed in evaluating the effectiveness of implementation of evidence-based practices. We aimed to systematically review available evidence to identify and evaluate the components in the implementation process at the facility level using cluster RCT designs. All cluster RCTs where the healthcare facility was the unit of randomisation, published or written from 1990 to 2014, were assessed. Included studies were analysed for the components of implementation interventions employed in each. Through iterative mapping and analysis, we synthesised a master list of components used and summarised the effects of different combinations of interventions on practices. Forty-six studies met the inclusion criteria and covered the specialty groups of obstetrics and gynaecology (n=9), paediatrics and neonatology (n=4), intensive care (n=4), internal medicine (n=20), and anaesthetics and surgery (n=3). Six studies included interventions that were delivered across specialties. Nine components of multifaceted implementation interventions were identified: leadership, barrier identification, tailoring to the context, patient involvement, communication, education, supportive supervision, provision of resources, and audit and feedback. The four main components that were most commonly used were education (n=42, 91%), audit and feedback (n=26, 57%), provision of resources (n=23, 50%) and leadership (n=21, 46%). Future implementation research should focus on better reporting of multifaceted approaches, incorporating sets of components that facilitate the translation of research into practice, and should employ rigorous monitoring and evaluation.

Variations in achievement of evidence-based, high-impact quality indicators in general practice: An observational study

PubMed Central

West, Robert; Rushforth, Bruno; Stokes, Tim; Glidewell, Liz; Carder, Paul; Faulkner, Simon; Foy, Robbie

2017-01-01

Background There are widely recognised variations in the delivery and outcomes of healthcare but an incomplete understanding of their causes. There is a growing interest in using routinely collected ‘big data’ in the evaluation of healthcare. We developed a set of evidence-based ‘high impact’ quality indicators (QIs) for primary care and examined variations in achievement of these indicators using routinely collected data in the United Kingdom (UK). Methods Cross-sectional analysis of routinely collected, electronic primary care data from a sample of general practices in West Yorkshire, UK (n = 89). The QIs covered aspects of care (including processes and intermediate clinical outcomes) in relation to diabetes, hypertension, atrial fibrillation, myocardial infarction, chronic kidney disease (CKD) and ‘risky’ prescribing combinations. Regression models explored the impact of practice and patient characteristics. Clustering within practice was accounted for by including a random intercept for practice. Results Median practice achievement of the QIs ranged from 43.2% (diabetes control) to 72.2% (blood pressure control in CKD). Considerable between-practice variation existed for all indicators: the difference between the highest and lowest performing practices was 26.3 percentage points for risky prescribing and 100 percentage points for anticoagulation in atrial fibrillation. Odds ratios associated with the random effects for practices emphasised this; there was a greater than ten-fold difference in the likelihood of achieving the hypertension indicator between the lowest and highest performing practices. Patient characteristics, in particular age, gender and comorbidity, were consistently but modestly associated with indicator achievement. Statistically significant practice characteristics were identified less frequently in adjusted models. Conclusions Despite various policy and improvement initiatives, there are enduring inappropriate variations in the delivery of evidence-based care. Much of this variation is not explained by routinely collected patient or practice variables, and is likely to be attributable to differences in clinical and organisational behaviour. PMID:28704407

Surgeon-Specific Reports in General Surgery: Establishing Benchmarks for Peer Comparison Within a Single Hospital.

PubMed

Hatfield, Mark D; Ashton, Carol M; Bass, Barbara L; Shirkey, Beverly A

2016-02-01

Methods to assess a surgeon's individual performance based on clinically meaningful outcomes have not been fully developed, due to small numbers of adverse outcomes and wide variation in case volumes. The Achievable Benchmark of Care (ABC) method addresses these issues by identifying benchmark-setting surgeons with high levels of performance and greater case volumes. This method was used to help surgeons compare their surgical practice to that of their peers by using merged National Surgical Quality Improvement Program (NSQIP) and Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) data to generate surgeon-specific reports. A retrospective cohort study at a single institution's department of surgery was conducted involving 107 surgeons (8,660 cases) over 5.5 years. Stratification of more than 32,000 CPT codes into 16 CPT clusters served as the risk adjustment. Thirty-day outcomes of interest included surgical site infection (SSI), acute kidney injury (AKI), and mortality. Performance characteristics of the ABC method were explored by examining how many surgeons were identified as benchmark-setters in view of volume and outcome rates within CPT clusters. For the data captured, most surgeons performed cases spanning a median of 5 CPT clusters (range 1 to 15 clusters), with a median of 26 cases (range 1 to 776 cases) and a median of 2.8 years (range 0 to 5.5 years). The highest volume surgeon for that CPT cluster set the benchmark for 6 of 16 CPT clusters for SSIs, 8 of 16 CPT clusters for AKIs, and 9 of 16 CPT clusters for mortality. The ABC method appears to be a sound and useful approach to identifying benchmark-setting surgeons within a single institution. Such surgeons may be able to help their peers improve their performance. Copyright © 2016 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Effectiveness of collaborative stepped care for anxiety disorders in primary care: a pragmatic cluster randomised controlled trial.

PubMed

Muntingh, Anna; van der Feltz-Cornelis, Christina; van Marwijk, Harm; Spinhoven, Philip; Assendelft, Willem; de Waal, Margot; Adèr, Herman; van Balkom, Anton

2014-01-01

Collaborative stepped care (CSC) may be an appropriate model to provide evidence-based treatment for anxiety disorders in primary care. In a cluster randomised controlled trial, the effectiveness of CSC compared to care as usual (CAU) for adults with panic disorder (PD) or generalised anxiety disorder (GAD) in primary care was evaluated. Thirty-one psychiatric nurses who provided their services to 43 primary care practices in the Netherlands were randomised to deliver CSC (16 psychiatric nurses, 23 practices) or CAU (15 psychiatric nurses, 20 practices). CSC was provided by the psychiatric nurses (care managers) in collaboration with the general practitioner and a consultant psychiatrist. The intervention consisted of 3 steps, namely guided self-help, cognitive behavioural therapy and antidepressants. Anxiety symptoms were measured with the Beck Anxiety Inventory (BAI) at baseline and after 3, 6, 9 and 12 months. We recruited 180 patients with a DSM-IV diagnosis of PD or GAD, of whom 114 received CSC and 66 received usual primary care. On the BAI, CSC was superior to CAU [difference in gain scores from baseline to 3 months: -5.11, 95% confidence interval (CI) -8.28 to -1.94; 6 months: -4.65, 95% CI -7.93 to -1.38; 9 months: -5.67, 95% CI -8.97 to -2.36; 12 months: -6.84, 95% CI -10.13 to -3.55]. CSC, with guided self-help as a first step, was more effective than CAU for primary care patients with PD or GAD.

A cluster design controlled trial of arts-based observational skills training in primary care.

PubMed

Kirklin, Deborah; Duncan, Jane; McBride, Sandy; Hunt, Sam; Griffin, Mark

2007-04-01

To investigate whether the observational skills of doctors and nurses can be improved by arts-based observational skills training. We carried out a cluster design, controlled trial involving 42 general practitioners and 26 primary care nurses in 12 primary care practices in London. Six practices were allocated to the intervention arm and 6 to the control arm. The intervention group received 90 minutes of arts-based observational skills training. The control group received practical training in the management of psoriasis. Before and after this, control and intervention participants were asked to describe 3 dermatological photographs. Descriptions were scored blindly against a predetermined marking key. Participants completed a questionnaire about the intervention, and about their own confidence in diagnosing and referring suspicious pigmented skin lesions. Post-intervention scores were significantly higher in the intervention group compared with the control group (P < 0.001). The majority of participants judged the intervention relevant, enjoyable and valuable. A majority lacked confidence in their dermatological knowledge and skills. This study provides statistically significant evidence that arts-based observational skills training can improve the observational skills of doctors and nurses. It is important not to overstate the clinical significance of these findings, and to recognise that observational skills are just one of many complex and subtle factors affecting the quality of the clinical process. Further research is needed to assess the existence, nature and clinical significance of longer-term benefits, and to identify differences between professional groups.

Quasi-planar elemental clusters in pair interactions approximation

NASA Astrophysics Data System (ADS)

Chkhartishvili, Levan

2016-01-01

The pair-interactions approximation, when applied to describe elemental clusters, only takes into account bonding between neighboring atoms. According to this approach, isomers of wrapped forms of 2D clusters - nanotubular and fullerene-like structures - and truly 3D clusters, are generally expected to be more stable than their quasi-planar counterparts. This is because quasi-planar clusters contain more peripheral atoms with dangling bonds and, correspondingly, fewer atoms with saturated bonds. However, the differences in coordination numbers between central and peripheral atoms lead to the polarization of bonds. The related corrections to the molar binding energy can make small, quasi-planar clusters more stable than their 2D wrapped allotropes and 3D isomers. The present work provides a general theoretical frame for studying the relative stability of small elemental clusters within the pair interactions approximation.

Molecular Regulation of Antibiotic Biosynthesis in Streptomyces

PubMed Central

Liu, Gang; Chandra, Govind; Niu, Guoqing

2013-01-01

SUMMARY Streptomycetes are the most abundant source of antibiotics. Typically, each species produces several antibiotics, with the profile being species specific. Streptomyces coelicolor, the model species, produces at least five different antibiotics. We review the regulation of antibiotic biosynthesis in S. coelicolor and other, nonmodel streptomycetes in the light of recent studies. The biosynthesis of each antibiotic is specified by a large gene cluster, usually including regulatory genes (cluster-situated regulators [CSRs]). These are the main point of connection with a plethora of generally conserved regulatory systems that monitor the organism's physiology, developmental state, population density, and environment to determine the onset and level of production of each antibiotic. Some CSRs may also be sensitive to the levels of different kinds of ligands, including products of the pathway itself, products of other antibiotic pathways in the same organism, and specialized regulatory small molecules such as gamma-butyrolactones. These interactions can result in self-reinforcing feed-forward circuitry and complex cross talk between pathways. The physiological signals and regulatory mechanisms may be of practical importance for the activation of the many cryptic secondary metabolic gene cluster pathways revealed by recent sequencing of numerous Streptomyces genomes. PMID:23471619

Harnessing Sparse and Low-Dimensional Structures for Robust Clustering of Imagery Data

ERIC Educational Resources Information Center

Rao, Shankar Ramamohan

2009-01-01

We propose a robust framework for clustering data. In practice, data obtained from real measurement devices can be incomplete, corrupted by gross errors, or not correspond to any assumed model. We show that, by properly harnessing the intrinsic low-dimensional structure of the data, these kinds of practical problems can be dealt with in a uniform…

Implementation of evidence-based weekend service recommendations for allied health managers: a cluster randomised controlled trial protocol.

PubMed

Sarkies, Mitchell N; White, Jennifer; Morris, Meg E; Taylor, Nicholas F; Williams, Cylie; O'Brien, Lisa; Martin, Jenny; Bardoel, Anne; Holland, Anne E; Carey, Leeanne; Skinner, Elizabeth H; Bowles, Kelly-Ann; Grant, Kellie; Philip, Kathleen; Haines, Terry P

2018-04-24

It is widely acknowledged that health policy and practice do not always reflect current research evidence. Whether knowledge transfer from research to practice is more successful when specific implementation approaches are used remains unclear. A model to assist engagement of allied health managers and clinicians with research implementation could involve disseminating evidence-based policy recommendations, along with the use of knowledge brokers. We developed such a model to aid decision-making for the provision of weekend allied health services. This protocol outlines the design and methods for a multi-centre cluster randomised controlled trial to evaluate the success of research implementation strategies to promote evidence-informed weekend allied health resource allocation decisions, especially in hospital managers. This multi-centre study will be a three-group parallel cluster randomised controlled trial. Allied health managers from Australian and New Zealand hospitals will be randomised to receive either (1) an evidence-based policy recommendation document to guide weekend allied health resource allocation decisions, (2) the same policy recommendation document with support from a knowledge broker to help implement weekend allied health policy recommendations, or (3) a usual practice control group. The primary outcome will be alignment of weekend allied health service provision with policy recommendations. This will be measured by the number of allied health service events (occasions of service) occurring on weekends as a proportion of total allied health service events for the relevant hospital wards at baseline and 12-month follow-up. Evidence-based policy recommendation documents communicate key research findings in an accessible format. This comparatively low-cost research implementation strategy could be combined with using a knowledge broker to work collaboratively with decision-makers to promote knowledge transfer. The results will assist managers to make decisions on resource allocation, based on evidence. More generally, the findings will inform the development of an allied health model for translating research into practice. This trial is registered with the Australian New Zealand Clinical Trials Registry (ANZCTR) ( ACTRN12618000029291 ). Universal Trial Number (UTN): U1111-1205-2621.

Generalized causal mediation and path analysis: Extensions and practical considerations.

PubMed

Albert, Jeffrey M; Cho, Jang Ik; Liu, Yiying; Nelson, Suchitra

2018-01-01

Causal mediation analysis seeks to decompose the effect of a treatment or exposure among multiple possible paths and provide casually interpretable path-specific effect estimates. Recent advances have extended causal mediation analysis to situations with a sequence of mediators or multiple contemporaneous mediators. However, available methods still have limitations, and computational and other challenges remain. The present paper provides an extended causal mediation and path analysis methodology. The new method, implemented in the new R package, gmediation (described in a companion paper), accommodates both a sequence (two stages) of mediators and multiple mediators at each stage, and allows for multiple types of outcomes following generalized linear models. The methodology can also handle unsaturated models and clustered data. Addressing other practical issues, we provide new guidelines for the choice of a decomposition, and for the choice of a reference group multiplier for the reduction of Monte Carlo error in mediation formula computations. The new method is applied to data from a cohort study to illuminate the contribution of alternative biological and behavioral paths in the effect of socioeconomic status on dental caries in adolescence.

Performance of the modified Poisson regression approach for estimating relative risks from clustered prospective data.

PubMed

Yelland, Lisa N; Salter, Amy B; Ryan, Philip

2011-10-15

Modified Poisson regression, which combines a log Poisson regression model with robust variance estimation, is a useful alternative to log binomial regression for estimating relative risks. Previous studies have shown both analytically and by simulation that modified Poisson regression is appropriate for independent prospective data. This method is often applied to clustered prospective data, despite a lack of evidence to support its use in this setting. The purpose of this article is to evaluate the performance of the modified Poisson regression approach for estimating relative risks from clustered prospective data, by using generalized estimating equations to account for clustering. A simulation study is conducted to compare log binomial regression and modified Poisson regression for analyzing clustered data from intervention and observational studies. Both methods generally perform well in terms of bias, type I error, and coverage. Unlike log binomial regression, modified Poisson regression is not prone to convergence problems. The methods are contrasted by using example data sets from 2 large studies. The results presented in this article support the use of modified Poisson regression as an alternative to log binomial regression for analyzing clustered prospective data when clustering is taken into account by using generalized estimating equations.

Effectiveness of a self-management program for dual sensory impaired seniors in aged care settings: study protocol for a cluster randomized controlled trial.

PubMed

Roets-Merken, Lieve M; Graff, Maud J L; Zuidema, Sytse U; Hermsen, Pieter G J M; Teerenstra, Steven; Kempen, Gertrudis I J M; Vernooij-Dassen, Myrra J F J

2013-10-07

Five to 25 percent of residents in aged care settings have a combined hearing and visual sensory impairment. Usual care is generally restricted to single sensory impairment, neglecting the consequences of dual sensory impairment on social participation and autonomy. The aim of this study is to evaluate the effectiveness of a self-management program for seniors who acquired dual sensory impairment at old age. In a cluster randomized, single-blind controlled trial, with aged care settings as the unit of randomization, the effectiveness of a self-management program will be compared to usual care. A minimum of 14 and maximum of 20 settings will be randomized to either the intervention cluster or the control cluster, aiming to include a total of 132 seniors with dual sensory impairment. Each senior will be linked to a licensed practical nurse working at the setting. During a five to six month intervention period, nurses at the intervention clusters will be trained in a self-management program to support and empower seniors to use self-management strategies. In two separate diaries, nurses keep track of the interviews with the seniors and their reflections on their own learning process. Nurses of the control clusters offer care as usual. At senior level, the primary outcome is the social participation of the seniors measured using the Hearing Handicap Questionnaire and the Activity Card Sort, and secondary outcomes are mood, autonomy and quality of life. At nurse level, the outcome is job satisfaction. Effectiveness will be evaluated using linear mixed model analysis. The results of this study will provide evidence for the effectiveness of the Self-Management Program for seniors with dual sensory impairment living in aged care settings. The findings are expected to contribute to the knowledge on the program's potential to enhance social participation and autonomy of the seniors, as well as increasing the job satisfaction of the licensed practical nurses. Furthermore, an extensive process evaluation will take place which will offer insight in the quality and feasibility of the sampling and intervention process. If it is shown to be effective and feasible, this Self-Management Program could be widely disseminated. ClinicalTrials.gov, NCT01217502.

Effectiveness of a self-management program for dual sensory impaired seniors in aged care settings: study protocol for a cluster randomized controlled trial

PubMed Central

2013-01-01

Background Five to 25 percent of residents in aged care settings have a combined hearing and visual sensory impairment. Usual care is generally restricted to single sensory impairment, neglecting the consequences of dual sensory impairment on social participation and autonomy. The aim of this study is to evaluate the effectiveness of a self-management program for seniors who acquired dual sensory impairment at old age. Methods/Design In a cluster randomized, single-blind controlled trial, with aged care settings as the unit of randomization, the effectiveness of a self-management program will be compared to usual care. A minimum of 14 and maximum of 20 settings will be randomized to either the intervention cluster or the control cluster, aiming to include a total of 132 seniors with dual sensory impairment. Each senior will be linked to a licensed practical nurse working at the setting. During a five to six month intervention period, nurses at the intervention clusters will be trained in a self-management program to support and empower seniors to use self-management strategies. In two separate diaries, nurses keep track of the interviews with the seniors and their reflections on their own learning process. Nurses of the control clusters offer care as usual. At senior level, the primary outcome is the social participation of the seniors measured using the Hearing Handicap Questionnaire and the Activity Card Sort, and secondary outcomes are mood, autonomy and quality of life. At nurse level, the outcome is job satisfaction. Effectiveness will be evaluated using linear mixed model analysis. Discussion The results of this study will provide evidence for the effectiveness of the Self-Management Program for seniors with dual sensory impairment living in aged care settings. The findings are expected to contribute to the knowledge on the program’s potential to enhance social participation and autonomy of the seniors, as well as increasing the job satisfaction of the licensed practical nurses. Furthermore, an extensive process evaluation will take place which will offer insight in the quality and feasibility of the sampling and intervention process. If it is shown to be effective and feasible, this Self-Management Program could be widely disseminated. Clinical trials registration ClinicalTrials.gov, NCT01217502. PMID:24099315

Preventing and lessening exacerbations of asthma in school-age children associated with a new term (PLEASANT): study protocol for a cluster randomised control trial

PubMed Central

2013-01-01

Background Within the UK, during September, there is a pronounced increase in the number of unscheduled medical contacts by school-aged children (4–16 years) with asthma. It is thought that that this might be caused by the return back to school after the summer holidays, suddenly mixing with other children again and picking up viruses which could affect their asthma. There is also a drop in the number of prescriptions administered in August. It is possible therefore that children might not be taking their medication as they should during the summer contributing to them becoming ill when they return to school. It is hoped that a simple intervention from the GP to parents of children with asthma at the start of the summer holiday period, highlighting the importance of maintaining asthma medication can help prevent increased asthma exacerbation, and unscheduled NHS appointments, following return to school in September. Methods/design PLEASANT is a cluster randomised trial. A total of 140 General Practices (GPs) will be recruited into the trial; 70 GPs randomised to the intervention and 70 control practices of “usual care”. An average practice is expected to have approximately 100 children (aged 4–16 with a diagnosis of asthma) hence observational data will be collected on around 14000 children over a 24-month period. The Clinical Practice Research Datalink will collect all data required for the study which includes diagnostic, prescription and referral data. Discussion The trial will assess whether the intervention can reduce exacerbation of asthma and unscheduled medical contacts in school-aged children associated with the return to school after the summer holidays. It has the potential to benefit the health and quality of life of children with asthma while also improving the effectiveness of NHS services by reducing NHS use in one of the busiest months of the year. An exploratory health economic analysis will gauge any cost saving associated with the intervention and subsequent impacts on quality of life. If results for the intervention are positive it is hoped that this could be adopted as part of routine care management of childhood asthma in general practice. Trial registration Current controlled trials: ISRCTN03000938 (assigned 19/10/12) http://www.controlled-trials.com/ISRCTN03000938/. UKCRN ID: 13572 PMID:24041259

The Diabetes Care Project: an Australian multicentre, cluster randomised controlled trial [study protocol

PubMed Central

2013-01-01

Background Diabetes mellitus is an increasingly prevalent metabolic disorder that is associated with substantial disease burden. Australia has an opportunity to improve ways of caring for the growing number of people with diabetes, but this may require changes to the way care is funded, organised and delivered. To inform how best to care for people with diabetes, and to identify the extent of change that is required to achieve this, the Diabetes Care Project (DCP) will evaluate the impact of two different, evidence-based models of care (compared to usual care) on clinical quality, patient and provider experience, and cost. Methods/Design The DCP uses a pragmatic, cluster randomised controlled trial design. Accredited general practices that are situated within any of the seven Australian Medicare Locals/Divisions of General Practice that have agreed to take part in the study were invited to participate. Consenting practices will be randomly assigned to one of three treatment groups for approximately 18 to 22 months: (a) control group (usual care); (b) Intervention 1 (which tests improvements that could be made within the current funding model, facilitated through the use of an online chronic disease management network); or (c) Intervention 2 (which includes the same components as Intervention 1, as well as altered funding to support voluntary patient registration with their practice, incentive payments and a care facilitator). Adult patients who attend the enrolled practices and have established (≥12 month’s duration) type 1 diabetes mellitus or newly diagnosed or established type 2 diabetes mellitus are invited to participate. Multiple outcomes will be studied, including changes in glycosylated haemoglobin (primary outcome), changes in other biochemical and clinical metrics, incidence of diabetes-related complications, quality of life, clinical depression, success of tailored care, patient and practitioner satisfaction, and budget sustainability. Discussion This project responds to a need for robust evidence of the clinical and economic effectiveness of coordinated care for the management of diabetes in the Australian primary care setting. The outcomes of the study will have implications not only for diabetes management, but also for the management of other chronic diseases, both in Australia and overseas. Trial registration Australian New Zealand Clinical Trials Registry (ACTRN12612000363886); World Health Organisation (U1111-1128-0481). PMID:24359432

Hepatitis C - Assessment to Treatment Trial (HepCATT) in primary care: study protocol for a cluster randomised controlled trial.

PubMed

Roberts, Kirsty; Macleod, John; Metcalfe, Chris; Simon, Joanne; Horwood, Jeremy; Hollingworth, William; Marlowe, Sharon; Gordon, Fiona H; Muir, Peter; Coleman, Barbara; Vickerman, Peter; Harrison, Graham I; Waldron, Cherry-Ann; Irving, William; Hickman, Matthew

2016-07-29

Public Health England (PHE) estimates that there are upwards of 160,000 individuals in England and Wales with chronic hepatitis C virus (HCV) infection, but until now only around 100,000 laboratory diagnoses have been reported to PHE and of these 28,000 have been treated. Targeted case-finding in primary care is estimated to be cost-effective; however, there has been no robust randomised controlled trial evidence available of specific interventions. Therefore, this study aims to develop and conduct a complex intervention within primary care and to evaluate this approach using a cluster randomised controlled trial. A total of 46 general practices in South West England will be randomised in a 1:1 ratio to receive either a complex intervention comprising: educational training on HCV for the practice; poster and leaflet display in the practice waiting rooms to raise awareness and encourage opportunistic testing; a HCV risk prediction algorithm based on information on possible risk markers in the electronic patient record run using Audit + software (BMJ Informatica). The audit will then be used to recall and offer patients a HCV test. Control practices will follow usual care. The effectiveness of the intervention will be measured by comparing number and rates of HCV testing, the number and proportion of patients testing positive, onward referral, rates of specialist assessment and treatment in control and intervention practices. Intervention costs and health service utilisation will be recorded to estimate the NHS cost per new HCV diagnosis and new HCV patient initiating treatment. Longer-term cost-effectiveness of the intervention in improving quality-adjusted life years (QALYs) will be extrapolated using a pre-existing dynamic health economic model. Patients' and health care workers' experiences and acceptability of the intervention will be explored through semi-structured qualitative interviews. This trial has the potential to make an important impact on patient care and will provide high-quality evidence to help general practitioners make important decisions on HCV testing and onward referral. If found to be effective and cost-effective the intervention is readily scalable and can be used to support the implementation of NICE recommendations on HCV case-finding. ISRCTN61788850 . Registered on 24 April 2015; Protocol Version: 2.0, 22 May 2015.

Site-Specific Biomolecule Labeling with Gold Clusters

PubMed Central

Ackerson, Christopher J.; Powell, Richard D.; Hainfeld, James F.

2013-01-01

Site-specific labeling of biomolecules in vitro with gold clusters can enhance the information content of electron cryomicroscopy experiments. This chapter provides a practical overview of well-established techniques for forming biomolecule/gold cluster conjugates. Three bioconjugation chemistries are covered: Linker-mediated bioconjugation, direct gold–biomolecule bonding, and coordination-mediated bonding of nickel(II) nitrilotriacetic acid (NTA)-derivatized gold clusters to polyhistidine (His)-tagged proteins. PMID:20887859

COSMOS--improving the quality of life in nursing home patients: protocol for an effectiveness-implementation cluster randomized clinical hybrid trial.

PubMed

Husebo, Bettina S; Flo, Elisabeth; Aarsland, Dag; Selbaek, Geir; Testad, Ingelin; Gulla, Christine; Aasmul, Irene; Ballard, Clive

2015-09-15

Nursing home patients have complex mental and physical health problems, disabilities and social needs, combined with widespread prescription of psychotropic drugs. Preservation of their quality of life is an important goal. This can only be achieved within nursing homes that offer competent clinical conditions of treatment and care. COmmunication, Systematic assessment and treatment of pain, Medication review, Occupational therapy, Safety (COSMOS) is an effectiveness-implementation hybrid trial that combines and implements organization of activities evidence-based interventions to improve staff competence and thereby the patients' quality of life, mental health and safety. The aim of this paper is to describe the development, content and implementation process of the COSMOS trial. COSMOS includes a 2-month pilot study with 128 participants distributed among nine Norwegian nursing homes, and a 4-month multicenter, cluster randomized effectiveness-implementation clinical hybrid trial with follow-up at month 9, including 571 patients from 67 nursing home units (one unit defined as one cluster). Clusters are randomized to COSMOS intervention or current best practice (control group). The intervention group will receive a 2-day education program including written guidelines, repeated theoretical and practical training (credited education of caregivers, physicians and nursing home managers), case discussions and role play. The 1-day midway evaluation, information and interviews of nursing staff and a telephone hotline all support the implementation process. Outcome measures include quality of life in late-stage dementia, neuropsychiatric symptoms, activities of daily living, pain, depression, sleep, medication, cost-utility analysis, hospital admission and mortality. Despite complex medical and psychosocial challenges, nursing home patients are often treated by staff possessing low level skills, lacking education and in facilities with a high staff turnover. Implementation of a research-based multicomponent intervention may improve staff's knowledge and competence and consequently the quality of life of nursing home patients in general and people with dementia in particular. ClinicalTrials.gov NCT02238652.

Social phobia subtypes in the general population revealed by cluster analysis.

PubMed

Furmark, T; Tillfors, M; Stattin, H; Ekselius, L; Fredrikson, M

2000-11-01

Epidemiological data on subtypes of social phobia are scarce and their defining features are debated. Hence, the present study explored the prevalence and descriptive characteristics of empirically derived social phobia subgroups in the general population. To reveal subtypes, data on social distress, functional impairment, number of social fears and criteria fulfilled for avoidant personality disorder were extracted from a previously published epidemiological study of 188 social phobics and entered into an hierarchical cluster analysis. Criterion validity was evaluated by comparing clusters on the Social Phobia Scale (SPS) and the Social Interaction Anxiety Scale (SIAS). Finally, profile analyses were performed in which clusters were compared on a set of sociodemographic and descriptive characteristics. Three clusters emerged, consisting of phobics scoring either high (generalized subtype), intermediate (non-generalized subtype) or low (discrete subtype) on all variables. Point prevalence rates were 2.0%, 5.9% and 7.7% respectively. All subtypes were distinguished on both SPS and SIAS. Generalized or severe social phobia tended to be over-represented among individuals with low levels of educational attainment and social support. Overall, public-speaking was the most common fear. Although categorical distinctions may be used, the present data suggest that social phobia subtypes in the general population mainly differ dimensionally along a mild moderate-severe continuum, and that the number of cases declines with increasing severity.

A new class of accelerated kinetic Monte Carlo algorithms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bulatov, V V; Oppelstrup, T; Athenes, M

2011-11-30

Kinetic (aka dynamic) Monte Carlo (KMC) is a powerful method for numerical simulations of time dependent evolution applied in a wide range of contexts including biology, chemistry, physics, nuclear sciences, financial engineering, etc. Generally, in a KMC the time evolution takes place one event at a time, where the sequence of events and the time intervals between them are selected (or sampled) using random numbers. While details of the method implementation vary depending on the model and context, there exist certain common issues that limit KMC applicability in almost all applications. Among such is the notorious 'flicker problem' where themore » same states of the systems are repeatedly visited but otherwise no essential evolution is observed. In its simplest form the flicker problem arises when two states are connected to each other by transitions whose rates far exceed the rates of all other transitions out of the same two states. In such cases, the model will endlessly hop between the two states otherwise producing no meaningful evolution. In most situation of practical interest, the trapping cluster includes more than two states making the flicker somewhat more difficult to detect and to deal with. Several methods have been proposed to overcome or mitigate the flicker problem, exactly [1-3] or approximately [4,5]. Of the exact methods, the one proposed by Novotny [1] is perhaps most relevant to our research. Novotny formulates the problem of escaping from a trapping cluster as a Markov system with absorbing states. Given an initial state inside the cluster, it is in principle possible to solve the Master Equation for the time dependent probabilities to find the walker in a given state (transient or absorbing) of the cluster at any time in the future. Novotny then proceeds to demonstrate implementation of his general method to trapping clusters containing the initial state plus one or two transient states and all of their absorbing states. Similar methods have been subsequently proposed in [refs] but applied in a different context. The most serious deficiency of the earlier methods is that size of the trapping cluster size is fixed and often too small to bring substantial simulation speedup. Furthermore, the overhead associated with solving for the probability distribution on the trapping cluster sometimes makes such simulations less efficient than the standard KMC. Here we report on a general and exact accelerated kinetic Monte Carlo algorithm generally applicable to arbitrary Markov models1. Two different implementations are attempted both based on incremental expansion of trapping sub-set of Markov states: (1) numerical solution of the Master Equation with absorbing states and (2) incremental graph reduction followed by randomization. Of the two implementations, the 2nd one performs better allowing, for the first time, to overcome trapping basins spanning several million Markov states. The new method is used for simulations of anomalous diffusion on a 2D substrate and of the kinetics of diffusive 1st order phase transformations in binary alloys. Depending on temperature and (alloy) super-saturation conditions, speedups of 3 to 7 orders of magnitude are demonstrated, with no compromise of simulation accuracy.« less

Analysis of ehealth search perspectives among female college students in the health professions using Q methodology.

PubMed

Stellefson, Michael; Hanik, Bruce; Chaney, J Don; Tennant, Bethany

2012-04-27

The current "Millennial Generation" of college students majoring in the health professions has unprecedented access to the Internet. Although some research has been initiated among medical professionals to investigate the cognitive basis for health information searches on the Internet, little is known about Internet search practices among health and medical professional students. To systematically identify health professional college student perspectives of personal eHealth search practices. Q methodology was used to examine subjective perspectives regarding personal eHealth search practices among allied health students majoring in a health education degree program. Thirteen (n = 13) undergraduate students were interviewed about their attitudes and experiences conducting eHealth searches. From the interviews, 36 statements were used in a structured ranking task to identify clusters and determine which specific perceptions of eHealth search practices discriminated students into different groups. Scores on an objective measure of eHealth literacy were used to help categorize participant perspectives. Q-technique factor analysis of the rankings identified 3 clusters of respondents with differing views on eHealth searches that generally coincided with participants' objective eHealth literacy scores. The proficient resourceful students (pattern/structure coefficient range 0.56-0.80) described themselves as using multiple resources to obtain eHealth information, as opposed to simply relying on Internet search engines. The intermediate reluctant students (pattern/structure coefficient range 0.75-0.90) reported engaging only Internet search engines to locate eHealth information, citing undeveloped evaluation skills when considering sources of information located on the Internet. Both groups of advanced students reported not knowing how to use Boolean operators to conduct Internet health searches. The basic hubristic students (pattern/structure coefficient range 0.54-0.76) described themselves as independent procrastinators when searching for eHealth information. Interestingly, basic hubristic students represented the only cluster of participants to describe themselves as (1) having received instruction on using the Internet to conduct eHealth searches, and (2) possessing relative confidence when completing a search task. Subjective perspectives of eHealth search practices differed among students possessing different levels of eHealth literacy. These multiple perspectives present both challenges and opportunities for empowering college students in the health professions to use the Internet to obtain and appraise evidence-based health information using the Internet.

The implementation of integrated care: the empirical validation of the Development Model for Integrated Care

PubMed Central

2011-01-01

Background Integrated care is considered as a strategy to improve the delivery, efficiency, client outcomes and satisfaction rates of health care. To integrate the care from multiple providers into a coherent client-focused service, a large number of activities and agreements have to be implemented like streamlining information flows and patient transfers. The Development Model for Integrated care (DMIC) describes nine clusters containing in total 89 elements that contribute to the integration of care. We have empirically validated this model in practice by assessing the relevance, implementation and plans of the elements in three integrated care service settings in The Netherlands: stroke, acute myocardial infarct (AMI), and dementia. Methods Based on the DMIC, a survey was developed for integrated care coordinators. We invited all Dutch stroke and AMI-services, as well as the dementia care networks to participate, of which 84 did (response rate 83%). Data were collected on relevance, presence, and year of implementation of the 89 elements. The data analysis was done by means of descriptive statistics, Chi Square, ANOVA and Kruskal-Wallis H tests. Results The results indicate that the integrated care practice organizations in all three care settings rated the nine clusters and 89 elements of the DMIC as highly relevant. The average number of elements implemented was 50 ± 18, 42 ± 13, and 45 ± 22 for stroke, acute myocardial infarction, and dementia care services, respectively. Although the dementia networks were significantly younger, their numbers of implemented elements were comparable to those of the other services. The analyses of the implementation timelines showed that the older integrated care services had fewer plans for further implementation than the younger ones. Integrated care coordinators stated that the DMIC helped them to assess their integrated care development in practice and supported them in obtaining ideas for expanding their integrated care activities. Conclusions Although the patient composites and the characteristics of the 84 participating integrated care services differed considerably, the results confirm that the clusters and the vast majority of DMIC elements are relevant to all three groups. Therefore, the DMIC can serve as a general quality management tool for integrated care. Applying the model in practice can help in steering further implementations as well as the development of new integrated care practices. PMID:21801428

Analysis of eHealth Search Perspectives Among Female College Students in the Health Professions Using Q Methodology

PubMed Central

Hanik, Bruce; Chaney, J. Don; Tennant, Bethany

2012-01-01

Background The current “Millennial Generation” of college students majoring in the health professions has unprecedented access to the Internet. Although some research has been initiated among medical professionals to investigate the cognitive basis for health information searches on the Internet, little is known about Internet search practices among health and medical professional students. Objective To systematically identify health professional college student perspectives of personal eHealth search practices. Methods Q methodology was used to examine subjective perspectives regarding personal eHealth search practices among allied health students majoring in a health education degree program. Thirteen (n = 13) undergraduate students were interviewed about their attitudes and experiences conducting eHealth searches. From the interviews, 36 statements were used in a structured ranking task to identify clusters and determine which specific perceptions of eHealth search practices discriminated students into different groups. Scores on an objective measure of eHealth literacy were used to help categorize participant perspectives. Results Q-technique factor analysis of the rankings identified 3 clusters of respondents with differing views on eHealth searches that generally coincided with participants’ objective eHealth literacy scores. The proficient resourceful students (pattern/structure coefficient range 0.56-0.80) described themselves as using multiple resources to obtain eHealth information, as opposed to simply relying on Internet search engines. The intermediate reluctant students (pattern/structure coefficient range 0.75-0.90) reported engaging only Internet search engines to locate eHealth information, citing undeveloped evaluation skills when considering sources of information located on the Internet. Both groups of advanced students reported not knowing how to use Boolean operators to conduct Internet health searches. The basic hubristic students (pattern/structure coefficient range 0.54-0.76) described themselves as independent procrastinators when searching for eHealth information. Interestingly, basic hubristic students represented the only cluster of participants to describe themselves as (1) having received instruction on using the Internet to conduct eHealth searches, and (2) possessing relative confidence when completing a search task. Conclusions Subjective perspectives of eHealth search practices differed among students possessing different levels of eHealth literacy. These multiple perspectives present both challenges and opportunities for empowering college students in the health professions to use the Internet to obtain and appraise evidence-based health information using the Internet. PMID:22543437

The implementation of integrated care: the empirical validation of the Development Model for Integrated care.

PubMed

Minkman, Mirella M N; Vermeulen, Robbert P; Ahaus, Kees T B; Huijsman, Robbert

2011-07-30

Integrated care is considered as a strategy to improve the delivery, efficiency, client outcomes and satisfaction rates of health care. To integrate the care from multiple providers into a coherent client-focused service, a large number of activities and agreements have to be implemented like streamlining information flows and patient transfers. The Development Model for Integrated care (DMIC) describes nine clusters containing in total 89 elements that contribute to the integration of care. We have empirically validated this model in practice by assessing the relevance, implementation and plans of the elements in three integrated care service settings in The Netherlands: stroke, acute myocardial infarct (AMI), and dementia. Based on the DMIC, a survey was developed for integrated care coordinators. We invited all Dutch stroke and AMI-services, as well as the dementia care networks to participate, of which 84 did (response rate 83%). Data were collected on relevance, presence, and year of implementation of the 89 elements. The data analysis was done by means of descriptive statistics, Chi Square, ANOVA and Kruskal-Wallis H tests. The results indicate that the integrated care practice organizations in all three care settings rated the nine clusters and 89 elements of the DMIC as highly relevant. The average number of elements implemented was 50 ± 18, 42 ± 13, and 45 ± 22 for stroke, acute myocardial infarction, and dementia care services, respectively. Although the dementia networks were significantly younger, their numbers of implemented elements were comparable to those of the other services. The analyses of the implementation timelines showed that the older integrated care services had fewer plans for further implementation than the younger ones. Integrated care coordinators stated that the DMIC helped them to assess their integrated care development in practice and supported them in obtaining ideas for expanding their integrated care activities. Although the patient composites and the characteristics of the 84 participating integrated care services differed considerably, the results confirm that the clusters and the vast majority of DMIC elements are relevant to all three groups. Therefore, the DMIC can serve as a general quality management tool for integrated care. Applying the model in practice can help in steering further implementations as well as the development of new integrated care practices.

Screening versus routine practice in detection of atrial fibrillation in patients aged 65 or over: cluster randomised controlled trial

PubMed Central

Fitzmaurice, David A; Jowett, Sue; Mant, Jonathon; Murray, Ellen T; Holder, Roger; Raftery, J P; Bryan, S; Davies, Michael; Lip, Gregory Y H; Allan, T F

2007-01-01

Objectives To assess whether screening improves the detection of atrial fibrillation (cluster randomisation) and to compare systematic and opportunistic screening. Design Multicentred cluster randomised controlled trial, with subsidiary trial embedded within the intervention arm. Setting 50 primary care centres in England, with further individual randomisation of patients in the intervention practices. Participants 14 802 patients aged 65 or over in 25 intervention and 25 control practices. Interventions Patients in intervention practices were randomly allocated to systematic screening (invitation for electrocardiography) or opportunistic screening (pulse taking and invitation for electrocardiography if the pulse was irregular). Screening took place over 12 months in each practice from October 2001 to February 2003. No active screening took place in control practices. Main outcome measure Newly identified atrial fibrillation. Results The detection rate of new cases of atrial fibrillation was 1.63% a year in the intervention practices and 1.04% in control practices (difference 0.59%, 95% confidence interval 0.20% to 0.98%). Systematic and opportunistic screening detected similar numbers of new cases (1.62% v 1.64%, difference 0.02%, −0.5% to 0.5%). Conclusion Active screening for atrial fibrillation detects additional cases over current practice. The preferred method of screening in patients aged 65 or over in primary care is opportunistic pulse taking with follow-up electrocardiography. Trial registration Current Controlled Trials ISRCTN19633732. PMID:17673732

Factors associated with nutritional status and dietary practices of Bangladeshi adolescents in early pregnancy.

PubMed

Mridha, Malay K; Matias, Susana L; Arnold, Charles D; Dewey, Kathryn G

2018-02-18

Bangladesh has a high prevalence of adolescent pregnancy, but little is known about the nutritional status and dietary practices of Bangladeshi adolescents in early pregnancy or associated factors. We used the baseline data of 1552 pregnant adolescents from a longitudinal, cluster-randomized effectiveness trial conducted in northwest Bangladesh. Forty-four percent of the adolescents were short for their age, 36% had low body mass index, 28% were anemic, 10% had iron deficiency, and 32% had vitamin A deficiency. The mean consumption of animal-source foods was 10.3 times/week. In multivariate analysis, socioeconomic status, education, and food security were generally positively associated with anthropometric indicators and dietary practices but not with iron or vitamin A status. Our findings confirm that there is a high burden of undernutrition among these Bangladeshi adolescents in early pregnancy. Understanding factors related to undernutrition can help to identify adolescent pregnant women at higher risk and provide appropriate counseling and care. © 2018 New York Academy of Sciences.

Preventing chronic disease in patients with low health literacy using eHealth and teamwork in primary healthcare: protocol for a cluster randomised controlled trial.

PubMed

Parker, Sharon M; Stocks, Nigel; Nutbeam, Don; Thomas, Louise; Denney-Wilson, Elizabeth; Zwar, Nicholas; Karnon, Jon; Lloyd, Jane; Noakes, Manny; Liaw, Siaw-Teng; Lau, Annie; Osborne, Richard; Harris, Mark F

2018-06-04

Adults with lower levels of health literacy are less likely to engage in health-promoting behaviours. Our trial evaluates the impacts and outcomes of a mobile health-enhanced preventive intervention in primary care for people who are overweight or obese. A two-arm pragmatic practice-level cluster randomised trial will be conducted in 40 practices in low socioeconomic areas in Sydney and Adelaide, Australia. Forty patients aged 40-70 years with a body mass index ≥28 kg/m 2 will be enrolled per practice. The HeLP-general practitioner (GP) intervention includes a practice-level quality improvement intervention (medical record audit and feedback, staff training and practice facilitation visits) to support practices to implement the clinical intervention for patients. The clinical intervention involves a health check visit with a practice nurse based on the 5As framework (assess, advise, agree, assist and arrange), the use of a purpose-built patient-facing app, my snapp , and referral for telephone coaching. The primary outcomes are change in health literacy, lifestyle behaviours, weight, waist circumference and blood pressure. The study will also evaluate changes in quality of life and health service use to determine the cost-effectiveness of the intervention and examine the experiences of practices in implementing the programme. The study has been approved by the University of New South Wales (UNSW) Human Research Ethics Committee (HC17474) and ratified by the University of Adelaide Human Research Ethics committee. There are no restrictions on publication, and findings of the study will be made available to the public via the Centre for Primary Health Care and Equity website and through conference presentations and research publications. Deidentified data and meta-data will be stored in a repository at UNSW and made available subject to ethics committee approval. ACTRN12617001508369; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Prevalence of chronic stress in general practitioners and practice assistants: Personal, practice and regional characteristics

PubMed Central

Kersting, Christine; Thielmann, Anika; Weltermann, Birgitta

2017-01-01

Background The majority of studies investigating stress in primary care have focused either on general practitioners (GPs) or practice assistants (PAs), but did not measure stress on a practice level. We analyzed the prevalence of chronic stress for both professional groups and on a practice level and investigated personal, practice, and regional characteristics. Methods Chronic stress was measured in GPs and PAs from 136 German practices using the standardized, self-administered TICS-SSCS questionnaire (12 items). Based on a sum-score, participants per professional group were categorized as having low or high strain due to chronic stress (≤ 25th and ≥ 75th percentile of the study population´s distribution, respectively). For a cluster-level analysis, the mean of all practice means was used to categorize low- and high-stress practices. The intra-class correlation coefficient (ICC) was calculated using ANOVA. Prevalence Ratios (PR) were used to compare low versus high strain due to stress, stratified for personal, practice and regional characteristics. Results The response rate was 74.1% (n = 137/185). Data from 214 GPs (34.1% female), 500 PAs (99.4% female), and 50 PAs in training (98.0% female) were analyzed. Chronic stress was highest in female GPs (median 19, IQR (interquartile range) 11.5), followed by PAs (16, IQR 12.25) and male GPs (15, IQR 10). On a practice level, 26.3% of the practice personnel reported a high stress level. We observed an overall ICC of 0.25, with higher ICCs when stratifying by professional group (PAs: ICC 0.36, GPs in group practices: ICC 0.51). High chronic stress was observed as the number of working hours per week increased (GPs: PR 2.03, 95% CI 1.16–3.56; PAs: PR 2.02, 95% CI 1.22–3.35). There were no differences for practice type (solo/group) and the various regional characteristics. Conclusion Personal and practice characteristics were associated with chronic stress in GPs, PAs, and on a practice level. The high ICCs indicate a need for stress-reduction strategies geared at both professions on a practice level. PMID:28489939

75 FR 41521 - Delphi Corporation, Automotive Holding Group, Instrument Cluster Plant, Currently Known as...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-16

..., Automotive Holding Group, Instrument Cluster Plant, Currently Known as General Motors Corporation, Including... Corporation, Automotive Holding Group, Instrument Cluster Plant, including on-site leased workers from... Material Management working on-site at Delphi Corporation, Automotive Holding Group, Instrument Cluster...

Do Dads Make a Difference? Family Feeding Dynamics and Child Fussy Eating.

PubMed

Harris, Holly A; Jansen, Elena; Mallan, Kimberley M; Daniels, Lynne; Thorpe, Karen

2018-06-01

Few studies on child feeding have focused on family dynamics or disadvantaged families, yet feeding occurs in the complex social, economic, and relational context of the family. We examined how the level (high vs low) and concordance (concordant vs discordant) of nonresponsive feeding practices of mothers and fathers are associated with child fussy eating, in a socioeconomically disadvantaged Australian sample. Mother-father pairs (N = 208) of children aged 2 to 5 years old independently completed validated questionnaires reporting their "persuasive feeding," "reward for eating," "reward for behavior," and child's "food fussiness." The fussiness scores did not differ between mother-father pairs and were averaged to derive a single dependent variable. K-means cluster analyses were used to assign mother-father pairs to clusters for each feeding practice, based on mean scores. Three ANCOVAs, corresponding to each feeding practice, tested differences in child fussiness across clusters while controlling for covariates. Four clusters were identified for each feeding practice-concordant: (1) high (MHi/FHi) for both parents and (2) low (MLo/FLo) for both parents; and discordant: (3) high for mother but low for father (MHi/FLo); and (4) low for mother but high for father (MLo/FHi). For "persuasive feeding," MLo/FLo reported lower levels of fussiness compared with MHi/FLo, MHi/FHi, and MLo/FHi (p values < 0.05). For "reward for eating," MLo/FLo reported lower levels of fussiness than did MHi/FHi (p < 0.05). Child fussiness did not differ across "reward for behavior" clusters. In socioeconomically disadvantaged families, when parents are concordant in avoiding nonresponsive feeding practices, less child "food fussiness" is reported. Findings suggest that feeding interventions should consider inclusion of both parents in 2-parent households.

Integrated solutions for sustainable fall prevention in primary care, the iSOLVE project: a type 2 hybrid effectiveness-implementation design.

PubMed

Clemson, Lindy; Mackenzie, Lynette; Roberts, Chris; Poulos, Roslyn; Tan, Amy; Lovarini, Meryl; Sherrington, Cathie; Simpson, Judy M; Willis, Karen; Lam, Mary; Tiedemann, Anne; Pond, Dimity; Peiris, David; Hilmer, Sarah; Pit, Sabrina Winona; Howard, Kirsten; Lovitt, Lorraine; White, Fiona

2017-02-07

Despite strong evidence giving guidance for effective fall prevention interventions in community-residing older people, there is currently no clear model for engaging general medical practitioners in fall prevention and routine use of allied health professionals in fall prevention has been slow, limiting widespread dissemination. This protocol paper outlines an implementation-effectiveness study of the Integrated Solutions for Sustainable Fall Prevention (iSOLVE) intervention which has developed integrated processes and pathways to identify older people at risk of falls and engage a whole of primary care approach to fall prevention. This protocol paper presents the iSOLVE implementation processes and change strategies and outlines the study design of a blended type 2 hybrid design. The study consists of a two-arm cluster randomized controlled trial in 28 general practices and recruiting 560 patients in Sydney, Australia, to evaluate effectiveness of the iSOLVE intervention in changing general practitioner fall management practices and reducing patient falls and the cost effectiveness from a healthcare funder perspective. Secondary outcomes include change in medications known to increase fall risk. We will simultaneously conduct a multi-methodology evaluation to investigate the workability and utility of the implementation intervention. The implementation evaluation includes in-depth interviews and surveys with general practitioners and allied health professionals to explore acceptability and uptake of the intervention, the coherence of the proposed changes for those in the work setting, and how to facilitate the collective action needed to implement changes in practice; social network mapping will explore professional relationships and influences on referral patterns; and, a survey of GPs in the geographical intervention zone will test diffusion of evidence-based fall prevention practices. The project works in partnership with a primary care health network, state fall prevention leaders, and a community of practice of fall prevention advocates. The design is aimed at providing clear direction for sustainability and informing decisions about generalization of the iSOLVE intervention processes and change strategies. While challenges exist in hybrid designs, there is a potential for significant outcomes as the iSOLVE pathways project brings together practice and research to collectively solve a major national problem with implications for policy service delivery. Australian New Zealand Clinial Trials Registry ACTRN12615000401550.

Cluster Randomized Controlled Trial: Clinical and Cost-Effectiveness of a System of Longer-Term Stroke Care.

PubMed

Forster, Anne; Young, John; Chapman, Katie; Nixon, Jane; Patel, Anita; Holloway, Ivana; Mellish, Kirste; Anwar, Shamaila; Breen, Rachel; Knapp, Martin; Murray, Jenni; Farrin, Amanda

2015-08-01

We developed a new postdischarge system of care comprising a structured assessment covering longer-term problems experienced by patients with stroke and their carers, linked to evidence-based treatment algorithms and reference guides (the longer-term stroke care system of care) to address the poor longer-term recovery experienced by many patients with stroke. A pragmatic, multicentre, cluster randomized controlled trial of this system of care. Eligible patients referred to community-based Stroke Care Coordinators were randomized to receive the new system of care or usual practice. The primary outcome was improved patient psychological well-being (General Health Questionnaire-12) at 6 months; secondary outcomes included functional outcomes for patients, carer outcomes, and cost-effectiveness. Follow-up was through self-completed postal questionnaires at 6 and 12 months. Thirty-two stroke services were randomized (29 participated); 800 patients (399 control; 401 intervention) and 208 carers (100 control; 108 intervention) were recruited. In intention to treat analysis, the adjusted difference in patient General Health Questionnaire-12 mean scores at 6 months was -0.6 points (95% confidence interval, -1.8 to 0.7; P=0.394) indicating no evidence of statistically significant difference between the groups. Costs of Stroke Care Coordinator inputs, total health and social care costs, and quality-adjusted life year gains at 6 months, 12 months, and over the year were similar between the groups. This robust trial demonstrated no benefit in clinical or cost-effectiveness outcomes associated with the new system of care compared with usual Stroke Care Coordinator practice. URL: http://www.controlled-trials.com. Unique identifier: ISRCTN 67932305. © 2015 Bradford Teaching Hospitals NHS Foundation Trust.

Cluster Randomized Controlled Trial

PubMed Central

Young, John; Chapman, Katie; Nixon, Jane; Patel, Anita; Holloway, Ivana; Mellish, Kirste; Anwar, Shamaila; Breen, Rachel; Knapp, Martin; Murray, Jenni; Farrin, Amanda

2015-01-01

Background and Purpose— We developed a new postdischarge system of care comprising a structured assessment covering longer-term problems experienced by patients with stroke and their carers, linked to evidence-based treatment algorithms and reference guides (the longer-term stroke care system of care) to address the poor longer-term recovery experienced by many patients with stroke. Methods— A pragmatic, multicentre, cluster randomized controlled trial of this system of care. Eligible patients referred to community-based Stroke Care Coordinators were randomized to receive the new system of care or usual practice. The primary outcome was improved patient psychological well-being (General Health Questionnaire-12) at 6 months; secondary outcomes included functional outcomes for patients, carer outcomes, and cost-effectiveness. Follow-up was through self-completed postal questionnaires at 6 and 12 months. Results— Thirty-two stroke services were randomized (29 participated); 800 patients (399 control; 401 intervention) and 208 carers (100 control; 108 intervention) were recruited. In intention to treat analysis, the adjusted difference in patient General Health Questionnaire-12 mean scores at 6 months was −0.6 points (95% confidence interval, −1.8 to 0.7; P=0.394) indicating no evidence of statistically significant difference between the groups. Costs of Stroke Care Coordinator inputs, total health and social care costs, and quality-adjusted life year gains at 6 months, 12 months, and over the year were similar between the groups. Conclusions— This robust trial demonstrated no benefit in clinical or cost-effectiveness outcomes associated with the new system of care compared with usual Stroke Care Coordinator practice. Clinical Trial Registration— URL: http://www.controlled-trials.com. Unique identifier: ISRCTN 67932305. PMID:26152298

Prevalence and risk factors of seizure clusters in adult patients with epilepsy.

PubMed

Chen, Baibing; Choi, Hyunmi; Hirsch, Lawrence J; Katz, Austen; Legge, Alexander; Wong, Rebecca A; Jiang, Alfred; Kato, Kenneth; Buchsbaum, Richard; Detyniecki, Kamil

2017-07-01

In the current study, we explored the prevalence of physician-confirmed seizure clusters. We also investigated potential clinical factors associated with the occurrence of seizure clusters overall and by epilepsy type. We reviewed medical records of 4116 adult (≥16years old) outpatients with epilepsy at our centers for documentation of seizure clusters. Variables including patient demographics, epilepsy details, medical and psychiatric history, AED history, and epilepsy risk factors were then tested against history of seizure clusters. Patients were then divided into focal epilepsy, idiopathic generalized epilepsy (IGE), or symptomatic generalized epilepsy (SGE), and the same analysis was run. Overall, seizure clusters were independently associated with earlier age of seizure onset, symptomatic generalized epilepsy (SGE), central nervous system (CNS) infection, cortical dysplasia, status epilepticus, absence of 1-year seizure freedom, and having failed 2 or more AEDs (P<0.0026). Patients with SGE (27.1%) were more likely to develop seizure clusters than patients with focal epilepsy (16.3%) and IGE (7.4%; all P<0.001). Analysis by epilepsy type showed that absence of 1-year seizure freedom since starting treatment at one of our centers was associated with seizure clustering in patients across all 3 epilepsy types. In patients with SGE, clusters were associated with perinatal/congenital brain injury. In patients with focal epilepsy, clusters were associated with younger age of seizure onset, complex partial seizures, cortical dysplasia, status epilepticus, CNS infection, and having failed 2 or more AEDs. In patients with IGE, clusters were associated with presence of an aura. Only 43.5% of patients with seizure clusters were prescribed rescue medications. Patients with intractable epilepsy are at a higher risk of developing seizure clusters. Factors such as having SGE, CNS infection, cortical dysplasia, status epilepticus or an early seizure onset, can also independently increase one's chance of having seizure clusters. Copyright © 2017. Published by Elsevier B.V.

Proactive and integrated primary care for frail older people: design and methodological challenges of the Utrecht primary care PROactive frailty intervention trial (U-PROFIT).

PubMed

Bleijenberg, Nienke; Drubbel, Irene; Ten Dam, Valerie H; Numans, Mattijs E; Schuurmans, Marieke J; de Wit, Niek J

2012-04-25

Currently, primary care for frail older people is reactive, time consuming and does not meet patients' needs. A transition is needed towards proactive and integrated care, so that daily functioning and a good quality of life can be preserved. To work towards these goals, two interventions were developed to enhance the care of frail older patients in general practice: a screening and monitoring intervention using routine healthcare data (U-PRIM) and a nurse-led multidisciplinary intervention program (U-CARE). The U-PROFIT trial was designed to evaluate the effectiveness of these interventions. The aim of this paper is to describe the U-PROFIT trial design and to discuss methodological issues and challenges. The effectiveness of U-PRIM and U-CARE is being tested in a three-armed, cluster randomized trial in 58 general practices in the Netherlands, with approximately 5000 elderly individuals expected to participate. The primary outcome is the effect on activities of daily living as measured with the Katz ADL index. Secondary outcomes are quality of life, mortality, nursing home admission, emergency department and out-of-hours General Practice (GP), surgery visits, and caregiver burden. In a large, pragmatic trial conducted in daily clinical practice with frail older patients, several challenges and methodological issues will occur. Recruitment and retention of patients and feasibility of the interventions are important issues. To enable broad generalizability of results, careful choices of the design and outcome measures are required. Taking this into account, the U-PROFIT trial aims to provide robust evidence for a structured and integrated approach to provide care for frail older people in primary care. NTR2288.

Improved guideline adherence to pharmacotherapy of chronic systolic heart failure in general practice--results from a cluster-randomized controlled trial of implementation of a clinical practice guideline.

PubMed

Peters-Klimm, Frank; Müller-Tasch, Thomas; Remppis, Andrew; Szecsenyi, Joachim; Schellberg, Dieter

2008-10-01

Clinical practice guidelines (CPG) reflect the evidence of effective pharmacotherapy of chronic (systolic) heart failure (CHF) which needs to be implemented. This study aimed to evaluate the effect of a new, multifaceted intervention (educational train-the-trainer course plus pharmacotherapy feedback = TTT) compared with standard education on guideline adherence (GA) in general practice. Thirty-seven participating general practitioners (GPs) were randomized (18 vs. 19) and included 168 patients with ascertained symptomatic CHF [New York Heart Association (NYHA) II-IV]. Groups received CPG, the TTT intervention consisted of four interactive educational meetings and a pharmacotherapy feedback, while the control group received a usual lecture (Standard). Outcome measure was GA assessed by prescription rates and target dosing of angiotensin converting enzyme (ACE) inhibitors (ACE-I) or angiotensin receptor blockers (ARB), beta-blockers (BB) and aldosterone antagonists (AA) at baseline and 7-month follow-up. Group comparisons at follow-up were adjusted to GA, sex, age and NYHA stage at baseline. Prescription rates at baseline (n = 168) were high (ACE-I/ARB 90, BB 79 and AA 29%) in both groups. At follow up (n = 146), TTT improved compared with Standard regarding AA (43% vs. 23%, P = 0.04) and the rates of reached target doses of ACE-I/ARB (28% vs. 15%, P = 0.04). TTT group achieved significantly higher mean percentages of daily target dose (52% vs. 42%, mean difference 10.3%, 95% CI 0.84-19.8, P = 0.03). Despite of pre-existing high GA in both groups and an active control group, the multifaceted intervention was effective in quality of care measured by GA. Further research is needed on the choice of interventions in different provider populations.

Lensed Type Ia supernovae as probes of cluster mass models

Science.gov Websites

SAO/NASA ADS Astronomy Abstract Service Title: Lensed Type Ia supernovae as probes of cluster mass Origin: OUP Astronomy Keywords: gravitational lensing: strong, supernovae: general, galaxies: clusters

Enrichment Clusters: A Practical Plan for Real-World, Student-Driven Learning.

ERIC Educational Resources Information Center

Renzulli, Joseph S.; Gentry, Marcia; Reis, Sally M.

This guidebook provides a rationale and guidelines for implementing a student-driven learning approach using enrichment clusters. Enrichment clusters allow students who share a common interest to meet each week to produce a product, performance, or targeted service based on that common interest. Chapter 1 discusses different models of learning.…

Improving Performance for Gifted Students in a Cluster Grouping Model

ERIC Educational Resources Information Center

Brulles, Dina; Saunders, Rachel; Cohn, Sanford J.

2010-01-01

Although experts in gifted education widely promote cluster grouping gifted students, little empirical evidence is available to attest to its effectiveness. This study is an example of comparative action research in the form of a quantitative case study that focused on the mandated cluster grouping practices for gifted students in an urban…

Implementation of the force decomposition machine for molecular dynamics simulations.

PubMed

Borštnik, Urban; Miller, Benjamin T; Brooks, Bernard R; Janežič, Dušanka

2012-09-01

We present the design and implementation of the force decomposition machine (FDM), a cluster of personal computers (PCs) that is tailored to running molecular dynamics (MD) simulations using the distributed diagonal force decomposition (DDFD) parallelization method. The cluster interconnect architecture is optimized for the communication pattern of the DDFD method. Our implementation of the FDM relies on standard commodity components even for networking. Although the cluster is meant for DDFD MD simulations, it remains general enough for other parallel computations. An analysis of several MD simulation runs on both the FDM and a standard PC cluster demonstrates that the FDM's interconnect architecture provides a greater performance compared to a more general cluster interconnect. Copyright © 2012 Elsevier Inc. All rights reserved.

Morbidity is related to a green living environment.

PubMed

Maas, J; Verheij, R A; de Vries, S; Spreeuwenberg, P; Schellevis, F G; Groenewegen, P P

2009-12-01

As a result of increasing urbanisation, people face the prospect of living in environments with few green spaces. There is increasing evidence for a positive relation between green space in people's living environment and self-reported indicators of physical and mental health. This study investigates whether physician-assessed morbidity is also related to green space in people's living environment. Morbidity data were derived from electronic medical records of 195 general practitioners in 96 Dutch practices, serving a population of 345,143 people. Morbidity was classified by the general practitioners according to the International Classification of Primary Care. The percentage of green space within a 1 km and 3 km radius around the postal code coordinates was derived from an existing database and was calculated for each household. Multilevel logistic regression analyses were performed, controlling for demographic and socioeconomic characteristics. The annual prevalence rate of 15 of the 24 disease clusters was lower in living environments with more green space in a 1 km radius. The relation was strongest for anxiety disorder and depression. The relation was stronger for children and people with a lower socioeconomic status. Furthermore, the relation was strongest in slightly urban areas and not apparent in very strongly urban areas. This study indicates that the previously established relation between green space and a number of self-reported general indicators of physical and mental health can also be found for clusters of specific physician-assessed morbidity. The study stresses the importance of green space close to home for children and lower socioeconomic groups.

An Investigation into the Lifestyle, Health Habits and Risk Factors of Young Adults

PubMed Central

Al-Nakeeb, Yahya; Lyons, Mark; Dodd, Lorna J.; Al-Nuaim, Anwar

2015-01-01

This project examined the lifestyle, health habits and risk factors of young adults at Qatar University. It explored the clustering and differences in dietary habits, body mass index (BMI) and physical activity (PA) amongst male and female students, both Qatari and non-Qatari. Seven hundred thirty two students aged 18–25 years completed a self-reported questionnaire and an objective measure of BMI. Males and females had a high prevalence of being overweight and obesity and low levels of PA, according to well-established international standards. Three clusters were identified based on the students’ lifestyle and dietary habits. Cluster 1 (high risk factors) included those who engaged the least in healthy dietary practices and consumed the most unhealthy foods, participated in less PA and had the highest BMI. Cluster 2 (moderate risk factors) included those with considerably more habits falling into the moderate category, engagement in the most PA, the least TV and computer viewing time and had the lowest BMI. Cluster 3 (low risk factors) included those who engaged the most with the four healthy dietary practices, the least with the four unhealthy dietary practices and participated in moderate PA per week. This project provides valuable data that could be used by policy makers to address issues concerning student’s health. PMID:25913183

Epidemiology and viral etiology of the influenza-like illness in corsica during the 2012-2013 Winter: an analysis of several sentinel surveillance systems.

PubMed

Minodier, Laëtitia; Arena, Christophe; Heuze, Guillaume; Ruello, Marc; Amoros, Jean Pierre; Souty, Cécile; Varesi, Laurent; Falchi, Alessandra

2014-01-01

Influenza-like illness (ILI) surveillance is important to identify circulating and emerging/reemerging strains and unusual epidemiological trends. The present study aimed to give an accurate picture of the 2012-2013 ILI outbreak in Corsica by combining data from several surveillance systems: general practice, emergency general practice, hospital emergency units, intensive care units, and nursing homes. Twenty-eight respiratory viruses were retrospectively investigated from patients in general practice with ILI. Sequence analysis of the genetic changes in the hemagglutinin gene of influenza viruses (A(H1N1)pdm2009, A(H3N2) and B) was performed. The trends in ILI/influenza consultation rates and the relative illness ratios (RIRs) of having an ILI consultation were estimated by age group for the different surveillance systems analyzed. Of the 182 ILI patients enrolled by general practitioners, 57.7% tested positive for influenza viruses. Phylogenetic analyses suggested a genetic drift for influenza B and A(H3N2) viruses. The ILI/influenza surveillance systems showed similar trends and were well correlated. In accordance with virological data, the RIRs of having an ILI consultation were highest among the young (<15 years old) and decreased with age. No clusters of acute respiratory illness were declared by the sentinel nursing homes. This study is noteworthy in that it is the first extensive description of the 2012-2013 ILI outbreak in Corsica as monitored through several surveillance systems. To improve ILI surveillance in Corsica, a consortium that links together the complementary regional surveillance ILI systems described here is being implemented.

Cross-sectional survey of older patients' views regarding multidisciplinary care for chronic conditions in general practice.

PubMed

Bonney, Andrew; Magee, Christopher; Pearson, Russell

2014-01-01

The ageing population and increasing prevalence of chronic illness have contributed to the need for significant primary care reform, including increased use of multidisciplinary care and task substitution. This cross-sectional study explores conditions under which older patients would accept having health professionals other than their general practitioner (GP) involved in their care for chronic disease management (CDM). Ten practices were randomly sampled from a contiguous major city and inner regional area. Questionnaires were distributed to consecutive patients aged 60 years and over in each practice. Agency theory was used to inform analyses. Statistical analysis was undertaken using Wald's test, growth modelling and linear regression, controlling for the clustered design. The response rate was 53% (n=272). Most respondents (79%) had at least one chronic health condition. Respondents were more comfortable with GP than with practice nurse management in the CDM scenario (Wald's test=105.49, P<0.001). Comfort with practice nurse CDM was positively associated with increased contact with their GP at the time of the visit (β=0.41, P<0.001), negatively associated with the number of the respondent's chronic conditions (β=-0.13, P=0.030) and not associated with the frequency of other health professional visits. Agency theory suggests that patients employ continuity of care to optimise factors important in CDM: information symmetry and goal alignment. Our findings are consistent with the theory and lend support to ensuring that interpersonal continuity of care is not lost in health care reform. Further research exploring patients' acceptance of differing systems of care is required.

Testing a generalized cubic Galileon gravity model with the Coma Cluster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Terukina, Ayumu; Yamamoto, Kazuhiro; Okabe, Nobuhiro

2015-10-01

We obtain a constraint on the parameters of a generalized cubic Galileon gravity model exhibiting the Vainshtein mechanism by using multi-wavelength observations of the Coma Cluster. The generalized cubic Galileon model is characterized by three parameters of the turning scale associated with the Vainshtein mechanism, and the amplitude of modifying a gravitational potential and a lensing potential. X-ray and Sunyaev-Zel'dovich (SZ) observations of the intra-cluster medium are sensitive to the gravitational potential, while the weak-lensing (WL) measurement is specified by the lensing potential. A joint fit of a complementary multi-wavelength dataset of X-ray, SZ and WL measurements enables us tomore » simultaneously constrain these three parameters of the generalized cubic Galileon model for the first time. We also find a degeneracy between the cluster mass parameters and the gravitational modification parameters, which is influential in the limit of the weak screening of the fifth force.« less

Enhanced conformational sampling to visualize a free-energy landscape of protein complex formation

PubMed Central

Iida, Shinji; Nakamura, Haruki; Higo, Junichi

2016-01-01

We introduce various, recently developed, generalized ensemble methods, which are useful to sample various molecular configurations emerging in the process of protein–protein or protein–ligand binding. The methods introduced here are those that have been or will be applied to biomolecular binding, where the biomolecules are treated as flexible molecules expressed by an all-atom model in an explicit solvent. Sampling produces an ensemble of conformations (snapshots) that are thermodynamically probable at room temperature. Then, projection of those conformations to an abstract low-dimensional space generates a free-energy landscape. As an example, we show a landscape of homo-dimer formation of an endothelin-1-like molecule computed using a generalized ensemble method. The lowest free-energy cluster at room temperature coincided precisely with the experimentally determined complex structure. Two minor clusters were also found in the landscape, which were largely different from the native complex form. Although those clusters were isolated at room temperature, with rising temperature a pathway emerged linking the lowest and second-lowest free-energy clusters, and a further temperature increment connected all the clusters. This exemplifies that the generalized ensemble method is a powerful tool for computing the free-energy landscape, by which one can discuss the thermodynamic stability of clusters and the temperature dependence of the cluster networks. PMID:27288028

Pure Gaussian state generation via dissipation: a quantum stochastic differential equation approach.

PubMed

Yamamoto, Naoki

2012-11-28

Recently, the complete characterization of a general Gaussian dissipative system having a unique pure steady state was obtained. This result provides a clear guideline for engineering an environment such that the dissipative system has a desired pure steady state such as a cluster state. In this paper, we describe the system in terms of a quantum stochastic differential equation (QSDE) so that the environment channels can be explicitly dealt with. Then, a physical meaning of that characterization, which cannot be seen without the QSDE representation, is clarified; more specifically, the nullifier dynamics of any Gaussian system generating a unique pure steady state is passive. In addition, again based on the QSDE framework, we provide a general and practical method to implement a desired dissipative Gaussian system, which has a structure of quantum state transfer.

Randomized clinical trial to assess the efficacy of a comprehensive programme of secondary prevention of cardiovascular disease in general practice: the PREseAP study.

PubMed

Brotons, Carlos; Soriano, Núria; Moral, Irene; Rodrigo, María P; Kloppe, Pilar; Rodríguez, Ana I; González, María L; Ariño, Dolores; Orozco, Domingo; Buitrago, Francisco; Pepió, Josep M; Borrás, Isabel

2011-01-01

To assess the efficacy of a comprehensive program of secondary prevention of cardiovascular disease in general practice. A cluster randomized clinical trial was carried out in a regular general practice setting. Male and female patients aged under 86 years with a diagnosis of ischemic heart disease, stroke or peripheral artery disease were recruited between January 2004 and May 2005. Study participants were seen at 42 health centers throughout the whole of Spain. The primary endpoint was the combination of all-cause mortality and hospital cardiovascular readmission at 3-year follow-up. In total, 1224 patients were recruited: 624 in the intervention group and 600 in the control group. The primary endpoint was observed in 29.9% (95% confidence interval [CI], 25.5-34.8%) in the intervention group and 25.6% (22.3-29.2%) in the control group (P=.15). At the end of follow-up, 8.5% (6.3-11.3%) in the intervention group and 11% (7.4-16%) in the control group were smokers (P=.07). The mean waist circumference of patients in the intervention and control groups was 100.44 cm (95% CI, 98.97-101.91 cm) and 102.58 cm (95% CI, 100.96-104.21 cm), respectively (P=.07). Overall, 20.9% (15.6-27.7%) of patients in the intervention group and 29.6% (23.9-36.1%) in the control group suffered from anxiety (P=.05), and 29.6% (22.4-37.9%) in the intervention group and 41.4% (35.8-47.3%) in the control group had depression (P=.02). A comprehensive program of secondary prevention of cardiovascular disease in general practice was not effective in reducing cardiovascular morbidity and mortality. However, some factors associated with a healthy lifestyle were improved and anxiety and depression were reduced. Copyright © 2010 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Prevalence of Screening-Detected Eating Disorders in Chinese Females and Exploratory Associations with Dietary Practices

PubMed Central

Watson, Hunna J.; Hamer, Robert M.; Thornton, Laura M.; Peat, Christine M.; Kleiman, Susan C.; Du, Shufa; Wang, Huijin; Bulik, Cynthia M.

2014-01-01

Objective China is undergoing dramatic Westernization, hence may be able to provide unique insights into the role of sociocultural factors in disease. The purpose of this exploratory study was two-fold: to describe the prevalence of screening-detected eating disorders and disordered eating in China at the first occasion of assessment in the large-scale China Health and Nutrition Survey (CHNS) and to explore the associations between dietary practices and disordered eating. Regarding the first objective, participants are provincially representative and in subsequent waves will be followed longitudinally. Method CHNS participants were recruited using multistage, cluster random sampling, beginning in 1989. In this study, participants comprised 259 female adolescents (12–17 years) and 979 women (18–35 years) who participated in the CHNS 2009 survey, which is the first CHNS survey to assess disordered eating. Dietary practice-disordered eating associations were investigated with logistic regression adjusting for age, body mass index, and urbanization. Results Of the participants, 6.3% (95% CI: 4.8, 8.2) of adults and 7.8% (95% CI: 5.0, 12.0) of adolescents had a screening-detected eating disorder. Dietary practices had non-significant associations with disordered eating at the general population level, except for protein consumption among women. There was evidence that skipping meals and a high-fat diet may confer risk. Discussion Screening-detected eating disorders in China are lower in prevalence than in developed countries. Dietary practices had fairly limited associations with disordered eating at the general population level; protein consumption, skipping meals, and a high-fat diet are candidate dietary practice exposures for disordered eating. PMID:25407415

Effectiveness of a diabetes education and self management programme (DESMOND) for people with newly diagnosed type 2 diabetes mellitus: three year follow-up of a cluster randomised controlled trial in primary care.

PubMed

Khunti, Kamlesh; Gray, Laura J; Skinner, Timothy; Carey, Marian E; Realf, Kathryn; Dallosso, Helen; Fisher, Harriet; Campbell, Michael; Heller, Simon; Davies, Melanie J

2012-04-26

To measure whether the benefits of a single education and self management structured programme for people with newly diagnosed type 2 diabetes mellitus are sustained at three years. Three year follow-up of a multicentre cluster randomised controlled trial in primary care, with randomisation at practice level. 207 general practices in 13 primary care sites in the United Kingdom. 731 of the 824 participants included in the original trial were eligible for follow-up. Biomedical data were collected on 604 (82.6%) and questionnaire data on 513 (70.1%) participants. A structured group education programme for six hours delivered in the community by two trained healthcare professional educators compared with usual care. The primary outcome was glycated haemoglobin (HbA(1c)) levels. The secondary outcomes were blood pressure, weight, blood lipid levels, smoking status, physical activity, quality of life, beliefs about illness, depression, emotional impact of diabetes, and drug use at three years. HbA(1c) levels at three years had decreased in both groups. After adjusting for baseline and cluster the difference was not significant (difference -0.02, 95% confidence interval -0.22 to 0.17). The groups did not differ for the other biomedical and lifestyle outcomes and drug use. The significant benefits in the intervention group across four out of five health beliefs seen at 12 months were sustained at three years (P<0.01). Depression scores and quality of life did not differ at three years. A single programme for people with newly diagnosed type 2 diabetes mellitus showed no difference in biomedical or lifestyle outcomes at three years although there were sustained improvements in some illness beliefs. Current Controlled Trials ISRCTN17844016.

Site-specific biomolecule labeling with gold clusters.

PubMed

Ackerson, Christopher J; Powell, Richard D; Hainfeld, James F

2010-01-01

Site-specific labeling of biomolecules in vitro with gold clusters can enhance the information content of electron cryomicroscopy experiments. This chapter provides a practical overview of well-established techniques for forming biomolecule/gold cluster conjugates. Three bioconjugation chemistries are covered: linker-mediated bioconjugation, direct gold-biomolecule bonding, and coordination-mediated bonding of nickel(II) nitrilotriacetic acid (NTA)-derivatized gold clusters to polyhistidine (His)-tagged proteins. Copyright © 2010 Elsevier Inc. All rights reserved.

Cluster randomized controlled trial of a psycho-educational intervention for people with a family history of depression for use in general practice

PubMed Central

2013-01-01

Background The strongest risk factor for depression is having a family history of the condition. Many individuals with a family history of depression are concerned about their personal risk for depression and report unmet educational and psychological support needs. No supportive and/or educational interventions are currently available that target this group of individuals. In this study we will develop and evaluate the first online psycho-educational intervention targeted to individuals with a family history of depression. Genetic risk information and evidence-rated information on preventive strategies for depression will be provided to such individuals in a general practice setting. The intervention will also incorporate a risk assessment tool. The content and delivery of the intervention will be pilot-tested. Methods/design The proposed intervention will be evaluated in the general practitioner (GPs) setting, using a cluster randomized controlled trial. GP practices will be randomized to provide either access to the online, targeted psycho-educational intervention or brief generic information about depression (control) to eligible patients. Eligibility criteria include having at least one first-degree relative with either major depressive disorder (MDD) or bipolar disorder (BD). The primary outcome measure is 'intention to adopt, or actual adoption of, risk-reducing strategies’. Secondary outcome measures include: depression symptoms, perceived stigma of depression, knowledge of risk factors for development of depression and risk-reducing strategies, and perceived risk of developing depression or having a recurrence of family history. Over the course of the study, participants will complete online questionnaires at three time points: at baseline, and two weeks and six months after receiving the intervention or control condition. Discussion This novel psycho-educational intervention will provide individuals with a family history of depression with information on evidence-based strategies for the prevention of depression, thus, we hypothesize, enabling them to make appropriate lifestyle choices and implement behaviors designed to reduce their risk for depression. The online psycho-educational intervention will also provide a model for similar interventions aimed at individuals at increased familial risk for other psychiatric disorders. Trial registration The study is registered with the Australian and New Zealand Clinical Trials Group (Registration no: ACTRN12613000402741). PMID:24289740

An Audit and Feedback Intervention for Reducing Antibiotic Prescribing in General Dental Practice: The RAPiD Cluster Randomised Controlled Trial.

PubMed

Elouafkaoui, Paula; Young, Linda; Newlands, Rumana; Duncan, Eilidh M; Elders, Andrew; Clarkson, Jan E; Ramsay, Craig R

2016-08-01

Dentists prescribe approximately 10% of antibiotics dispensed in UK community pharmacies. Despite clear clinical guidance, dentists often prescribe antibiotics inappropriately. This cluster-randomised controlled trial used routinely collected National Health Service (NHS) dental prescribing and treatment claim data to compare the impact of individualised audit and feedback (A&F) interventions on dentists' antibiotic prescribing rates. All 795 antibiotic prescribing NHS general dental practices in Scotland were included. Practices were randomised to the control (practices = 163; dentists = 567) or A&F intervention group (practices = 632; dentists = 1,999). A&F intervention practices were allocated to one of two A&F groups: (1) individualised graphical A&F comprising a line graph plotting an individual dentist's monthly antibiotic prescribing rate (practices = 316; dentists = 1,001); or (2) individualised graphical A&F plus a written behaviour change message synthesising and reiterating national guidance recommendations for dental antibiotic prescribing (practices = 316; dentists = 998). Intervention practices were also simultaneously randomised to receive A&F: (i) with or without a health board comparator comprising the addition of a line to the graphical A&F plotting the monthly antibiotic prescribing rate of all dentists in the health board; and (ii) delivered at 0 and 6 mo or at 0, 6, and 9 mo, giving a total of eight intervention groups. The primary outcome, measured by the trial statistician who was blinded to allocation, was the total number of antibiotic items dispensed per 100 NHS treatment claims over the 12 mo post-delivery of the baseline A&F. Primary outcome data was available for 152 control practices (dentists = 438) and 609 intervention practices (dentists = 1,550). At baseline, the number of antibiotic items prescribed per 100 NHS treatment claims was 8.3 in the control group and 8.5 in the intervention group. At follow-up, antibiotic prescribing had decreased by 0.4 antibiotic items per 100 NHS treatment claims in control practices and by 1.0 in intervention practices. This represents a significant reduction (-5.7%; 95% CI -10.2% to -1.1%; p = 0.01) in dentists' prescribing rate in the intervention group relative to the control group. Intervention subgroup analyses found a 6.1% reduction in the antibiotic prescribing rate of dentists who had received the written behaviour change message relative to dentists who had not (95% CI -10.4% to -1.9%; p = 0.01). There was no significant between-group difference in the prescribing rate of dentists who received a health board comparator relative to those who did not (-4.3%; 95% CI -8.6% to 0.1%; p = 0.06), nor between dentists who received A&F at 0 and 6 mo relative to those who received A&F at 0, 6, and 9 mo (0.02%; 95% CI -4.2% to 4.2%; p = 0.99). The key limitations relate to the use of routinely collected datasets which did not allow evaluation of any effects on inappropriate prescribing. A&F derived from routinely collected datasets led to a significant reduction in the antibiotic prescribing rate of dentists. Current Controlled Trials ISRCTN49204710.

Improving chronic disease prevention and screening in primary care: results of the BETTER pragmatic cluster randomized controlled trial.

PubMed

Grunfeld, Eva; Manca, Donna; Moineddin, Rahim; Thorpe, Kevin E; Hoch, Jeffrey S; Campbell-Scherer, Denise; Meaney, Christopher; Rogers, Jess; Beca, Jaclyn; Krueger, Paul; Mamdani, Muhammad

2013-11-20

Primary care provides most of the evidence-based chronic disease prevention and screening services offered by the healthcare system. However, there remains a gap between recommended preventive services and actual practice. This trial (the BETTER Trial) aimed to improve preventive care of heart disease, diabetes, colorectal, breast and cervical cancers, and relevant lifestyle factors through a practice facilitation intervention set in primary care. Pragmatic two-way factorial cluster RCT with Primary Care Physicians' practices as the unit of allocation and individual patients as the unit of analysis. The setting was urban Primary Care Team practices in two Canadian provinces. Eight Primary Care Team practices were randomly assigned to receive the practice-level intervention or wait-list control; 4 physicians in each team (32 physicians) were randomly assigned to receive the patient-level intervention or wait-list control. Patients randomly selected from physicians' rosters were stratified into two groups: 1) general and 2) moderate mental illness. The interventions involved a multifaceted, evidence-based, tailored practice-level intervention with a Practice Facilitator, and a patient-level intervention involving a one-hour visit with a Prevention Practitioner where patients received a tailored 'prevention prescription'. The primary outcome was a composite Summary Quality Index of 28 evidence-based chronic disease prevention and screening actions with pre-defined targets, expressed as the ratio of eligible actions at baseline that were met at follow-up. A cost-effectiveness analysis was conducted. 789 of 1,260 (63%) eligible patients participated. On average, patients were eligible for 8.96 (SD 3.2) actions at baseline. In the adjusted analysis, control patients met 23.1% (95% CI: 19.2% to 27.1%) of target actions, compared to 28.5% (95% CI: 20.9% to 36.0%) receiving the practice-level intervention, 55.6% (95% CI: 49.0% to 62.1%) receiving the patient-level intervention, and 58.9% (95% CI: 54.7% to 63.1%) receiving both practice- and patient-level interventions (patient-level intervention versus control, P < 0.001). The benefit of the patient-level intervention was seen in both strata. The extra cost of the intervention was $26.43CAN (95% CI: $16 to $44) per additional action met. A Prevention Practitioner can improve the implementation of clinically important prevention and screening for chronic diseases in a cost-effective manner.

STEM professional volunteers in K-12 competition programs: Educator practices and impact on pedagogy

NASA Astrophysics Data System (ADS)

Zintgraff, Alfred Clifton

This mixed methods dissertation study explored how secondary school educators in specific K-12 competition programs recruited and deployed STEM professional volunteers. The study explored which practices were viewed as most important, and how practices related to constructivist pedagogy, all from the viewpoint of educators. The non-positivist approach sought new knowledge without pursuing generalized results. Review of the literature uncovered extensive anecdotal information about current practices, and suggested that large investments are made in engaging volunteers. One National Science Foundation-sponsored study was identified, and its recommendations for a sustained research agenda were advanced. Three study phases were performed, one to explore practices and operationalize definitions, a second to rate practice's importance and their relation to pedagogy, and a third to seek explanations. Educators preferred recruiting local, meaning recruiting parents and former students, versus from industry or other employers. Most educators preferred volunteers with mentoring skills, and placing them in direct contact with students, versus deploying volunteers to help with behind-the-scenes tasks supporting the educator. Relationships were identified between the highest-rated practices and constructivism in programs. In STEM professional volunteers, educators see affordances, in the same way a classroom tool opens affordances. A model is proposed which shows educators considering practicality, pedagogy, knowledge and skills, and rapport when accessing the affordances opened by STEM professional volunteers. Benefits are maximized when programs align with strong industry clusters in the community.

Generalized clustering conditions of Jack polynomials at negative Jack parameter {alpha}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernevig, B. Andrei; Department of Physics, Princeton University, Princeton, New Jersey 08544; Haldane, F. D. M.

We present several conjectures on the behavior and clustering properties of Jack polynomials at a negative parameter {alpha}=-(k+1/r-1), with partitions that violate the (k,r,N)- admissibility rule of [Feigin et al. [Int. Math. Res. Notices 23, 1223 (2002)]. We find that the ''highest weight'' Jack polynomials of specific partitions represent the minimum degree polynomials in N variables that vanish when s distinct clusters of k+1 particles are formed, where s and k are positive integers. Explicit counting formulas are conjectured. The generalized clustering conditions are useful in a forthcoming description of fractional quantum Hall quasiparticles.

Multiple Imputation based Clustering Validation (MIV) for Big Longitudinal Trial Data with Missing Values in eHealth.

PubMed

Zhang, Zhaoyang; Fang, Hua; Wang, Honggang

2016-06-01

Web-delivered trials are an important component in eHealth services. These trials, mostly behavior-based, generate big heterogeneous data that are longitudinal, high dimensional with missing values. Unsupervised learning methods have been widely applied in this area, however, validating the optimal number of clusters has been challenging. Built upon our multiple imputation (MI) based fuzzy clustering, MIfuzzy, we proposed a new multiple imputation based validation (MIV) framework and corresponding MIV algorithms for clustering big longitudinal eHealth data with missing values, more generally for fuzzy-logic based clustering methods. Specifically, we detect the optimal number of clusters by auto-searching and -synthesizing a suite of MI-based validation methods and indices, including conventional (bootstrap or cross-validation based) and emerging (modularity-based) validation indices for general clustering methods as well as the specific one (Xie and Beni) for fuzzy clustering. The MIV performance was demonstrated on a big longitudinal dataset from a real web-delivered trial and using simulation. The results indicate MI-based Xie and Beni index for fuzzy-clustering are more appropriate for detecting the optimal number of clusters for such complex data. The MIV concept and algorithms could be easily adapted to different types of clustering that could process big incomplete longitudinal trial data in eHealth services.

Multiple Imputation based Clustering Validation (MIV) for Big Longitudinal Trial Data with Missing Values in eHealth

PubMed Central

Zhang, Zhaoyang; Wang, Honggang

2016-01-01

Web-delivered trials are an important component in eHealth services. These trials, mostly behavior-based, generate big heterogeneous data that are longitudinal, high dimensional with missing values. Unsupervised learning methods have been widely applied in this area, however, validating the optimal number of clusters has been challenging. Built upon our multiple imputation (MI) based fuzzy clustering, MIfuzzy, we proposed a new multiple imputation based validation (MIV) framework and corresponding MIV algorithms for clustering big longitudinal eHealth data with missing values, more generally for fuzzy-logic based clustering methods. Specifically, we detect the optimal number of clusters by auto-searching and -synthesizing a suite of MI-based validation methods and indices, including conventional (bootstrap or cross-validation based) and emerging (modularity-based) validation indices for general clustering methods as well as the specific one (Xie and Beni) for fuzzy clustering. The MIV performance was demonstrated on a big longitudinal dataset from a real web-delivered trial and using simulation. The results indicate MI-based Xie and Beni index for fuzzy-clustering is more appropriate for detecting the optimal number of clusters for such complex data. The MIV concept and algorithms could be easily adapted to different types of clustering that could process big incomplete longitudinal trial data in eHealth services. PMID:27126063

The effect of clustering on lot quality assurance sampling: a probabilistic model to calculate sample sizes for quality assessments

PubMed Central

2013-01-01

Background Traditional Lot Quality Assurance Sampling (LQAS) designs assume observations are collected using simple random sampling. Alternatively, randomly sampling clusters of observations and then individuals within clusters reduces costs but decreases the precision of the classifications. In this paper, we develop a general framework for designing the cluster(C)-LQAS system and illustrate the method with the design of data quality assessments for the community health worker program in Rwanda. Results To determine sample size and decision rules for C-LQAS, we use the beta-binomial distribution to account for inflated risk of errors introduced by sampling clusters at the first stage. We present general theory and code for sample size calculations. The C-LQAS sample sizes provided in this paper constrain misclassification risks below user-specified limits. Multiple C-LQAS systems meet the specified risk requirements, but numerous considerations, including per-cluster versus per-individual sampling costs, help identify optimal systems for distinct applications. Conclusions We show the utility of C-LQAS for data quality assessments, but the method generalizes to numerous applications. This paper provides the necessary technical detail and supplemental code to support the design of C-LQAS for specific programs. PMID:24160725

The effect of clustering on lot quality assurance sampling: a probabilistic model to calculate sample sizes for quality assessments.

PubMed

Hedt-Gauthier, Bethany L; Mitsunaga, Tisha; Hund, Lauren; Olives, Casey; Pagano, Marcello

2013-10-26

Traditional Lot Quality Assurance Sampling (LQAS) designs assume observations are collected using simple random sampling. Alternatively, randomly sampling clusters of observations and then individuals within clusters reduces costs but decreases the precision of the classifications. In this paper, we develop a general framework for designing the cluster(C)-LQAS system and illustrate the method with the design of data quality assessments for the community health worker program in Rwanda. To determine sample size and decision rules for C-LQAS, we use the beta-binomial distribution to account for inflated risk of errors introduced by sampling clusters at the first stage. We present general theory and code for sample size calculations.The C-LQAS sample sizes provided in this paper constrain misclassification risks below user-specified limits. Multiple C-LQAS systems meet the specified risk requirements, but numerous considerations, including per-cluster versus per-individual sampling costs, help identify optimal systems for distinct applications. We show the utility of C-LQAS for data quality assessments, but the method generalizes to numerous applications. This paper provides the necessary technical detail and supplemental code to support the design of C-LQAS for specific programs.

Using Concept Mapping to Develop a Conceptual Framework for Creating Virtual Communities of Practice to Translate Cancer Research into Practice

PubMed Central

2014-01-01

Introduction Translating government-funded cancer research into clinical practice can be accomplished via virtual communities of practice that include key players in the process: researchers, health care practitioners, and intermediaries. This study, conducted from November 2012 through January 2013, examined issues that key stakeholders believed should be addressed to create and sustain government-sponsored virtual communities of practice to integrate cancer control research, practice, and policy and demonstrates how concept mapping can be used to present relevant issues. Methods Key stakeholders brainstormed statements describing what is needed to create and sustain virtual communities of practice for moving cancer control research into practice. Participants rated them on importance and feasibility, selected most relevant statements, and sorted them into clusters. I used concept mapping to examine the issues identified and multidimensional scaling analyses to create a 2-dimensional conceptual map of the statement clusters. Results Participants selected 70 statements and sorted them into 9 major clusters related to creating and sustaining virtual communities of practice: 1) standardization of best practices, 2) external validity, 3) funding and resources, 4) social learning and collaboration, 5) cooperation, 6) partnerships, 7) inclusiveness, 8) social determinants and cultural competency, and 9) preparing the environment. Researchers, health care practitioners, and intermediaries were in relative agreement regarding issues of importance for creating these communities. Conclusion Virtual communities of practice can be created to address the needs of researchers, health care practitioners, and intermediaries by using input from these key stakeholders. Increasing linkages between these subgroups can improve the translation of research into practice. Similarities and differences between groups can provide valuable information to assist the government in developing virtual communities of practice. PMID:24762532

Using concept mapping to develop a conceptual framework for creating virtual communities of practice to translate cancer research into practice.

PubMed

Vinson, Cynthia A

2014-04-24

Translating government-funded cancer research into clinical practice can be accomplished via virtual communities of practice that include key players in the process: researchers, health care practitioners, and intermediaries. This study, conducted from November 2012 through January 2013, examined issues that key stakeholders believed should be addressed to create and sustain government-sponsored virtual communities of practice to integrate cancer control research, practice, and policy and demonstrates how concept mapping can be used to present relevant issues. Key stakeholders brainstormed statements describing what is needed to create and sustain virtual communities of practice for moving cancer control research into practice. Participants rated them on importance and feasibility, selected most relevant statements, and sorted them into clusters. I used concept mapping to examine the issues identified and multidimensional scaling analyses to create a 2-dimensional conceptual map of the statement clusters. Participants selected 70 statements and sorted them into 9 major clusters related to creating and sustaining virtual communities of practice: 1) standardization of best practices, 2) external validity, 3) funding and resources, 4) social learning and collaboration, 5) cooperation, 6) partnerships, 7) inclusiveness, 8) social determinants and cultural competency, and 9) preparing the environment. Researchers, health care practitioners, and intermediaries were in relative agreement regarding issues of importance for creating these communities. Virtual communities of practice can be created to address the needs of researchers, health care practitioners, and intermediaries by using input from these key stakeholders. Increasing linkages between these subgroups can improve the translation of research into practice. Similarities and differences between groups can provide valuable information to assist the government in developing virtual communities of practice.

Cluster Approach to Network Interaction in Pedagogical University

ERIC Educational Resources Information Center

Chekaleva, Nadezhda V.; Makarova, Natalia S.; Drobotenko, Yulia B.

2016-01-01

The study presented in the article is devoted to the analysis of theory and practice of network interaction within the framework of education clusters. Education clusters are considered to be a novel form of network interaction in pedagogical education in Russia. The aim of the article is to show the advantages and disadvantages of the cluster…

Effects of lifestyle education program for type 2 diabetes patients in clinics: study design of a cluster randomized trial.

PubMed

Adachi, Misa; Yamaoka, Kazue; Watanabe, Mariko; Nishikawa, Masako; Hida, Eisuke; Kobayashi, Itsuro; Tango, Toshiro

2010-11-30

The number of patients with type 2 diabetes is drastically increasing worldwide. It is a serious health problem in Japan as well. Lifestyle interventions can reduce progression from impaired glucose tolerance to type 2 diabetes, and glycemic control has been shown to improve postprandial plasma glucose levels. Moreover, several studies have suggested that continuous interventions (combined diet and exercise) can improve the plasma glucose level and reduce dosage of hypoglycemic agents.Although many interventional studies of lifestyle education for persons with diabetes in hospitals have been reported, only a few have been clinic-based studies employing an evidence-based lifestyle education program. This article describes the design of a cluster randomized controlled trial of the effectiveness of lifestyle education for patients with type 2 diabetes in clinics by registered dietitians. In Japan, general practitioners generally have their own medical clinics to provide medical care for outpatients in the community, including those with type 2 diabetes. With the collaboration of such general practitioners, the study patients were enrolled in the present study. Twenty general practitioners were randomly allocated to each provide patients for entry into either an intervention group (10) or a control group (10). In total, 200 participants will be included in the study. The intervention group will receive intensive education on lifestyle improvement related to type 2 diabetes by registered dietitians in clinics. Lifestyle education will be conducted several times during the study period. The control group will receive information on dietary intake and standard advice on glycemic control by registered dietitians. The primary endpoint is the change from the baseline value of HbA1c at 6 months. Data on health behavior and related issues will be gathered continuously over a 6-month period. This is the first study to evaluate lifestyle education in clinics by a cluster randomization trial in Japan. The proposed study will provide practical information about the usefulness of the intensive lifestyle improvement education program in primary care settings. The study was started in September 2007 and entry of subjects was completed in December 2010. Data on the effect evaluation will be available in 2011. UMIN000004049.

Generalized fuzzy C-means clustering algorithm with improved fuzzy partitions.

PubMed

Zhu, Lin; Chung, Fu-Lai; Wang, Shitong

2009-06-01

The fuzziness index m has important influence on the clustering result of fuzzy clustering algorithms, and it should not be forced to fix at the usual value m = 2. In view of its distinctive features in applications and its limitation in having m = 2 only, a recent advance of fuzzy clustering called fuzzy c-means clustering with improved fuzzy partitions (IFP-FCM) is extended in this paper, and a generalized algorithm called GIFP-FCM for more effective clustering is proposed. By introducing a novel membership constraint function, a new objective function is constructed, and furthermore, GIFP-FCM clustering is derived. Meanwhile, from the viewpoints of L(p) norm distance measure and competitive learning, the robustness and convergence of the proposed algorithm are analyzed. Furthermore, the classical fuzzy c-means algorithm (FCM) and IFP-FCM can be taken as two special cases of the proposed algorithm. Several experimental results including its application to noisy image texture segmentation are presented to demonstrate its average advantage over FCM and IFP-FCM in both clustering and robustness capabilities.

On the effects of subvirial initial conditions and the birth temperature of R136

NASA Astrophysics Data System (ADS)

Caputo, Daniel P.; de Vries, Nathan; Portegies Zwart, Simon

2014-11-01

We investigate the effect of different initial virial temperatures, Q, on the dynamics of star clusters. We find that the virial temperature has a strong effect on many aspects of the resulting system, including among others: the fraction of bodies escaping from the system, the depth of the collapse of the system, and the strength of the mass segregation. These differences deem the practice of using `cold' initial conditions no longer a simple choice of convenience. The choice of initial virial temperature must be carefully considered as its impact on the remainder of the simulation can be profound. We discuss the pitfalls and aim to describe the general behaviour of the collapse and the resultant system as a function of the virial temperature so that a well-reasoned choice of initial virial temperature can be made. We make a correction to the previous theoretical estimate for the minimum radius, Rmin, of the cluster at the deepest moment of collapse to include a Q dependency, Rmin ≈ Q + N(-1/3), where N is the number of particles. We use our numerical results to infer more about the initial conditions of the young cluster R136. Based on our analysis, we find that R136 was likely formed with a rather cool, but not cold, initial virial temperature (Q ≈ 0.13). Using the same analysis method, we examined 15 other young clusters and found the most common initial virial temperature to be between 0.18 and 0.25.

Coupled multipolar interactions in small-particle metallic clusters.

PubMed

Pustovit, Vitaly N; Sotelo, Juan A; Niklasson, Gunnar A

2002-03-01

We propose a new formalism for computing the optical properties of small clusters of particles. It is a generalization of the coupled dipole-dipole particle-interaction model and allows one in principle to take into account all multipolar interactions in the long-wavelength limit. The method is illustrated by computations of the optical properties of N = 6 particle clusters for different multipolar approximations. We examine the effect of separation between particles and compare the optical spectra with the discrete-dipole approximation and the generalized Mie theory.

Effectiveness and cost-effectiveness of implementing HIV testing in primary care in East London: protocol for an interrupted time series analysis.

PubMed

Leber, Werner; Beresford, Lee; Nightingale, Claire; Barbosa, Estela Capelas; Morris, Stephen; El-Shogri, Farah; McMullen, Heather; Boomla, Kambiz; Delpech, Valerie; Brown, Alison; Hutchinson, Jane; Apea, Vanessa; Symonds, Merle; Gilliham, Samantha; Creighton, Sarah; Shahmanesh, Maryam; Fulop, Naomi; Estcourt, Claudia; Anderson, Jane; Figueroa, Jose; Griffiths, Chris

2017-12-14

HIV remains underdiagnosed. Guidelines recommend routine HIV testing in primary care, but evidence on implementing testing is lacking. In a previous study, the Rapid HIV Assessment 2 (RHIVA2) cluster randomised controlled trial, we showed that providing training and rapid point-of-care HIV testing at general practice registration (RHIVA2 intervention) in Hackney led to cost-effective, increased and earlier diagnosis of HIV. However, interventions effective in a trial context may be less so when implemented in routine practice. We describe the protocol for an MRC phase IV implementation programme, evaluating the impact of rolling out the RHIVA2 intervention in a post-trial setting. We will use a longitudinal study to examine if the post-trial implementation in Hackney practices is effective and cost-effective, and a cross-sectional study to compare Hackney with two adjacent boroughs providing usual primary care (Newham) and an enhanced service promoting HIV testing in primary care (Tower Hamlets). Service evaluation using interrupted time series and cost-effectiveness analyses. We will include all general practices in three contiguous high HIV prevalence East London boroughs. All adults aged 16 and above registered with the practices will be included. The interventions to be examined are: a post-trial RHIVA2 implementation programme (including practice-based education and training, external quality assurance, incentive payments for rapid HIV testing and incorporation of rapid HIV testing in the sexual health Local Enhanced Service) in Hackney; the general practice sexual health Network Improved Service in Tower Hamlets and usual care in Newham. Coprimary outcomes are rates of HIV testing and new HIV diagnoses. The chair of the Camden and Islington NHS Research Ethics Committee, London, has endorsed this programme as an evaluation of routine care. Study results will be published in peer-reviewed journals and reported to commissioners. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Parallel, Gradient-Based Anisotropic Mesh Adaptation for Re-entry Vehicle Configurations

NASA Technical Reports Server (NTRS)

Bibb, Karen L.; Gnoffo, Peter A.; Park, Michael A.; Jones, William T.

2006-01-01

Two gradient-based adaptation methodologies have been implemented into the Fun3d refine GridEx infrastructure. A spring-analogy adaptation which provides for nodal movement to cluster mesh nodes in the vicinity of strong shocks has been extended for general use within Fun3d, and is demonstrated for a 70 sphere cone at Mach 2. A more general feature-based adaptation metric has been developed for use with the adaptation mechanics available in Fun3d, and is applicable to any unstructured, tetrahedral, flow solver. The basic functionality of general adaptation is explored through a case of flow over the forebody of a 70 sphere cone at Mach 6. A practical application of Mach 10 flow over an Apollo capsule, computed with the Felisa flow solver, is given to compare the adaptive mesh refinement with uniform mesh refinement. The examples of the paper demonstrate that the gradient-based adaptation capability as implemented can give an improvement in solution quality.

Special and general superatoms.

PubMed

Luo, Zhixun; Castleman, A Welford

2014-10-21

Bridging the gap between atoms and macroscopic matter, clusters continue to be a subject of increasing research interest. Among the realm of cluster investigations, an exciting development is the realization that chosen stable clusters can mimic the chemical behavior of an atom or a group of the periodic table of elements. This major finding known as a superatom concept was originated experimentally from the study of aluminum cluster reactivity conducted in 1989 by noting a dramatic size dependence of the reactivity where cluster anions containing a certain number of Al atoms were unreactive toward oxygen while the other species were etched away. This observation was well interpreted by shell closings on the basis of the jellium model, and the related concept (originally termed "unified atom") spawned a wide range of pioneering studies in the 1990s pertaining to the understanding of factors governing the properties of clusters. Under the inspiration of a superatom concept, advances in cluster science in finding stable species not only shed light on magic clusters (i.e., superatomic noble gas) but also enlightened the exploration of stable clusters to mimic the chemical behavior of atoms leading to the discovery of superhalogens, alkaline-earth metals, superalkalis, etc. Among them, certain clusters could enable isovalent isomorphism of precious metals, indicating application potential for inexpensive superatoms for industrial catalysis, while a few superalkalis were found to validate the interesting "harpoon mechanism" involved in the superatomic cluster reactivity; recently also found were the magnetic superatoms of which the cluster-assembled materials could be used in spin electronics. Up to now, extensive studies in cluster science have allowed the stability of superatomic clusters to be understood within a few models, including the jellium model, also aromaticity and Wade-Mingos rules depending on the geometry and metallicity of the cluster. However, the scope of application of the jellium model and modification of the theory to account for nonspherical symmetry and nonmetal-doped metal clusters are still illusive to be further developed. It is still worth mentioning that a superatom concept has also been introduced in ligand-stabilized metal clusters which could also follow the major shell-closing electron count for a spherical, square-well potential. By proposing a new concept named as special and general superatoms, herein we try to summarize all these investigations in series, expecting to provide an overview of this field with a primary focus on the joint undertakings which have given rise to the superatom concept. To be specific, for special superatoms, we limit to clusters under a strict jellium model and simply classify them into groups based on their valence electron counts. While for general superatoms we emphasize on nonmetal-doped metal clusters and ligand-stabilized metal clusters, as well as a few isovalent cluster systems. Hopefully this summary of special and general superatoms benefits the further development of cluster-related theory, and lights up the prospect of using them as building blocks of new materials with tailored properties, such as inexpensive isovalent systems for industrial catalysis, semiconductive superatoms for transistors, and magnetic superatoms for spin electronics.

Illinois Occupational Skill Standards: Industrial Maintenance General Maintenance Cluster.

ERIC Educational Resources Information Center

Illinois Occupational Skill Standards and Credentialing Council, Carbondale.

These skill standards for the industrial maintenance general maintenance cluster are intended to be a guide to workforce preparation program providers in defining content for their programs and to employers to establish the skills and standards necessary for job acquisition. An introduction provides the Illinois perspective; Illinois Occupational…

Subgroups of physically abusive parents based on cluster analysis of parenting behavior and affect.

PubMed

Haskett, Mary E; Smith Scott, Susan; Sabourin Ward, Caryn

2004-10-01

Cluster analysis of observed parenting and self-reported discipline was used to categorize 83 abusive parents into subgroups. A 2-cluster solution received support for validity. Cluster 1 parents were relatively warm, positive, sensitive, and engaged during interactions with their children, whereas Cluster 2 parents were relatively negative, disengaged or intrusive, and insensitive. Further, clusters differed in emotional health, parenting stress, perceptions of children, and problem solving. Children of parents in the 2 clusters differed on several indexes of social adjustment. Cluster 1 parents were similar to nonabusive parents (n = 66) on parenting and related constructs, but Cluster 2 parents differed from nonabusive parents on all clustering variables and many validation variables. Results highlight clinically relevant diversity in parenting practices and functioning among abusive parents. ((c) 2004 APA, all rights reserved).

Gravitational redshift of galaxies in clusters as predicted by general relativity.

PubMed

Wojtak, Radosław; Hansen, Steen H; Hjorth, Jens

2011-09-28

The theoretical framework of cosmology is mainly defined by gravity, of which general relativity is the current model. Recent tests of general relativity within the Lambda Cold Dark Matter (ΛCDM) model have found a concordance between predictions and the observations of the growth rate and clustering of the cosmic web. General relativity has not hitherto been tested on cosmological scales independently of the assumptions of the ΛCDM model. Here we report an observation of the gravitational redshift of light coming from galaxies in clusters at the 99 per cent confidence level, based on archival data. Our measurement agrees with the predictions of general relativity and its modification created to explain cosmic acceleration without the need for dark energy (the f(R) theory), but is inconsistent with alternative models designed to avoid the presence of dark matter. © 2011 Macmillan Publishers Limited. All rights reserved

Optimizing Cluster Heads for Energy Efficiency in Large-Scale Heterogeneous Wireless Sensor Networks

DOE PAGES

Gu, Yi; Wu, Qishi; Rao, Nageswara S. V.

2010-01-01

Many complex sensor network applications require deploying a large number of inexpensive and small sensors in a vast geographical region to achieve quality through quantity. Hierarchical clustering is generally considered as an efficient and scalable way to facilitate the management and operation of such large-scale networks and minimize the total energy consumption for prolonged lifetime. Judicious selection of cluster heads for data integration and communication is critical to the success of applications based on hierarchical sensor networks organized as layered clusters. We investigate the problem of selecting sensor nodes in a predeployed sensor network to be the cluster heads tomore » minimize the total energy needed for data gathering. We rigorously derive an analytical formula to optimize the number of cluster heads in sensor networks under uniform node distribution, and propose a Distance-based Crowdedness Clustering algorithm to determine the cluster heads in sensor networks under general node distribution. The results from an extensive set of experiments on a large number of simulated sensor networks illustrate the performance superiority of the proposed solution over the clustering schemes based on k -means algorithm.« less

Practice nurse health checks for adults with intellectual disabilities: a cluster-design, randomised controlled trial.

PubMed

Cooper, Sally-Ann; Morrison, Jill; Allan, Linda M; McConnachie, Alex; Greenlaw, Nicola; Melville, Craig A; Baltzer, Marion C; McArthur, Laura A; Lammie, Claire; Martin, Gordon; Grieve, Eleanor A D; Fenwick, Elisabeth

2014-12-01

Adults with intellectual disabilities have substantial health inequalities and poor access to health care. We assessed whether practice nurse-delivered health checks could improve the health of adults with intellectual disabilities compared with standard care. In this cluster-design, single-blind, randomised controlled trial, we included general practices in Scotland, UK. From June to December, 2011, we randomly assigned (1:1) these general practices to either health checks plus standard care (health-checks group), or standard care only (control group), and we recruited the patients from these practices. Randomisation was done with stratification by number of GPs per practice and number of registered patients with intellectual disabilities (<20 or ≥20). Two research assistants were masked to allocation, and undertook the review of 9 month medical records and interviews. Participants and carers were not masked. The intervention was one health check designed especially for people with intellectual disabilities delivered by a practice nurse. The objective was improvement in health and health care 9 months after randomisation, and the primary outcome was the incidence of newly detected health needs being met by this timepoint. Whether needs were met was established by the investigators being masked to group allocation. The analysis was by intention to treat. This trial is registered with Current Controlled Trials, number ISRCTN43324841. Between June 26 and Dec 20, 2011, we recruited 38 practices. 85 participants (from 16 practices) were randomly assigned to intervention and 67 (from 17 practices) to standard care; five of the identified practices did not supply any participants. 83 intervention and 66 standard care participants completed the trial. More newly detected health needs were met in the intervention group than in the control standard care group (median 1 [range 0-8], 76·4% met [SD 36·5] vs 2 [0-11], 72·6% met [35·4]; odds ratio [OR] 1·73 [95% CI 0·93-3·22], p=0·085), although this difference was not significant. Significantly more health monitoring needs were met in the intervention group than standard care (median 2 [0-20], 69·9% [SD 34·2] vs 2 [0-22], 56·8% [29·4], OR 2·38 [95% CI 1·31-4·32, p=0·0053]). The probability that health checks are cost effective was between 0·6 and 0·8, irrespective of the cost-effectiveness threshold level. Costs per patient were -£71·48 for health checks and -£20·56 for standard care. The difference (-£50·92) was not significant [95% CI -434 to 362]. No adverse events were attributable to the intervention. Health checks given by practice nurses to adults with intellectual disabilities produced health-care improvements that were more conducive to longer-term health than standard care given to this population. The intervention dominated standard care, being both cheaper and more effective. Health-check programmes might therefore be indicated for adults with intellectual disabilities. Scottish Government Change Fund, NHS Greater Glasgow and Clyde Research and Development. Copyright © 2014 Elsevier Ltd. All rights reserved.

Space-Time Cluster Analysis to Detect Innovative Clinical Practices: A Case Study of Aripiprazole in the Department of Veterans Affairs.

PubMed

Penfold, Robert B; Burgess, James F; Lee, Austin F; Li, Mingfei; Miller, Christopher J; Nealon Seibert, Marjorie; Semla, Todd P; Mohr, David C; Kazis, Lewis E; Bauer, Mark S

2018-02-01

To identify space-time clusters of changes in prescribing aripiprazole for bipolar disorder among providers in the VA. VA administrative data from 2002 to 2010 were used to identify prescriptions of aripiprazole for bipolar disorder. Prescriber characteristics were obtained using the Personnel and Accounting Integrated Database. We conducted a retrospective space-time cluster analysis using the space-time permutation statistic. All VA service users with a diagnosis of bipolar disorder were included in the patient population. Individuals with any schizophrenia spectrum diagnoses were excluded. We also identified all clinicians who wrote a prescription for any bipolar disorder medication. The study population included 32,630 prescribers. Of these, 8,643 wrote qualifying prescriptions. We identified three clusters of aripiprazole prescribing centered in Massachusetts, Ohio, and the Pacific Northwest. Clusters were associated with prescribing by VA-employed (vs. contracted) prescribers. Nurses with prescribing privileges were more likely to make a prescription for aripiprazole in cluster locations compared with psychiatrists. Primary care physicians were less likely. Early prescribing of aripiprazole for bipolar disorder clustered geographically and was associated with prescriber subgroups. These methods support prospective surveillance of practice changes and identification of associated health system characteristics. © Health Research and Educational Trust.

Randomised controlled trial of a brief intervention targeting predominantly non-verbal communication in general practice consultations.

PubMed

Little, Paul; White, Peter; Kelly, Joanne; Everitt, Hazel; Mercer, Stewart

2015-06-01

The impact of changing non-verbal consultation behaviours is unknown. To assess brief physician training on improving predominantly non-verbal communication. Cluster randomised parallel group trial among adults aged ≥16 years attending general practices close to the study coordinating centres in Southampton. Sixteen GPs were randomised to no training, or training consisting of a brief presentation of behaviours identified from a prior study (acronym KEPe Warm: demonstrating Knowledge of the patient; Encouraging [back-channelling by saying 'hmm', for example]; Physically engaging [touch, gestures, slight lean]; Warm-up: cool/professional initially, warming up, avoiding distancing or non-verbal cut-offs at the end of the consultation); and encouragement to reflect on videos of their consultation. Outcomes were the Medical Interview Satisfaction Scale (MISS) mean item score (1-7) and patients' perceptions of other domains of communication. Intervention participants scored higher MISS overall (0.23, 95% confidence interval [CI] = 0.06 to 0.41), with the largest changes in the distress-relief and perceived relationship subscales. Significant improvement occurred in perceived communication/partnership (0.29, 95% CI = 0.09 to 0.49) and health promotion (0.26, 95% CI = 0.05 to 0.46). Non-significant improvements occurred in perceptions of a personal relationship, a positive approach, and understanding the effects of the illness on life. Brief training of GPs in predominantly non-verbal communication in the consultation and reflection on consultation videotapes improves patients' perceptions of satisfaction, distress, a partnership approach, and health promotion. © British Journal of General Practice 2015.

Responding to Young People’s Health Risks in Primary Care: A Cluster Randomised Trial of Training Clinicians in Screening and Motivational Interviewing

PubMed Central

Sanci, Lena; Chondros, Patty; Sawyer, Susan; Pirkis, Jane; Ozer, Elizabeth; Hegarty, Kelsey; Yang, Fan; Grabsch, Brenda; Shiell, Alan; Cahill, Helen; Ambresin, Anne-Emmanuelle; Patterson, Elizabeth; Patton, George

2015-01-01

Objective To evaluate the effectiveness of a complex intervention implementing best practice guidelines recommending clinicians screen and counsel young people across multiple psychosocial risk factors, on clinicians’ detection of health risks and patients’ risk taking behaviour, compared to a didactic seminar on young people’s health. Design Pragmatic cluster randomised trial where volunteer general practices were stratified by postcode advantage or disadvantage score and billing type (private, free national health, community health centre), then randomised into either intervention or comparison arms using a computer generated random sequence. Three months post-intervention, patients were recruited from all practices post-consultation for a Computer Assisted Telephone Interview and followed up three and 12 months later. Researchers recruiting, consenting and interviewing patients and patients themselves were masked to allocation status; clinicians were not. Setting General practices in metropolitan and rural Victoria, Australia Participants General practices with at least one interested clinician (general practitioner or nurse) and their 14–24 year old patients. Intervention This complex intervention was designed using evidence based practice in learning and change in clinician behaviour and general practice systems, and included best practice approaches to motivating change in adolescent risk taking behaviours. The intervention involved training clinicians (nine hours) in health risk screening, use of a screening tool and motivational interviewing; training all practice staff (receptionists and clinicians) in engaging youth; provision of feedback to clinicians of patients’ risk data; and two practice visits to support new screening and referral resources. Comparison clinicians received one didactic educational seminar (three hours) on engaging youth and health risk screening. Outcome Measures Primary outcomes were patient report of (1) clinician detection of at least one of six health risk behaviours (tobacco, alcohol and illicit drug use, risks for sexually transmitted infection, STI, unplanned pregnancy, and road risks); and (2) change in one or more of the six health risk behaviours, at three months or at 12 months. Secondary outcomes were likelihood of future visits, trust in the clinician after exit interview, clinician detection of emotional distress and fear and abuse in relationships, and emotional distress at three and 12 months. Patient acceptability of the screening tool was also described for the intervention arm. Analyses were adjusted for practice location and billing type, patients’ sex, age, and recruitment method, and past health risks, where appropriate. An intention to treat analysis approach was used, which included multilevel multiple imputation for missing outcome data. Results 42 practices were randomly allocated to intervention or comparison arms. Two intervention practices withdrew post allocation, prior to training, leaving 19 intervention (53 clinicians, 377 patients) and 21 comparison (79 clinicians, 524 patients) practices. 69% of patients in both intervention (260) and comparison (360) arms completed the 12 month follow-up. Intervention clinicians discussed more health risks per patient (59.7%) than comparison clinicians (52.7%) and thus were more likely to detect a higher proportion of young people with at least one of the six health risk behaviours (38.4% vs 26.7%, risk difference [RD] 11.6%, Confidence Interval [CI] 2.93% to 20.3%; adjusted odds ratio [OR] 1.7, CI 1.1 to 2.5). Patients reported less illicit drug use (RD -6.0, CI -11 to -1.2; OR 0·52, CI 0·28 to 0·96), and less risk for STI (RD -5.4, CI -11 to 0.2; OR 0·66, CI 0·46 to 0·96) at three months in the intervention relative to the comparison arm, and for unplanned pregnancy at 12 months (RD -4.4; CI -8.7 to -0.1; OR 0·40, CI 0·20 to 0·80). No differences were detected between arms on other health risks. There were no differences on secondary outcomes, apart from a greater detection of abuse (OR 13.8, CI 1.71 to 111). There were no reports of harmful events and intervention arm youth had high acceptance of the screening tool. Conclusions A complex intervention, compared to a simple educational seminar for practices, improved detection of health risk behaviours in young people. Impact on health outcomes was inconclusive. Technology enabling more efficient, systematic health-risk screening may allow providers to target counselling toward higher risk individuals. Further trials require more power to confirm health benefits. Trial Registration ISRCTN.com ISRCTN16059206. PMID:26422235

A practical Bayesian stepped wedge design for community-based cluster-randomized clinical trials: The British Columbia Telehealth Trial.

PubMed

Cunanan, Kristen M; Carlin, Bradley P; Peterson, Kevin A

2016-12-01

Many clinical trial designs are impractical for community-based clinical intervention trials. Stepped wedge trial designs provide practical advantages, but few descriptions exist of their clinical implementational features, statistical design efficiencies, and limitations. Enhance efficiency of stepped wedge trial designs by evaluating the impact of design characteristics on statistical power for the British Columbia Telehealth Trial. The British Columbia Telehealth Trial is a community-based, cluster-randomized, controlled clinical trial in rural and urban British Columbia. To determine the effect of an Internet-based telehealth intervention on healthcare utilization, 1000 subjects with an existing diagnosis of congestive heart failure or type 2 diabetes will be enrolled from 50 clinical practices. Hospital utilization is measured using a composite of disease-specific hospital admissions and emergency visits. The intervention comprises online telehealth data collection and counseling provided to support a disease-specific action plan developed by the primary care provider. The planned intervention is sequentially introduced across all participating practices. We adopt a fully Bayesian, Markov chain Monte Carlo-driven statistical approach, wherein we use simulation to determine the effect of cluster size, sample size, and crossover interval choice on type I error and power to evaluate differences in hospital utilization. For our Bayesian stepped wedge trial design, simulations suggest moderate decreases in power when crossover intervals from control to intervention are reduced from every 3 to 2 weeks, and dramatic decreases in power as the numbers of clusters decrease. Power and type I error performance were not notably affected by the addition of nonzero cluster effects or a temporal trend in hospitalization intensity. Stepped wedge trial designs that intervene in small clusters across longer periods can provide enhanced power to evaluate comparative effectiveness, while offering practical implementation advantages in geographic stratification, temporal change, use of existing data, and resource distribution. Current population estimates were used; however, models may not reflect actual event rates during the trial. In addition, temporal or spatial heterogeneity can bias treatment effect estimates. © The Author(s) 2016.

Enhanced conformational sampling to visualize a free-energy landscape of protein complex formation.

PubMed

Iida, Shinji; Nakamura, Haruki; Higo, Junichi

2016-06-15

We introduce various, recently developed, generalized ensemble methods, which are useful to sample various molecular configurations emerging in the process of protein-protein or protein-ligand binding. The methods introduced here are those that have been or will be applied to biomolecular binding, where the biomolecules are treated as flexible molecules expressed by an all-atom model in an explicit solvent. Sampling produces an ensemble of conformations (snapshots) that are thermodynamically probable at room temperature. Then, projection of those conformations to an abstract low-dimensional space generates a free-energy landscape. As an example, we show a landscape of homo-dimer formation of an endothelin-1-like molecule computed using a generalized ensemble method. The lowest free-energy cluster at room temperature coincided precisely with the experimentally determined complex structure. Two minor clusters were also found in the landscape, which were largely different from the native complex form. Although those clusters were isolated at room temperature, with rising temperature a pathway emerged linking the lowest and second-lowest free-energy clusters, and a further temperature increment connected all the clusters. This exemplifies that the generalized ensemble method is a powerful tool for computing the free-energy landscape, by which one can discuss the thermodynamic stability of clusters and the temperature dependence of the cluster networks. © 2016 The Author(s).

Generalized Self-Organizing Maps for Automatic Determination of the Number of Clusters and Their Multiprototypes in Cluster Analysis.

PubMed

Gorzalczany, Marian B; Rudzinski, Filip

2017-06-07

This paper presents a generalization of self-organizing maps with 1-D neighborhoods (neuron chains) that can be effectively applied to complex cluster analysis problems. The essence of the generalization consists in introducing mechanisms that allow the neuron chain--during learning--to disconnect into subchains, to reconnect some of the subchains again, and to dynamically regulate the overall number of neurons in the system. These features enable the network--working in a fully unsupervised way (i.e., using unlabeled data without a predefined number of clusters)--to automatically generate collections of multiprototypes that are able to represent a broad range of clusters in data sets. First, the operation of the proposed approach is illustrated on some synthetic data sets. Then, this technique is tested using several real-life, complex, and multidimensional benchmark data sets available from the University of California at Irvine (UCI) Machine Learning repository and the Knowledge Extraction based on Evolutionary Learning data set repository. A sensitivity analysis of our approach to changes in control parameters and a comparative analysis with an alternative approach are also performed.

Effect of telehealth on quality of life and psychological outcomes over 12 months (Whole Systems Demonstrator telehealth questionnaire study): nested study of patient reported outcomes in a pragmatic, cluster randomised controlled trial.

PubMed

Cartwright, Martin; Hirani, Shashivadan P; Rixon, Lorna; Beynon, Michelle; Doll, Helen; Bower, Peter; Bardsley, Martin; Steventon, Adam; Knapp, Martin; Henderson, Catherine; Rogers, Anne; Sanders, Caroline; Fitzpatrick, Ray; Barlow, James; Newman, Stanton P

2013-02-26

To assess the effect of second generation, home based telehealth on health related quality of life, anxiety, and depressive symptoms over 12 months in patients with long term conditions. A study of patient reported outcomes (the Whole Systems Demonstrator telehealth questionnaire study; baseline n=1573) was nested in a pragmatic, cluster randomised trial of telehealth (the Whole Systems Demonstrator telehealth trial, n=3230). General practice was the unit of randomisation, and telehealth was compared with usual care. Data were collected at baseline, four months (short term), and 12 months (long term). Primary intention to treat analyses tested treatment effectiveness; multilevel models controlled for clustering by general practice and a range of covariates. Analyses were conducted for 759 participants who completed questionnaire measures at all three time points (complete case cohort) and 1201 who completed the baseline assessment plus at least one other assessment (available case cohort). Secondary per protocol analyses tested treatment efficacy and included 633 and 1108 participants in the complete case and available case cohorts, respectively. Provision of primary and secondary care via general practices, specialist nurses, and hospital clinics in three diverse regions of England (Cornwall, Kent, and Newham), with established integrated health and social care systems. Patients with chronic obstructive pulmonary disease (COPD), diabetes, or heart failure recruited between May 2008 and December 2009. Generic, health related quality of life (assessed by physical and mental health component scores of the SF-12, and the EQ-5D), anxiety (assessed by the six item Brief State-Trait Anxiety Inventory), and depressive symptoms (assessed by the 10 item Centre for Epidemiological Studies Depression Scale). In the intention to treat analyses, differences between treatment groups were small and non-significant for all outcomes in the complete case (0.480 ≤ P ≤ 0.904) or available case (0.181 ≤ P ≤ 0.905) cohorts. The magnitude of differences between trial arms did not reach the trial defined, minimal clinically important difference (0.3 standardised mean difference) for any outcome in either cohort at four or 12 months. Per protocol analyses replicated the primary analyses; the main effect of trial arm (telehealth v usual care) was non-significant for any outcome (complete case cohort 0.273 ≤ P ≤ 0.761; available case cohort 0.145 ≤ P ≤ 0.696). Second generation, home based telehealth as implemented in the Whole Systems Demonstrator Evaluation was not effective or efficacious compared with usual care only. Telehealth did not improve quality of life or psychological outcomes for patients with chronic obstructive pulmonary disease, diabetes, or heart failure over 12 months. The findings suggest that concerns about potentially deleterious effect of telehealth are unfounded for most patients. ISRCTN43002091.

Clustering determines the dynamics of complex contagions in multiplex networks

NASA Astrophysics Data System (ADS)

Zhuang, Yong; Arenas, Alex; Yaǧan, Osman

2017-01-01

We present the mathematical analysis of generalized complex contagions in a class of clustered multiplex networks. The model is intended to understand spread of influence, or any other spreading process implying a threshold dynamics, in setups of interconnected networks with significant clustering. The contagion is assumed to be general enough to account for a content-dependent linear threshold model, where each link type has a different weight (for spreading influence) that may depend on the content (e.g., product, rumor, political view) that is being spread. Using the generating functions formalism, we determine the conditions, probability, and expected size of the emergent global cascades. This analysis provides a generalization of previous approaches and is especially useful in problems related to spreading and percolation. The results present nontrivial dependencies between the clustering coefficient of the networks and its average degree. In particular, several phase transitions are shown to occur depending on these descriptors. Generally speaking, our findings reveal that increasing clustering decreases the probability of having global cascades and their size, however, this tendency changes with the average degree. There exists a certain average degree from which on clustering favors the probability and size of the contagion. By comparing the dynamics of complex contagions over multiplex networks and their monoplex projections, we demonstrate that ignoring link types and aggregating network layers may lead to inaccurate conclusions about contagion dynamics, particularly when the correlation of degrees between layers is high.

Bayesian network meta-analysis for cluster randomized trials with binary outcomes.

PubMed

Uhlmann, Lorenz; Jensen, Katrin; Kieser, Meinhard

2017-06-01

Network meta-analysis is becoming a common approach to combine direct and indirect comparisons of several treatment arms. In recent research, there have been various developments and extensions of the standard methodology. Simultaneously, cluster randomized trials are experiencing an increased popularity, especially in the field of health services research, where, for example, medical practices are the units of randomization but the outcome is measured at the patient level. Combination of the results of cluster randomized trials is challenging. In this tutorial, we examine and compare different approaches for the incorporation of cluster randomized trials in a (network) meta-analysis. Furthermore, we provide practical insight on the implementation of the models. In simulation studies, it is shown that some of the examined approaches lead to unsatisfying results. However, there are alternatives which are suitable to combine cluster randomized trials in a network meta-analysis as they are unbiased and reach accurate coverage rates. In conclusion, the methodology can be extended in such a way that an adequate inclusion of the results obtained in cluster randomized trials becomes feasible. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

The development and optimisation of a primary care-based whole system complex intervention (CARE Plus) for patients with multimorbidity living in areas of high socioeconomic deprivation

PubMed Central

O'Brien, Rosaleen; Fitzpatrick, Bridie; Higgins, Maria; Guthrie, Bruce; Watt, Graham; Wyke, Sally

2016-01-01

Objectives To develop and optimise a primary care-based complex intervention (CARE Plus) to enhance the quality of life of patients with multimorbidity in the deprived areas. Methods Six co-design discussion groups involving 32 participants were held separately with multimorbid patients from the deprived areas, voluntary organisations, general practitioners and practice nurses working in the deprived areas. This was followed by piloting in two practices and further optimisation based on interviews with 11 general practitioners, 2 practice nurses and 6 participating multimorbid patients. Results Participants endorsed the need for longer consultations, relational continuity and a holistic approach. All felt that training and support of the health care staff was important. Most participants welcomed the idea of additional self-management support, though some practitioners were dubious about whether patients would use it. The pilot study led to changes including a revised care plan, the inclusion of mindfulness-based stress reduction techniques in the support of practitioners and patients, and the stream-lining of the written self-management support material for patients. Discussion We have co-designed and optimised an augmented primary care intervention involving a whole-system approach to enhance quality of life in multimorbid patients living in the deprived areas. CARE Plus will next be tested in a phase 2 cluster randomised controlled trial. PMID:27068113

Effects of distance learning on clinical management of LUTS in primary care: a randomised trial.

PubMed

Wolters, René; Wensing, Michel; Klomp, Maarten; Lagro-Jansen, Toine; Weel, Chris van; Grol, Richard

2005-11-01

To determine the effect of a distance learning programme on general practice management of men with lower urinary tract symptoms (LUTS). A cluster randomised controlled trial was performed. General practitioners (GPs) were randomised to a distance learning programme accompanied with educational materials or to a control group only receiving mailed clinical guidelines on LUTS. Clinical management was considered as outcome. Sixty-three GPs registered care management of 187 patients older than 50 years attending the practice because of LUTS. The intervention group showed a lower referral rate to a urologist (OR: 0.08 (95% CI: 0.02-0.40)), but no effect on PSA testing or prescription of medication. PSA testing tended to be requested more frequently by intervention group GPs. Secondary analysis showed patients in the intervention group received more educational materials (OR: 75.6 (95% CI: 13.60-419.90)). The educational programme had impact on clinical management without changing PSA testing. Distance learning is an promising method for continuing education. Activating distance learning packages are a potentially effective method for improving professional performance. Emotional matters as PSA testing probably need a more complex approach.

Process evaluation of the Data-driven Quality Improvement in Primary Care (DQIP) trial: quantitative examination of variation between practices in recruitment, implementation and effectiveness.

PubMed

Dreischulte, Tobias; Grant, Aileen; Hapca, Adrian; Guthrie, Bruce

2018-01-05

The cluster randomised trial of the Data-driven Quality Improvement in Primary Care (DQIP) intervention showed that education, informatics and financial incentives for general medical practices to review patients with ongoing high-risk prescribing of non-steroidal anti-inflammatory drugs and antiplatelets reduced the primary end point of high-risk prescribing by 37%, where both ongoing and new high-risk prescribing were significantly reduced. This quantitative process evaluation examined practice factors associated with (1) participation in the DQIP trial, (2) review activity (extent and nature of documented reviews) and (3) practice level effectiveness (relative reductions in the primary end point). Invited practices recruited (n=33) and not recruited (n=32) to the DQIP trial in Scotland, UK. (1) Characteristics of recruited versus non-recruited practices. Associations of (2) practice characteristics and 'adoption' (self-reported implementation work done by practices) with documented review activity and (3) of practice characteristics, DQIP adoption and review activity with effectiveness. (1) Recruited practices had lower performance in the quality and outcomes framework than those declining participation. (2) Not being an approved general practitioner training practice and higher self-reported adoption were significantly associated with higher review activity. (3) Effectiveness ranged from a relative increase in high-risk prescribing of 24.1% to a relative reduction of 77.2%. High-risk prescribing and DQIP adoption (but not documented review activity) were significantly associated with greater effectiveness in the final multivariate model, explaining 64.0% of variation in effectiveness. Intervention implementation and effectiveness of the DQIP intervention varied substantially between practices. Although the DQIP intervention primarily targeted review of ongoing high-risk prescribing, the finding that self-reported DQIP adoption was a stronger predictor of effectiveness than documented review activity supports that reducing initiation and/or re-initiation of high-risk prescribing is key to its effectiveness. NCT01425502; Post-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Seizure clustering.

PubMed

Haut, Sheryl R

2006-02-01

Seizure clusters, also known as repetitive or serial seizures, occur commonly in epilepsy. Clustering implies that the occurrence of one seizure may influence the probability of a subsequent seizure; thus, the investigation of the clustering phenomenon yields insights into both specific mechanisms of seizure clustering and more general concepts of seizure occurrence. Seizure clustering has been defined clinically as a number of seizures per unit time and, statistically, as a deviation from a random distribution, or interseizure interval dependence. This review explores the pathophysiology, epidemiology, and clinical implications of clustering, as well as other periodic patterns of seizure occurrence. Risk factors for experiencing clusters and potential precipitants of clustering are also addressed.

New gas phase inorganic ion cluster species and their atmospheric implications

NASA Technical Reports Server (NTRS)

Maerk, T. D.; Peterson, K. I.; Castleman, A. W., Jr.

1980-01-01

Recent experimental laboratory observations, with high-pressure mass spectroscopy, have revealed the existence of previously unreported species involving water clustered to sodium dimer ions, and alkali metal hydroxides clustered to alkali metal ions. The important implications of these results concerning the existence of such species are here discussed, as well as how from a practical aspect they confirm the stability of certain cluster species proposed by Ferguson (1978) to explain masses recently detected at upper altitudes using mass spectrometric techniques.

Effective Feedback to Improve Primary Care Prescribing Safety (EFIPPS) a pragmatic three-arm cluster randomised trial: designing the intervention (ClinicalTrials.gov registration NCT01602705).

PubMed

Barnett, Karen N; Bennie, Marion; Treweek, Shaun; Robertson, Christopher; Petrie, Dennis J; Ritchie, Lewis D; Guthrie, Bruce

2014-10-11

High-risk prescribing in primary care is common and causes considerable harm. Feedback interventions have small/moderate effects on clinical practice, but few trials explicitly compare different forms of feedback. There is growing recognition that intervention development should be theory-informed, and that comprehensive reporting of intervention design is required by potential users of trial findings. The paper describes intervention development for the Effective Feedback to Improve Primary Care Prescribing Safety (EFIPPS) study, a pragmatic three-arm cluster randomised trial in 262 Scottish general practices. The NHS chose to implement a feedback intervention to utilise a new resource, new Prescribing Information System (newPIS). The development phase required selection of high-risk prescribing outcome measures and design of intervention components: (1) educational material (the usual care comparison), (2) feedback of practice rates of high-risk prescribing received by both intervention arms and (3) a theory-informed behaviour change component to be received by one intervention arm. Outcome measures, educational material and feedback design, were developed with a National Health Service Advisory Group. The behaviour change component was informed by the Theory of Planned Behaviour and the Health Action Process Approach. A focus group elicitation study and an email Delphi study with general practitioners (GPs) identified key attitudes and barriers of responding to the prescribing feedback. Behaviour change techniques were mapped to the psychological constructs, and the content was informed by the results of the elicitation and Delphi study. Six high-risk prescribing measures were selected in a consensus process based on importance and feasibility. Educational material and feedback design were based on current NHS Scotland practice and Advisory Group recommendations. The behaviour change component was resource constrained in development, mirroring what is feasible in an NHS context. Four behaviour change interventions were developed and embedded in five quarterly rounds of feedback targeting attitudes, subjective norms, perceived behavioural control and action planning (2×). The paper describes a process which is feasible to use in the resource-constrained environment of NHS-led intervention development and documents the intervention to make its design and implementation explicit to potential users of the trial findings. ClinicalTrials.gov: NCT01602705.

Implementing the NICE osteoarthritis guidelines: a mixed methods study and cluster randomised trial of a model osteoarthritis consultation in primary care--the Management of OsteoArthritis In Consultations (MOSAICS) study protocol.

PubMed

Dziedzic, Krysia S; Healey, Emma L; Porcheret, Mark; Ong, Bie Nio; Main, Chris J; Jordan, Kelvin P; Lewis, Martyn; Edwards, John J; Jinks, Clare; Morden, Andrew; McHugh, Gretl A; Ryan, Sarah; Finney, Andrew; Jowett, Sue; Oppong, Raymond; Afolabi, Ebenezer; Pushpa-Rajah, Angela; Handy, June; Clarkson, Kris; Mason, Elizabeth; Whitehurst, Tracy; Hughes, Rhian W; Croft, Peter R; Hay, Elaine M

2014-08-27

There is as yet no evidence on the feasibility of implementing recommendations from the National Institute of Health and Care Excellence (NICE) osteoarthritis (OA) guidelines in primary care, or of the effect these recommendations have on the condition. The primary aim of this study is to determine the clinical and cost effectiveness of a model OA consultation (MOAC), implementing the core recommendations from the NICE OA guidelines in primary care. Secondary aims are to investigate the impact, feasibility and acceptability of the MOAC intervention; to develop and evaluate a training package for management of OA by general practitioners (GPs) and practice nurses; test the feasibility of deriving 'quality markers' of OA management using a new consultation template and medical record review; and describe the uptake of core NICE OA recommendations in participants aged 45 years and over with joint pain. A mixed methods study with a nested cluster randomised controlled trial. This study was developed according to a defined theoretical framework (the Whole System Informing Self-management Engagement). An overarching model (the Normalisation Process Theory) will be employed to undertake a comprehensive 'whole-system' evaluation of the processes and outcomes of implementing the MOAC intervention. The primary outcome is general physical health (Short Form-12 Physical component score [PCS]) (Ware 1996). The impact, acceptability and feasibility of the MOAC intervention at practice level will be assessed by comparing intervention and control practices using a Quality Indicators template and medical record review. Impact and acceptability of the intervention for patients will be assessed via self-completed outcome measures and semi-structured interviews. The impact, acceptability and feasibility of the MOAC intervention and training for GPs and practice nurses will be evaluated using a variety of methods including questionnaires, semi-structured interviews, and observations. The main output from the study will be to determine whether the MOAC intervention is clinically and cost effective. Additional outputs will be the development of the MOAC for patients consulting with joint pain in primary care, training and educational materials, and resources for patients and professionals regarding supported self-management and uptake of NICE guidance. ISRCTN number: ISRCTN06984617.

Mathematical Geology

ERIC Educational Resources Information Center

Merriam, Daniel F.

1978-01-01

Geomathematics is a developing field that is being used in practical applications. Classification is an important element and the dynamic-cluster method (DCM), a nonhierarchial procedure, was introduced this past year. A method for testing the degree of cluster distinctness was developed also. (MA)

A Cluster-Randomized Trial of Restorative Practices: An Illustration to Spur High-Quality Research and Evaluation.

PubMed

Acosta, Joie D; Chinman, Matthew; Ebener, Patricia; Phillips, Andrea; Xenakis, Lea; Malone, Patrick S

2016-01-01

Restorative Practices in schools lack rigorous evaluation studies. As an example of rigorous school-based research, this paper describes the first randomized control trial of restorative practices to date, the Study of Restorative Practices. It is a 5-year, cluster-randomized controlled trial (RCT) of the Restorative Practices Intervention (RPI) in 14 middle schools in Maine to assess whether RPI impacts both positive developmental outcomes and problem behaviors and whether the effects persist during the transition from middle to high school. The two-year RPI intervention began in the 2014-2015 school year. The study's rationale and theoretical concerns are discussed along with methodological concerns including teacher professional development. The theoretical rationale and description of the methods from this study may be useful to others conducting rigorous research and evaluation in this area.

Convergence of the Graph Allen-Cahn Scheme

NASA Astrophysics Data System (ADS)

Luo, Xiyang; Bertozzi, Andrea L.

2017-05-01

The graph Laplacian and the graph cut problem are closely related to Markov random fields, and have many applications in clustering and image segmentation. The diffuse interface model is widely used for modeling in material science, and can also be used as a proxy to total variation minimization. In Bertozzi and Flenner (Multiscale Model Simul 10(3):1090-1118, 2012), an algorithm was developed to generalize the diffuse interface model to graphs to solve the graph cut problem. This work analyzes the conditions for the graph diffuse interface algorithm to converge. Using techniques from numerical PDE and convex optimization, monotonicity in function value and convergence under an a posteriori condition are shown for a class of schemes under a graph-independent stepsize condition. We also generalize our results to incorporate spectral truncation, a common technique used to save computation cost, and also to the case of multiclass classification. Various numerical experiments are done to compare theoretical results with practical performance.

Evaluation of external biosecurity practices on southern Ontario sow farms.

PubMed

Bottoms, Kate; Poljak, Zvonimir; Dewey, Cate; Deardon, Rob; Holtkamp, Derald; Friendship, Robert

2013-04-01

External biosecurity protocols, aimed at preventing the introduction of new pathogens to the farm environment, are becoming increasingly important in the swine industry. Although assessments at the individual farm level occur regularly, efforts to cluster swine herds into meaningful biosecurity groups and to summarize this information at the regional level are relatively infrequent. The objectives of this study were: (i) to summarize external biosecurity practices on sow farms in southern Ontario; (ii) to cluster these farms into discrete biosecurity groups and to describe their characteristics, the variables of importance in differentiating between these groups, and their geographic distribution; and (iii) to identify significant predictors of biosecurity group membership. Data were collected using the Production Animal Disease Risk Assessment Program's Survey for the Breeding Herd. A subset of variables pertaining to external biosecurity practices was selected for two-step cluster analysis, which resulted in 3 discrete biosecurity groups. These groups were named by the authors as: (i) high biosecurity herds that were open with respect to replacement animals, (ii) high biosecurity herds that were closed with respect to replacement animals, and (iii) low biosecurity herds. Variables pertaining to trucking practices and the source of replacement animals were the most important in differentiating between these groups. Multinomial logistic regression provided insight into which demographic and neighborhood variables serve as significant predictors of biosecurity group membership (p<0.05). Variables in the final regression model include: herd density within a 4.8 km radius, number of sows on the premises, and site production type. The odds of belonging to the high biosecurity group that was open with respect to replacement animals, relative to the low biosecurity group, increased 1.001 times for each additional sow (p=0.001). The odds of belonging to the high biosecurity group that was open with respect to replacement animals, relative to the low biosecurity group, were 6.5 times greater for farms that produced genetic animals than for farms that produced commercial animals (p=0.003). The information obtained through this work allows a better understanding of biosecurity in sow herds at the regional level, and the implementation of biosecurity protocols in North American swine herds in general. Copyright © 2012 Elsevier B.V. All rights reserved.

Consistency of Cluster Analysis for Cognitive Diagnosis: The Reduced Reparameterized Unified Model and the General Diagnostic Model.

PubMed

Chiu, Chia-Yi; Köhn, Hans-Friedrich

2016-09-01

The asymptotic classification theory of cognitive diagnosis (ACTCD) provided the theoretical foundation for using clustering methods that do not rely on a parametric statistical model for assigning examinees to proficiency classes. Like general diagnostic classification models, clustering methods can be useful in situations where the true diagnostic classification model (DCM) underlying the data is unknown and possibly misspecified, or the items of a test conform to a mix of multiple DCMs. Clustering methods can also be an option when fitting advanced and complex DCMs encounters computational difficulties. These can range from the use of excessive CPU times to plain computational infeasibility. However, the propositions of the ACTCD have only been proven for the Deterministic Input Noisy Output "AND" gate (DINA) model and the Deterministic Input Noisy Output "OR" gate (DINO) model. For other DCMs, there does not exist a theoretical justification to use clustering for assigning examinees to proficiency classes. But if clustering is to be used legitimately, then the ACTCD must cover a larger number of DCMs than just the DINA model and the DINO model. Thus, the purpose of this article is to prove the theoretical propositions of the ACTCD for two other important DCMs, the Reduced Reparameterized Unified Model and the General Diagnostic Model.

Noise-enhanced clustering and competitive learning algorithms.

PubMed

Osoba, Osonde; Kosko, Bart

2013-01-01

Noise can provably speed up convergence in many centroid-based clustering algorithms. This includes the popular k-means clustering algorithm. The clustering noise benefit follows from the general noise benefit for the expectation-maximization algorithm because many clustering algorithms are special cases of the expectation-maximization algorithm. Simulations show that noise also speeds up convergence in stochastic unsupervised competitive learning, supervised competitive learning, and differential competitive learning. Copyright © 2012 Elsevier Ltd. All rights reserved.

Variance-Based Cluster Selection Criteria in a K-Means Framework for One-Mode Dissimilarity Data.

PubMed

Vera, J Fernando; Macías, Rodrigo

2017-06-01

One of the main problems in cluster analysis is that of determining the number of groups in the data. In general, the approach taken depends on the cluster method used. For K-means, some of the most widely employed criteria are formulated in terms of the decomposition of the total point scatter, regarding a two-mode data set of N points in p dimensions, which are optimally arranged into K classes. This paper addresses the formulation of criteria to determine the number of clusters, in the general situation in which the available information for clustering is a one-mode [Formula: see text] dissimilarity matrix describing the objects. In this framework, p and the coordinates of points are usually unknown, and the application of criteria originally formulated for two-mode data sets is dependent on their possible reformulation in the one-mode situation. The decomposition of the variability of the clustered objects is proposed in terms of the corresponding block-shaped partition of the dissimilarity matrix. Within-block and between-block dispersion values for the partitioned dissimilarity matrix are derived, and variance-based criteria are subsequently formulated in order to determine the number of groups in the data. A Monte Carlo experiment was carried out to study the performance of the proposed criteria. For simulated clustered points in p dimensions, greater efficiency in recovering the number of clusters is obtained when the criteria are calculated from the related Euclidean distances instead of the known two-mode data set, in general, for unequal-sized clusters and for low dimensionality situations. For simulated dissimilarity data sets, the proposed criteria always outperform the results obtained when these criteria are calculated from their original formulation, using dissimilarities instead of distances.

Effectiveness and costs of a vocational advice service to improve work outcomes in patients with musculoskeletal pain in primary care: a cluster randomised trial (SWAP trial ISRCTN 52269669).

PubMed

Wynne-Jones, Gwenllian; Artus, Majid; Bishop, Annette; Lawton, Sarah A; Lewis, Martyn; Jowett, Sue; Kigozi, Jesse; Main, Chris; Sowden, Gail; Wathall, Simon; Burton, A Kim; van der Windt, Danielle A; Hay, Elaine M; Foster, Nadine E

2017-10-30

Musculoskeletal pain is a common cause of work absence, and early intervention is advocated to prevent the adverse health and economic consequences of longer-term absence. This cluster randomised controlled trial investigated the effect of introducing a vocational advice service into primary care to provide occupational support. Six general practices were randomised; patients were eligible if they were consulting their general practitioner with musculoskeletal pain and were employed and struggling at work or absent from work <6 months. Practices in the intervention arm could refer patients to a vocational advisor embedded within the practice providing a case-managed stepwise intervention addressing obstacles to working. The primary outcome was number of days off work, over 4 months. Participants in the intervention arm (n = 158) had fewer days work absence compared with the control arm (n = 180) (mean 9.3 [SD 21·7] vs 14·4 [SD 27·7]) days, incidence rate ratio 0·51 (95% confidence interval 0·26, 0·99), P = 0·048). The net societal benefit of the intervention compared with best care was £733: £748 gain (work absence) vs £15 loss (health care costs). The addition of a vocational advice service to best current primary care for patients consulting with musculoskeletal pain led to reduced absence and cost savings for society. If a similar early intervention to the one tested in this trial was implemented widely, it could potentially reduce days absent over 12 months by 16%, equating to an overall societal cost saving of approximately £500 million (US $6 billion) and requiring an investment of only £10 million.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial License 4.0 (CCBY-NC), where it is permissible to download, share, remix, transform, and buildup the work provided it is properly cited. The work cannot be used commercially without permission from the journal.

Overcoming clinical inertia in insulin initiation in primary care for patients with type 2 diabetes: 24-month follow-up of the Stepping Up cluster randomised controlled trial.

PubMed

Manski-Nankervis, Jo-Anne; Furler, John; O'Neal, David; Ginnivan, Louise; Thuraisingam, Sharmala; Blackberry, Irene

2017-10-01

To examine the two-year impact of Stepping Up, a general practice based model of care intervention for insulin initiation and titration in Australia. 266 participants from 74 general practices participated in the Stepping Up cluster randomised controlled trial between 2012-2014. Control practices received training in the model of care on completion of the 12-month trial. Patients were followed for 24 months. Participant baseline characteristics, insulin and non-insulin medication use were summarised for each study group. Linear mixed-effects models with random intercepts were used to estimate differences in mean outcome (HbA1c and weight) between the study groups using restricted maximum likelihood estimation. At baseline 61% of patients were male, mean (SD) age 62 (10) years, diabetes duration 9 (5, 13) years and mean (95% CI) HbA1c was 8.9 (8.8-9.1)% (74 (73-76)mmol/mol) for both groups. There was a significant between group difference at 6 months which was sustained at 24 months; Mean (95% CI) HbA1c at 24 months in the intervention group was 7.6 (7.5-7.8)% (60 (58-62)mmol/mol) and 8.0 (7.7-8.4)% (64 (61-68)mmol/mol) in the control group. At 24 months 97 (71.3%) of the intervention group and 26 (31.0%) of the control group were prescribed insulin; there was no significant difference in weight. Use of non-insulin anti-hyperglycaemic agents was similar in both groups with the exception of dipeptidyl peptidase-4 inhibitors which were prescribed more frequently in the control group (30(36%) vs 21(16%)). Stepping Up was associated with improved glycaemic control compared to usual care for 24 months, suggesting that the model facilitated more timely treatment intensification. Ongoing RN-CDE support may be needed to facilitate ongoing treatment intensification. Copyright © 2017 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.

A cluster randomised controlled trial of advice, exercise or multifactorial assessment to prevent falls and fractures in community-dwelling older adults: protocol for the prevention of falls injury trial (PreFIT)

PubMed Central

Lall, Ranjit; Withers, Emma J; Finnegan, Susanne; Underwood, Martin; Hulme, Claire; Sheridan, Ray; Skelton, Dawn A; Martin, Finbarr; Lamb, Sarah E

2016-01-01

Introduction Falls are the leading cause of accident-related mortality in older adults. Injurious falls are associated with functional decline, disability, healthcare utilisation and significant National Health Service (NHS)-related costs. The evidence base for multifactorial or exercise interventions reducing fractures in the general population is weak. This protocol describes a large-scale UK trial investigating the clinical and cost-effectiveness of alternative falls prevention interventions targeted at community dwelling older adults. Methods and analysis A three-arm, pragmatic, cluster randomised controlled trial, conducted within primary care in England, UK. Sixty-three general practices will be randomised to deliver one of three falls prevention interventions: (1) advice only; (2) advice with exercise; or (3) advice with multifactorial falls prevention (MFFP). We aim to recruit over 9000 community-dwelling adults aged 70 and above. Practices randomised to deliver advice will mail out advice booklets. Practices randomised to deliver ‘active’ interventions, either exercise or MFFP, send all trial participants the advice booklet and a screening survey to identify participants with a history of falling or balance problems. Onward referral to ‘active’ intervention will be based on falls risk determined from balance screen. The primary outcome is peripheral fracture; secondary outcomes include number with at least one fracture, falls, mortality, quality of life and health service resource use at 18 months, captured using self-report and routine healthcare activity data. Ethics and dissemination The study protocol has approval from the National Research Ethics Service (REC reference 10/H0401/36; Protocol V.3.1, 21/May/2013). User groups and patient representatives were consulted to inform trial design. Results will be reported at conferences and in peer-reviewed publications. A patient-friendly summary of trial findings will be published on the prevention of falls injury trial (PreFIT) website. This protocol adheres to the recommended SPIRIT Checklist. Amendments will be reported to relevant regulatory parties. Trial registration number ISRCTN 71002650; Pre-results. PMID:26781504

A cluster randomised controlled trial of advice, exercise or multifactorial assessment to prevent falls and fractures in community-dwelling older adults: protocol for the prevention of falls injury trial (PreFIT).

PubMed

Bruce, Julie; Lall, Ranjit; Withers, Emma J; Finnegan, Susanne; Underwood, Martin; Hulme, Claire; Sheridan, Ray; Skelton, Dawn A; Martin, Finbarr; Lamb, Sarah E

2016-01-18

Falls are the leading cause of accident-related mortality in older adults. Injurious falls are associated with functional decline, disability, healthcare utilisation and significant National Health Service (NHS)-related costs. The evidence base for multifactorial or exercise interventions reducing fractures in the general population is weak. This protocol describes a large-scale UK trial investigating the clinical and cost-effectiveness of alternative falls prevention interventions targeted at community dwelling older adults. A three-arm, pragmatic, cluster randomised controlled trial, conducted within primary care in England, UK. Sixty-three general practices will be randomised to deliver one of three falls prevention interventions: (1) advice only; (2) advice with exercise; or (3) advice with multifactorial falls prevention (MFFP). We aim to recruit over 9000 community-dwelling adults aged 70 and above. Practices randomised to deliver advice will mail out advice booklets. Practices randomised to deliver 'active' interventions, either exercise or MFFP, send all trial participants the advice booklet and a screening survey to identify participants with a history of falling or balance problems. Onward referral to 'active' intervention will be based on falls risk determined from balance screen. The primary outcome is peripheral fracture; secondary outcomes include number with at least one fracture, falls, mortality, quality of life and health service resource use at 18 months, captured using self-report and routine healthcare activity data. The study protocol has approval from the National Research Ethics Service (REC reference 10/H0401/36; Protocol V.3.1, 21/May/2013). User groups and patient representatives were consulted to inform trial design. Results will be reported at conferences and in peer-reviewed publications. A patient-friendly summary of trial findings will be published on the prevention of falls injury trial (PreFIT) website. This protocol adheres to the recommended SPIRIT Checklist. Amendments will be reported to relevant regulatory parties. ISRCTN 71002650; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Understanding diagnosis and management of dementia and guideline implementation in general practice: a qualitative study using the theoretical domains framework.

PubMed

Murphy, Kerry; O'Connor, Denise A; Browning, Colette J; French, Simon D; Michie, Susan; Francis, Jill J; Russell, Grant M; Workman, Barbara; Flicker, Leon; Eccles, Martin P; Green, Sally E

2014-03-03

Dementia is a growing problem, causing substantial burden for patients, their families, and society. General practitioners (GPs) play an important role in diagnosing and managing dementia; however, there are gaps between recommended and current practice. The aim of this study was to explore GPs' reported practice in diagnosing and managing dementia and to describe, in theoretical terms, the proposed explanations for practice that was and was not consistent with evidence-based guidelines. Semi-structured interviews were conducted with GPs in Victoria, Australia. The Theoretical Domains Framework (TDF) guided data collection and analysis. Interviews explored the factors hindering and enabling achievement of 13 recommended behaviours. Data were analysed using content and thematic analysis. This paper presents an in-depth description of the factors influencing two behaviours, assessing co-morbid depression using a validated tool, and conducting a formal cognitive assessment using a validated scale. A total of 30 GPs were interviewed. Most GPs reported that they did not assess for co-morbid depression using a validated tool as per recommended guidance. Barriers included the belief that depression can be adequately assessed using general clinical indicators and that validated tools provide little additional information (theoretical domain of 'Beliefs about consequences'); discomfort in using validated tools ('Emotion'), possibly due to limited training and confidence ('Skills'; 'Beliefs about capabilities'); limited awareness of the need for, and forgetting to conduct, a depression assessment ('Knowledge'; 'Memory, attention and decision processes'). Most reported practising in a manner consistent with the recommendation that a formal cognitive assessment using a validated scale be undertaken. Key factors enabling this were having an awareness of the need to conduct a cognitive assessment ('Knowledge'); possessing the necessary skills and confidence ('Skills'; 'Beliefs about capabilities'); and having adequate time and resources ('Environmental context and resources'). This is the first study to our knowledge to use a theoretical approach to investigate the barriers and enablers to guideline-recommended diagnosis and management of dementia in general practice. It has identified key factors likely to explain GPs' uptake of the guidelines. The results have informed the design of an intervention aimed at supporting practice change in line with dementia guidelines, which is currently being evaluated in a cluster randomised trial.

A Novel Clustering Methodology Based on Modularity Optimisation for Detecting Authorship Affinities in Shakespearean Era Plays

PubMed Central

Craig, Hugh; Berretta, Regina; Moscato, Pablo

2016-01-01

In this study we propose a novel, unsupervised clustering methodology for analyzing large datasets. This new, efficient methodology converts the general clustering problem into the community detection problem in graph by using the Jensen-Shannon distance, a dissimilarity measure originating in Information Theory. Moreover, we use graph theoretic concepts for the generation and analysis of proximity graphs. Our methodology is based on a newly proposed memetic algorithm (iMA-Net) for discovering clusters of data elements by maximizing the modularity function in proximity graphs of literary works. To test the effectiveness of this general methodology, we apply it to a text corpus dataset, which contains frequencies of approximately 55,114 unique words across all 168 written in the Shakespearean era (16th and 17th centuries), to analyze and detect clusters of similar plays. Experimental results and comparison with state-of-the-art clustering methods demonstrate the remarkable performance of our new method for identifying high quality clusters which reflect the commonalities in the literary style of the plays. PMID:27571416

Formation of Very Young Massive Clusters and Implications for Globular Clusters

NASA Astrophysics Data System (ADS)

Banerjee, Sambaran; Kroupa, Pavel

How Very Young Massive star Clusters (VYMCs; also known as "starburst" clusters), which typically are of ≳ 104 M ⊙ and are a few Myr old, form out of Giant Molecular Clouds is still largely an open question. Increasingly detailed observations of young star clusters and star-forming molecular clouds and computational studies provide clues about their formation scenarios and the underlying physical processes involved. This chapter is focused on reviewing the decade-long studies that attempt to computationally reproduce the well-observed nearby VYMCs, such as the Orion Nebula Cluster, R136 and NGC 3603 young cluster, thereby shedding light on birth conditions of massive star clusters, in general. On this regard, focus is given on direct N-body modelling of real-sized massive star clusters, with a monolithic structure and undergoing residual gas expulsion, which have consistently reproduced the observed characteristics of several VYMCs and also of young star clusters, in general. The connection of these relatively simplified model calculations with the structural richness of dense molecular clouds and the complexity of hydrodynamic calculations of star cluster formation is presented in detail. Furthermore, the connections of such VYMCs with globular clusters, which are nearly as old as our Universe, is discussed. The chapter is concluded by addressing long-term deeply gas-embedded (at least apparently) and substructured systems like W3 Main. While most of the results are quoted from existing and up-to-date literature, in an integrated fashion, several new insights and discussions are provided.

The clinical effectiveness and cost-effectiveness of telephone triage for managing same-day consultation requests in general practice: a cluster randomised controlled trial comparing general practitioner-led and nurse-led management systems with usual care (the ESTEEM trial).

PubMed

Campbell, John L; Fletcher, Emily; Britten, Nicky; Green, Colin; Holt, Tim; Lattimer, Valerie; Richards, David A; Richards, Suzanne H; Salisbury, Chris; Taylor, Rod S; Calitri, Raff; Bowyer, Vicky; Chaplin, Katherine; Kandiyali, Rebecca; Murdoch, Jamie; Price, Linnie; Roscoe, Julia; Varley, Anna; Warren, Fiona C

2015-02-01

Telephone triage is proposed as a method of managing increasing demand for primary care. Previous studies have involved small samples in limited settings, and focused on nurse roles. Evidence is limited regarding the impact on primary care workload, costs, and patient safety and experience when triage is used to manage patients requesting same-day consultations in general practice. In comparison with usual care (UC), to assess the impact of GP-led telephone triage (GPT) and nurse-led computer-supported telephone triage (NT) on primary care workload and cost, patient experience of care, and patient safety and health status for patients requesting same-day consultations in general practice. Pragmatic cluster randomised controlled trial, incorporating economic evaluation and qualitative process evaluation. General practices (n = 42) in four regions of England, UK (Devon, Bristol/Somerset, Warwickshire/Coventry, Norfolk/Suffolk). Patients requesting same-day consultations. Practices were randomised to GPT, NT or UC. Data collection was not blinded; however, analysis was conducted by a statistician blinded to practice allocation. Primary - primary care contacts [general practice, out-of-hours primary care, accident and emergency (A&E) and walk-in centre attendances] in the 28 days following the index consultation request. Secondary - resource use and costs, patient safety (deaths and emergency hospital admissions within 7 days of index request, and A&E attendance within 28 days), health status and experience of care. Of 20,990 eligible randomised patients (UC n = 7283; GPT n = 6695; NT n = 7012), primary outcome data were analysed for 16,211 patients (UC n = 5572; GPT n = 5171; NT n = 5468). Compared with UC, GPT and NT increased primary outcome contacts (over 28-day follow-up) by 33% [rate ratio (RR) 1.33, 95% confidence interval (CI) 1.30 to 1.36] and 48% (RR 1.48, 95% CI 1.44 to 1.52), respectively. Compared with GPT, NT was associated with a marginal increase in primary outcome contacts by 4% (RR 1.04, 95% CI 1.01 to 1.08). Triage was associated with a redistribution of primary care contacts. Although GPT, compared with UC, increased the rate of overall GP contacts (face to face and telephone) over the 28 days by 38% (RR 1.38, 95% CI 1.28 to 1.50), GP face-to-face contacts were reduced by 39% (RR 0.61, 95% CI 0.54 to 0.69). NT reduced the rate of overall GP contacts by 16% (RR 0.84, 95% CI 0.78 to 0.91) and GP face-to-face contacts by 20% (RR 0.80, 95% CI 0.71 to 0.90), whereas nurse contacts increased. The increased rate of primary care contacts in triage arms is largely attributable to increased telephone contacts. Estimated overall patient-clinician contact time on the index day increased in triage (GPT = 10.3 minutes; NT = 14.8 minutes; UC = 9.6 minutes), although patterns of clinician use varied between arms. Taking account of both the pattern and duration of primary outcome contacts, overall costs over the 28-day follow-up were similar in all three arms (approximately £75 per patient). Triage appeared safe, and no differences in patient health status were observed. NT was somewhat less acceptable to patients than GPT or UC. The process evaluation identified the complexity associated with introducing triage but found no consistency across practices about what works and what does not work when implementing it. Introducing GPT or NT was associated with a redistribution of primary care workload for patients requesting same-day consultations, and at similar cost to UC. Although triage seemed to be safe, investigation of the circumstances of a larger number of deaths or admissions after triage might be warranted, and monitoring of these events is necessary as triage is implemented. Current Controlled Trials ISRCTN20687662. This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 13. See the NIHR Journals Library website for further project information.

Cluster Randomized Trial of a Toolkit and Early Vaccine Delivery to Improve Childhood Influenza Vaccination Rates in Primary Care

PubMed Central

Zimmerman, Richard K.; Nowalk, Mary Patricia; Lin, Chyongchiou Jeng; Hannibal, Kristin; Moehling, Krissy K.; Huang, Hsin-Hui; Matambanadzo, Annamore; Troy, Judith; Allred, Norma J.; Gallik, Greg; Reis, Evelyn C.

2014-01-01

Purpose To increase childhood influenza vaccination rates using a toolkit and early vaccine delivery in a randomized cluster trial. Methods Twenty primary care practices treating children (range for n=536-8,183) were randomly assigned to Intervention and Control arms to test the effectiveness of an evidence-based practice improvement toolkit (4 Pillars Toolkit) and early vaccine supplies for use among disadvantaged children on influenza vaccination rates among children 6 months-18 years. Follow-up staff meetings and surveys were used to assess use and acceptability of the intervention strategies in the Intervention arm. Rates for the 2010-2011 and 2011-2012 influenza seasons were compared. Two-level generalized linear mixed modeling was used to evaluate outcomes. Results Overall increases in influenza vaccination rates were significantly greater in the Intervention arm (7.9 percentage points) compared with the Control arm (4.4 percentage points; P<0.034). These rate changes represent 4522 additional doses in the Intervention arm vs. 1,390 additional doses in the Control arm. This effect of the intervention was observed despite the fact that rates increased significantly in both arms - 8/10 Intervention (P<0.001) and 7/10 Control sites (P-values 0.04 to <0.001). Rates in two Intervention sites with pre-intervention vaccination rates >58% did not significantly increase. In regression analyses, a child's likelihood of being vaccinated was significantly higher with: younger age, white race (Odds ratio [OR]=1.29; 95% confidence interval [CI]=1.23-1.34), having commercial insurance (OR=1.30; 95%CI=1.25-1.35), higher pre-intervention practice vaccination rate (OR=1.25; 95%CI=1.16-1.34), and being in the Intervention arm (OR=1.23; 95%CI=1.01-1.50). Early delivery of influenza vaccine was rated by Intervention practices as an effective strategy for raising rates. Conclusions Implementation of a multi-strategy toolkit and early vaccine supplies can significantly improve influenza vaccination rates among children in primary care practices but the effect may be less pronounced in practices with moderate to high existing vaccination rates. PMID:24793941

Automated Risk Assessment for Stroke in Atrial Fibrillation (AURAS-AF)--an automated software system to promote anticoagulation and reduce stroke risk: study protocol for a cluster randomised controlled trial.

PubMed

Holt, Tim A; Fitzmaurice, David A; Marshall, Tom; Fay, Matthew; Qureshi, Nadeem; Dalton, Andrew R H; Hobbs, F D Richard; Lasserson, Daniel S; Kearley, Karen; Hislop, Jenny; Jin, Jing

2013-11-13

Patients with atrial fibrillation (AF) are at significantly increased risk of stroke. Oral anticoagulants (OACs) substantially reduce this risk, with gains seen across the spectrum of baseline risk. Despite the benefit to patients, OAC prescribing remains suboptimal in the United Kingdom (UK). We will investigate whether an automated software system, operating within primary care electronic medical records, can improve the management of AF by identifying patients eligible for OAC therapy and increasing uptake of this treatment. We will conduct a cluster randomised controlled trial, involving general practices using the Egton Medical Information Systems (EMIS) Web clinical system. We will randomise practices to use an electronic software tool or to continue with usual care. The tool will a) produce (and continually refresh) a list of patients with AF who are eligible for OAC therapy--practices will invite these patients to discuss therapy at the start of the trial--and b) generate electronic screen reminders in the medical records of those eligible, appearing throughout the trial. The software will run for 6 months in 23 intervention practices. A total of 23 control practices will manage their AF register in line with the usual care offered. The primary outcome is change in proportion of eligible patients with AF who have been prescribed OAC therapy after six months. Secondary outcomes are incidence of stroke, transient ischaemic attack, other major thromboembolism, major haemorrhage and reports of inappropriate OAC prescribing in the data collection sample--those deemed eligible for OACs. We will conduct a process evaluation in parallel with the randomised trial. We will use qualitative methods to examine patient and practitioner views of the intervention and its impact on primary care practice, including its time implications. AURAS-AF will investigate whether a simple intervention, using electronic primary care records, can improve OAC uptake in a high risk group for stroke. Given previous concerns about safety, especially surrounding inappropriate prescribing, we will also examine whether electronic reminders safely impact care in this clinical area. http://ISRCTN 55722437.

The cost-effectiveness of a structured education pulmonary rehabilitation programme for chronic obstructive pulmonary disease in primary care: the PRINCE cluster randomised trial.

PubMed

Gillespie, Paddy; O'Shea, Eamon; Casey, Dympna; Murphy, Kathy; Devane, Declan; Cooney, Adeline; Mee, Lorraine; Kirwan, Collette; McCarthy, Bernard; Newell, John

2013-11-25

To assess the cost-effectiveness of a structured education pulmonary rehabilitation programme (SEPRP) for chronic obstructive pulmonary disease (COPD) relative to usual practice in primary care. The programme consisted of group-based sessions delivered jointly by practice nurses and physiotherapists over 8 weeks. Cost-effectiveness and cost-utility analysis alongside a cluster randomised controlled trial. 32 general practices in Ireland. 350 adults with COPD, 69% of whom were moderately affected. Intervention arm (n=178) received a 2 h group-based SEPRP session per week over 8 weeks delivered jointly by a practice nurse and physiotherapist at the practice surgery or nearby venue. The control arm (n=172) received the usual practice in primary care. Incremental costs, Chronic Respiratory Questionnaire (CRQ) scores, quality-adjusted life years (QALYs) gained estimated using the generic EQ5D instrument, and expected cost-effectiveness at 22 weeks trial follow-up. The intervention was associated with an increase of €944 (95% CIs 489 to 1400) in mean healthcare cost and €261 (95% CIs 226 to 296) in mean patient cost. The intervention was associated with a mean improvement of 1.11 (95% CIs 0.35 to 1.87) in CRQ Total score and 0.002 (95% CIs -0.006 to 0.011) in QALYs gained. These translated into incremental cost-effectiveness ratios of €850 per unit increase in CRQ Total score and €472 000 per additional QALY gained. The probability of the intervention being cost-effective at respective threshold values of €5000, €15 000, €25 000, €35 000 and €45 000 was 0.980, 0.992, 0.994, 0.994 and 0.994 in the CRQ Total score analysis compared to 0.000, 0.001, 0.001, 0.003 and 0.007 in the QALYs gained analysis. While analysis suggests that SEPRP was cost-effective if society is willing to pay at least €850 per one-point increase in disease-specific CRQ, no evidence exists when effectiveness was measured in QALYS gained. Current Controlled Trials ISRCTN52 403 063.

Development of the REFOCUS intervention to increase mental health team support for personal recovery.

PubMed

Slade, Mike; Bird, Victoria; Le Boutillier, Clair; Farkas, Marianne; Grey, Barbara; Larsen, John; Leamy, Mary; Oades, Lindsay; Williams, Julie

2015-12-01

There is an emerging evidence base about best practice in supporting recovery. This is usually framed in relation to general principles, and specific pro-recovery interventions are lacking. To develop a theoretically based and empirically defensible new pro-recovery manualised intervention--called the REFOCUS intervention. Seven systematic and two narrative reviews were undertaken. Identified evidence gaps were addressed in three qualitative studies. The findings were synthesised to produce the REFOCUS intervention, manual and model. The REFOCUS intervention comprises two components: recovery-promoting relationships and working practices. Approaches to supporting relationships comprise coaching skills training for staff, developing a shared team understanding of recovery, exploring staff values, a Partnership Project with people who use the service and raising patient expectations. Working practices comprise the following: understanding values and treatment preferences; assessing strengths; and supporting goal-striving. The REFOCUS model describes the causal pathway from the REFOCUS intervention to improved recovery. The REFOCUS intervention is an empirically supported pro-recovery intervention for use in mental health services. It will be evaluated in a multisite cluster randomised controlled trial (ISRCTN02507940). © The Royal College of Psychiatrists 2015.

Challenges in microarray class discovery: a comprehensive examination of normalization, gene selection and clustering

PubMed Central

2010-01-01

Background Cluster analysis, and in particular hierarchical clustering, is widely used to extract information from gene expression data. The aim is to discover new classes, or sub-classes, of either individuals or genes. Performing a cluster analysis commonly involve decisions on how to; handle missing values, standardize the data and select genes. In addition, pre-processing, involving various types of filtration and normalization procedures, can have an effect on the ability to discover biologically relevant classes. Here we consider cluster analysis in a broad sense and perform a comprehensive evaluation that covers several aspects of cluster analyses, including normalization. Result We evaluated 2780 cluster analysis methods on seven publicly available 2-channel microarray data sets with common reference designs. Each cluster analysis method differed in data normalization (5 normalizations were considered), missing value imputation (2), standardization of data (2), gene selection (19) or clustering method (11). The cluster analyses are evaluated using known classes, such as cancer types, and the adjusted Rand index. The performances of the different analyses vary between the data sets and it is difficult to give general recommendations. However, normalization, gene selection and clustering method are all variables that have a significant impact on the performance. In particular, gene selection is important and it is generally necessary to include a relatively large number of genes in order to get good performance. Selecting genes with high standard deviation or using principal component analysis are shown to be the preferred gene selection methods. Hierarchical clustering using Ward's method, k-means clustering and Mclust are the clustering methods considered in this paper that achieves the highest adjusted Rand. Normalization can have a significant positive impact on the ability to cluster individuals, and there are indications that background correction is preferable, in particular if the gene selection is successful. However, this is an area that needs to be studied further in order to draw any general conclusions. Conclusions The choice of cluster analysis, and in particular gene selection, has a large impact on the ability to cluster individuals correctly based on expression profiles. Normalization has a positive effect, but the relative performance of different normalizations is an area that needs more research. In summary, although clustering, gene selection and normalization are considered standard methods in bioinformatics, our comprehensive analysis shows that selecting the right methods, and the right combinations of methods, is far from trivial and that much is still unexplored in what is considered to be the most basic analysis of genomic data. PMID:20937082

7 CFR 51.913 - Clusters.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Clusters. 51.913 Section 51.913 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

7 CFR 51.913 - Clusters.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Clusters. 51.913 Section 51.913 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

7 CFR 51.913 - Clusters.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Clusters. 51.913 Section 51.913 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

7 CFR 51.913 - Clusters.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Clusters. 51.913 Section 51.913 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

7 CFR 51.913 - Clusters.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Clusters. 51.913 Section 51.913 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

The Best of Both Worlds: Building on the COPUS and RTOP Observation Protocols to Easily and Reliably Measure Various Levels of Reformed Instructional Practice

PubMed Central

Lund, Travis J.; Pilarz, Matthew; Velasco, Jonathan B.; Chakraverty, Devasmita; Rosploch, Kaitlyn; Undersander, Molly; Stains, Marilyne

2015-01-01

Researchers, university administrators, and faculty members are increasingly interested in measuring and describing instructional practices provided in science, technology, engineering, and mathematics (STEM) courses at the college level. Specifically, there is keen interest in comparing instructional practices between courses, monitoring changes over time, and mapping observed practices to research-based teaching. While increasingly common observation protocols (Reformed Teaching Observation Protocol [RTOP] and Classroom Observation Protocol in Undergraduate STEM [COPUS]) at the postsecondary level help achieve some of these goals, they also suffer from weaknesses that limit their applicability. In this study, we leverage the strengths of these protocols to provide an easy method that enables the reliable and valid characterization of instructional practices. This method was developed empirically via a cluster analysis using observations of 269 individual class periods, corresponding to 73 different faculty members, 28 different research-intensive institutions, and various STEM disciplines. Ten clusters, called COPUS profiles, emerged from this analysis; they represent the most common types of instructional practices enacted in the classrooms observed for this study. RTOP scores were used to validate the alignment of the 10 COPUS profiles with reformed teaching. Herein, we present a detailed description of the cluster analysis method, the COPUS profiles, and the distribution of the COPUS profiles across various STEM courses at research-intensive universities. PMID:25976654

No need for dark matter in galaxy clusters within Galileon theory

NASA Astrophysics Data System (ADS)

Salzano, Vincenzo; Mota, David F.; Dabrowski, Mariusz P.; Capozziello, Salvatore

2016-10-01

Modified gravity theories with a screening mechanism have acquired much interest recently in the quest for a viable alternative to General Relativity on cosmological scales, given their intrinsic property of being able to pass Solar System scale tests and, at the same time, to possibly drive universe acceleration on much larger scales. Here, we explore the possibility that the same screening mechanism, or its breaking at a certain astrophysical scale, might be responsible of those gravitational effects which, in the context of general relativity, are generally attributed to Dark Matter. We consider a recently proposed extension of covariant Galileon models in the so-called ``beyond Horndeski'' scenario, where a breaking of the Vainshtein mechanism is possible and, thus, some peculiar observational signatures should be detectable and make it distinguishable from general relativity. We apply this model to a sample of clusters of galaxies observed under the CLASH survey, using both new data from gravitational lensing events and archival data from X-ray intra-cluster hot gas observations. In particular, we use the latter to model the gas density, and then use it as the only ingredient in the matter clusters' budget to calculate the expected lensing convergence map. Results show that, in the context of this extended Galileon, the assumption of having only gas and no Dark Matter at all in the clusters is able to match observations. We also obtain narrow and very interesting bounds on the parameters which characterize this model. In particular, we find that, at least for one of them, the general relativity limit is excluded at 2σ confidence level, thus making this model clearly statistically different and competitive with respect to general relativity.

Generalizing MOND to explain the missing mass in galaxy clusters

NASA Astrophysics Data System (ADS)

Hodson, Alistair O.; Zhao, Hongsheng

2017-02-01

Context. MOdified Newtonian Dynamics (MOND) is a gravitational framework designed to explain the astronomical observations in the Universe without the inclusion of particle dark matter. MOND, in its current form, cannot explain the missing mass in galaxy clusters without the inclusion of some extra mass, be it in the form of neutrinos or non-luminous baryonic matter. We investigate whether the MOND framework can be generalized to account for the missing mass in galaxy clusters by boosting gravity in high gravitational potential regions. We examine and review Extended MOND (EMOND), which was designed to increase the MOND scale acceleration in high potential regions, thereby boosting the gravity in clusters. Aims: We seek to investigate galaxy cluster mass profiles in the context of MOND with the primary aim at explaining the missing mass problem fully without the need for dark matter. Methods: Using the assumption that the clusters are in hydrostatic equilibrium, we can compute the dynamical mass of each cluster and compare the result to the predicted mass of the EMOND formalism. Results: We find that EMOND has some success in fitting some clusters, but overall has issues when trying to explain the mass deficit fully. We also investigate an empirical relation to solve the cluster problem, which is found by analysing the cluster data and is based on the MOND paradigm. We discuss the limitations in the text.

Cluster Adjusted Regression for Displaced Subject Data (CARDS): Marginal Inference under Potentially Informative Temporal Cluster Size Profiles

PubMed Central

Bible, Joe; Beck, James D.; Datta, Somnath

2016-01-01

Summary Ignorance of the mechanisms responsible for the availability of information presents an unusual problem for analysts. It is often the case that the availability of information is dependent on the outcome. In the analysis of cluster data we say that a condition for informative cluster size (ICS) exists when the inference drawn from analysis of hypothetical balanced data varies from that of inference drawn on observed data. Much work has been done in order to address the analysis of clustered data with informative cluster size; examples include Inverse Probability Weighting (IPW), Cluster Weighted Generalized Estimating Equations (CWGEE), and Doubly Weighted Generalized Estimating Equations (DWGEE). When cluster size changes with time, i.e., the data set possess temporally varying cluster sizes (TVCS), these methods may produce biased inference for the underlying marginal distribution of interest. We propose a new marginalization that may be appropriate for addressing clustered longitudinal data with TVCS. The principal motivation for our present work is to analyze the periodontal data collected by Beck et al. (1997, Journal of Periodontal Research 6, 497–505). Longitudinal periodontal data often exhibits both ICS and TVCS as the number of teeth possessed by participants at the onset of study is not constant and teeth as well as individuals may be displaced throughout the study. PMID:26682911

Collective translational and rotational Monte Carlo cluster move for general pairwise interaction

NASA Astrophysics Data System (ADS)

Růžička, Štěpán; Allen, Michael P.

2014-09-01

Virtual move Monte Carlo is a cluster algorithm which was originally developed for strongly attractive colloidal, molecular, or atomistic systems in order to both approximate the collective dynamics and avoid sampling of unphysical kinetic traps. In this paper, we present the algorithm in the form, which selects the moving cluster through a wider class of virtual states and which is applicable to general pairwise interactions, including hard-core repulsion. The newly proposed way of selecting the cluster increases the acceptance probability by up to several orders of magnitude, especially for rotational moves. The results have their applications in simulations of systems interacting via anisotropic potentials both to enhance the sampling of the phase space and to approximate the dynamics.

A Multiple Sphere T-Matrix Fortran Code for Use on Parallel Computer Clusters

NASA Technical Reports Server (NTRS)

Mackowski, D. W.; Mishchenko, M. I.

2011-01-01

A general-purpose Fortran-90 code for calculation of the electromagnetic scattering and absorption properties of multiple sphere clusters is described. The code can calculate the efficiency factors and scattering matrix elements of the cluster for either fixed or random orientation with respect to the incident beam and for plane wave or localized- approximation Gaussian incident fields. In addition, the code can calculate maps of the electric field both interior and exterior to the spheres.The code is written with message passing interface instructions to enable the use on distributed memory compute clusters, and for such platforms the code can make feasible the calculation of absorption, scattering, and general EM characteristics of systems containing several thousand spheres.

FACTOR ANALYTIC MODELS OF CLUSTERED MULTIVARIATE DATA WITH INFORMATIVE CENSORING

EPA Science Inventory

This paper describes a general class of factor analytic models for the analysis of clustered multivariate data in the presence of informative missingness. We assume that there are distinct sets of cluster-level latent variables related to the primary outcomes and to the censorin...

Occupational Listings Arranged by Cluster and Subject Matter Areas.

ERIC Educational Resources Information Center

Schwarz, Otto

Approximately 850 occupations are listed under 27 occupational clusters. The Dictionary of Occupational Title (DOT) number is specified for occupations in the clusters of business training and distributive education, chemistry, general shop and industrial arts, home economics, foreign language, music, social studies, art, agriculture, physics, and…

Effectiveness of an electronic patient-centred self-management tool for gout sufferers: a cluster randomised controlled trial protocol.

PubMed

Day, Richard O; Frensham, Lauren J; Nguyen, Amy D; Baysari, Melissa T; Aung, Eindra; Lau, Annie Y S; Zwar, Nicholas; Reath, Jennifer; Laba, Tracey; Li, Ling; McLachlan, Andrew; Runciman, William B; Buchbinder, Rachelle; Clay-Williams, Robyn; Coiera, Enrico; Braithwaite, Jeffrey; McNeil, H Patrick; Hunter, David J; Pile, Kevin D; Portek, Ian; WIlliams, Kenneth Mapson; Westbrook, Johanna I

2017-10-16

Gout is increasing despite effective therapies to lower serum urate concentrations to 0.36 mmol/L or less, which, if sustained, significantly reduces acute attacks of gout. Adherence to urate-lowering therapy (ULT) is poor, with rates of less than 50% 1 year after initiation of ULT. Attempts to increase adherence in gout patients have been disappointing. We aim to evaluate the effectiveness of use of a personal, self-management, 'smartphone' application (app) to achieve target serum urate concentrations in people with gout. We hypothesise that personalised feedback of serum urate concentrations will improve adherence to ULT. Setting and designPrimary care. A prospective, cluster randomised (by general practitioner (GP) practices), controlled trial. GP practices will be randomised to either intervention or control clusters with their patients allocated to the same cluster. The intervention group will have access to the Healthy.me app tailored for the self-management of gout. The control group patients will have access to the same app modified to remove all functions except the Gout Attack Diary. The proportion of patients whose serum urate concentrations are less than or equal to 0.36 mmol/L after 6 months. Secondary outcomes will be proportions of patients achieving target urate concentrations at 12 months, ULT adherence rates, serum urate concentrations at 6 and 12 months, rates of attacks of gout, quality of life estimations and process and economic evaluations. The study is designed to detect a ≥30% improvement in the intervention group above the expected 50% achievement of target serum urate at 6 months in the control group: power 0.80, significance level 0.05, assumed 'dropout' rate 20%. This study has been approved by the University of New South Wales Human Research Ethics Committee. Study findings will be disseminated in international conferences and peer-reviewed journal. ACTRN12616000455460. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Effectiveness of an electronic patient-centred self-management tool for gout sufferers: a cluster randomised controlled trial protocol

PubMed Central

Frensham, Lauren J; Nguyen, Amy D; Baysari, Melissa T; Aung, Eindra; Lau, Annie Y S; Zwar, Nicholas; Reath, Jennifer; Li, Ling; McLachlan, Andrew; Runciman, William B; Buchbinder, Rachelle; Clay-Williams, Robyn; Braithwaite, Jeffrey; McNeil, H Patrick; Pile, Kevin D; Portek, Ian; WIlliams, Kenneth Mapson; Westbrook, Johanna I

2017-01-01

Introduction Gout is increasing despite effective therapies to lower serum urate concentrations to 0.36 mmol/L or less, which, if sustained, significantly reduces acute attacks of gout. Adherence to urate-lowering therapy (ULT) is poor, with rates of less than 50% 1 year after initiation of ULT. Attempts to increase adherence in gout patients have been disappointing. We aim to evaluate the effectiveness of use of a personal, self-management, ‘smartphone’ application (app) to achieve target serum urate concentrations in people with gout. We hypothesise that personalised feedback of serum urate concentrations will improve adherence to ULT. Methods and analysis Setting and design Primary care. A prospective, cluster randomised (by general practitioner (GP) practices), controlled trial. Participants GP practices will be randomised to either intervention or control clusters with their patients allocated to the same cluster. Intervention The intervention group will have access to the Healthy.me app tailored for the self-management of gout. The control group patients will have access to the same app modified to remove all functions except the Gout Attack Diary. Primary and secondary outcomes The proportion of patients whose serum urate concentrations are less than or equal to 0.36 mmol/L after 6 months. Secondary outcomes will be proportions of patients achieving target urate concentrations at 12 months, ULT adherence rates, serum urate concentrations at 6 and 12 months, rates of attacks of gout, quality of life estimations and process and economic evaluations. The study is designed to detect a ≥30% improvement in the intervention group above the expected 50% achievement of target serum urate at 6 months in the control group: power 0.80, significance level 0.05, assumed ‘dropout’ rate 20%. Ethics and dissemination This study has been approved by the University of New South Wales Human Research Ethics Committee. Study findings will be disseminated in international conferences and peer-reviewed journal. Trial registration number ACTRN12616000455460. PMID:29042386

Cluster analysis of Southeastern U.S. climate stations

NASA Astrophysics Data System (ADS)

Stooksbury, D. E.; Michaels, P. J.

1991-09-01

A two-step cluster analysis of 449 Southeastern climate stations is used to objectively determine general climate clusters (groups of climate stations) for eight southeastern states. The purpose is objectively to define regions of climatic homogeneity that should perform more robustly in subsequent climatic impact models. This type of analysis has been successfully used in many related climate research problems including the determination of corn/climate districts in Iowa (Ortiz-Valdez, 1985) and the classification of synoptic climate types (Davis, 1988). These general climate clusters may be more appropriate for climate research than the standard climate divisions (CD) groupings of climate stations, which are modifications of the agro-economic United States Department of Agriculture crop reporting districts. Unlike the CD's, these objectively determined climate clusters are not restricted by state borders and thus have reduced multicollinearity which makes them more appropriate for the study of the impact of climate and climatic change.

Effectiveness of two interventions based on improving patient-practitioner communication on diabetes self-management in patients with low educational level: study protocol of a clustered randomized trial in primary care.

PubMed

Ricci-Cabello, Ignacio; Olry de Labry-Lima, Antonio; Bolívar-Muñoz, Julia; Pastor-Moreno, Guadalupe; Bermudez-Tamayo, Clara; Ruiz-Pérez, Isabel; Quesada-Jiménez, Fermín; Moratalla-López, Enrique; Domínguez-Martín, Susana; de los Ríos-Álvarez, Ana M; Cruz-Vela, Pilar; Prados-Quel, Miguel A; López-De Hierro, José A

2013-10-23

In the last decades the presence of social inequalities in diabetes care has been observed in multiple countries, including Spain. These inequalities have been at least partially attributed to differences in diabetes self-management behaviours. Communication problems during medical consultations occur more frequently to patients with a lower educational level. The purpose of this cluster randomized trial is to determine whether an intervention implemented in a General Surgery, based in improving patient-provider communication, results in a better diabetes self-management in patients with lower educational level. A secondary objective is to assess whether telephone reinforcement enhances the effect of such intervention. We report the design and implementation of this on-going study. The study is being conducted in a General Practice located in a deprived neighbourhood of Granada, Spain. Diabetic patients 18 years old or older with a low educational level and inadequate glycaemic control (HbA1c > 7%) were recruited. General Practitioners (GPs) were randomised to three groups: intervention A, intervention B and control group. GPs allocated to intervention groups A and B received training in communication skills and are providing graphic feedback about glycosylated haemoglobin levels. Patients whose GPs were allocated to group B are additionally receiving telephone reinforcement whereas patients from the control group are receiving usual care. The described interventions are being conducted during 7 consecutive medical visits which are scheduled every three months. The main outcome measure will be HbA1c; blood pressure, lipidemia, body mass index and waist circumference will be considered as secondary outcome measures. Statistical analysis to evaluate the effectiveness of the interventions will include multilevel regression analysis with three hierarchical levels: medical visit level, patient level and GP level. The results of this study will provide new knowledge about possible strategies to promote a better diabetes self-management in a particularly vulnerable group. If effective, this low cost intervention will have the potential to be easily incorporated into routine clinical practice, contributing to decrease health inequalities in diabetic patients. Clinical Trials U.S. National Institutes of Health, NCT01849731.

Elevated Risk for Antimicrobial Drug-Resistant Shigella Infection among Men Who Have Sex with Men, United States, 2011-2015.

PubMed

Bowen, Anna; Grass, Julian; Bicknese, Amelia; Campbell, Davina; Hurd, Jacqueline; Kirkcaldy, Robert D

2016-09-01

Shigella spp. cause ≈500,000 illnesses in the United States annually, and resistance to ciprofloxacin, ceftriaxone, and azithromycin is emerging. We investigated associations between transmission route and antimicrobial resistance among US shigellosis clusters reported during 2011-2015. Of 32 clusters, 9 were caused by shigellae resistant to ciprofloxacin (3 clusters), ceftriaxone (2 clusters), or azithromycin (7 clusters); 3 clusters were resistant to >1 of these drugs. We observed resistance to any of these drugs in all 7 clusters among men who have sex with men (MSM) but in only 2 of the other 25 clusters (p<0.001). Azithromycin resistance was more common among MSM-associated clusters than other clusters (86% vs. 4% of clusters; p<0.001). For adults with suspected shigellosis, clinicians should culture feces; obtain sex histories; discuss shigellosis prevention; and choose treatment, when needed, according to antimicrobial drug susceptibility. Public health interviews for enteric illnesses should encompass sex practices; health messaging for MSM must include shigellosis prevention.

An Audit and Feedback Intervention for Reducing Antibiotic Prescribing in General Dental Practice: The RAPiD Cluster Randomised Controlled Trial

PubMed Central

Elouafkaoui, Paula; Young, Linda; Newlands, Rumana; Duncan, Eilidh M.; Elders, Andrew; Ramsay, Craig R.

2016-01-01

Background Dentists prescribe approximately 10% of antibiotics dispensed in UK community pharmacies. Despite clear clinical guidance, dentists often prescribe antibiotics inappropriately. This cluster-randomised controlled trial used routinely collected National Health Service (NHS) dental prescribing and treatment claim data to compare the impact of individualised audit and feedback (A&F) interventions on dentists’ antibiotic prescribing rates. Methods and Findings All 795 antibiotic prescribing NHS general dental practices in Scotland were included. Practices were randomised to the control (practices = 163; dentists = 567) or A&F intervention group (practices = 632; dentists = 1,999). A&F intervention practices were allocated to one of two A&F groups: (1) individualised graphical A&F comprising a line graph plotting an individual dentist’s monthly antibiotic prescribing rate (practices = 316; dentists = 1,001); or (2) individualised graphical A&F plus a written behaviour change message synthesising and reiterating national guidance recommendations for dental antibiotic prescribing (practices = 316; dentists = 998). Intervention practices were also simultaneously randomised to receive A&F: (i) with or without a health board comparator comprising the addition of a line to the graphical A&F plotting the monthly antibiotic prescribing rate of all dentists in the health board; and (ii) delivered at 0 and 6 mo or at 0, 6, and 9 mo, giving a total of eight intervention groups. The primary outcome, measured by the trial statistician who was blinded to allocation, was the total number of antibiotic items dispensed per 100 NHS treatment claims over the 12 mo post-delivery of the baseline A&F. Primary outcome data was available for 152 control practices (dentists = 438) and 609 intervention practices (dentists = 1,550). At baseline, the number of antibiotic items prescribed per 100 NHS treatment claims was 8.3 in the control group and 8.5 in the intervention group. At follow-up, antibiotic prescribing had decreased by 0.4 antibiotic items per 100 NHS treatment claims in control practices and by 1.0 in intervention practices. This represents a significant reduction (-5.7%; 95% CI -10.2% to -1.1%; p = 0.01) in dentists' prescribing rate in the intervention group relative to the control group. Intervention subgroup analyses found a 6.1% reduction in the antibiotic prescribing rate of dentists who had received the written behaviour change message relative to dentists who had not (95% CI -10.4% to -1.9%; p = 0.01). There was no significant between-group difference in the prescribing rate of dentists who received a health board comparator relative to those who did not (-4.3%; 95% CI -8.6% to 0.1%; p = 0.06), nor between dentists who received A&F at 0 and 6 mo relative to those who received A&F at 0, 6, and 9 mo (0.02%; 95% CI -4.2% to 4.2%; p = 0.99). The key limitations relate to the use of routinely collected datasets which did not allow evaluation of any effects on inappropriate prescribing. Conclusions A&F derived from routinely collected datasets led to a significant reduction in the antibiotic prescribing rate of dentists. Trial Registration Current Controlled Trials ISRCTN49204710 PMID:27575599

Collaborative care for panic disorder, generalised anxiety disorder and social phobia in general practice: study protocol for three cluster-randomised, superiority trials.

PubMed

Curth, Nadja Kehler; Brinck-Claussen, Ursula Ødum; Davidsen, Annette Sofie; Lau, Marianne Engelbrecht; Lundsteen, Merete; Mikkelsen, John Hagel; Csillag, Claudio; Hjorthøj, Carsten; Nordentoft, Merete; Eplov, Lene Falgaard

2017-08-16

People with anxiety disorders represent a significant part of a general practitioner's patient population. However, there are organisational obstacles for optimal treatment, such as a lack of coordination of illness management and limited access to evidence-based treatment such as cognitive behavioral therapy. A limited number of studies suggest that collaborative care has a positive effect on symptoms for people with anxiety disorders. However, most studies are carried out in the USA and none have reported results for social phobia or generalised anxiety disorder separately. Thus, there is a need for studies carried out in different settings for specific anxiety populations. A Danish model for collaborative care (the Collabri model) has been developed for people diagnosed with depression or anxiety disorders. The model is evaluated through four trials, of which three will be outlined in this protocol and focus on panic disorder, generalised anxiety disorder and social phobia. The aim is to investigate whether treatment according to the Collabri model has a better effect than usual treatment on symptoms when provided to people with anxiety disorders. Three cluster-randomised, clinical superiority trials are set up to investigate treatment according to the Collabri model for collaborative care compared to treatment-as-usual for 364 patients diagnosed with panic disorder, generalised anxiety disorder and social phobia, respectively (total n = 1092). Patients are recruited from general practices located in the Capital Region of Denmark. For all trials, the primary outcome is anxiety symptoms (Beck Anxiety Inventory (BAI)) 6 months after baseline. Secondary outcomes include BAI after 15 months, depression symptoms (Beck Depression Inventory) after 6 months, level of psychosocial functioning (Global Assessment of Functioning) and general psychological symptoms (Symptom Checklist-90-R) after 6 and 15 months. Results will add to the limited pool of information about collaborative care for patients with anxiety disorders. To our knowledge, these will be the first carried out in a Danish context and the first to report results for generalised anxiety and social phobia separately. If the trials show positive results, they could contribute to the improvement of future treatment of anxiety disorders. ClinicalTrials.gov, ID: NCT02678624 . Retrospectively registered 7 February 2016; last updated 15 August 2016.

Dementia care initiative in primary practice – study protocol of a cluster randomized trial on dementia management in a general practice setting

PubMed Central

Holle, Rolf; Gräßel, Elmar; Ruckdäschel, Stefan; Wunder, Sonja; Mehlig, Hilmar; Marx, Peter; Pirk, Olaf; Butzlaff, Martin; Kunz, Simone; Lauterberg, Jörg

2009-01-01

Background Current guidelines for dementia care recommend the combination of drug therapy with non-pharmaceutical measures like counselling and social support. However, the scientific evidence concerning non-pharmaceutical interventions for dementia patients and their informal caregivers remains inconclusive. Targets of modern comprehensive dementia care are to enable patients to live at home as long and as independent as possible and to reduce the burden of caregivers. The objective of the study is to compare a complex intervention including caregiver support groups and counselling against usual care in terms of time to nursing home placement. In this paper the study protocol is described. Methods/Design The IDA (Initiative Demenzversorgung in der Allgemeinmedizin) project is designed as a three armed cluster-randomized trial where dementia patients and their informal caregivers are recruited by general practitioners. Patients in the study region of Middle Franconia, Germany, are included if they have mild or moderate dementia, are at least 65 years old, and are members of the German AOK (Allgemeine Ortskrankenkasse) sickness fund. In the control group patients receive regular treatment, whereas in the two intervention groups general practitioners participate in a training course in evidence based dementia treatment, recommend support groups and offer counseling to the family caregivers either beginning at baseline or after the 1-year follow-up. The study recruitment and follow-up took place from July 2005 to January 2009. 303 general practitioners were randomized of which 129 recruited a total of 390 patients. Time to nursing home admission within the two year intervention and follow-up period is the primary endpoint. Secondary endpoints are cognitive status, activities of daily living, burden of care giving as well as healthcare costs. For an economic analysis from the societal perspective, data are collected from caregivers as well as by the use of routine data from statutory health insurance and long-term care insurance. Discussion From a public health perspective, the IDA trial is expected to lead to evidence based results on the community effectiveness of non-pharmaceutical support measures for dementia patients and their caregivers in the primary care sector. For health policy makers it is necessary to make their decisions about financing new services based on strong knowledge about the acceptance of measures in the population and their cost-effectiveness. Trial registration ISRCTN68329593 PMID:19500383

Industry structures in private dental markets in Finland.

PubMed

Widström, E; Mikkola, H

2012-12-01

To use industrial organisation and organisational ecology research methods to survey industry structures and performance in the markets for private dental services and the effect of competition. Data on practice characteristics, performance, and perceived competition were collected from full-time private dentists (n = 1,121) using a questionnaire. The response rate was 59.6%. Cluster analysis was used to identify practice type based on service differentiation and process integration variables formulated from the questionnaire. Four strategic groups were identified in the Finnish markets: Solo practices formed one distinct group and group practices were classified into three clusters Integrated practices, Small practices, and Loosely integrated practices. Statistically significant differences were found in performance and perceived competitiveness between the groups. Integrated practices with the highest level of process integration and service differentiation performed better than solo and small practices. Moreover, loosely integrated and small practices outperformed solo practises. Competitive intensity was highest among small practices which had a low level of service differentiation and was above average among solo practises. Private dental care providers that had differentiated their services from public services and that had a high number of integrated service production processes enjoyed higher performance and less competitive pressures than those who had not.

A Cluster-Randomized Trial of Restorative Practices: An Illustration to Spur High-Quality Research and Evaluation

PubMed Central

Acosta, Joie D.; Chinman, Matthew; Ebener, Patricia; Phillips, Andrea; Xenakis, Lea; Malone, Patrick S.

2017-01-01

Restorative Practices in schools lack rigorous evaluation studies. As an example of rigorous school-based research, this paper describes the first randomized control trial of restorative practices to date, the Study of Restorative Practices. It is a 5-year, cluster-randomized controlled trial (RCT) of the Restorative Practices Intervention (RPI) in 14 middle schools in Maine to assess whether RPI impacts both positive developmental outcomes and problem behaviors and whether the effects persist during the transition from middle to high school. The two-year RPI intervention began in the 2014–2015 school year. The study’s rationale and theoretical concerns are discussed along with methodological concerns including teacher professional development. The theoretical rationale and description of the methods from this study may be useful to others conducting rigorous research and evaluation in this area. PMID:28936104

Emergence of jams in the generalized totally asymmetric simple exclusion process

NASA Astrophysics Data System (ADS)

Derbyshev, A. E.; Povolotsky, A. M.; Priezzhev, V. B.

2015-02-01

The generalized totally asymmetric exclusion process (TASEP) [J. Stat. Mech. (2012) P05014, 10.1088/1742-5468/2012/05/P05014] is an integrable generalization of the TASEP equipped with an interaction, which enhances the clustering of particles. The process interpolates between two extremal cases: the TASEP with parallel update and the process with all particles irreversibly merging into a single cluster moving as an isolated particle. We are interested in the large time behavior of this process on a ring in the whole range of the parameter λ controlling the interaction. We study the stationary state correlations, the cluster size distribution, and the large-time fluctuations of integrated particle current. When λ is finite, we find the usual TASEP-like behavior: The correlation length is finite; there are only clusters of finite size in the stationary state and current fluctuations belong to the Kardar-Parisi-Zhang universality class. When λ grows with the system size, so does the correlation length. We find a nontrivial transition regime with clusters of all sizes on the lattice. We identify a crossover parameter and derive the large deviation function for particle current, which interpolates between the case considered by Derrida-Lebowitz and a single-particle diffusion.

Cosmological Simulations of Galaxy Clusters

NASA Astrophysics Data System (ADS)

Borgani, Stefano; Kravtsov, Andrey

2011-02-01

We review recent progress in the description of the formation and evolution of galaxy clusters in a cosmological context by using state-of-art numerical simulations. We focus our presentation on the comparison between simulated and observed X-ray properties, while we will also discuss numerical predictions on properties of the galaxy population in clusters, as observed in the optical band. Many of the salient observed properties of clusters, such as scaling relations between X-ray observables and total mass, radial profiles of entropy and density of the intracluster gas, and radial distribution of galaxies are reproduced quite well. In particular, the outer regions of cluster at radii beyond about 10 per cent of the virial radius are quite regular and exhibit scaling with mass remarkably close to that expected in the simplest case in which only the action of gravity determines the evolution of the intra-cluster gas. However, simulations generally fail at reproducing the observed "cool core" structure of clusters: simulated clusters generally exhibit a significant excess of gas cooling in their central regions, which causes both an overestimate of the star formation in the cluster centers and incorrect temperature and entropy profiles. The total baryon fraction in clusters is below the mean universal value, by an amount which depends on the cluster-centric distance and the physics included in the simulations, with interesting tensions between observed stellar and gas fractions in clusters and predictions of simulations. Besides their important implications for the cosmological application of clusters, these puzzles also point towards the important role played by additional physical processes, beyond those already included in the simulations. We review the role played by these processes, along with the difficulty for their implementation, and discuss the outlook for the future progress in numerical modeling of clusters.

The Development of Web-based Graphical User Interface for Unified Modeling Data with Multi (Correlated) Responses

NASA Astrophysics Data System (ADS)

Made Tirta, I.; Anggraeni, Dian

2018-04-01

Statistical models have been developed rapidly into various directions to accommodate various types of data. Data collected from longitudinal, repeated measured, clustered data (either continuous, binary, count, or ordinal), are more likely to be correlated. Therefore statistical model for independent responses, such as Generalized Linear Model (GLM), Generalized Additive Model (GAM) are not appropriate. There are several models available to apply for correlated responses including GEEs (Generalized Estimating Equations), for marginal model and various mixed effect model such as GLMM (Generalized Linear Mixed Models) and HGLM (Hierarchical Generalized Linear Models) for subject spesific models. These models are available on free open source software R, but they can only be accessed through command line interface (using scrit). On the othe hand, most practical researchers very much rely on menu based or Graphical User Interface (GUI). We develop, using Shiny framework, standard pull down menu Web-GUI that unifies most models for correlated responses. The Web-GUI has accomodated almost all needed features. It enables users to do and compare various modeling for repeated measure data (GEE, GLMM, HGLM, GEE for nominal responses) much more easily trough online menus. This paper discusses the features of the Web-GUI and illustrates the use of them. In General we find that GEE, GLMM, HGLM gave very closed results.

Effectiveness of a Peer Support Programme versus Usual Care in Disease Management of Diabetes Mellitus Type 2 regarding Improvement of Metabolic Control: A Cluster-Randomised Controlled Trial.

PubMed

Johansson, Tim; Keller, Sophie; Winkler, Henrike; Ostermann, Thomas; Weitgasser, Raimund; Sönnichsen, Andreas C

2016-01-01

Testing the effectiveness of peer support additionally to a disease management programme (DMP) for type 2 diabetes patients. Unblinded cluster-randomised controlled trial (RCT) involving 49 general practices, province of Salzburg, Austria. All patients enrolled in the DMP were eligible, n = 337 participated (intervention: 148 in 19 clusters; control: 189 in 20 clusters). The peer support intervention ran over 24 months and consisted of peer supporter recruitment and training, and group meetings weekly for physical exercise and monthly for discussion of diabetes related topics. At two-year follow-up, adjusted analysis revealed a nonsignificant difference in HbA1c change of 0.14% (21.97 mmol/mol) in favour of the intervention (95% CI -0.08 to 0.36%, p = 0.22). Baseline values were 7.02 ± 1.25% in the intervention and 7.08 ± 1.25 in the control group. None of the secondary outcome measures showed significant differences except for improved quality of life (EQ-5D-VAS) in controls (4.3 points on a scale of 100; 95% CI 0.08 to 8.53, p = 0.046) compared to the intervention group. Our peer support intervention as an additional DMP component showed no significant effect on HbA1c and secondary outcome measures. Further RTCs with a longer follow-up are needed to reveal whether peer support will have clinically relevant effects. This trial has been registered with Current Controlled Trials Ltd. (ISRCTN10291077).

Stepped wedge designs: insights from a design of experiments perspective.

PubMed

Matthews, J N S; Forbes, A B

2017-10-30

Stepped wedge designs (SWDs) have received considerable attention recently, as they are potentially a useful way to assess new treatments in areas such as health services implementation. Because allocation is usually by cluster, SWDs are often viewed as a form of cluster-randomized trial. However, since the treatment within a cluster changes during the course of the study, they can also be viewed as a form of crossover design. This article explores SWDs from the perspective of crossover trials and designed experiments more generally. We show that the treatment effect estimator in a linear mixed effects model can be decomposed into a weighted mean of the estimators obtained from (1) regarding an SWD as a conventional row-column design and (2) a so-called vertical analysis, which is a row-column design with row effects omitted. This provides a precise representation of "horizontal" and "vertical" comparisons, respectively, which to date have appeared without formal description in the literature. This decomposition displays a sometimes surprising way the analysis corrects for the partial confounding between time and treatment effects. The approach also permits the quantification of the loss of efficiency caused by mis-specifying the correlation parameter in the mixed-effects model. Optimal extensions of the vertical analysis are obtained, and these are shown to be highly inefficient for values of the within-cluster dependence that are likely to be encountered in practice. Some recently described extensions to the classic SWD incorporating multiple treatments are also compared using the experimental design framework. Copyright © 2017 John Wiley & Sons, Ltd.

Brain changes following four weeks of unimanual motor training: Evidence from behavior, neural stimulation, cortical thickness, and functional MRI.

PubMed

Sale, Martin V; Reid, Lee B; Cocchi, Luca; Pagnozzi, Alex M; Rose, Stephen E; Mattingley, Jason B

2017-09-01

Although different aspects of neuroplasticity can be quantified with behavioral probes, brain stimulation, and brain imaging assessments, no study to date has combined all these approaches into one comprehensive assessment of brain plasticity. Here, 24 healthy right-handed participants practiced a sequence of finger-thumb opposition movements for 10 min each day with their left hand. After 4 weeks, performance for the practiced sequence improved significantly (P < 0.05 FWE) relative to a matched control sequence, with both the left (mean increase: 53.0% practiced, 6.5% control) and right (21.0%; 15.8%) hands. Training also induced significant (cluster p-FWE < 0.001) reductions in functional MRI activation for execution of the trained sequence, relative to the control sequence. These changes were observed as clusters in the premotor and supplementary motor cortices (right hemisphere, 301 voxel cluster; left hemisphere 700 voxel cluster), and sensorimotor cortices and superior parietal lobules (right hemisphere 864 voxel cluster; left hemisphere, 1947 voxel cluster). Transcranial magnetic stimulation over the right ("trained") primary motor cortex yielded a 58.6% mean increase in a measure of motor evoked potential amplitude, as recorded at the left abductor pollicis brevis muscle. Cortical thickness analyses based on structural MRI suggested changes in the right precentral gyrus, right post central gyrus, right dorsolateral prefrontal cortex, and potentially the right supplementary motor area. Such findings are consistent with LTP-like neuroplastic changes in areas that were already responsible for finger sequence execution, rather than improved recruitment of previously nonutilized tissue. Hum Brain Mapp 38:4773-4787, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Using Cluster Bootstrapping to Analyze Nested Data With a Few Clusters.

PubMed

Huang, Francis L

2018-04-01

Cluster randomized trials involving participants nested within intact treatment and control groups are commonly performed in various educational, psychological, and biomedical studies. However, recruiting and retaining intact groups present various practical, financial, and logistical challenges to evaluators and often, cluster randomized trials are performed with a low number of clusters (~20 groups). Although multilevel models are often used to analyze nested data, researchers may be concerned of potentially biased results due to having only a few groups under study. Cluster bootstrapping has been suggested as an alternative procedure when analyzing clustered data though it has seen very little use in educational and psychological studies. Using a Monte Carlo simulation that varied the number of clusters, average cluster size, and intraclass correlations, we compared standard errors using cluster bootstrapping with those derived using ordinary least squares regression and multilevel models. Results indicate that cluster bootstrapping, though more computationally demanding, can be used as an alternative procedure for the analysis of clustered data when treatment effects at the group level are of primary interest. Supplementary material showing how to perform cluster bootstrapped regressions using R is also provided.

The theory of variational hybrid quantum-classical algorithms

NASA Astrophysics Data System (ADS)

McClean, Jarrod R.; Romero, Jonathan; Babbush, Ryan; Aspuru-Guzik, Alán

2016-02-01

Many quantum algorithms have daunting resource requirements when compared to what is available today. To address this discrepancy, a quantum-classical hybrid optimization scheme known as ‘the quantum variational eigensolver’ was developed (Peruzzo et al 2014 Nat. Commun. 5 4213) with the philosophy that even minimal quantum resources could be made useful when used in conjunction with classical routines. In this work we extend the general theory of this algorithm and suggest algorithmic improvements for practical implementations. Specifically, we develop a variational adiabatic ansatz and explore unitary coupled cluster where we establish a connection from second order unitary coupled cluster to universal gate sets through a relaxation of exponential operator splitting. We introduce the concept of quantum variational error suppression that allows some errors to be suppressed naturally in this algorithm on a pre-threshold quantum device. Additionally, we analyze truncation and correlated sampling in Hamiltonian averaging as ways to reduce the cost of this procedure. Finally, we show how the use of modern derivative free optimization techniques can offer dramatic computational savings of up to three orders of magnitude over previously used optimization techniques.

Practice-Near and Practice-Distant Methods in Human Services Research

ERIC Educational Resources Information Center

Froggett, Lynn; Briggs, Stephen

2012-01-01

This article discusses practice-near research in human services, a cluster of methodologies that may include thick description, intensive reflexivity, and the study of emotional and relational processes. Such methods aim to get as near as possible to experiences at the relational interface between institutions and the practice field.…

A General Framework for Power Analysis to Detect the Moderator Effects in Two- and Three-Level Cluster Randomized Trials

ERIC Educational Resources Information Center

Dong, Nianbo; Spybrook, Jessaca; Kelcey, Ben

2016-01-01

The purpose of this study is to propose a general framework for power analyses to detect the moderator effects in two- and three-level cluster randomized trials (CRTs). The study specifically aims to: (1) develop the statistical formulations for calculating statistical power, minimum detectable effect size (MDES) and its confidence interval to…

Clustering of health behaviours in adult survivors of childhood cancer and the general population.

PubMed

Rebholz, C E; Rueegg, C S; Michel, G; Ammann, R A; von der Weid, N X; Kuehni, C E; Spycher, B D

2012-07-10

Little is known about engagement in multiple health behaviours in childhood cancer survivors. Using latent class analysis, we identified health behaviour patterns in 835 adult survivors of childhood cancer (age 20-35 years) and 1670 age- and sex-matched controls from the general population. Behaviour groups were determined from replies to questions on smoking, drinking, cannabis use, sporting activities, diet, sun protection and skin examination. The model identified four health behaviour patterns: 'risk-avoidance', with a generally healthy behaviour; 'moderate drinking', with higher levels of sporting activities, but moderate alcohol-consumption; 'risk-taking', engaging in several risk behaviours; and 'smoking', smoking but not drinking. Similar proportions of survivors and controls fell into the 'risk-avoiding' (42% vs 44%) and the 'risk-taking' cluster (14% vs 12%), but more survivors were in the 'moderate drinking' (39% vs 28%) and fewer in the 'smoking' cluster (5% vs 16%). Determinants of health behaviour clusters were gender, migration background, income and therapy. A comparable proportion of childhood cancer survivors as in the general population engage in multiple health-compromising behaviours. Because of increased vulnerability of survivors, multiple risk behaviours should be addressed in targeted health interventions.

Let’s prevent diabetes: study protocol for a cluster randomised controlled trial of an educational intervention in a multi-ethnic UK population with screen detected impaired glucose regulation

PubMed Central

2012-01-01

Background The prevention of type 2 diabetes is a globally recognised health care priority, but there is a lack of rigorous research investigating optimal methods of translating diabetes prevention programmes, based on the promotion of a healthy lifestyle, into routine primary care. The aim of the study is to establish whether a pragmatic structured education programme targeting lifestyle and behaviour change in conjunction with motivational maintenance via the telephone can reduce the incidence of type 2 diabetes in people with impaired glucose regulation (a composite of impaired glucose tolerance and/or impaired fasting glucose) identified through a validated risk score screening programme in primary care. Design Cluster randomised controlled trial undertaken at the level of primary care practices. Follow-up will be conducted at 12, 24 and 36 months. The primary outcome is the incidence of type 2 diabetes. Secondary outcomes include changes in HbA1c, blood glucose levels, cardiovascular risk, the presence of the Metabolic Syndrome and the cost-effectiveness of the intervention. Methods The study consists of screening and intervention phases within 44 general practices coordinated from a single academic research centre. Those at high risk of impaired glucose regulation or type 2 diabetes are identified using a risk score and invited for screening using a 75 g-oral glucose tolerance test. Those with screen detected impaired glucose regulation will be invited to take part in the trial. Practices will be randomised to standard care or the intensive arm. Participants from intensive arm practices will receive a structured education programme with motivational maintenance via the telephone and annual refresher sessions. The study will run from 2009–2014. Discussion This study will provide new evidence surrounding the long-term effectiveness of a diabetes prevention programme conducted within routine primary care in the United Kingdom. Trial registration Clinicaltrials.gov NCT00677937 PMID:22607160

Testing use of payers to facilitate evidence-based practice adoption: protocol for a cluster-randomized trial

PubMed Central

2013-01-01

Background More effective methods are needed to implement evidence-based findings into practice. The Advancing Recovery Framework offers a multi-level approach to evidence-based practice implementation by aligning purchasing and regulatory policies at the payer level with organizational change strategies at the organizational level. Methods The Advancing Recovery Buprenorphine Implementation Study is a cluster-randomized controlled trial designed to increase use of the evidence-based practice buprenorphine medication to treat opiate addiction. Ohio Alcohol, Drug Addiction, and Mental Health Services Boards (ADAMHS), who are payers, and their addiction treatment organizations were recruited for a trial to assess the effects of payer and treatment organization changes (using the Advancing Recovery Framework) versus treatment organization changes alone on the use of buprenorphine. A matched-pair randomization, based on county characteristics, was applied, resulting in seven county ADAMHS boards and twenty-five treatment organizations in each arm. Opioid dependent patients are nested within cluster (treatment organization), and treatment organization clusters are nested within ADAMHS county board. The primary outcome is the percentage of individuals with an opioid dependence diagnosis who use buprenorphine during the 24-month intervention period and the 12-month sustainability period. The trial is currently in the baseline data collection stage. Discussion Although addiction treatment providers are under increasing pressure to implement evidence-based practices that have been proven to improve patient outcomes, adoption of these practices lags, compared to other areas of healthcare. Reasons frequently cited for the slow adoption of EBPs in addiction treatment include, regulatory issues, staff, or client resistance and lack of resources. Yet the way addiction treatment is funded, the payer’s role—has not received a lot of attention in research on EBP adoption. This research is unique because it investigates the role of payers in evidence-based practice implementation using a randomized controlled design instead of case examples. The testing of the Advancing Recovery Framework is designed to broaden the understanding of the impact payers have on evidence-based practice (EBP) adoption. Trial registration http://NCT01702142 (ClinicalTrials.gov registry, USA) PMID:23663749

Clustered for Success

ERIC Educational Resources Information Center

Brulles, Dina; Winebrenner, Susan

2012-01-01

Schools need to address the needs of their students with high ability. Not only does this raise achievement levels schoolwide, it also attracts students from surrounding districts and recaptures advanced learners who left the school because their needs weren't being met. One practical intervention--cluster grouping--provides an inclusive…

Fall Prevention in a Primary Care Setting.

PubMed

Siegrist, Monika; Freiberger, Ellen; Geilhof, Barbara; Salb, Johannes; Hentschke, Christian; Landendoerfer, Peter; Linde, Klause; Halle, Martin; Blank, Wolfgang A

2016-05-27

Falls and fall-related injuries are common in community-dwelling elderly people. Effective multifactorial fall prevention programs in the primary care setting may be a promising approach to reduce the incidence rate of falls. In a cluster randomized trial in 33 general practices 378 people living independently and at high risk of falling (65 to 94 years old; 285 women) were allocated to either a 16 week exercise-based fall prevention program including muscle strengthening and challenging balance training exercises, combined with a 12 week home-based exercise program (222 participants), or to usual care (156 participants). The main outcome was number of falls over a period of 12 months. Secondary outcomes were the number of fall-related injuries, physical function (Timed-Up-and-Go-Test, TUG, Chair-Stand-Test, CST, modified Romberg Test), and fear of falling. In the intervention group (n=222 patients in 17 general practices) 291 falls occurred, compared to 367 falls in the usual care group (n=156 patients in 16 general practices). We observed a lower incidence rate for falls in the intervention group (incidence rate ratio/IRR: 0.54; 95% confidence interval (CI): [0.35; 0.84], p=0.007) and for fall-related injuries (IRR: 0.66; [0.42; 0.94], p=0.033). Additionally, patients in the intervention group showed significant improvements in secondary endpoints (TUG: -2.39 s, [-3.91; -0.87], p=0.014; mRomberg: 1.70 s, [0.35; 3.04], p=0.037; fear of falling: -2.28 points, [-3.87; -0.69], p=0.022) compared to usual care. A complex falls prevention program in a primary care setting was effective in reducing falls and fall-related injuries in community dwelling older adults at risk.

Cost-effectiveness of a multicomponent primary care program targeting frail elderly people.

PubMed

Ruikes, Franca G H; Adang, Eddy M; Assendelft, Willem J J; Schers, Henk J; Koopmans, Raymond T C M; Zuidema, Sytse U

2018-05-16

Over the last 20 years, integrated care programs for frail elderly people aimed to prevent functional dependence and reduce hospitalization and institutionalization. However, results have been inconsistent and merely modest. To date, evidence on the cost-effectiveness of these programs is scarce. We evaluated the cost-effectiveness of the CareWell program, a multicomponent integrated care program for frail elderly people. Economic evaluation from a healthcare perspective embedded in a cluster controlled trial of 12 months in 12 general practices in (the region of) Nijmegen. Two hundred and four frail elderly from 6 general practices in the intervention group received care according to the CareWell program, consisting of multidisciplinary team meetings, proactive care planning, case management, and medication reviews; 165 frail elderly from 6 general practices in the control group received usual care. In cost-effectiveness analyses, we related costs to daily functioning (Katz-15 change score i.e. follow up score minus baseline score) and quality adjusted life years (EQ-5D-3 L). Adjusted mean costs directly related to the intervention were €456 per person. Adjusted mean total costs, i.e. intervention costs plus healthcare utilization costs, were €1583 (95% CI -4647 to 1481) higher in the intervention group than in the control group. Incremental Net Monetary Benefits did not show significant differences between groups, but on average tended to favour usual care. The CareWell primary program was not cost-effective after 12 months. From a cost-effectiveness perspective, widespread implementation of the program in its current form cannot be recommended. The study was registered in the ClinicalTrials.govProtocol Registration System: ( NCT01499797 ; December 26, 2011). Retrospectively registered.

A Theoretical Model for the Practice of Residential Treatment.

ERIC Educational Resources Information Center

Miskimins, R. W.

1990-01-01

Presents theoretical model describing practice of psychiatric residential treatment for children and adolescents. Emphasis is on 40 practice principles, guiding concepts which dictate specific treatment techniques and administrative procedures for Southern Oregon Adolescent Study and Treatment Center. Groups principles into six clusters: program…

Effects of cluster thinning on vine photosynthesis, berry ripeness and flavonoid composition of Cabernet Sauvignon.

PubMed

Wang, Yu; He, Yan-Nan; Chen, Wei-Kai; He, Fei; Chen, Wu; Cai, Xiao-Dong; Duan, Chang-Qing; Wang, Jun

2018-05-15

Cluster thinning is a common practice for regulating vine yield and grape quality. The effects of cluster thinning on vine photosynthesis, berry ripeness and flavonoid composition of V. vinifera L. Cabernet Sauvignon were evaluated during two seasons. Half of the clusters were removed at pea-size and veraison relative to two controls, respectively. Both cluster thinning treatments significantly increased pruning weight and decreased yield. No effects of cluster thinning on berry growth, ripeness and flavonol composition were observed. Early cluster thinning decreased the photosynthetic rate at pea-size, but the effect diminished at post-veraison. Early cluster thinning significantly promoted the biosynthesis of anthocyanins but decreased the proportion of 3'5'-hydroxylated and acylated anthocyanins at veraison. Late cluster thinning decreased the proportions of 3'5'-hydroxylated and acylated anthocyanins. Additionally, Cluster thinning showed inconsistent effects on flavan-3-ol composition over the two seasons. Copyright © 2017 Elsevier Ltd. All rights reserved.

Speaker Segmentation and Clustering Using Gender Information

DTIC Science & Technology

2006-02-01

used in the first stages of segmentation forder information in the clustering of the opposite-gender speaker diarization of news broadcasts. files, the...AFRL-HE-WP-TP-2006-0026 AIR FORCE RESEARCH LABORATORY Speaker Segmentation and Clustering Using Gender Information Brian M. Ore General Dynamics...COVERED (From - To) February 2006 ProceedinLgs 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Speaker Segmentation and Clustering Using Gender Information 5b

Hidden electronic rule in the “cluster-plus-glue-atom” model

PubMed Central

Du, Jinglian; Dong, Chuang; Melnik, Roderick; Kawazoe, Yoshiyuki; Wen, Bin

2016-01-01

Electrons and their interactions are intrinsic factors to affect the structure and properties of materials. Based on the “cluster-cluster-plus-glue-atom” model, an electron counting rule for complex metallic alloys (CMAs) has been revealed in this work (i. e. the CPGAMEC rule). Our results on the cluster structure and electron concentration of CMAs with apparent cluster features, indicate that the valence electrons’ number per unit cluster formula for these CMAs are specific constants of eight-multiples and twelve-multiples. It is thus termed as specific electrons cluster formula. This CPGAMEC rule has been demonstrated as a useful guidance to direct the design of CMAs with desired properties, while its practical applications and underlying mechanism have been illustrated on the basis of CMAs’ cluster structural features. Our investigation provides an aggregate picture with intriguing electronic rule and atomic structural features of CMAs. PMID:27642002

An efficient matrix-matrix multiplication based antisymmetric tensor contraction engine for general order coupled cluster.

PubMed

Hanrath, Michael; Engels-Putzka, Anna

2010-08-14

In this paper, we present an efficient implementation of general tensor contractions, which is part of a new coupled-cluster program. The tensor contractions, used to evaluate the residuals in each coupled-cluster iteration are particularly important for the performance of the program. We developed a generic procedure, which carries out contractions of two tensors irrespective of their explicit structure. It can handle coupled-cluster-type expressions of arbitrary excitation level. To make the contraction efficient without loosing flexibility, we use a three-step procedure. First, the data contained in the tensors are rearranged into matrices, then a matrix-matrix multiplication is performed, and finally the result is backtransformed to a tensor. The current implementation is significantly more efficient than previous ones capable of treating arbitrary high excitations.

Off-road truck-related accidents in U.S. mines

PubMed Central

Dindarloo, Saeid R.; Pollard, Jonisha P.; Siami-Irdemoosa, Elnaz

2016-01-01

Introduction Off-road trucks are one of the major sources of equipment-related accidents in the U.S. mining industries. A systematic analysis of all off-road truck-related accidents, injuries, and illnesses, which are reported and published by the Mine Safety and Health Administration (MSHA), is expected to provide practical insights for identifying the accident patterns and trends in the available raw database. Therefore, appropriate safety management measures can be administered and implemented based on these accident patterns/trends. Methods A hybrid clustering-classification methodology using K-means clustering and gene expression programming (GEP) is proposed for the analysis of severe and non-severe off-road truck-related injuries at U.S. mines. Using the GEP sub-model, a small subset of the 36 recorded attributes was found to be correlated to the severity level. Results Given the set of specified attributes, the clustering sub-model was able to cluster the accident records into 5 distinct groups. For instance, the first cluster contained accidents related to minerals processing mills and coal preparation plants (91%). More than two-thirds of the victims in this cluster had less than 5 years of job experience. This cluster was associated with the highest percentage of severe injuries (22 severe accidents, 3.4%). Almost 50% of all accidents in this cluster occurred at stone operations. Similarly, the other four clusters were characterized to highlight important patterns that can be used to determine areas of focus for safety initiatives. Conclusions The identified clusters of accidents may play a vital role in the prevention of severe injuries in mining. Further research into the cluster attributes and identified patterns will be necessary to determine how these factors can be mitigated to reduce the risk of severe injuries. Practical application Analyzing injury data using data mining techniques provides some insight into attributes that are associated with high accuracies for predicting injury severity. PMID:27620937

The distribution of mass for spiral galaxies in clusters and in the field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forbes, D.A.; Whitmore, B.C.

1989-04-01

A comparison is made between the mass distributions of spiral galaxies in clusters and in the field using Burstein's mass-type methodology. Both the H-alpha emission-line rotation curves and more extended H I rotation curves are used. The fitting technique for determining mass types used by Burstein and coworkers has been replaced by an objective chi-sq method. Mass types are shown to be a function of both the Hubble type and luminosity, contrary to earlier results. The present data show a difference in the distribution of mass types for spiral galaxies in the field and in clusters, in the sense thatmore » mass type I galaxies, where the inner and outer velocity gradients are similar, are generally found in the field rather than in clusters. This can be understood in terms of the results of Whitmore, Forbes, and Rubin (1988), who find that the rotation curves of galaxies in the central region of clusters are generally failing, while the outer galaxies in a cluster and field galaxies tend to have flat or rising rotation curves. 15 refs.« less

Generation and collision-induced dissociation of ammonium tetrafluoroborate cluster ions.

PubMed

Dain, Ryan P; Van Stipdonk, Michael J

2008-07-01

Singly and doubly charged cluster ions of ammonium tetrafluoroborate (NH4BF4) with general formula [(NH4BF4)nNH4]+ and [(NH4BF4)m(NH4)2]2+, respectively, were generated by electrospray ionization (ESI) and their fragmentation examined using collision-induced dissociation (CID) and ion-trap tandem mass spectrometry. CID of [(NH4BF4)nNH4]+ caused the loss of one or more neutral NH4BF4 units. The n = 2 cluster, [(NH4BF4)2NH4]+, was unique in that it also exhibited a dissociation pathway in which HBF4 was eliminated to create [(NH4BF4)(NH3)NH4]+. Dissociation of [(NH4BF4)m(NH4)2]2+ occurred through two general pathways: (a) 'fission' to produce singly charged cluster ions and (b) elimination of one or more neutral NH4BF4 units to leave doubly charged product ions. CID profiles, and measurements of changing precursor and product ion signal intensity as a function of applied collision voltage, were collected for [(NH4BF4)nNH4]+ and compared with those for analogous [(NaBF4)nNa]+ and [(KBF4)nK]+ ions to determine the influence of the cation on the relative stability of cluster ions. In general, the [(NH4BF4)nNH4]+ clusters were found to be easier to dissociate than both the sodium and potassium clusters of comparable size, with [(KBF4)nK]+ ions the most difficult to dissociate.

Heads in the Cloud: A Primer on Neuroimaging Applications of High Performance Computing.

PubMed

Shatil, Anwar S; Younas, Sohail; Pourreza, Hossein; Figley, Chase R

2015-01-01

With larger data sets and more sophisticated analyses, it is becoming increasingly common for neuroimaging researchers to push (or exceed) the limitations of standalone computer workstations. Nonetheless, although high-performance computing platforms such as clusters, grids and clouds are already in routine use by a small handful of neuroimaging researchers to increase their storage and/or computational power, the adoption of such resources by the broader neuroimaging community remains relatively uncommon. Therefore, the goal of the current manuscript is to: 1) inform prospective users about the similarities and differences between computing clusters, grids and clouds; 2) highlight their main advantages; 3) discuss when it may (and may not) be advisable to use them; 4) review some of their potential problems and barriers to access; and finally 5) give a few practical suggestions for how interested new users can start analyzing their neuroimaging data using cloud resources. Although the aim of cloud computing is to hide most of the complexity of the infrastructure management from end-users, we recognize that this can still be an intimidating area for cognitive neuroscientists, psychologists, neurologists, radiologists, and other neuroimaging researchers lacking a strong computational background. Therefore, with this in mind, we have aimed to provide a basic introduction to cloud computing in general (including some of the basic terminology, computer architectures, infrastructure and service models, etc.), a practical overview of the benefits and drawbacks, and a specific focus on how cloud resources can be used for various neuroimaging applications.

Heads in the Cloud: A Primer on Neuroimaging Applications of High Performance Computing

PubMed Central

Shatil, Anwar S.; Younas, Sohail; Pourreza, Hossein; Figley, Chase R.

2015-01-01

With larger data sets and more sophisticated analyses, it is becoming increasingly common for neuroimaging researchers to push (or exceed) the limitations of standalone computer workstations. Nonetheless, although high-performance computing platforms such as clusters, grids and clouds are already in routine use by a small handful of neuroimaging researchers to increase their storage and/or computational power, the adoption of such resources by the broader neuroimaging community remains relatively uncommon. Therefore, the goal of the current manuscript is to: 1) inform prospective users about the similarities and differences between computing clusters, grids and clouds; 2) highlight their main advantages; 3) discuss when it may (and may not) be advisable to use them; 4) review some of their potential problems and barriers to access; and finally 5) give a few practical suggestions for how interested new users can start analyzing their neuroimaging data using cloud resources. Although the aim of cloud computing is to hide most of the complexity of the infrastructure management from end-users, we recognize that this can still be an intimidating area for cognitive neuroscientists, psychologists, neurologists, radiologists, and other neuroimaging researchers lacking a strong computational background. Therefore, with this in mind, we have aimed to provide a basic introduction to cloud computing in general (including some of the basic terminology, computer architectures, infrastructure and service models, etc.), a practical overview of the benefits and drawbacks, and a specific focus on how cloud resources can be used for various neuroimaging applications. PMID:27279746

Trends in extreme learning machines: a review.

PubMed

Huang, Gao; Huang, Guang-Bin; Song, Shiji; You, Keyou

2015-01-01

Extreme learning machine (ELM) has gained increasing interest from various research fields recently. In this review, we aim to report the current state of the theoretical research and practical advances on this subject. We first give an overview of ELM from the theoretical perspective, including the interpolation theory, universal approximation capability, and generalization ability. Then we focus on the various improvements made to ELM which further improve its stability, sparsity and accuracy under general or specific conditions. Apart from classification and regression, ELM has recently been extended for clustering, feature selection, representational learning and many other learning tasks. These newly emerging algorithms greatly expand the applications of ELM. From implementation aspect, hardware implementation and parallel computation techniques have substantially sped up the training of ELM, making it feasible for big data processing and real-time reasoning. Due to its remarkable efficiency, simplicity, and impressive generalization performance, ELM have been applied in a variety of domains, such as biomedical engineering, computer vision, system identification, and control and robotics. In this review, we try to provide a comprehensive view of these advances in ELM together with its future perspectives.

Efficacy of nurse-led and general practitioner-led comprehensive geriatric assessment in primary care: protocol of a pragmatic three-arm cluster randomised controlled trial (CEpiA study)

PubMed Central

Ferrat, Emilie; Bastuji-Garin, Sylvie; Paillaud, Elena; Caillet, Philippe; Clerc, Pascal; Moscova, Laura; Gouja, Amel; Renard, Vincent; Attali, Claude; Breton, Julien Le; Audureau, Etienne

2018-01-01

Introduction Older patients raise therapeutic challenges, because they constitute a heterogeneous population with multimorbidity. To appraise this complexity, geriatricians have developed a multidimensional comprehensive geriatric assessment (CGA), which may be difficult to apply in primary care settings. Our primary objective was to compare the effect on morbimortality of usual care compared with two complex interventions combining educational seminars about CGA: a dedicated geriatric hotline for general practitioners (GPs) and CGA by trained nurses or GPs. Methods and analysis The Clinical Epidemiology and Ageing study is an open-label, pragmatic, multicentre, three-arm, cluster randomised controlled trial comparing two intervention groups and one control group. Patients must be 70 years or older with a long-term illness or with unscheduled hospitalisation in the past 3 months (750 patients planned). This study involves volunteering GPs practising in French primary care centres, with randomisation at the practice level. The multifaceted interventions for interventional arms comprise an educational interactive multiprofessional seminar for GPs and nurses, a geriatric hotline dedicated to GPs in case of difficulties and the performance of a CGA updated to primary care. The CGA is systematically performed by a nurse in arm 1 but is GP-led on a case-by-case basis in arm 2. The primary endpoint is a composite criterion comprising overall death, unscheduled hospitalisations, emergency admissions and institutionalisation within 12 months after inclusion. Intention-to-treat analysis will be performed using mixed-effects logistic regression models, with adjustment for potential confounders. Ethics and dissemination The protocol was approved by an appropriate ethics committee (CPP Ile-de-France IV, Paris, France, approval April 2015;15 664). This study is conducted according to principles of good clinical practice in the context of current care and will provide useful knowledge on the clinical benefits achievable by CGA in primary care. Trial registration number NCT02664454; Pre-results. PMID:29654038

Design and methodology of a community-based cluster-randomized controlled trial for dietary behaviour change in rural Kerala.

PubMed

Daivadanam, Meena; Wahlstrom, Rolf; Sundari Ravindran, T K; Sarma, P S; Sivasankaran, S; Thankappan, K R

2013-07-17

Interventions targeting lifestyle-related risk factors and non-communicable diseases have contributed to the mainstream knowledge necessary for action. However, there are gaps in how this knowledge can be translated for practical day-to-day use in complex multicultural settings like that in India. Here, we describe the design of the Behavioural Intervention for Diet study, which was developed as a community-based intervention to change dietary behaviour among middle-income households in rural Kerala. This was a cluster-randomized controlled trial to assess the effectiveness of a sequential stage-matched intervention to bring about dietary behaviour change by targeting the procurement and consumption of five dietary components: fruits, vegetables, salt, sugar, and oil. Following a step-wise process of pairing and exclusion of outliers, six out of 22 administrative units in the northern part of Trivandrum district, Kerala state were randomly selected and allocated to intervention or control arms. Trained community volunteers carried out the data collection and intervention delivery. An innovative tool was developed to assess household readiness-to-change, and a household measurement kit and easy formulas were introduced to facilitate the practical side of behaviour change. The 1-year intervention included a household component with sequential stage-matched intervention strategies at 0, 6, and 12 months along with counselling sessions, telephonic reminders, and home visits and a community component with general awareness sessions in the intervention arm. Households in the control arm received information on recommended levels of intake of the five dietary components and general dietary information leaflets. Formative research provided the knowledge to contextualise the design of the study in accordance with socio-cultural aspects, felt needs of the community, and the ground realities associated with existing dietary procurement, preparation, and consumption patterns. The study also addressed two key issues, namely the central role of the household as the decision unit and the long-term sustainability through the use of existing local and administrative networks and community volunteers.

Interdisciplinary model of care (RADICALS) for early detection and management of chronic obstructive pulmonary disease (COPD) in Australian primary care: study protocol for a cluster randomised controlled trial

PubMed Central

Liang, Jenifer; Abramson, Michael J; Zwar, Nicholas; Russell, Grant; Holland, Anne E; Bonevski, Billie; Mahal, Ajay; van Hecke, Benjamin; Phillips, Kirsten; Eustace, Paula; Paul, Eldho; Petrie, Kate; Wilson, Sally; George, Johnson

2017-01-01

Introduction Up to half of all smokers develop clinically significant chronic obstructive pulmonary disease (COPD). Gaps exist in the implementation and uptake of evidence-based guidelines for managing COPD in primary care. We describe the methodology of a cluster randomised controlled trial (cRCT) evaluating the efficacy and cost-effectiveness of an interdisciplinary model of care aimed at reducing the burden of smoking and COPD in Australian primary care settings. Methods and analysis A cRCT is being undertaken to evaluate an interdisciplinary model of care (RADICALS — Review of Airway Dysfunction and Interdisciplinary Community-based care of Adult Long-term Smokers). General practice clinics across Melbourne, Australia, are identified and randomised to the intervention group (RADICALS) or usual care. Patients who are current or ex-smokers, of at least 10 pack years, including those with an existing diagnosis of COPD, are being recruited to identify 280 participants with a spirometry-confirmed diagnosis of COPD. Handheld lung function devices are being used to facilitate case-finding. RADICALS includes individualised smoking cessation support, home-based pulmonary rehabilitation and home medicines review. Patients at control group sites receive usual care and Quitline referral, as appropriate. Follow-ups occur at 6 and 12 months from baseline to assess changes in quality of life, abstinence rates, health resource utilisation, symptom severity and lung function. The primary outcome is change in St George’s Respiratory Questionnaire score of patients with COPD at 6 months from baseline. Ethics and dissemination This project has been approved by the Monash University Human Research Ethics Committee and La Trobe University Human Ethics Committee (CF14/1018 – 2014000433). Results of the study will be disseminated in peer-reviewed journals and research conferences. If the intervention is successful, the RADICALS programme could potentially be integrated into general practices across Australia and sustained over time. Trial registration number ACTRN12614001155684; Pre-results. PMID:28928190

Whether the Autism Spectrum Quotient Consists of Two Different Subgroups? Cluster Analysis of the Autism Spectrum Quotient in General Population

ERIC Educational Resources Information Center

Kitazoe, Noriko; Fujita, Naofumi; Izumoto, Yuji; Terada, Shin-ichi; Hatakenaka, Yuhei

2017-01-01

The purpose of this study was to investigate whether the individuals in the general population with high scores on the Autism Spectrum Quotient constituted a single homogeneous group or not. A cohort of university students (n = 4901) was investigated by cluster analysis based on the original five subscales of the Autism Spectrum Quotient. Based on…

Farm, household, and farmer characteristics associated with changes in management practices and technology adoption among dairy smallholders.

PubMed

Martínez-García, Carlos Galdino; Ugoretz, Sarah Janes; Arriaga-Jordán, Carlos Manuel; Wattiaux, Michel André

2015-02-01

This study explored whether technology adoption and changes in management practices were associated with farm structure, household, and farmer characteristics and to identify processes that may foster productivity and sustainability of small-scale dairy farming in the central highlands of Mexico. Factor analysis of survey data from 44 smallholders identified three factors-related to farm size, farmer's engagement, and household structure-that explained 70 % of cumulative variance. The subsequent hierarchical cluster analysis yielded three clusters. Cluster 1 included the most senior farmers with fewest years of education but greatest years of experience. Cluster 2 included farmers who reported access to extension, cooperative services, and more management changes. Cluster 2 obtained 25 and 35 % more milk than farmers in clusters 1 and 3, respectively. Cluster 3 included the youngest farmers, with most years of education and greatest availability of family labor. Access to a network and membership in a community of peers appeared as important contributors to success. Smallholders gravitated towards easy to implement technologies that have immediate benefits. Nonusers of high investment technologies found them unaffordable because of cost, insufficient farm size, and lack of knowledge or reliable electricity. Multivariate analysis may be a useful tool in planning extension activities and organizing channels of communication to effectively target farmers with varying needs, constraints, and motivations for change and in identifying farmers who may exemplify models of change for others who manage farms that are structurally similar but performing at a lower level.

A comparative study of DIGNET, average, complete, single hierarchical and k-means clustering algorithms in 2D face image recognition

NASA Astrophysics Data System (ADS)

Thanos, Konstantinos-Georgios; Thomopoulos, Stelios C. A.

2014-06-01

The study in this paper belongs to a more general research of discovering facial sub-clusters in different ethnicity face databases. These new sub-clusters along with other metadata (such as race, sex, etc.) lead to a vector for each face in the database where each vector component represents the likelihood of participation of a given face to each cluster. This vector is then used as a feature vector in a human identification and tracking system based on face and other biometrics. The first stage in this system involves a clustering method which evaluates and compares the clustering results of five different clustering algorithms (average, complete, single hierarchical algorithm, k-means and DIGNET), and selects the best strategy for each data collection. In this paper we present the comparative performance of clustering results of DIGNET and four clustering algorithms (average, complete, single hierarchical and k-means) on fabricated 2D and 3D samples, and on actual face images from various databases, using four different standard metrics. These metrics are the silhouette figure, the mean silhouette coefficient, the Hubert test Γ coefficient, and the classification accuracy for each clustering result. The results showed that, in general, DIGNET gives more trustworthy results than the other algorithms when the metrics values are above a specific acceptance threshold. However when the evaluation results metrics have values lower than the acceptance threshold but not too low (too low corresponds to ambiguous results or false results), then it is necessary for the clustering results to be verified by the other algorithms.

STRUCTURAL PARAMETERS FOR 10 HALO GLOBULAR CLUSTERS IN M33

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Jun, E-mail: majun@nao.cas.cn

2015-05-15

In this paper, we present the properties of 10 halo globular clusters (GCs) with luminosities L ≃ 5–7 × 10{sup 5} L{sub ⊙} in the Local Group galaxy M33 using images from the Hubble Space Telescope WFPC2 in the F555W and F814W bands. We obtained the ellipticities, position angles, and surface brightness profiles for each GC. In general, the ellipticities of the M33 sample clusters are similar to those of the M31 clusters. The structural and dynamical parameters are derived by fitting the profiles to three different models combined with mass-to-light ratios (M/L values) from population-synthesis models. The structural parametersmore » include core radii, concentration, half-light radii, and central surface brightness. The dynamical parameters include the integrated cluster mass, integrated binding energy, central surface mass density, and predicted line of sight velocity dispersion at the cluster center. The velocity dispersions of the four clusters predicted here agree well with the observed dispersions by Larsen et al. The results here showed that the majority of the sample halo GCs are better fitted by both the King model and the Wilson model than the Sérsic model. In general, the properties of the clusters in M33, M31, and the Milky Way fall in the same regions of parameter spaces. The tight correlations of cluster properties indicate a “fundamental plane” for clusters, which reflects some universal physical conditions and processes operating at the epoch of cluster formation.« less

Improving antibiotic prescribing by general practitioners: a protocol for a systematic review of interventions involving pharmacists

PubMed Central

Saha, Sajal K; Hawes, Lesley; Mazza, Danielle

2018-01-01

Introduction Effective antibiotic options in general practice for patients with infections are declining significantly due to antibiotic over-prescribing and emerging antibiotic resistance. To better improve antibiotic prescribing by general practitioner (GP), pharmacist–GP collaborations have been promoted under antibiotic stewardship programmes. However, there is insufficient information about whether and how pharmacists help GPs to more appropriately prescribe antibiotics. This systematic review aims to determine whether pharmacist-led or pharmacist-involved interventions are effective at improving antibiotic prescribing by GPs. Methods and analysis A systematic review of English language randomised controlled trials (RCTs), cluster RCTs, controlled before-and-after studies and interrupted time series studies cited in MEDLINE, EMBASE, EMCARE, CINAHL Plus, PubMed, PsycINFO, Cochrane Central Register of Controlled Trials and Web of Science databases will be conducted. Studies will be included if a pharmacist is involved as the intervention provider and GPs are the intervention recipients in general practice setting. Data extraction and management will be conducted using Effective Practice and Organisation of Care data abstraction tools and a template for intervention description and replication. The Cochrane and ROBINS-I risk of bias assessment tools will be used to assess the methodological quality of studies. Primary outcome measures include changes (overall, broad spectrum and guidelines concordance) of GP-prescribed antibiotics. Secondary outcomes include quality of antibiotic prescribing, delayed antibiotic use, acceptability and feasibility of interventions. Meta-analysis for combined effect and forest plots, χ2 test and I2 statistics for detailed heterogeneity and sensitivity analysis will be performed if data permit. Grading of Recommendations Assessment, Development and Evaluation and Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidance will be used to report findings. Ethics and dissemination No ethics approval is required as no primary, personal or confidential data are being collected in this study. The findings will be disseminated to national and international scientific sessions and published in a peer-reviewed journal. PROSPERO registration number CRD42017078478. PMID:29654036

Energy spectra of X-ray clusters of galaxies

NASA Technical Reports Server (NTRS)

Avni, Y.

1976-01-01

A procedure for estimating the ranges of parameters that describe the spectra of X-rays from clusters of galaxies is presented. The applicability of the method is proved by statistical simulations of cluster spectra; such a proof is necessary because of the nonlinearity of the spectral functions. Implications for the spectra of the Perseus, Coma, and Virgo clusters are discussed. The procedure can be applied in more general problems of parameter estimation.

Application of adaptive cluster sampling to low-density populations of freshwater mussels

USGS Publications Warehouse

Smith, D.R.; Villella, R.F.; Lemarie, D.P.

2003-01-01

Freshwater mussels appear to be promising candidates for adaptive cluster sampling because they are benthic macroinvertebrates that cluster spatially and are frequently found at low densities. We applied adaptive cluster sampling to estimate density of freshwater mussels at 24 sites along the Cacapon River, WV, where a preliminary timed search indicated that mussels were present at low density. Adaptive cluster sampling increased yield of individual mussels and detection of uncommon species; however, it did not improve precision of density estimates. Because finding uncommon species, collecting individuals of those species, and estimating their densities are important conservation activities, additional research is warranted on application of adaptive cluster sampling to freshwater mussels. However, at this time we do not recommend routine application of adaptive cluster sampling to freshwater mussel populations. The ultimate, and currently unanswered, question is how to tell when adaptive cluster sampling should be used, i.e., when is a population sufficiently rare and clustered for adaptive cluster sampling to be efficient and practical? A cost-effective procedure needs to be developed to identify biological populations for which adaptive cluster sampling is appropriate.

Atomically precise cluster catalysis towards quantum controlled catalysts

PubMed Central

Watanabe, Yoshihide

2014-01-01

Catalysis of atomically precise clusters supported on a substrate is reviewed in relation to the type of reactions. The catalytic activity of supported clusters has generally been discussed in terms of electronic structure. Several lines of evidence have indicated that the electronic structure of clusters and the geometry of clusters on a support, including the accompanying cluster-support interaction, are strongly correlated with catalytic activity. The electronic states of small clusters would be easily affected by cluster–support interactions. Several studies have suggested that it is possible to tune the electronic structure through atomic control of the cluster size. It is promising to tune not only the number of cluster atoms, but also the hybridization between the electronic states of the adsorbed reactant molecules and clusters in order to realize a quantum-controlled catalyst. PMID:27877723

A novel artificial immune algorithm for spatial clustering with obstacle constraint and its applications.

PubMed

Sun, Liping; Luo, Yonglong; Ding, Xintao; Zhang, Ji

2014-01-01

An important component of a spatial clustering algorithm is the distance measure between sample points in object space. In this paper, the traditional Euclidean distance measure is replaced with innovative obstacle distance measure for spatial clustering under obstacle constraints. Firstly, we present a path searching algorithm to approximate the obstacle distance between two points for dealing with obstacles and facilitators. Taking obstacle distance as similarity metric, we subsequently propose the artificial immune clustering with obstacle entity (AICOE) algorithm for clustering spatial point data in the presence of obstacles and facilitators. Finally, the paper presents a comparative analysis of AICOE algorithm and the classical clustering algorithms. Our clustering model based on artificial immune system is also applied to the case of public facility location problem in order to establish the practical applicability of our approach. By using the clone selection principle and updating the cluster centers based on the elite antibodies, the AICOE algorithm is able to achieve the global optimum and better clustering effect.

CHIMERA: Top-down model for hierarchical, overlapping and directed cluster structures in directed and weighted complex networks

NASA Astrophysics Data System (ADS)

Franke, R.

2016-11-01

In many networks discovered in biology, medicine, neuroscience and other disciplines special properties like a certain degree distribution and hierarchical cluster structure (also called communities) can be observed as general organizing principles. Detecting the cluster structure of an unknown network promises to identify functional subdivisions, hierarchy and interactions on a mesoscale. It is not trivial choosing an appropriate detection algorithm because there are multiple network, cluster and algorithmic properties to be considered. Edges can be weighted and/or directed, clusters overlap or build a hierarchy in several ways. Algorithms differ not only in runtime, memory requirements but also in allowed network and cluster properties. They are based on a specific definition of what a cluster is, too. On the one hand, a comprehensive network creation model is needed to build a large variety of benchmark networks with different reasonable structures to compare algorithms. On the other hand, if a cluster structure is already known, it is desirable to separate effects of this structure from other network properties. This can be done with null model networks that mimic an observed cluster structure to improve statistics on other network features. A third important application is the general study of properties in networks with different cluster structures, possibly evolving over time. Currently there are good benchmark and creation models available. But what is left is a precise sandbox model to build hierarchical, overlapping and directed clusters for undirected or directed, binary or weighted complex random networks on basis of a sophisticated blueprint. This gap shall be closed by the model CHIMERA (Cluster Hierarchy Interconnection Model for Evaluation, Research and Analysis) which will be introduced and described here for the first time.

Within-Cluster and Across-Cluster Matching with Observational Multilevel Data

ERIC Educational Resources Information Center

Kim, Jee-Seon; Steiner, Peter M.; Hall, Courtney; Thoemmes, Felix

2013-01-01

When randomized experiments cannot be conducted in practice, propensity score (PS) techniques for matching treated and control units are frequently used for estimating causal treatment effects from observational data. Despite the popularity of PS techniques, they are not yet well studied for matching multilevel data where selection into treatment…

Exploring Undergraduates' Understanding of Photosynthesis Using Diagnostic Question Clusters

ERIC Educational Resources Information Center

Parker, Joyce M.; Anderson, Charles W.; Heidemann, Merle; Merrill, John; Merritt, Brett; Richmond, Gail; Urban-Lurain, Mark

2012-01-01

We present a diagnostic question cluster (DQC) that assesses undergraduates' thinking about photosynthesis. This assessment tool is not designed to identify individual misconceptions. Rather, it is focused on students' abilities to apply basic concepts about photosynthesis by reasoning with a coordinated set of practices based on a few scientific…

TargetCOPD: a pragmatic randomised controlled trial of targeted case finding for COPD versus routine practice in primary care: protocol.

PubMed

Jordan, Rachel E; Adab, Peymané; Jowett, Sue; Marsh, Jen L; Riley, Richard D; Enocson, Alexandra; Miller, Martin R; Cooper, Brendan G; Turner, Alice M; Ayres, Jon G; Cheng, Kar Keung; Jolly, Kate; Stockley, Robert A; Greenfield, Sheila; Siebert, Stanley; Daley, Amanda; Fitzmaurice, David A

2014-10-04

Many people with clinically significant chronic obstructive pulmonary disease (COPD) remain undiagnosed worldwide. There are a number of small studies which have examined possible methods of case finding through primary care, but no large RCTs that have adequately assessed the most cost-effective approach. In this study, using a cluster randomised controlled trial (RCT) in 56 general practices in the West Midlands, we plan to investigate the effectiveness and cost-effectiveness of a Targeted approach to case finding for COPD compared with routine practice. Using an individual patient RCT nested in the Targeted arm, we plan also to compare the effectiveness and cost-effectiveness of Active case finding using a postal questionnaire (with supplementary opportunistic questionnaires), and Opportunistic-only case finding during routine surgery consultations.All ever-smoking patients aged 40-79 years, without a current diagnosis of COPD and registered with participating practices will be eligible. Patients in the Targeted arm who report positive respiratory symptoms (chronic cough or phlegm, wheeze or dyspnoea) using a brief questionnaire will be invited for further spirometric assessment to ascertain whether they have COPD or not. Post-bronchodilator spirometry will be conducted to ATS standards using an Easy One spirometer by trained research assistants.The primary outcomes will be new cases of COPD and cost per new case identified, comparing targeted case finding with routine care, and two types of targeted case finding (active versus opportunistic). A multilevel logistic regression model will be used to model the probability of detecting a new case of COPD for each treatment arm, with clustering of patients (by practice and household) accounted for using a multi-level structure.A trial-based analysis will be undertaken using costs and outcomes collected during the trial. Secondary outcomes include the feasibility, efficiency, long-term cost-effectiveness, patient and primary care staff views of each approach. This will be the largest RCT of its kind, and should inform how best to identify undiagnosed patients with COPD in the UK and other similar healthcare systems. Sensitivity analyses will help local policy-makers decide which sub-groups of the population to target first. Current controlled trials ISRCTN14930255.

The reduction of disability in community-dwelling frail older people: design of a two-arm cluster randomized controlled trial.

PubMed

Metzelthin, Silke F; van Rossum, Erik; de Witte, Luc P; Hendriks, Marike R C; Kempen, Gertrudis I J M

2010-08-23

Frailty among older people is related to an increased risk of adverse health outcomes such as acute and chronic diseases, disability and mortality. Although many intervention studies for frail older people have been reported, only a few have shown positive effects regarding disability prevention. This article presents the design of a two-arm cluster randomized controlled trial on the effectiveness, cost-effectiveness and feasibility of a primary care intervention that combines the most promising elements of disability prevention in community-dwelling frail older people. In this study twelve general practitioner practices were randomly allocated to the intervention group (6 practices) or to the control group (6 practices). Three thousand four hundred ninety-eight screening questionnaires including the Groningen Frailty Indicator (GFI) were sent out to identify frail older people. Based on their GFI score (≥5), 360 participants will be included in the study. The intervention will receive an interdisciplinary primary care intervention. After a comprehensive assessment by a practice nurse and additional assessments by other professionals, if needed, an individual action plan will be defined. The action plan is related to a flexible toolbox of interventions, which will be conducted by an interdisciplinary team. Effects of the intervention, both for the frail older people and their informal caregivers, will be measured after 6, 12 and 24 months using postal questionnaires and telephone interviews. Data for the process evaluation and economic evaluation will be gathered continuously over a 24-month period. The proposed study will provide information about the usefulness of an interdisciplinary primary care intervention. The postal screening procedure was conducted in two cycles between December 2009 and April 2010 and turned out to be a feasible method. The response rate was 79.7%. According to GFI scores 29.3% of the respondents can be considered as frail (GFI ≥ 5). Nearly half of them (48.1%) were willing to participate. The baseline measurements started in January 2010. In February 2010 the first older people were approached by the practice nurse for a comprehensive assessment. Data on the effect, process, and economic evaluation will be available in 2012. ISRCTN31954692.

Vocational trainees' views and experiences regarding the learning and teaching of communication skills in general practice.

PubMed

Van Nuland, Marc; Thijs, Gabie; Van Royen, Paul; Van den Noortgate, Wim; Goedhuys, Jo

2010-01-01

To explore the views and experiences of general practice (GP) vocational trainees regarding communication skills (CS) and the teaching and learning of these skills. A purposive sample of second and third (final) year GP trainees took part in six focus group (FG) discussions. Transcripts were coded and analysed in accordance with a grounded theory approach by two investigators using Alas-ti software. Finally results were triangulated by means of semi-structured telephone interviews. The analysis led to three thematic clusters: (1) trainees acknowledge the essential importance of communication skills and identified contextual factors influencing the learning and application of these skills; (2) trainees identified preferences for learning and receiving feedback on their communication skills; and (3) trainees perceived that the assessment of communication skills is subjective. These themes are organised into a framework for a better understanding of trainees' communication skills as part of their vocational training. The framework helps in leading to a better understanding of the way in which trainees learn and apply communication skills. The unique context of vocational training should be taken into account when trainees' communication skills are assessed. The teaching and learning should be guided by a learner-centred approach. The framework is valuable for informing curricular reform and future research.

Higher-order clustering in networks

NASA Astrophysics Data System (ADS)

Yin, Hao; Benson, Austin R.; Leskovec, Jure

2018-05-01

A fundamental property of complex networks is the tendency for edges to cluster. The extent of the clustering is typically quantified by the clustering coefficient, which is the probability that a length-2 path is closed, i.e., induces a triangle in the network. However, higher-order cliques beyond triangles are crucial to understanding complex networks, and the clustering behavior with respect to such higher-order network structures is not well understood. Here we introduce higher-order clustering coefficients that measure the closure probability of higher-order network cliques and provide a more comprehensive view of how the edges of complex networks cluster. Our higher-order clustering coefficients are a natural generalization of the traditional clustering coefficient. We derive several properties about higher-order clustering coefficients and analyze them under common random graph models. Finally, we use higher-order clustering coefficients to gain new insights into the structure of real-world networks from several domains.

An unsupervised classification technique for multispectral remote sensing data.

NASA Technical Reports Server (NTRS)

Su, M. Y.; Cummings, R. E.

1973-01-01

Description of a two-part clustering technique consisting of (a) a sequential statistical clustering, which is essentially a sequential variance analysis, and (b) a generalized K-means clustering. In this composite clustering technique, the output of (a) is a set of initial clusters which are input to (b) for further improvement by an iterative scheme. This unsupervised composite technique was employed for automatic classification of two sets of remote multispectral earth resource observations. The classification accuracy by the unsupervised technique is found to be comparable to that by traditional supervised maximum-likelihood classification techniques.

2-Way k-Means as a Model for Microbiome Samples.

PubMed

Jackson, Weston J; Agarwal, Ipsita; Pe'er, Itsik

2017-01-01

Motivation . Microbiome sequencing allows defining clusters of samples with shared composition. However, this paradigm poorly accounts for samples whose composition is a mixture of cluster-characterizing ones and which therefore lie in between them in the cluster space. This paper addresses unsupervised learning of 2-way clusters. It defines a mixture model that allows 2-way cluster assignment and describes a variant of generalized k -means for learning such a model. We demonstrate applicability to microbial 16S rDNA sequencing data from the Human Vaginal Microbiome Project.

2-Way k-Means as a Model for Microbiome Samples

PubMed Central

2017-01-01

Motivation. Microbiome sequencing allows defining clusters of samples with shared composition. However, this paradigm poorly accounts for samples whose composition is a mixture of cluster-characterizing ones and which therefore lie in between them in the cluster space. This paper addresses unsupervised learning of 2-way clusters. It defines a mixture model that allows 2-way cluster assignment and describes a variant of generalized k-means for learning such a model. We demonstrate applicability to microbial 16S rDNA sequencing data from the Human Vaginal Microbiome Project. PMID:29177026

Unsupervised classification of earth resources data.

NASA Technical Reports Server (NTRS)

Su, M. Y.; Jayroe, R. R., Jr.; Cummings, R. E.

1972-01-01

A new clustering technique is presented. It consists of two parts: (a) a sequential statistical clustering which is essentially a sequential variance analysis and (b) a generalized K-means clustering. In this composite clustering technique, the output of (a) is a set of initial clusters which are input to (b) for further improvement by an iterative scheme. This unsupervised composite technique was employed for automatic classification of two sets of remote multispectral earth resource observations. The classification accuracy by the unsupervised technique is found to be comparable to that by existing supervised maximum liklihood classification technique.

Electronic structure, stability and magnetic properties of small M1-4(M = Fe, Co, Ni) clusters encapsulated inside a (BN)48 cage

NASA Astrophysics Data System (ADS)

Liang, Wenjuan; Jia, Jianfeng; Lv, Jin; Wu, Haishun

2015-02-01

The geometrical structure and magnetic properties of M1-4(M = Fe, Co and Ni) clusters within a (BN)48 cage were calculated at the BPW91/LanL2DZ level. The small M1-4 clusters generally prefer an off-centered position near the hexagonal rings in the (BN)48 cages. The (BN)48 cages can increase the stability of these small magnetic clusters while protecting the magnetic nature of M and M2 clusters.

Dark Energy and Key Physical Parameters of Clusters of Galaxies

NASA Astrophysics Data System (ADS)

Chernin, A. D.; Bisnovatyi-Kogan, G. S.

We discuss the physics of clusters of galaxies embedded in the cosmic dark energy background and show that 1) the halo cut-off radius of a cluster like the Virgo cluster is practically, if not exactly, equal to the zero-gravity radius at which the dark matter gravity is balanced by the dark energy antigravity; 2) the halo averaged density is equal to two densities of dark energy; 3) the halo edge (cut-off) density is the dark energy density with a numerical factor of the unity order slightly depending on the halo profile.

When is Constrained Clustering Beneficial, and Why?

NASA Technical Reports Server (NTRS)

Wagstaff, Kiri L.; Basu, Sugato; Davidson, Ian

2006-01-01

Several researchers have shown that constraints can improve the results of a variety of clustering algorithms. However, there can be a large variation in this improvement, even for a fixed number of constraints for a given data set. We present the first attempt to provide insight into this phenomenon by characterizing two constraint set properties: informativeness and coherence. We show that these measures can help explain why some constraint sets are more beneficial to clustering algorithms than others. Since they can be computed prior to clustering, these measures can aid in deciding which constraints to use in practice.

Einstein's Theory Fights off Challengers

NASA Astrophysics Data System (ADS)

2010-04-01

Two new and independent studies have put Einstein's General Theory of Relativity to the test like never before. These results, made using NASA's Chandra X-ray Observatory, show Einstein's theory is still the best game in town. Each team of scientists took advantage of extensive Chandra observations of galaxy clusters, the largest objects in the Universe bound together by gravity. One result undercuts a rival gravity model to General Relativity, while the other shows that Einstein's theory works over a vast range of times and distances across the cosmos. The first finding significantly weakens a competitor to General Relativity known as "f(R) gravity". "If General Relativity were the heavyweight boxing champion, this other theory was hoping to be the upstart contender," said Fabian Schmidt of the California Institute of Technology in Pasadena, who led the study. "Our work shows that the chances of its upsetting the champ are very slim." In recent years, physicists have turned their attention to competing theories to General Relativity as a possible explanation for the accelerated expansion of the universe. Currently, the most popular explanation for the acceleration is the so-called cosmological constant, which can be understood as energy that exists in empty space. This energy is referred to as dark energy to emphasize that it cannot be directly detected. In the f(R) theory, the cosmic acceleration comes not from an exotic form of energy but from a modification of the gravitational force. The modified force also affects the rate at which small enhancements of matter can grow over the eons to become massive clusters of galaxies, opening up the possibility of a sensitive test of the theory. Schmidt and colleagues used mass estimates of 49 galaxy clusters in the local universe from Chandra observations, and compared them with theoretical model predictions and studies of supernovas, the cosmic microwave background, and the large-scale distribution of galaxies. They found no evidence that gravity is different from General Relativity on scales larger than 130 million light years. This limit corresponds to a hundred-fold improvement on the bounds of the modified gravitational force's range that can be set without using the cluster data. "This is the strongest ever constraint set on an alternative to General Relativity on such large distance scales," said Schmidt. "Our results show that we can probe gravity stringently on cosmological scales by using observations of galaxy clusters." The reason for this dramatic improvement in constraints can be traced to the greatly enhanced gravitational forces acting in clusters as opposed to the universal background expansion of the universe. The cluster-growth technique also promises to be a good probe of other modified gravity scenarios, such as models motivated by higher-dimensional theories and string theory. A second, independent study also bolsters General Relativity by directly testing it across cosmological distances and times. Up until now, General Relativity had been verified only using experiments from laboratory to Solar System scales, leaving the door open to the possibility that General Relativity breaks down on much larger scales. To probe this question, a group at Stanford University compared Chandra observations of how rapidly galaxy clusters have grown over time to the predictions of General Relativity. The result is nearly complete agreement between observation and theory. "Einstein's theory succeeds again, this time in calculating how many massive clusters have formed under gravity's pull over the last five billion years," said David Rapetti of the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) at Stanford University and SLAC National Accelerator Laboratory, who led the new study. "Excitingly and reassuringly, our results are the most robust consistency test of General Relativity yet carried out on cosmological scales." Rapetti and his colleagues based their results on a sample of 238 clusters detected across the whole sky by the now-defunct ROSAT X-ray telescope. These data were enhanced by detailed mass measurements for 71 distant clusters using Chandra, and 23 relatively nearby clusters using ROSAT, and combined with studies of supernovas, the cosmic microwave background, the distribution of galaxies and distance estimates to galaxy clusters. Galaxy clusters are important objects in the quest to understand the Universe as a whole. Because the observations of the masses of galaxy clusters are directly sensitive to the properties of gravity, they provide crucial information. Other techniques such as observations of supernovas or the distribution of galaxies measure cosmic distances, which depend only on the expansion rate of the universe. In contrast, the cluster technique used by Rapetti and his colleagues measure in addition the growth rate of the cosmic structure, as driven by gravity. "Cosmic acceleration represents a great challenge to our modern understanding of physics," said Rapetti's co-author Adam Mantz of NASA's Goddard Space Flight Center in Maryland. "Measurements of acceleration have highlighted how little we know about gravity at cosmic scales, but we're now starting to push back our ignorance." The paper by Fabian Schmidt was published in Physics Review D, Volume 80 in October 2009 and is co-authored by Alexey Vikhlinin of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and Wayne Hu of the University of Chicago, Illinois. The paper by David Rapetti was recently accepted for publication in the Monthly Notices of the Royal Astronomical Society and is co-authored by Mantz, Steve Allen of KIPAC at Stanford and Harald Ebeling of the Institute for Astronomy in Hawaii. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. More information, including images and other multimedia, can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

To assess whether indoor residual spraying can provide additional protection against clinical malaria over current best practice of long-lasting insecticidal mosquito nets in The Gambia: study protocol for a two-armed cluster-randomised trial

PubMed Central

2011-01-01

Background Recently, there has been mounting interest in scaling-up vector control against malaria in Africa. It needs to be determined if indoor residual spraying (IRS with DDT) will provide significant marginal protection against malaria over current best practice of long-lasting insecticidal nets (LLINs) and prompt treatment in a controlled trial, given that DDT is currently the most persistent insecticide for IRS. Methods A 2 armed cluster-randomised controlled trial will be conducted to assess whether DDT IRS and LLINs combined provide better protection against clinical malaria in children than LLINs alone in rural Gambia. Each cluster will be a village, or a group of small adjacent villages; all clusters will receive LLINs and half will receive IRS in addition. Study children, aged 6 months to 13 years, will be enrolled from all clusters and followed for clinical malaria using passive case detection to estimate malaria incidence for 2 malaria transmission seasons in 2010 and 2011. This will be the primary endpoint. Exposure to malaria parasites will be assessed using light and exit traps followed by detection of Anopheles gambiae species and sporozoite infection. Study children will be surveyed at the end of each transmission season to estimate the prevalence of Plasmodium falciparum infection and the prevalence of anaemia. Discussion Practical issues concerning intervention implementation, as well as the potential benefits and risks of the study, are discussed. Trial Registration ISRCTN01738840 - Spraying And Nets Towards malaria Elimination (SANTE) PMID:21663656

The composite sequential clustering technique for analysis of multispectral scanner data

NASA Technical Reports Server (NTRS)

Su, M. Y.

1972-01-01

The clustering technique consists of two parts: (1) a sequential statistical clustering which is essentially a sequential variance analysis, and (2) a generalized K-means clustering. In this composite clustering technique, the output of (1) is a set of initial clusters which are input to (2) for further improvement by an iterative scheme. This unsupervised composite technique was employed for automatic classification of two sets of remote multispectral earth resource observations. The classification accuracy by the unsupervised technique is found to be comparable to that by traditional supervised maximum likelihood classification techniques. The mathematical algorithms for the composite sequential clustering program and a detailed computer program description with job setup are given.

Structural and electronic properties Te62+ and Te82+: A DFT study

NASA Astrophysics Data System (ADS)

Sharma, Tamanna; Tamboli, Rohit; Kanhere, D. G.; Sharma, Raman

2018-05-01

Structural and electronic properties of Tellurium cluster (Ten) and their cations (Ten2+) (n = 6, 8) have been studied theoretically using VASP within generalized gradient approximation. Ground state geometries and higher energy isomers of these clusters have been examined on the basis of total free energy calculations. Lowest energy isomers of neutral clusters are ring like structures whereas the lowest energy isomers of cations are polyhedral cages. HOMO-LUMO gap in cationic clusters is small compared to its neutral clusters. Removal of two electrons from the neutral cluster raises the free energy. Analysis of free energy, HOMO-LUMO gap and density of states (DOS) show that neutral cluster are more stable than their cations.

The Canadian Preterm Birth Network: a study protocol for improving outcomes for preterm infants and their families

PubMed Central

Shah, Prakesh S.; McDonald, Sarah D.; Barrett, Jon; Synnes, Anne; Robson, Kate; Foster, Jonathan; Pasquier, Jean-Charles; Joseph, K.S.; Piedboeuf, Bruno; Lacaze-Masmonteil, Thierry; O'Brien, Karel; Shivananda, Sandesh; Chaillet, Nils; Pechlivanoglou, Petros

2018-01-01

Background: Preterm birth (birth before 37 wk of gestation) occurs in about 8% of pregnancies in Canada and is associated with high mortality and morbidity rates that substantially affect infants, their families and the health care system. Our overall goal is to create a transdisciplinary platform, the Canadian Preterm Birth Network (CPTBN), where investigators, stakeholders and families will work together to improve childhood outcomes of preterm neonates. Methods: Our national cohort will include 24 maternal-fetal/obstetrical units, 31 neonatal intensive care units and 26 neonatal follow-up programs across Canada with planned linkages to provincial health information systems. Three broad clusters of projects will be undertaken. Cluster 1 will focus on quality-improvement efforts that use the Evidence-based Practice for Improving Quality method to evaluate information from the CPTBN database and review the current literature, then identify potentially better health care practices and implement identified strategies. Cluster 2 will assess the impact of current practices and practice changes in maternal, perinatal and neonatal care on maternal, neonatal and neurodevelopmental outcomes. Cluster 3 will evaluate the effect of preterm birth on babies, their families and the health care system by integrating CPTBN data, parent feedback, and national and provincial database information in order to identify areas where more parental support is needed, and also generate robust estimates of resource use, cost and cost-effectiveness around preterm neonatal care. Interpretation: These collaborative efforts will create a flexible, transdisciplinary, evaluable and informative research and quality-improvement platform that supports programs, projects and partnerships focused on improving outcomes of preterm neonates. PMID:29348260

Towards a PTAS for the generalized TSP in grid clusters

NASA Astrophysics Data System (ADS)

Khachay, Michael; Neznakhina, Katherine

2016-10-01

The Generalized Traveling Salesman Problem (GTSP) is a combinatorial optimization problem, which is to find a minimum cost cycle visiting one point (city) from each cluster exactly. We consider a geometric case of this problem, where n nodes are given inside the integer grid (in the Euclidean plane), each grid cell is a unit square. Clusters are induced by cells `populated' by nodes of the given instance. Even in this special setting, the GTSP remains intractable enclosing the classic Euclidean TSP on the plane. Recently, it was shown that the problem has (1.5+8√2+ɛ)-approximation algorithm with complexity bound depending on n and k polynomially, where k is the number of clusters. In this paper, we propose two approximation algorithms for the Euclidean GTSP on grid clusters. For any fixed k, both algorithms are PTAS. Time complexity of the first one remains polynomial for k = O(log n) while the second one is a PTAS, when k = n - O(log n).

The effect of an anti-malarial subsidy programme on the quality of service provision of artemisinin-based combination therapy in Kenya: a cluster-randomized, controlled trial

PubMed Central

2013-01-01

Background Many patients with suspected malaria in sub-Saharan Africa seek treatment from private providers, but this sector suffers from sub-standard medicine dispensing practices. To improve the quality of care received for presumptive malaria from the highly accessed private retail sector in western Kenya, subsidized pre-packaged artemether-lumefantrine (AL) was provided to private retailers, together with a one day training for retail staff on malaria diagnosis and treatment, job aids and community engagement activities. Methods The intervention was assessed using a cluster-randomized, controlled design. Provider and mystery-shopper cross-sectional surveys were conducted at baseline and eight months post-intervention to assess provider practices. Data were analysed based on cluster-level summaries, comparing control and intervention arms. Results On average, 564 retail outlets were interviewed per year. At follow-up, 43% of respondents reported that at least one staff member had attended the training in the intervention arm. The intervention significantly increased the percentage of providers knowing the first line treatment for uncomplicated malaria by 24.2% points (confidence interval (CI): 14.8%, 33.6%; adjusted p=0.0001); the percentage of outlets stocking AL by 31.7% points (CI: 22.0%, 41.3%; adjusted p=0.0001); and the percentage of providers prescribing AL for presumptive malaria by 23.6% points (CI: 18.7%, 28.6%; adjusted p=0.0001). Generally outlets that received training and job aids performed better than those receiving one or none of these intervention components. Conclusion Overall, subsidizing ACT and retailer training can significantly increase the percentage of outlets stocking and selling AL for the presumptive treatment of malaria, but further research is needed on strategies to improve the provision of counselling advice to retail customers. PMID:23452547

Evaluating a computer aid for assessing stomach symptoms (ECASS): study protocol for a randomised controlled trial.

PubMed

Moore, Helen J; Nixon, Catherine; Tariq, Anisah; Emery, Jon; Hamilton, Willie; Hoare, Zoë; Kershenbaum, Anne; Neal, Richard D; Ukoumunne, Obioha C; Usher-Smith, Juliet; Walter, Fiona M; Whyte, Sophie; Rubin, Greg

2016-04-04

For most cancers, only a minority of patients have symptoms meeting the National Institute for Health and Clinical Excellence guidance for urgent referral. For gastro-oesophageal cancers, the 'alarm' symptoms of dysphagia and weight loss are reported by only 32 and 8 % of patients, respectively, and their presence correlates with advanced-stage disease. Electronic clinical decision-support tools that integrate with clinical computer systems have been developed for general practice, although uncertainty remains concerning their effectiveness. The objectives of this trial are to optimise the intervention and establish the acceptability of both the intervention and randomisation, confirm the suitability and selection of outcome measures, finalise the design for the phase III definitive trial, and obtain preliminary estimates of the intervention effect. This is a two-arm, multi-centre, cluster-randomised, controlled phase II trial design, which will extend over a 16-month period, across 60 general practices within the North East and North Cumbria and the Eastern Local Clinical Research Network areas. Practices will be randomised to receive either the intervention (the electronic clinical decision-support tool) or to act as a control (usual care). From these practices, we will recruit 3000 adults who meet the trial eligibility criteria and present to their GP with symptoms suggestive of gastro-oesophageal cancer. The main measures are the process data, which include the practitioner outcomes, service outcomes, diagnostic intervals, health economic outcomes, and patient outcomes. One-on-one interviews in a sub-sample of 30 patient-GP dyads will be undertaken to understand the impact of the use or non-use of the electronic clinical decision-support tool in the consultation. A further 10-15 GPs will be interviewed to identify and gain an understanding of the facilitators and constraints influencing implementation of the electronic clinical decision-support tool in practice. We aim to generate new knowledge on the process measures regarding the use of electronic clinical decision-support tools in primary care in general and to inform a subsequent definitive phase III trial. Preliminary data on the impact of the support tool on resource utilisation and health care costs will also be collected. ISRCTN Registry, ISRCTN12595588 .

Socio-demographic and structural barriers to being tested for chlamydia in general practice.

PubMed

Lau, Andrew; Spark, Simone; Tomnay, Jane; Smith, Meredith T; Fairley, Christopher K; Guy, Rebecca J; Donovan, Basil; Hocking, Jane S

2016-02-15

To investigate socio-demographic and structural factors associated with not providing a specimen for chlamydia testing following a request by a general practitioner. Cross-sectional analysis of chlamydia testing data for men and women aged 16-29 years attending general practice clinics participating in a cluster randomised controlled trial evaluating the effectiveness of a chlamydia testing intervention. The study period was the 2013 calendar year. The proportion of chlamydia test requests for which the patient did not provide a specimen for testing. During the study period, there were 13 225 chlamydia test requests, for which a chlamydia test was not performed in 2545 instances (19.2%; 95% CI, 16.5-22.3%). Multivariate analysis indicated that the odds for not undertaking a requested test were higher for men (adjusted odds ratio [aOR], 1.4; 95% CI, 1.3-1.6), those aged 16-19 years (aOR, 1.3; 95% CI, 1.1-1.4), those living in areas of greater socio-economic disadvantage (aOR, 1.2; 95% CI, 1.1-1.4 for each additional quintile of Index of Relative Socio-economic Disadvantage), and those attending clinics without on-site pathology collection (aOR, 1.4; 95% CI, 1.0-1.9). One in five young people did not submit a specimen for chlamydia testing despite their GP requesting it. This highlights the need for clinics to establish systems which ensure that men and those aged 16-19 years undertake chlamydia tests requested by a GP.

Interpersonal Pathoplasticity in Individuals with Generalized Anxiety Disorder

PubMed Central

Przeworski, Amy; Newman, Michelle G.; Pincus, Aaron L.; Kasoff, Michele B.; Yamasaki, Alissa S.; Castonguay, Louis G.; Berlin, Kristoffer S.

2011-01-01

Recent theories of Generalized Anxiety Disorder (GAD) have emphasized interpersonal and personality functioning as important aspects of the disorder. The current paper examines heterogeneity in interpersonal problems in two studies of individuals with GAD (n = 47 and n = 83). Interpersonal subtypes were assessed using the Inventory of Interpersonal Problems (IIP-C; Alden, Wiggins, & Pincus, 1990). Across both studies, individuals with GAD exhibited heterogeneous interpersonal problems, and cluster analyses of these patients' interpersonal characteristics yielded four replicable clusters identified as intrusive, exploitable, cold, and nonassertive subtypes. Consistent with our pathoplasticity hypotheses, clusters did not differ in GAD severity, anxiety severity, depression severity. Clusters in study two differed on rates of personality disorders, including avoidant personality disorder, further providing support for the validity of interpersonal subtypes. The presence of interpersonal subtypes in GAD may have important implications for treatment planning and efficacy. PMID:21553942

Multiscale visual quality assessment for cluster analysis with self-organizing maps

NASA Astrophysics Data System (ADS)

Bernard, Jürgen; von Landesberger, Tatiana; Bremm, Sebastian; Schreck, Tobias

2011-01-01

Cluster analysis is an important data mining technique for analyzing large amounts of data, reducing many objects to a limited number of clusters. Cluster visualization techniques aim at supporting the user in better understanding the characteristics and relationships among the found clusters. While promising approaches to visual cluster analysis already exist, these usually fall short of incorporating the quality of the obtained clustering results. However, due to the nature of the clustering process, quality plays an important aspect, as for most practical data sets, typically many different clusterings are possible. Being aware of clustering quality is important to judge the expressiveness of a given cluster visualization, or to adjust the clustering process with refined parameters, among others. In this work, we present an encompassing suite of visual tools for quality assessment of an important visual cluster algorithm, namely, the Self-Organizing Map (SOM) technique. We define, measure, and visualize the notion of SOM cluster quality along a hierarchy of cluster abstractions. The quality abstractions range from simple scalar-valued quality scores up to the structural comparison of a given SOM clustering with output of additional supportive clustering methods. The suite of methods allows the user to assess the SOM quality on the appropriate abstraction level, and arrive at improved clustering results. We implement our tools in an integrated system, apply it on experimental data sets, and show its applicability.

CLUSTERS OF TASKS PERFORMED BY WASHINGTON STATE FARM OPERATORS ENGAGED IN SEVEN TYPES OF AGRICULTURAL PRODUCTION--GRAIN, DAIRY, FORESTRY, LIVESTOCK, POULTRY, HORTICULTURE, AND GENERAL FARMING. REPORT NO. 27.

ERIC Educational Resources Information Center

LONG, GILBERT A.

THE OBJECTIVE OF THIS STUDY WAS TO OBTAIN UP-TO-DATE FACTS ABOUT CLUSTERS OF TASKS PERFORMED BY WASHINGTON STATE FARM OPERATORS ENGAGED PRIMARILY IN PRODUCING GRAIN, LIVESTOCK, DAIRY COMMODITIES, POULTRY, FOREST PRODUCTS, HORTICULTURAL COMMODITIES, AND GENERAL FARMING COMMODITIES. FROM A RANDOM SAMPLE OF 267 FARMERS REPRESENTING THOSE CATEGORIES…

Clustering of health behaviours in adult survivors of childhood cancer and the general population

PubMed Central

Rebholz, C E; Rueegg, C S; Michel, G; Ammann, R A; von der Weid, N X; Kuehni, C E; Spycher, B D

2012-01-01

Background: Little is known about engagement in multiple health behaviours in childhood cancer survivors. Methods: Using latent class analysis, we identified health behaviour patterns in 835 adult survivors of childhood cancer (age 20–35 years) and 1670 age- and sex-matched controls from the general population. Behaviour groups were determined from replies to questions on smoking, drinking, cannabis use, sporting activities, diet, sun protection and skin examination. Results: The model identified four health behaviour patterns: ‘risk-avoidance', with a generally healthy behaviour; ‘moderate drinking', with higher levels of sporting activities, but moderate alcohol-consumption; ‘risk-taking', engaging in several risk behaviours; and ‘smoking', smoking but not drinking. Similar proportions of survivors and controls fell into the ‘risk-avoiding' (42% vs 44%) and the ‘risk-taking' cluster (14% vs 12%), but more survivors were in the ‘moderate drinking' (39% vs 28%) and fewer in the ‘smoking' cluster (5% vs 16%). Determinants of health behaviour clusters were gender, migration background, income and therapy. Conclusion: A comparable proportion of childhood cancer survivors as in the general population engage in multiple health-compromising behaviours. Because of increased vulnerability of survivors, multiple risk behaviours should be addressed in targeted health interventions. PMID:22722311

Audit-based education lowers systolic blood pressure in chronic kidney disease: the Quality Improvement in CKD (QICKD) trial results

PubMed Central

de Lusignana, Simon; Gallagher, Hugh; Jones, Simon; Chan, Tom; van Vlymen, Jeremy; Tahir, Aumran; Thomas, Nicola; Jain, Neerja; Dmitrieva, Olga; Rafi, Imran; McGovern, Andrew; Harris, Kevin

2013-01-01

Strict control of systolic blood pressure is known to slow progression of chronic kidney disease (CKD). Here we compared audit-based education (ABE) to guidelines and prompts or usual practice in lowering systolic blood pressure in people with CKD. This 2-year cluster randomized trial included 93 volunteer general practices randomized into three arms with 30 ABE practices, 32 with guidelines and prompts, and 31 usual practices. An intervention effect on the primary outcome, systolic blood pressure, was calculated using a multilevel model to predict changes after the intervention. The prevalence of CKD was 7.29% (41,183 of 565,016 patients) with all cardiovascular comorbidities more common in those with CKD. Our models showed that the systolic blood pressure was significantly lowered by 2.41 mm Hg (CI 0.59–4.29 mm Hg), in the ABE practices with an odds ratio of achieving at least a 5 mm Hg reduction in systolic blood pressure of 1.24 (CI 1.05–1.45). Practices exposed to guidelines and prompts produced no significant change compared to usual practice. Male gender, ABE, ischemic heart disease, and congestive heart failure were independently associated with a greater lowering of systolic blood pressure but the converse applied to hypertension and age over 75 years. There were no reports of harm. Thus, individuals receiving ABE are more likely to achieve a lower blood pressure than those receiving only usual practice. The findings should be interpreted with caution due to the wide confidence intervals. PMID:23536132

Dentist and practice characteristics associated with restorative treatment of enamel caries in permanent teeth: multiple-regression modeling of observational clinical data from The National Dental PBRN

PubMed Central

Fellows, Jeffrey L; Gordan, Valeria V.; Gilbert, Gregg H.; Rindal, D. Brad; Qvist, Vibeke; Litaker, Mark S.; Benjamin, Paul; Flink, Håkan; Pihlstrom, Daniel J.; Johnson, Neil

2014-01-01

Purpose Current evidence in dentistry recommends non-surgical treatment to manage enamel caries lesions. However, surveyed practitioners report they would restore enamel lesions that are confined to the enamel. We used actual clinical data to evaluate patient, dentist, and practice characteristics associated with restoration of enamel caries, while accounting for other factors. Methods We combined data from a National Dental Practice-Based Research Network observational study of consecutive restorations placed in previously unrestored permanent tooth surfaces and practice/demographic data from 229 participating network dentists. Analysis of variance and logistic regression, using generalized estimating equations (GEE) and variable selection within blocks, were used to test the hypothesis that patient, dentist, and practice characteristics were associated with variations in enamel restorations of occlusal and proximal caries compared to dentin lesions, accounting for dentist and patient clustering. Results Network dentists from 5 regions placed 6,891 restorations involving occlusal and/or proximal caries lesions. Enamel restorations accounted for 16% of enrolled occlusal caries lesions and 6% of enrolled proximal caries lesions. Enamel occlusal restorations varied significantly (p<0.05) by patient age and race/ethnicity, dentist use of caries risk assessment, network region, and practice type. Enamel proximal restorations varied significantly (p<0.05) by dentist race/ethnicity, network region, and practice type. CLINICAL SIGNIFICANCE Identifying patient, dentist, and practice characteristics associated with enamel caries restorations can guide strategies to improve provider adherence to evidence-based clinical recommendations. PMID:25000667

Cluster Analysis in Nursing Research: An Introduction, Historical Perspective, and Future Directions.

PubMed

Dunn, Heather; Quinn, Laurie; Corbridge, Susan J; Eldeirawi, Kamal; Kapella, Mary; Collins, Eileen G

2017-05-01

The use of cluster analysis in the nursing literature is limited to the creation of classifications of homogeneous groups and the discovery of new relationships. As such, it is important to provide clarity regarding its use and potential. The purpose of this article is to provide an introduction to distance-based, partitioning-based, and model-based cluster analysis methods commonly utilized in the nursing literature, provide a brief historical overview on the use of cluster analysis in nursing literature, and provide suggestions for future research. An electronic search included three bibliographic databases, PubMed, CINAHL and Web of Science. Key terms were cluster analysis and nursing. The use of cluster analysis in the nursing literature is increasing and expanding. The increased use of cluster analysis in the nursing literature is positioning this statistical method to result in insights that have the potential to change clinical practice.

Heterogeneous Tensor Decomposition for Clustering via Manifold Optimization.

PubMed

Sun, Yanfeng; Gao, Junbin; Hong, Xia; Mishra, Bamdev; Yin, Baocai

2016-03-01

Tensor clustering is an important tool that exploits intrinsically rich structures in real-world multiarray or Tensor datasets. Often in dealing with those datasets, standard practice is to use subspace clustering that is based on vectorizing multiarray data. However, vectorization of tensorial data does not exploit complete structure information. In this paper, we propose a subspace clustering algorithm without adopting any vectorization process. Our approach is based on a novel heterogeneous Tucker decomposition model taking into account cluster membership information. We propose a new clustering algorithm that alternates between different modes of the proposed heterogeneous tensor model. All but the last mode have closed-form updates. Updating the last mode reduces to optimizing over the multinomial manifold for which we investigate second order Riemannian geometry and propose a trust-region algorithm. Numerical experiments show that our proposed algorithm compete effectively with state-of-the-art clustering algorithms that are based on tensor factorization.

Robustness of serial clustering of extra-tropical cyclones to the choice of tracking method

NASA Astrophysics Data System (ADS)

Pinto, Joaquim G.; Ulbrich, Sven; Karremann, Melanie K.; Stephenson, David B.; Economou, Theodoros; Shaffrey, Len C.

2016-04-01

Cyclone families are a frequent synoptic weather feature in the Euro-Atlantic area in winter. Given appropriate large-scale conditions, the occurrence of such series (clusters) of storms may lead to large socio-economic impacts and cumulative losses. Recent studies analyzing Reanalysis data using single cyclone tracking methods have shown that serial clustering of cyclones occurs on both flanks and downstream regions of the North Atlantic storm track. This study explores the sensitivity of serial clustering to the choice of tracking method. With this aim, the IMILAST cyclone track database based on ERA-interim data is analysed. Clustering is estimated by the dispersion (ratio of variance to mean) of winter (DJF) cyclones passages near each grid point over the Euro-Atlantic area. Results indicate that while the general pattern of clustering is identified for all methods, there are considerable differences in detail. This can primarily be attributed to the differences in the variance of cyclone counts between the methods, which range up to one order of magnitude. Nevertheless, clustering over the Eastern North Atlantic and Western Europe can be identified for all methods and can thus be generally considered as a robust feature. The statistical links between large-scale patterns like the NAO and clustering are obtained for all methods, though with different magnitudes. We conclude that the occurrence of cyclone clustering over the Eastern North Atlantic and Western Europe is largely independent from the choice of tracking method and hence from the definition of a cyclone.

Visualizing and Clustering Protein Similarity Networks: Sequences, Structures, and Functions.

PubMed

Mai, Te-Lun; Hu, Geng-Ming; Chen, Chi-Ming

2016-07-01

Research in the recent decade has demonstrated the usefulness of protein network knowledge in furthering the study of molecular evolution of proteins, understanding the robustness of cells to perturbation, and annotating new protein functions. In this study, we aimed to provide a general clustering approach to visualize the sequence-structure-function relationship of protein networks, and investigate possible causes for inconsistency in the protein classifications based on sequences, structures, and functions. Such visualization of protein networks could facilitate our understanding of the overall relationship among proteins and help researchers comprehend various protein databases. As a demonstration, we clustered 1437 enzymes by their sequences and structures using the minimum span clustering (MSC) method. The general structure of this protein network was delineated at two clustering resolutions, and the second level MSC clustering was found to be highly similar to existing enzyme classifications. The clustering of these enzymes based on sequence, structure, and function information is consistent with each other. For proteases, the Jaccard's similarity coefficient is 0.86 between sequence and function classifications, 0.82 between sequence and structure classifications, and 0.78 between structure and function classifications. From our clustering results, we discussed possible examples of divergent evolution and convergent evolution of enzymes. Our clustering approach provides a panoramic view of the sequence-structure-function network of proteins, helps visualize the relation between related proteins intuitively, and is useful in predicting the structure and function of newly determined protein sequences.

Local Higher-Order Graph Clustering

PubMed Central

Yin, Hao; Benson, Austin R.; Leskovec, Jure; Gleich, David F.

2018-01-01

Local graph clustering methods aim to find a cluster of nodes by exploring a small region of the graph. These methods are attractive because they enable targeted clustering around a given seed node and are faster than traditional global graph clustering methods because their runtime does not depend on the size of the input graph. However, current local graph partitioning methods are not designed to account for the higher-order structures crucial to the network, nor can they effectively handle directed networks. Here we introduce a new class of local graph clustering methods that address these issues by incorporating higher-order network information captured by small subgraphs, also called network motifs. We develop the Motif-based Approximate Personalized PageRank (MAPPR) algorithm that finds clusters containing a seed node with minimal motif conductance, a generalization of the conductance metric for network motifs. We generalize existing theory to prove the fast running time (independent of the size of the graph) and obtain theoretical guarantees on the cluster quality (in terms of motif conductance). We also develop a theory of node neighborhoods for finding sets that have small motif conductance, and apply these results to the case of finding good seed nodes to use as input to the MAPPR algorithm. Experimental validation on community detection tasks in both synthetic and real-world networks, shows that our new framework MAPPR outperforms the current edge-based personalized PageRank methodology. PMID:29770258

Semisupervised Clustering by Iterative Partition and Regression with Neuroscience Applications

PubMed Central

Qian, Guoqi; Wu, Yuehua; Ferrari, Davide; Qiao, Puxue; Hollande, Frédéric

2016-01-01

Regression clustering is a mixture of unsupervised and supervised statistical learning and data mining method which is found in a wide range of applications including artificial intelligence and neuroscience. It performs unsupervised learning when it clusters the data according to their respective unobserved regression hyperplanes. The method also performs supervised learning when it fits regression hyperplanes to the corresponding data clusters. Applying regression clustering in practice requires means of determining the underlying number of clusters in the data, finding the cluster label of each data point, and estimating the regression coefficients of the model. In this paper, we review the estimation and selection issues in regression clustering with regard to the least squares and robust statistical methods. We also provide a model selection based technique to determine the number of regression clusters underlying the data. We further develop a computing procedure for regression clustering estimation and selection. Finally, simulation studies are presented for assessing the procedure, together with analyzing a real data set on RGB cell marking in neuroscience to illustrate and interpret the method. PMID:27212939

Alternative Parameterizations for Cluster Editing

NASA Astrophysics Data System (ADS)

Komusiewicz, Christian; Uhlmann, Johannes

Given an undirected graph G and a nonnegative integer k, the NP-hard Cluster Editing problem asks whether G can be transformed into a disjoint union of cliques by applying at most k edge modifications. In the field of parameterized algorithmics, Cluster Editing has almost exclusively been studied parameterized by the solution size k. Contrastingly, in many real-world instances it can be observed that the parameter k is not really small. This observation motivates our investigation of parameterizations of Cluster Editing different from the solution size k. Our results are as follows. Cluster Editing is fixed-parameter tractable with respect to the parameter "size of a minimum cluster vertex deletion set of G", a typically much smaller parameter than k. Cluster Editing remains NP-hard on graphs with maximum degree six. A restricted but practically relevant version of Cluster Editing is fixed-parameter tractable with respect to the combined parameter "number of clusters in the target graph" and "maximum number of modified edges incident to any vertex in G". Many of our results also transfer to the NP-hard Cluster Deletion problem, where only edge deletions are allowed.

bcl::Cluster : A method for clustering biological molecules coupled with visualization in the Pymol Molecular Graphics System.

PubMed

Alexander, Nathan; Woetzel, Nils; Meiler, Jens

2011-02-01

Clustering algorithms are used as data analysis tools in a wide variety of applications in Biology. Clustering has become especially important in protein structure prediction and virtual high throughput screening methods. In protein structure prediction, clustering is used to structure the conformational space of thousands of protein models. In virtual high throughput screening, databases with millions of drug-like molecules are organized by structural similarity, e.g. common scaffolds. The tree-like dendrogram structure obtained from hierarchical clustering can provide a qualitative overview of the results, which is important for focusing detailed analysis. However, in practice it is difficult to relate specific components of the dendrogram directly back to the objects of which it is comprised and to display all desired information within the two dimensions of the dendrogram. The current work presents a hierarchical agglomerative clustering method termed bcl::Cluster. bcl::Cluster utilizes the Pymol Molecular Graphics System to graphically depict dendrograms in three dimensions. This allows simultaneous display of relevant biological molecules as well as additional information about the clusters and the members comprising them.

Ensemble averaged structure–function relationship for nanocrystals: effective superparamagnetic Fe clusters with catalytically active Pt skin [Ensemble averaged structure-function relationship for composite nanocrystals: magnetic bcc Fe clusters with catalytically active fcc Pt skin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petkov, Valeri; Prasai, Binay; Shastri, Sarvjit

Practical applications require the production and usage of metallic nanocrystals (NCs) in large ensembles. Besides, due to their cluster-bulk solid duality, metallic NCs exhibit a large degree of structural diversity. This poses the question as to what atomic-scale basis is to be used when the structure–function relationship for metallic NCs is to be quantified precisely. In this paper, we address the question by studying bi-functional Fe core-Pt skin type NCs optimized for practical applications. In particular, the cluster-like Fe core and skin-like Pt surface of the NCs exhibit superparamagnetic properties and a superb catalytic activity for the oxygen reduction reaction,more » respectively. We determine the atomic-scale structure of the NCs by non-traditional resonant high-energy X-ray diffraction coupled to atomic pair distribution function analysis. Using the experimental structure data we explain the observed magnetic and catalytic behavior of the NCs in a quantitative manner. Lastly, we demonstrate that NC ensemble-averaged 3D positions of atoms obtained by advanced X-ray scattering techniques are a very proper basis for not only establishing but also quantifying the structure–function relationship for the increasingly complex metallic NCs explored for practical applications.« less

The Porto Alegre Early Life Nutrition and Health Study.

PubMed

Chaffee, Benjamin Wilk; Vítolo, Márcia Regina; Feldens, Carlos Alberto

2014-12-01

Early childhood caries is a persistent worldwide problem. The etiologic contribution of feeding practices has been less frequently investigated in prospective studies of young children. The Porto Alegre Early Life Nutrition and Health Study has followed a birth cohort of 715 mother-child pairs, recruited from municipal health centers, originally involved in a cluster-randomized controlled trial of healthcare worker training. The birth cohort links prospectively collected socio-demographic, infant feeding, and general and oral health information. To date, oral health data, including caries status and oral health-related quality of life, have been collected for 458 children at the age of 2-3 years. Studies are underway to investigate possible determinants and consequences of oral health among these children.

Differentials in colostrum feeding among lactating women of block RS Pura of J and K: A lesson for nursing practice.

PubMed

Raina, Sunil Kumar; Mengi, Vijay; Singh, Gurdeep

2012-07-01

Breast feeding is universally and traditionally practicised in India. Experts advocate breast feeding as the best method of feeding young infants. To assess the role of various factors in determining colostrum feeding in block R. S. Pura of district Jammu. A stratified two-stage design with villages as the primary sampling unit and lactating mothers as secondary sampling unit. Villages were divided into different clusters on the basis of population and sampling units were selected by a simple random technique. Breastfeeding is almost universal in R. S. Pura. Differentials in discarding the first milk were not found to be important among various socioeconomic groups and the phenomenon appeared more general than specific.

Predictors of vaginal practices for sex and hygiene in KwaZulu-Natal, South Africa: findings of a household survey and qualitative inquiry.

PubMed

Scorgie, Fiona; Smit, Jennifer A; Kunene, Busisiwe; Martin-Hilber, Adriane; Beksinska, Mags; Chersich, Matthew F

2011-04-01

Vaginal practices in sub-Saharan Africa may increase HIV transmission and have important implications for development of microbicides and future HIV prevention technologies. It remains unclear which women undertake vaginal practices and what factors predict prevalence, practice type and choice of products. Using cross-sectional data from mixed research methods, we identify factors associated with vaginal practices among women in KwaZulu-Natal, South Africa. Data were gathered through focus group discussions, in-depth and key-informant interviews, followed by a province-wide, multi-stage cluster household survey, using structured questionnaires in face-to-face interviews with 867 women. This paper details six types of vaginal practices, which--despite their individual distinctiveness and diverse motivations--may be clustered into two broad groups: those undertaken for purposes of 'hygiene' (genital washing, douching and application) and those for 'sexual motivations' (application, insertion, ingestion and incisions). Multivariate analysis found significant associations between 'hygiene' practices and media access, religiosity and transactional sex. 'Sexual' practices were associated with partner concurrency, religiosity and use of injectable hormonal contraceptives. Future interventions relating to vaginal practices as well as microbicides need to reflect this characterisation of practices as sexual- and/or hygiene-related.

Effective implementation of hierarchical clustering

NASA Astrophysics Data System (ADS)

Verma, Mudita; Vijayarajan, V.; Sivashanmugam, G.; Bessie Amali, D. Geraldine

2017-11-01

Hierarchical clustering is generally used for cluster analysis in which we build up a hierarchy of clusters. In order to find that which cluster should be split a large amount of observations are being carried out. Here the data set of US based personalities has been considered for clustering. After implementation of hierarchical clustering on the data set we group it in three different clusters one is of politician, sports person and musicians. Training set is the main parameter which decides the category which has to be assigned to the observations that are being collected. The category of these observations must be known. Recognition comes from the formulation of classification. Supervised learning has the main instance in the form of classification. While on the other hand Clustering is an instance of unsupervised procedure. Clustering consists of grouping of data that have similar properties which are either their own or are inherited from some other sources.

Preventing Sexual Violence in Adolescence: Comparison of a Scientist-Practitioner Program and a Practitioner Program Using a Cluster-Randomized Design.

PubMed

Muck, Christoph; Schiller, Eva-Maria; Zimmermann, Maria; Kärtner, Joscha

2018-02-01

Numerous school-based prevention programs have been developed by scientists and practitioners to address sexual violence in adolescence. However, such programs struggle with two major challenges. First, the effectiveness of many well-established practitioner programs has not been rigorously evaluated. Second, effective scientific programs may be hard to implement into everyday school practice. Combining the knowledge of scientists and practitioners in a scientist-practitioner program could be a helpful compromise. The aim of the present study is to evaluate the effects of a scientist-practitioner program and a practitioner program using a cluster-randomized experimental design. Twenty-seven school classes were randomly assigned to either one of two programs or a control group. Outcome variables (knowledge, attitudes, behavior, and iatrogenic effects) were assessed at pretest, posttest, and a 6-month follow-up for 453 adolescents (55% female, Mage = 14.18). Short-term effects were found in both programs regarding general knowledge, knowledge of professional help, and victim-blaming attitudes. Long-term effects were found in both programs regarding general knowledge and knowledge of professional help and, in the practitioner program, in a reduction of victimization. No other effects were found on attitudes and behavior. No iatrogenic effects in the form of increased anxiety were found. Both the scientist-practitioner and the practitioner program show promise for the prevention of sexual violence in adolescence; in particular, the practitioner program may be a more cost-effective method.

What constitutes an effective community pharmacy?--development of a preliminary model of organizational effectiveness through concept mapping with multiple stakeholders.

PubMed

Scahill, S L; Harrison, J; Carswell, P

2010-08-01

To develop a multi-constituent model of organizational effectiveness for community pharmacy. Using Concept Systems software, a project with 14 stakeholders included a three stage process: (i) face to face brainstorming to generate statements describing what constitutes an effective community pharmacy, followed by (ii) statement reduction and approval by participants, followed by (iii) sorting of the statements into themes with rating of each statement for importance. Primary care in a government-funded, national health care system. A multi-constituent group representing policy-makers and health care providers including; community pharmacy, professional pharmacy organizations, primary health care funders and policy-makers, general practitioners and general practice support organizations. Statement clusters included: 'has safe and effective workflows', 'contributes to the safe use of medicines', 'manages human resources and has leadership', 'has a community focus', 'is integrated within primary care', 'is a respected innovator', 'provides health promotion and preventative care', 'communicates and advocates'. These clusters fit into a quadrant model setting stakeholder focus against role development. The poles of stakeholder focus are 'internal capacity' and 'social utility'. The poles of role development are labelled 'traditional safety roles' and 'integration and innovation'. Organizational effectiveness in community pharmacy includes the internal and external focus of the organization and role development. Our preliminary model describes an effective community pharmacy and provides a platform for investigation of the factors that may influence the organizational effectiveness of individual community pharmacies now and into the future.

Membership determination of open clusters based on a spectral clustering method

NASA Astrophysics Data System (ADS)

Gao, Xin-Hua

2018-06-01

We present a spectral clustering (SC) method aimed at segregating reliable members of open clusters in multi-dimensional space. The SC method is a non-parametric clustering technique that performs cluster division using eigenvectors of the similarity matrix; no prior knowledge of the clusters is required. This method is more flexible in dealing with multi-dimensional data compared to other methods of membership determination. We use this method to segregate the cluster members of five open clusters (Hyades, Coma Ber, Pleiades, Praesepe, and NGC 188) in five-dimensional space; fairly clean cluster members are obtained. We find that the SC method can capture a small number of cluster members (weak signal) from a large number of field stars (heavy noise). Based on these cluster members, we compute the mean proper motions and distances for the Hyades, Coma Ber, Pleiades, and Praesepe clusters, and our results are in general quite consistent with the results derived by other authors. The test results indicate that the SC method is highly suitable for segregating cluster members of open clusters based on high-precision multi-dimensional astrometric data such as Gaia data.

Alerts in electronic medical records to promote a colorectal cancer screening programme: a cluster randomised controlled trial in primary care.

PubMed

Guiriguet, Carolina; Muñoz-Ortiz, Laura; Burón, Andrea; Rivero, Irene; Grau, Jaume; Vela-Vallespín, Carmen; Vilarrubí, Mercedes; Torres, Miquel; Hernández, Cristina; Méndez-Boo, Leonardo; Toràn, Pere; Caballeria, Llorenç; Macià, Francesc; Castells, Antoni

2016-07-01

Participation rates in colorectal cancer screening are below recommended European targets. To evaluate the effectiveness of an alert in primary care electronic medical records (EMRs) to increase individuals' participation in an organised, population-based colorectal cancer screening programme when compared with usual care. Cluster randomised controlled trial in primary care centres of Barcelona, Spain. Participants were males and females aged 50-69 years, who were invited to the first round of a screening programme based on the faecal immunochemical test (FIT) (n = 41 042), and their primary care professional. The randomisation unit was the physician cluster (n = 130) and patients were blinded to the study group. The control group followed usual care as per the colorectal cancer screening programme. In the intervention group, as well as usual care, an alert to health professionals (cluster level) to promote screening was introduced in the individual's primary care EMR for 1 year. The main outcome was colorectal cancer screening participation at individual participant level. In total, 67 physicians and 21 619 patients (intervention group) and 63 physicians and 19 423 patients (control group) were randomised. In the intention-to-treat analysis screening participation was 44.1% and 42.2% respectively (odds ratio 1.08, 95% confidence interval [CI] = 0.97 to 1.20, P = 0.146). However, in the per-protocol analysis screening uptake in the intervention group showed a statistically significant increase, after adjusting for potential confounders (OR, 1.11; 95% CI = 1.02 to 1.22; P = 0.018). The use of an alert in an individual's primary care EMR is associated with a statistically significant increased uptake of an organised, FIT-based colorectal cancer screening programme in patients attending primary care centres. © British Journal of General Practice 2016.

Effectiveness and cost-effectiveness of telehealthcare for chronic obstructive pulmonary disease: study protocol for a cluster randomized controlled trial.

PubMed

Udsen, Flemming Witt; Lilholt, Pernille Heyckendorff; Hejlesen, Ole; Ehlers, Lars Holger

2014-05-21

Several feasibility studies show promising results of telehealthcare on health outcomes and health-related quality of life for patients suffering from chronic obstructive pulmonary disease, and some of these studies show that telehealthcare may even lower healthcare costs. However, the only large-scale trial we have so far - the Whole System Demonstrator Project in England - has raised doubts about these results since it conclude that telehealthcare as a supplement to usual care is not likely to be cost-effective compared with usual care alone. The present study is known as 'TeleCare North' in Denmark. It seeks to address these doubts by implementing a large-scale, pragmatic, cluster-randomized trial with nested economic evaluation. The purpose of the study is to assess the effectiveness and the cost-effectiveness of a telehealth solution for patients suffering from chronic obstructive pulmonary disease compared to usual practice. General practitioners will be responsible for recruiting eligible participants (1,200 participants are expected) for the trial in the geographical area of the North Denmark Region. Twenty-six municipality districts in the region define the randomization clusters. The primary outcomes are changes in health-related quality of life, and the incremental cost-effectiveness ratio measured from baseline to follow-up at 12 months. Secondary outcomes are changes in mortality and physiological indicators (diastolic and systolic blood pressure, pulse, oxygen saturation, and weight). There has been a call for large-scale clinical trials with rigorous cost-effectiveness assessments in telehealthcare research. This study is meant to improve the international evidence base for the effectiveness and cost-effectiveness of telehealthcare to patients suffering from chronic obstructive pulmonary disease by implementing a large-scale pragmatic cluster-randomized clinical trial. Clinicaltrials.gov, http://NCT01984840, November 14, 2013.

Brimstone chemistry under laser light assists mass spectrometric detection and imaging the distribution of arsenic in minerals.

PubMed

Lal, Swapnil; Zheng, Zhaoyu; Pavlov, Julius; Attygalle, Athula B

2018-05-23

Singly charged As2n+1 ion clusters (n = 2-11) were generated from elemental arsenic by negative-ion laser-ablation mass spectrometry. The overall abundance of the gaseous As ions generated upon laser irradiation was enhanced nearly a hundred times when As-bearing samples were admixed with sulfur. However, sulfur does not act purely as an inert matrix: irradiating arsenic-sulfur mixtures revealed a novel pathway to generate and detect a series of [AsSn]- clusters (n = 2-6). Intriguingly, the spectra recorded from As2O3, NaAsO2, Na3AsO4, cacodylic acid and 3-amino-4-hydroxyphenylarsonic acid together with sulfur as the matrix were remarkably similar to that acquired from an elemental arsenic and sulfur mixture. This result indicated that arsenic sulfide cluster-ions are generated directly from arsenic compounds by a hitherto unknown pathway. The mechanism of elemental sulfur extracting chemically bound arsenic from compounds and forming [AsSn]- clusters is enigmatic; however, this discovery has a practical value as a general detection method for arsenic compounds. For example, the method was employed for the detection of As in its minerals, and for the imaging of arsenic distribution in minerals such as domeykite. LDI-MS data recorded from a latent image imprinted on a piece of paper from a flat mineral surface, and wetting the paper with a solution of sulfur, enabled the localization of arsenic in the mineral. The distribution of As was visualized as false-color images by extracting from acquired data the relative intensities of m/z 139 (AsS2-) and m/z 171 (AsS3-) ions.

Techniques to derive geometries for image-based Eulerian computations

PubMed Central

Dillard, Seth; Buchholz, James; Vigmostad, Sarah; Kim, Hyunggun; Udaykumar, H.S.

2014-01-01

Purpose The performance of three frequently used level set-based segmentation methods is examined for the purpose of defining features and boundary conditions for image-based Eulerian fluid and solid mechanics models. The focus of the evaluation is to identify an approach that produces the best geometric representation from a computational fluid/solid modeling point of view. In particular, extraction of geometries from a wide variety of imaging modalities and noise intensities, to supply to an immersed boundary approach, is targeted. Design/methodology/approach Two- and three-dimensional images, acquired from optical, X-ray CT, and ultrasound imaging modalities, are segmented with active contours, k-means, and adaptive clustering methods. Segmentation contours are converted to level sets and smoothed as necessary for use in fluid/solid simulations. Results produced by the three approaches are compared visually and with contrast ratio, signal-to-noise ratio, and contrast-to-noise ratio measures. Findings While the active contours method possesses built-in smoothing and regularization and produces continuous contours, the clustering methods (k-means and adaptive clustering) produce discrete (pixelated) contours that require smoothing using speckle-reducing anisotropic diffusion (SRAD). Thus, for images with high contrast and low to moderate noise, active contours are generally preferable. However, adaptive clustering is found to be far superior to the other two methods for images possessing high levels of noise and global intensity variations, due to its more sophisticated use of local pixel/voxel intensity statistics. Originality/value It is often difficult to know a priori which segmentation will perform best for a given image type, particularly when geometric modeling is the ultimate goal. This work offers insight to the algorithm selection process, as well as outlining a practical framework for generating useful geometric surfaces in an Eulerian setting. PMID:25750470

Methanol Oxidative Dehydrogenation on Oxide Catalysts: Molecular and Dissociative Routes and Hydrogen Addition Energies as Descriptors of Reactivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deshlahra, Prashant; Iglesia, Enrique

The oxidative dehydrogenation (ODH) of alkanols on oxide catalysts is generally described as involving H-abstraction from alkoxy species formed via O–H dissociation. Kinetic and isotopic data cannot discern between such routes and those involving kinetically-relevant H-abstraction from undissociated alkanols. Here, we combine such experiments with theoretical estimates of activation energies and entropies to show that the latter molecular routes prevail over dissociative routes for methanol reactions on polyoxometalate (POM) clusters at all practical reaction temperatures. The stability of the late transition states that mediate H-abstraction depend predominantly on the stability of the O–H bond formed, making H-addition energies (HAE) accuratemore » and single-valued descriptors of reactivity. Density functional theory-derived activation energies depend linearly on HAE values at each O-atom location on clusters with a range of composition (H3PMo12, H4SiMo12, H3PW12, H4PV1Mo11, and H4PV1W11); both barriers and HAE values reflect the lowest unoccupied molecular orbital energy of metal centers that accept the electron and the protonation energy of O-atoms that accept the proton involved in the H-atom transfer. Bridging O-atoms form O–H bonds that are stronger than those of terminal atoms and therefore exhibit more negative HAE values and higher ODH reactivity on all POM clusters. For each cluster composition, ODH turnover rates reflect the reactivity-averaged HAE of all accessible O-atoms, which can be evaluated for each cluster composition to provide a rigorous and accurate predictor of ODH reactivity for catalysts with known structure. These relations together with oxidation reactivity measurements can then be used to estimate HAE values and to infer plausible structures for catalysts with uncertain active site structures.« less

Statistical analysis and handling of missing data in cluster randomized trials: a systematic review.

PubMed

Fiero, Mallorie H; Huang, Shuang; Oren, Eyal; Bell, Melanie L

2016-02-09

Cluster randomized trials (CRTs) randomize participants in groups, rather than as individuals and are key tools used to assess interventions in health research where treatment contamination is likely or if individual randomization is not feasible. Two potential major pitfalls exist regarding CRTs, namely handling missing data and not accounting for clustering in the primary analysis. The aim of this review was to evaluate approaches for handling missing data and statistical analysis with respect to the primary outcome in CRTs. We systematically searched for CRTs published between August 2013 and July 2014 using PubMed, Web of Science, and PsycINFO. For each trial, two independent reviewers assessed the extent of the missing data and method(s) used for handling missing data in the primary and sensitivity analyses. We evaluated the primary analysis and determined whether it was at the cluster or individual level. Of the 86 included CRTs, 80 (93%) trials reported some missing outcome data. Of those reporting missing data, the median percent of individuals with a missing outcome was 19% (range 0.5 to 90%). The most common way to handle missing data in the primary analysis was complete case analysis (44, 55%), whereas 18 (22%) used mixed models, six (8%) used single imputation, four (5%) used unweighted generalized estimating equations, and two (2%) used multiple imputation. Fourteen (16%) trials reported a sensitivity analysis for missing data, but most assumed the same missing data mechanism as in the primary analysis. Overall, 67 (78%) trials accounted for clustering in the primary analysis. High rates of missing outcome data are present in the majority of CRTs, yet handling missing data in practice remains suboptimal. Researchers and applied statisticians should carry out appropriate missing data methods, which are valid under plausible assumptions in order to increase statistical power in trials and reduce the possibility of bias. Sensitivity analysis should be performed, with weakened assumptions regarding the missing data mechanism to explore the robustness of results reported in the primary analysis.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ben-Naim, Eli; Krapivsky, Paul

Here we generalize the ordinary aggregation process to allow for choice. In ordinary aggregation, two random clusters merge and form a larger aggregate. In our implementation of choice, a target cluster and two candidate clusters are randomly selected and the target cluster merges with the larger of the two candidate clusters.We study the long-time asymptotic behavior and find that as in ordinary aggregation, the size density adheres to the standard scaling form. However, aggregation with choice exhibits a number of different features. First, the density of the smallest clusters exhibits anomalous scaling. Second, both the small-size and the large-size tailsmore » of the density are overpopulated, at the expense of the density of moderate-size clusters. Finally, we also study the complementary case where the smaller candidate cluster participates in the aggregation process and find an abundance of moderate clusters at the expense of small and large clusters. Additionally, we investigate aggregation processes with choice among multiple candidate clusters and a symmetric implementation where the choice is between two pairs of clusters.« less

Making Sense of Cluster Analysis: Revelations from Pakistani Science Classes

ERIC Educational Resources Information Center

Pell, Tony; Hargreaves, Linda

2011-01-01

Cluster analysis has been applied to quantitative data in educational research over several decades and has been a feature of the Maurice Galton's research in primary and secondary classrooms. It has offered potentially useful insights for teaching yet its implications for practice are rarely implemented. It has been subject also to negative…

7 CFR 52.1851 - Sizes of raisins with seeds-layer or cluster.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Sizes of raisins with seeds-layer or cluster. 52.1851 Section 52.1851 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

7 CFR 52.1842 - Product description of Layer or (Cluster) raisins with seeds.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Product description of Layer or (Cluster) raisins with seeds. 52.1842 Section 52.1842 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL...

7 CFR 52.1853 - Grades of raisins with seeds-layer or cluster.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Grades of raisins with seeds-layer or cluster. 52.1853 Section 52.1853 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

7 CFR 52.1853 - Grades of raisins with seeds-layer or cluster.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Grades of raisins with seeds-layer or cluster. 52.1853 Section 52.1853 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

7 CFR 52.1842 - Product description of Layer or (Cluster) raisins with seeds.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Product description of Layer or (Cluster) raisins with seeds. 52.1842 Section 52.1842 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL...

7 CFR 52.1852 - Grades of raisins with seeds-except layer or cluster.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Grades of raisins with seeds-except layer or cluster. 52.1852 Section 52.1852 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT O...

7 CFR 52.1851 - Sizes of raisins with seeds-layer or cluster.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Sizes of raisins with seeds-layer or cluster. 52.1851 Section 52.1851 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

7 CFR 52.1853 - Grades of raisins with seeds-layer or cluster.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Grades of raisins with seeds-layer or cluster. 52.1853 Section 52.1853 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

7 CFR 52.1850 - Sizes of raisins with seeds-except layer or cluster.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Sizes of raisins with seeds-except layer or cluster. 52.1850 Section 52.1850 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF...

7 CFR 52.1852 - Grades of raisins with seeds-except layer or cluster.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Grades of raisins with seeds-except layer or cluster. 52.1852 Section 52.1852 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT O...

7 CFR 52.1850 - Sizes of raisins with seeds-except layer or cluster.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Sizes of raisins with seeds-except layer or cluster. 52.1850 Section 52.1850 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF...

7 CFR 52.1851 - Sizes of raisins with seeds-layer or cluster.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Sizes of raisins with seeds-layer or cluster. 52.1851 Section 52.1851 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

7 CFR 52.1842 - Product description of Layer or (Cluster) raisins with seeds.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Product description of Layer or (Cluster) raisins with seeds. 52.1842 Section 52.1842 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL...

7 CFR 52.1842 - Product description of Layer or (Cluster) raisins with seeds.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Product description of Layer or (Cluster) raisins with seeds. 52.1842 Section 52.1842 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL...

7 CFR 52.1852 - Grades of raisins with seeds-except layer or cluster.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Grades of raisins with seeds-except layer or cluster. 52.1852 Section 52.1852 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT O...

7 CFR 52.1850 - Sizes of raisins with seeds-except layer or cluster.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Sizes of raisins with seeds-except layer or cluster. 52.1850 Section 52.1850 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF...

7 CFR 52.1852 - Grades of raisins with seeds-except layer or cluster.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Grades of raisins with seeds-except layer or cluster. 52.1852 Section 52.1852 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT O...

7 CFR 52.1851 - Sizes of raisins with seeds-layer or cluster.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Sizes of raisins with seeds-layer or cluster. 52.1851 Section 52.1851 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

7 CFR 52.1853 - Grades of raisins with seeds-layer or cluster.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Grades of raisins with seeds-layer or cluster. 52.1853 Section 52.1853 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946...

7 CFR 52.1850 - Sizes of raisins with seeds-except layer or cluster.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Sizes of raisins with seeds-except layer or cluster. 52.1850 Section 52.1850 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF...

Communication via Chalkboard and on Paper. TLA-100.00 (F.U.F.).

ERIC Educational Resources Information Center

Hardison, Margaret J.

The purpose of this cluster of learning modules is to increase the teacher intern's understanding and skills with regard to his role as a communicator. The cluster contains three modules: (a) objectives for teaching handwriting, (b) methodology of manuscript writing, and (c) practice teaching of manuscript handwriting. Each module contains a…

Time dependent density functional calculation of plasmon response in clusters

NASA Astrophysics Data System (ADS)

Wang, Feng; Zhang, Feng-Shou; Eric, Suraud

2003-02-01

We have introduced a theoretical scheme for the efficient description of the optical response of a cluster based on the time-dependent density functional theory. The practical implementation is done by means of the fully fledged time-dependent local density approximation scheme, which is solved directly in the time domain without any linearization. As an example we consider the simple Na2 cluster and compute its surface plasmon photoabsorption cross section, which is in good agreement with the experiments.

Word-initial /r/-clusters in Swedish speaking children with typical versus protracted phonological development.

PubMed

Lundeborg Hammarström, Inger

2018-01-01

The present study investigated word-initial (WI) /r/-clusters in Central Swedish-speaking children with and without protracted phonological development (PPD). Data for WI singleton /r/ and singleton and cluster /l/ served as comparisons. Participants were twelve 4-year-olds with PPD and twelve age- and gender-matched typically developing (TD) controls. Native speakers audio-recorded and transcribed 109 target single words using a Swedish phonology test with 12 WI C+/r/-clusters and three WI CC+/r/-clusters. The results showed significantly higher match scores for the TD children, a lower match proportion for the /r/ targets and for singletons compared with clusters, and differences in mismatch patterns between the groups. There were no matches for /r/-cluster targets in the PPD group, with all children except two in that group showing deletions for both /r/-cluster types. The differences in mismatch proportions and types between the PPD group and controls suggests new directions for future clinical practice.

Correlation networks among currencies

NASA Astrophysics Data System (ADS)

Mizuno, Takayuki; Takayasu, Hideki; Takayasu, Misako

2006-05-01

By analyzing the foreign exchange market data of various currencies, we derive a hierarchical taxonomy of currencies constructing minimal-spanning trees. Clustered structure of the currencies and the key currency in each cluster are found. The clusters match nicely with the geographical regions of corresponding countries in the world such as Asia or East Europe, the key currencies are generally given by major economic countries as expected.

Using Early Literacy Profiles of Hispanic English Language Learners to Predict Later Reading Achievement

ERIC Educational Resources Information Center

Huang, Francis; Ford, Karen; Invernizzi, Marcia

2011-01-01

Following a cohort of students from fall of kindergarten to spring of first grade, the authors investigated whether the general cluster profiles identified in Burrow et al.'s (2010) study remained consistent over time. If cluster profiles in the fall of kindergarten held, their goal was to investigate the differences between clusters in terms of…

Constraints on the Energy Density Content of the Universe Using Only Clusters of Galaxies

NASA Technical Reports Server (NTRS)

Molnar, Sandor M.; Haiman, Zoltan; Birkinshaw, Mark

2003-01-01

We demonstrate that it is possible to constrain the energy content of the Universe with high accuracy using observations of clusters of galaxies only. The degeneracies in the cosmological parameters are lifted by combining constraints from different observables of galaxy clusters. We show that constraints on cosmological parameters from galaxy cluster number counts as a function of redshift and accurate angular diameter distance measurements to clusters are complementary to each other and their combination can constrain the energy density content of the Universe well. The number counts can be obtained from X-ray and/or SZ (Sunyaev-Zeldovich effect) surveys, the angular diameter distances can be determined from deep observations of the intra-cluster gas using their thermal bremsstrahlung X-ray emission and the SZ effect (X-SZ method). In this letter we combine constraints from simulated cluster number counts expected from a 12 deg2 SZ cluster survey and constraints from simulated angular diameter distance measurements based on using the X-SZ method assuming an expected accuracy of 7% in the angular diameter distance determination of 70 clusters with redshifts less than 1.5. We find that R, can be determined within about 25%, A within 20%, and w within 16%. Any cluster survey can be used to select clusters for high accuracy distance measurements, but we assumed accurate angular diameter distance measurements for only 70 clusters since long observations are necessary to achieve high accuracy in distance measurements. Thus the question naturally arises: How to select clusters of galaxies for accurate diameter distance determinations? In this letter, as an example, we demonstrate that it is possible to optimize this selection changing the number of clusters observed, and the upper cut off of their redshift range. We show that constraints on cosmological parameters from combining cluster number counts and angular diameter distance measurements, as opposed to general expectations, will not improve substantially selecting clusters with redshifts higher than one. This important conclusion allow us to restrict our cluster sample to clusters closer than one, in a range where the observational time for accurate distance measurements are more manageable. Subject headings: cosmological parameters - cosmology: theory - galaxies: clusters: general - X-rays: galaxies: clusters

Testing modified gravity with globular clusters: the case of NGC 2419

NASA Astrophysics Data System (ADS)

Llinares, Claudio

2018-05-01

The dynamics of globular clusters has been studied in great detail in the context of general relativity as well as with modifications of gravity that strongly depart from the standard paradigm such as Modified Newtonian Dynamics. However, at present there are no studies that aim to test the impact that less extreme modifications of gravity (e.g. models constructed as alternatives to dark energy) have on the behaviour of globular clusters. This Letter presents fits to the velocity dispersion profile of the cluster NGC 2419 under the symmetron-modified gravity model. The data show an increase in the velocity dispersion towards the centre of the cluster which could be difficult to explain within general relativity. By finding the best-fitting solution associated with the symmetron model, we show that this tension does not exist in modified gravity. However, the best-fitting parameters give a model that is inconsistent with the dynamics of the Solar system. Exploration of different screening mechanisms should give us the chance to understand if it is possible to maintain the appealing properties of the symmetron model when it comes to globular clusters and at the same time recover the Solar system dynamics properly.

The mond external field effect on the dynamics of the globular clusters: general considerations and application to NGC 2419

DOE Office of Scientific and Technical Information (OSTI.GOV)

Derakhshani, Kamran, E-mail: kderakhshani@iasbs.ac.ir

2014-03-01

In this paper, we investigate the external field effect in the context of the MOdified Newtonian Dynamics (MOND) on the surface brightness and velocity dispersion profiles of globular clusters (GCs). Using N-MODY, which is an N-body simulation code with a MOND potential solver, we show that the general effect of the external field for diffuse clusters, which obey MOND in most of their parts, is that it pushes the dynamics toward the Newtonian regime. On the other hand, for more compact clusters, which are essentially Newtonian in their inner parts, the external field is effective mainly in the outer partsmore » of compact clusters. As a case study, we then choose the remote Galactic GC NGC 2419. By varying the cluster mass, half-light radius, and mass-to-light ratio, we aim to find a model that will reproduce the observational data most effectively, using N-MODY. We find that even if we take the Galactic external field into account, a Newtonian Plummer sphere represents the observational data better than MOND to an order of magnitude in terms of the total χ{sup 2} of surface brightness and velocity dispersion.« less

The MOND External Field Effect on the Dynamics of the Globular Clusters: General Considerations and Application to NGC 2419

NASA Astrophysics Data System (ADS)

Derakhshani, Kamran

2014-03-01

In this paper, we investigate the external field effect in the context of the MOdified Newtonian Dynamics (MOND) on the surface brightness and velocity dispersion profiles of globular clusters (GCs). Using N-MODY, which is an N-body simulation code with a MOND potential solver, we show that the general effect of the external field for diffuse clusters, which obey MOND in most of their parts, is that it pushes the dynamics toward the Newtonian regime. On the other hand, for more compact clusters, which are essentially Newtonian in their inner parts, the external field is effective mainly in the outer parts of compact clusters. As a case study, we then choose the remote Galactic GC NGC 2419. By varying the cluster mass, half-light radius, and mass-to-light ratio, we aim to find a model that will reproduce the observational data most effectively, using N-MODY. We find that even if we take the Galactic external field into account, a Newtonian Plummer sphere represents the observational data better than MOND to an order of magnitude in terms of the total χ2 of surface brightness and velocity dispersion.

Android Malware Classification Using K-Means Clustering Algorithm

NASA Astrophysics Data System (ADS)

Hamid, Isredza Rahmi A.; Syafiqah Khalid, Nur; Azma Abdullah, Nurul; Rahman, Nurul Hidayah Ab; Chai Wen, Chuah

2017-08-01

Malware was designed to gain access or damage a computer system without user notice. Besides, attacker exploits malware to commit crime or fraud. This paper proposed Android malware classification approach based on K-Means clustering algorithm. We evaluate the proposed model in terms of accuracy using machine learning algorithms. Two datasets were selected to demonstrate the practicing of K-Means clustering algorithms that are Virus Total and Malgenome dataset. We classify the Android malware into three clusters which are ransomware, scareware and goodware. Nine features were considered for each types of dataset such as Lock Detected, Text Detected, Text Score, Encryption Detected, Threat, Porn, Law, Copyright and Moneypak. We used IBM SPSS Statistic software for data classification and WEKA tools to evaluate the built cluster. The proposed K-Means clustering algorithm shows promising result with high accuracy when tested using Random Forest algorithm.

The Student-Teacher Relationship Quality of Abused Children

PubMed Central

Haskett, Mary E.; Hawkins, Amy L.

2016-01-01

Considering the association between children’s quality of relationships with teachers and their academic adjustment, information pertaining to how abused children are functioning in their relationships with teachers could be useful in promoting their academic success— yet there has been limited research in this area. The purpose of this study was to use cluster analyses to explore within-group differences in relational schemas and quality of student-teacher relationships for 70 abused children. Two clusters of abused children emerged, and as hypothesized, there were significant differences in student-teacher relationships for the two clusters. The cluster with more positive relational schemas had less conflict and less dependency reported by their teachers compared to the cluster with negative relational schemas. However, there were no differences between the clusters in terms of closeness with teachers. Implications for practice in schools is discussed. PMID:28713179

A psychometric validation study of the Impulsive-Compulsive Behaviours Checklist: A transdiagnostic tool for addictive and compulsive behaviours.

PubMed

Guo, Karen; Youssef, George J; Dawson, Andrew; Parkes, Linden; Oostermeijer, Sanne; López-Solà, Clara; Lorenzetti, Valentina; Greenwood, Christopher; Fontenelle, Leonardo F; Yücel, Murat

2017-04-01

The occurrence of repetitive behaviours that are often harmful has been attributed to traits traditionally described as "impulsive" or "compulsive" e.g. substance dependence, excessive gambling, and hoarding. These behaviours are common and often co-occur in both the general population and psychiatric populations. The lack of measures to concurrently index a range of such behaviours led to the development of the Impulsive-Compulsive Behaviours (ICB) Checklist. This study aims to validate the ICB Checklist in a general community sample. Factor analyses revealed a two-factor structure, demonstrating good model fit in two independent samples. These were labelled Impulsive-Compulsions and Compulsive-Impulsions, comprising of classically compulsive and impulsive behaviours respectively. Reliability and construct validity were further confirmed using correlations with existing measures of impulsivity and compulsivity. Results suggest that the ICB Checklist is a valid and practical assessment that can be used to monitor behavioural clusters characterised by deficits in inhibition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Faculty Meetings: Hidden Conversational Dynamics

ERIC Educational Resources Information Center

Bowman, Richard F.

2015-01-01

In the everydayness of faculty meetings, collegial conversations mirror distinctive dynamics and practices, which either enhance or undercut organizational effectiveness. A cluster of conversational practices affect how colleagues connect, engage, interact, and influence others during faculty meetings in diverse educational settings. The…

Clusters of community exposure to coastal flooding hazards based on storm and sea level rise scenarios—implications for adaptation networks in the San Francisco Bay region

USGS Publications Warehouse

Hummel, Michelle; Wood, Nathan J.; Schweikert, Amy; Stacey, Mark T.; Jones, Jeanne; Barnard, Patrick L.; Erikson, Li H.

2018-01-01

Sea level is projected to rise over the coming decades, further increasing the extent of flooding hazards in coastal communities. Efforts to address potential impacts from climate-driven coastal hazards have called for collaboration among communities to strengthen the application of best practices. However, communities currently lack practical tools for identifying potential partner communities based on similar hazard exposure characteristics. This study uses statistical cluster analysis to identify similarities in community exposure to flooding hazards for a suite of sea level rise and storm scenarios. We demonstrate this approach using 63 jurisdictions in the San Francisco Bay region of California (USA) and compare 21 distinct exposure variables related to residents, employees, and structures for six hazard scenario combinations of sea level rise and storms. Results indicate that cluster analysis can provide an effective mechanism for identifying community groupings. Cluster compositions changed based on the selected societal variables and sea level rise scenarios, suggesting that a community could participate in multiple networks to target specific issues or policy interventions. The proposed clustering approach can serve as a data-driven foundation to help communities identify other communities with similar adaptation challenges and to enhance regional efforts that aim to facilitate adaptation planning and investment prioritization.

Predictors of primary care referrals to a vascular disease prevention lifestyle program among participants in a cluster randomised trial.

PubMed

Passey, Megan E; Laws, Rachel A; Jayasinghe, Upali W; Fanaian, Mahnaz; McKenzie, Suzanne; Powell-Davies, Gawaine; Lyle, David; Harris, Mark F

2012-08-03

Cardiovascular disease accounts for a large burden of disease, but is amenable to prevention through lifestyle modification. This paper examines patient and practice predictors of referral to a lifestyle modification program (LMP) offered as part of a cluster randomised controlled trial (RCT) of prevention of vascular disease in primary care. Data from the intervention arm of a cluster RCT which recruited 36 practices through two rural and three urban primary care organisations were used. In each practice, 160 eligible high risk patients were invited to participate. Practices were randomly allocated to intervention or control groups. Intervention practice staff were trained in screening, motivational interviewing and counselling and encouraged to refer high risk patients to a LMP involving individual and group sessions. Data include patient surveys; clinical audit; practice survey on capacity for preventive care; referral records from the LMP. Predictors of referral were examined using multi-level logistic regression modelling after adjustment for confounding factors. Of 301 eligible patients, 190 (63.1%) were referred to the LMP. Independent predictors of referral were baseline BMI ≥ 25 (OR 2.87 95%CI:1.10, 7.47), physical inactivity (OR 2.90 95%CI:1.36,6.14), contemplation/preparation/action stage of change for physical activity (OR 2.75 95%CI:1.07, 7.03), rural location (OR 12.50 95%CI:1.43, 109.7) and smaller practice size (1-3 GPs) (OR 16.05 95%CI:2.74, 94.24). Providing a well-structured evidence-based lifestyle intervention, free of charge to patients, with coordination and support for referral processes resulted in over 60% of participating high risk patients being referred for disease prevention. Contrary to expectations, referrals were more frequent from rural and smaller practices suggesting that these practices may be more ready to engage with these programs. ACTRN12607000423415.

Network-based spatial clustering technique for exploring features in regional industry

NASA Astrophysics Data System (ADS)

Chou, Tien-Yin; Huang, Pi-Hui; Yang, Lung-Shih; Lin, Wen-Tzu

2008-10-01

In the past researches, industrial cluster mainly focused on single or particular industry and less on spatial industrial structure and mutual relations. Industrial cluster could generate three kinds of spillover effects, including knowledge, labor market pooling, and input sharing. In addition, industrial cluster indeed benefits industry development. To fully control the status and characteristics of district industrial cluster can facilitate to improve the competitive ascendancy of district industry. The related researches on industrial spatial cluster were of great significance for setting up industrial policies and promoting district economic development. In this study, an improved model, GeoSOM, that combines DBSCAN (Density-Based Spatial Clustering of Applications with Noise) and SOM (Self-Organizing Map) was developed for analyzing industrial cluster. Different from former distance-based algorithm for industrial cluster, the proposed GeoSOM model can calculate spatial characteristics between firms based on DBSCAN algorithm and evaluate the similarity between firms based on SOM clustering analysis. The demonstrative data sets, the manufacturers around Taichung County in Taiwan, were analyzed for verifying the practicability of the proposed model. The analyzed results indicate that GeoSOM is suitable for evaluating spatial industrial cluster.

Grid heterogeneity in in-silico experiments: an exploration of drug screening using DOCK on cloud environments.

PubMed

Yim, Wen-Wai; Chien, Shu; Kusumoto, Yasuyuki; Date, Susumu; Haga, Jason

2010-01-01

Large-scale in-silico screening is a necessary part of drug discovery and Grid computing is one answer to this demand. A disadvantage of using Grid computing is the heterogeneous computational environments characteristic of a Grid. In our study, we have found that for the molecular docking simulation program DOCK, different clusters within a Grid organization can yield inconsistent results. Because DOCK in-silico virtual screening (VS) is currently used to help select chemical compounds to test with in-vitro experiments, such differences have little effect on the validity of using virtual screening before subsequent steps in the drug discovery process. However, it is difficult to predict whether the accumulation of these discrepancies over sequentially repeated VS experiments will significantly alter the results if VS is used as the primary means for identifying potential drugs. Moreover, such discrepancies may be unacceptable for other applications requiring more stringent thresholds. This highlights the need for establishing a more complete solution to provide the best scientific accuracy when executing an application across Grids. One possible solution to platform heterogeneity in DOCK performance explored in our study involved the use of virtual machines as a layer of abstraction. This study investigated the feasibility and practicality of using virtual machine and recent cloud computing technologies in a biological research application. We examined the differences and variations of DOCK VS variables, across a Grid environment composed of different clusters, with and without virtualization. The uniform computer environment provided by virtual machines eliminated inconsistent DOCK VS results caused by heterogeneous clusters, however, the execution time for the DOCK VS increased. In our particular experiments, overhead costs were found to be an average of 41% and 2% in execution time for two different clusters, while the actual magnitudes of the execution time costs were minimal. Despite the increase in overhead, virtual clusters are an ideal solution for Grid heterogeneity. With greater development of virtual cluster technology in Grid environments, the problem of platform heterogeneity may be eliminated through virtualization, allowing greater usage of VS, and will benefit all Grid applications in general.

Targeted case finding for chronic obstructive pulmonary disease versus routine practice in primary care (TargetCOPD): a cluster-randomised controlled trial.

PubMed

Jordan, Rachel E; Adab, Peymané; Sitch, Alice; Enocson, Alexandra; Blissett, Deirdre; Jowett, Sue; Marsh, Jen; Riley, Richard D; Miller, Martin R; Cooper, Brendan G; Turner, Alice M; Jolly, Kate; Ayres, Jon G; Haroon, Shamil; Stockley, Robert; Greenfield, Sheila; Siebert, Stanley; Daley, Amanda J; Cheng, K K; Fitzmaurice, David

2016-09-01

Many individuals with chronic obstructive pulmonary disease (COPD) remain undiagnosed worldwide. Health-care organisations are implementing case-finding programmes without good evidence of which are the most effective and cost-effective approaches. We assessed the effectiveness and cost-effectiveness of two alternative approaches to targeted case finding for COPD compared with routine practice. In this cluster-randomised controlled trial, participating general practices in the West Midlands, UK, were randomly assigned (1:1), via a computer-generated block randomisation sequence, to either a targeted case-finding group or a routine care group. Eligible patients were ever-smokers aged 40-79 years without a previously recorded diagnosis of COPD. Patients in the targeted case-finding group were further randomly assigned (1:1) via their household to receive either a screening questionnaire at the general practitioner (GP) consultation (opportunistic) or a screening questionnaire at the GP consultation plus a mailed questionnaire (active). Respondents reporting relevant respiratory symptoms were invited for post-bronchodilator spirometry. Patients, clinicians, and investigators were not masked to allocation, but group allocation was concealed from the researchers who performed the spirometry assessments. Primary outcomes were the percentage of the eligible population diagnosed with COPD within 1 year (defined as post-bronchodilator forced expiratory volume in 1 s [FEV1] to forced vital capacity [FVC] ratio <0·7 in patients with symptoms or a new diagnosis on their GP record) and cost per new COPD diagnosis. Multiple logistic and Poisson regression were used to estimate effect sizes. Costs were obtained from the trial. This trial is registered with ISRCTN, number ISRCTN14930255. From Aug 10, 2012, to June 22, 2014, 74 818 eligible patients from 54 diverse general practices were randomly assigned and completed the trial. At 1 year, 1278 (4%) cases of COPD were newly detected in 32 789 eligible patients in the targeted case-finding group compared with 337 (1%) cases in 42 029 patients in the routine care group (adjusted odds ratio [OR] 7·45 [95% CI 4·80-11·55], p<0·0001). The percentage of newly detected COPD cases was higher in the active case-finding group (822 [5%] of 15 378) than in the opportunistic case-finding group (370 [2%] of 15 387; adjusted OR 2·34 [2·06-2·66], p<0·0001; adjusted risk difference 2·9 per 100 patients [95% CI 2·3-3·6], p<0·0001). Active case finding was more cost-effective than opportunistic case finding (£333 vs £376 per case detected, respectively). In this well established primary care system, routine practice identified few new cases of COPD. An active targeted approach to case finding including mailed screening questionnaires before spirometry is a cost-effective way to identify undiagnosed patients and has the potential to improve their health. National Institute for Health Research. Copyright © 2016 Elsevier Ltd. All rights reserved.