Validation of an image-based technique to assess the perceptual quality of clinical chest radiographs with an observer study

NASA Astrophysics Data System (ADS)

Lin, Yuan; Choudhury, Kingshuk R.; McAdams, H. Page; Foos, David H.; Samei, Ehsan

2014-03-01

We previously proposed a novel image-based quality assessment technique1 to assess the perceptual quality of clinical chest radiographs. In this paper, an observer study was designed and conducted to systematically validate this technique. Ten metrics were involved in the observer study, i.e., lung grey level, lung detail, lung noise, riblung contrast, rib sharpness, mediastinum detail, mediastinum noise, mediastinum alignment, subdiaphragm-lung contrast, and subdiaphragm area. For each metric, three tasks were successively presented to the observers. In each task, six ROI images were randomly presented in a row and observers were asked to rank the images only based on a designated quality and disregard the other qualities. A range slider on the top of the images was used for observers to indicate the acceptable range based on the corresponding perceptual attribute. Five boardcertificated radiologists from Duke participated in this observer study on a DICOM calibrated diagnostic display workstation and under low ambient lighting conditions. The observer data were analyzed in terms of the correlations between the observer ranking orders and the algorithmic ranking orders. Based on the collected acceptable ranges, quality consistency ranges were statistically derived. The observer study showed that, for each metric, the averaged ranking orders of the participated observers were strongly correlated with the algorithmic orders. For the lung grey level, the observer ranking orders completely accorded with the algorithmic ranking orders. The quality consistency ranges derived from this observer study were close to these derived from our previous study. The observer study indicates that the proposed image-based quality assessment technique provides a robust reflection of the perceptual image quality of the clinical chest radiographs. The derived quality consistency ranges can be used to automatically predict the acceptability of a clinical chest radiograph.

Exploring the Ethics of Observational Research: The Case of an HIV Study in Tanzania

PubMed Central

Norris, Alison; Jackson, Ashley; Khoshnood, Kaveh

2013-01-01

Background Observational studies have generally been viewed as incurring minimal risk to participants, resulting in fewer ethical obligations for investigators than intervention studies. In 2004, the lead author (AN) carried out an observational study measuring sexual behavior and the prevalence of HIV, syphilis, and herpes simplex virus type 2 (HSV-2), among Tanzanian agricultural plantation residents (results reported elsewhere). This article uses an ethical lens to consider the consequences of the observational study and explore what, if any, effects it had on participants and their community. Methods Using a case study approach, we critically examine three core principles of research ethics—respect for persons/autonomy; beneficence/nonmaleficence; and distributive justice—as manifested in the 2004 observational study. We base our findings on three sources: discussions with plantation residents following presentations of observational research findings; in-depth interviews with key informants; and researcher observations. Results The observational research team was found to have ensured confidentiality and noncoercive recruitment. Ironically, maintenance of confidentiality and voluntary participation led some participants to doubt study results. Receiving HIV test results was important for participants and contributed to changing community norms about HIV testing. Conclusions Observational studies may act like de facto intervention studies and thus incur obligations similar to those of intervention studies. We found that ensuring respect for persons may have compromised the principles of beneficence and distributive justice. While in theory these three ethical principles have equal moral force, in practice, researchers may have to prioritize one over the others. Careful community engagement is necessary to promote well-considered ethical decisions. PMID:24069546

Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration

PubMed Central

Vandenbroucke, Jan P; von Elm, Erik; Altman, Douglas G; Gøtzsche, Peter C; Mulrow, Cynthia D; Pocock, Stuart J; Poole, Charles; Schlesselman, James J; Egger, Matthias

2007-01-01

Much medical research is observational. The reporting of observational studies is often of insufficient quality. Poor reporting hampers the assessment of the strengths and weaknesses of a study and the generalisability of its results. Taking into account empirical evidence and theoretical considerations, a group of methodologists, researchers, and editors developed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations to improve the quality of reporting of observational studies. The STROBE Statement consists of a checklist of 22 items, which relate to the title, abstract, introduction, methods, results and discussion sections of articles. Eighteen items are common to cohort studies, case-control studies and cross-sectional studies and four are specific to each of the three study designs. The STROBE Statement provides guidance to authors about how to improve the reporting of observational studies and facilitates critical appraisal and interpretation of studies by reviewers, journal editors and readers. This explanatory and elaboration document is intended to enhance the use, understanding, and dissemination of the STROBE Statement. The meaning and rationale for each checklist item are presented. For each item, one or several published examples and, where possible, references to relevant empirical studies and methodological literature are provided. Examples of useful flow diagrams are also included. The STROBE Statement, this document, and the associated Web site (http://www.strobe-statement.org/) should be helpful resources to improve reporting of observational research. PMID:17941715

Bayesian data analysis in observational comparative effectiveness research: rationale and examples.

PubMed

Olson, William H; Crivera, Concetta; Ma, Yi-Wen; Panish, Jessica; Mao, Lian; Lynch, Scott M

2013-11-01

Many comparative effectiveness research and patient-centered outcomes research studies will need to be observational for one or both of two reasons: first, randomized trials are expensive and time-consuming; and second, only observational studies can answer some research questions. It is generally recognized that there is a need to increase the scientific validity and efficiency of observational studies. Bayesian methods for the design and analysis of observational studies are scientifically valid and offer many advantages over frequentist methods, including, importantly, the ability to conduct comparative effectiveness research/patient-centered outcomes research more efficiently. Bayesian data analysis is being introduced into outcomes studies that we are conducting. Our purpose here is to describe our view of some of the advantages of Bayesian methods for observational studies and to illustrate both realized and potential advantages by describing studies we are conducting in which various Bayesian methods have been or could be implemented.

Standards and guidelines for observational studies: quality is in the eye of the beholder.

PubMed

Morton, Sally C; Costlow, Monica R; Graff, Jennifer S; Dubois, Robert W

2016-03-01

Patient care decisions demand high-quality research. To assist those decisions, numerous observational studies are being performed. Are the standards and guidelines to assess observational studies consistent and actionable? What policy considerations should be considered to ensure decision makers can determine if an observational study is of high-quality and valid to inform treatment decisions? Based on a literature review and input from six experts, we compared and contrasted nine standards/guidelines using 23 methodological elements involved in observational studies (e.g., study protocol, data analysis, and so forth). Fourteen elements (61%) were addressed by at least seven standards/guidelines; 12 of these elements disagreed in the approach. Nine elements (39%) were addressed by six or fewer standards/guidelines. Ten elements (43%) were not actionable in at least one standard/guideline that addressed the element. The lack of observational study standard/guideline agreement may contribute to variation in study conduct; disparities in what is considered credible research; and ultimately, what evidence is adopted. A common set of agreed on standards/guidelines for conducting observational studies will benefit funders, researchers, journal editors, and decision makers. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Medication safety research by observational study design.

PubMed

Lao, Kim S J; Chui, Celine S L; Man, Kenneth K C; Lau, Wallis C Y; Chan, Esther W; Wong, Ian C K

2016-06-01

Observational studies have been recognised to be essential for investigating the safety profile of medications. Numerous observational studies have been conducted on the platform of large population databases, which provide adequate sample size and follow-up length to detect infrequent and/or delayed clinical outcomes. Cohort and case-control are well-accepted traditional methodologies for hypothesis testing, while within-individual study designs are developing and evolving, addressing previous known methodological limitations to reduce confounding and bias. Respective examples of observational studies of different study designs using medical databases are shown. Methodology characteristics, study assumptions, strengths and weaknesses of each method are discussed in this review.

Generalizability and decision studies to inform observational and experimental research in classroom settings.

PubMed

Bottema-Beutel, Kristen; Lloyd, Blair; Carter, Erik W; Asmus, Jennifer M

2014-11-01

Attaining reliable estimates of observational measures can be challenging in school and classroom settings, as behavior can be influenced by multiple contextual factors. Generalizability (G) studies can enable researchers to estimate the reliability of observational data, and decision (D) studies can inform how many observation sessions are necessary to achieve a criterion level of reliability. We conducted G and D studies using observational data from a randomized control trial focusing on social and academic participation of students with severe disabilities in inclusive secondary classrooms. Results highlight the importance of anchoring observational decisions to reliability estimates from existing or pilot data sets. We outline steps for conducting G and D studies and address options when reliability estimates are lower than desired.

Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): explanation and elaboration.

PubMed

Vandenbroucke, Jan P; von Elm, Erik; Altman, Douglas G; Gøtzsche, Peter C; Mulrow, Cynthia D; Pocock, Stuart J; Poole, Charles; Schlesselman, James J; Egger, Matthias

2014-12-01

Much medical research is observational. The reporting of observational studies is often of insufficient quality. Poor reporting hampers the assessment of the strengths and weaknesses of a study and the generalisability of its results. Taking into account empirical evidence and theoretical considerations, a group of methodologists, researchers, and editors developed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations to improve the quality of reporting of observational studies. The STROBE Statement consists of a checklist of 22 items, which relate to the title, abstract, introduction, methods, results and discussion sections of articles. Eighteen items are common to cohort studies, case-control studies and cross-sectional studies and four are specific to each of the three study designs. The STROBE Statement provides guidance to authors about how to improve the reporting of observational studies and facilitates critical appraisal and interpretation of studies by reviewers, journal editors and readers. This explanatory and elaboration document is intended to enhance the use, understanding, and dissemination of the STROBE Statement. The meaning and rationale for each checklist item are presented. For each item, one or several published examples and, where possible, references to relevant empirical studies and methodological literature are provided. Examples of useful flow diagrams are also included. The STROBE Statement, this document, and the associated Web site (http://www.strobe-statement.org/) should be helpful resources to improve reporting of observational research. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

[Mortality study of asbestos cement workers in Emilia-Romagna].

PubMed

Luberto, Ferdinando; Amendola, Plinio; Belli, Stefano; Bruno, Caterina; Candela, Silvia; Grignoli, Mario; Comba, Pietro

2004-01-01

The present study updates to 06/30/1998 the cohort mortality study of 3358 workers employed in 10 asbestos cement production plants in the Italian region Emilia-Romagna. The cohort includes 2712 males and 646 females. Overall mortality was significantly increased (SMR=131, IC95%:108-127). Excess mortality has been observed for all malignant neoplasms (SMR=131, IC95%: 115-149, 250 observed) and for respiratory diseases (SMR=153, IC: 105-216, 32 observed), 3 deaths due to asbestosis. Mortality for all respiratory tract neoplasms (SMR=179, IC: 148-215, 114 observed), pulmonary cancer (SMR=157, IC: 126-192, 90 observed) and pleural cancer (SMR=1922, IC: 1139-3038, 18 observed) are significantly increased. This study confirms the previous cohort study observation of increased mortality for all causes, all neoplasm and cancer affecting lungs and pleura.

Strengthening the reliability and credibility of observational epidemiology studies by creating an Observational Studies Register.

PubMed

Swaen, Gerard M H; Carmichael, Neil; Doe, John

2011-05-01

To evaluate the need for the creation of a system in which observational epidemiology studies are registered; an Observational Studies Register (OSR). The current scientific process for observational epidemiology studies is described. Next, a parallel is made with the clinical trials area, where the creation of clinical trial registers has greatly restored and improved their credibility and reliability. Next, the advantages and disadvantages of an OSR are compared. The advantages of an OSR outweigh its disadvantages. The creation of an OSR, similar to the existing Clinical Trials Registers, will improve the assessment of publication bias and will provide an opportunity to compare the original study protocol with the results reported in the publication. Reliability, credibility, and transparency of observational epidemiology studies are strengthened by the creation of an OSR. We propose a structured, collaborative, and coordinated approach for observational epidemiology studies that can provide solutions for existing weaknesses and will strengthen credibility and reliability, similar to the approach currently used in clinical trials, where Clinical Trials Registers have played a key role in strengthening their scientific value. Copyright © 2011 Elsevier Inc. All rights reserved.

Generalizability and Decision Studies to Inform Observational and Experimental Research in Classroom Settings

ERIC Educational Resources Information Center

Bottema-Beutel, Kristen; Lloyd, Blair; Carter, Erik W.; Asmus, Jennifer M.

2014-01-01

Attaining reliable estimates of observational measures can be challenging in school and classroom settings, as behavior can be influenced by multiple contextual factors. Generalizability (G) studies can enable researchers to estimate the reliability of observational data, and decision (D) studies can inform how many observation sessions are…

Challenges in translating endpoints from trials to observational cohort studies in oncology

PubMed Central

Ording, Anne Gulbech; Cronin-Fenton, Deirdre; Ehrenstein, Vera; Lash, Timothy L; Acquavella, John; Rørth, Mikael; Sørensen, Henrik Toft

2016-01-01

Clinical trials are considered the gold standard for examining drug efficacy and for approval of new drugs. Medical databases and population surveillance registries are valuable resources for post-approval observational research, which are increasingly used in studies of benefits and risk of new cancer drugs. Here, we address the challenges in translating endpoints from oncology trials to observational studies. Registry-based cohort studies can investigate real-world safety issues – including previously unrecognized concerns – by examining rare endpoints or multiple endpoints at once. In contrast to clinical trials, observational cohort studies typically do not exclude real-world patients from clinical practice, such as old and frail patients with comorbidity. The observational cohort study complements the clinical trial by examining the effectiveness of interventions applied in clinical practice and by providing evidence on long-term clinical outcomes, which are often not feasible to study in a clinical trial. Various endpoints can be included in clinical trials, such as hard endpoints, soft endpoints, surrogate endpoints, and patient-reported endpoints. Each endpoint has it strengths and limitations for use in research studies. Endpoints used in oncology trials are often not applicable in observational cohort studies which are limited by the setting of standard clinical practice and by non-standardized endpoint determination. Observational studies can be more helpful moving research forward if they restrict focus to appropriate and valid endpoints. PMID:27354827

Cultivating cohort studies for observational translational research.

PubMed

Ransohoff, David F

2013-04-01

"Discovery" research about molecular markers for diagnosis, prognosis, or prediction of response to therapy has frequently produced results that were not reproducible in subsequent studies. What are the reasons, and can observational cohorts be cultivated to provide strong and reliable answers to those questions? Experimental Selected examples are used to illustrate: (i) what features of research design provide strength and reliability in observational studies about markers of diagnosis, prognosis, and response to therapy? (ii) How can those design features be cultivated in existing observational cohorts, for example, within randomized controlled clinical trial (RCT), other existing observational research studies, or practice settings like health maintenance organization (HMOs)? Examples include a study of RNA expression profiles of tumor tissue to predict prognosis of breast cancer, a study of serum proteomics profiles to diagnose ovarian cancer, and a study of stool-based DNA assays to screen for colon cancer. Strengths and weaknesses of observational study design features are discussed, along with lessons about how features that help assure strength might be "cultivated" in the future. By considering these examples and others, it may be possible to develop a process of "cultivating cohorts" in ongoing RCTs, observational cohort studies, and practice settings like HMOs that have strong features of study design. Such an effort could produce sources of data and specimens to reliably answer questions about the use of molecular markers in diagnosis, prognosis, and response to therapy.

"Lies, damned lies ..." and observational studies in comparative effectiveness research.

PubMed

Albert, Richard K

2013-06-01

A new federal initiative has allocated $1.1 billion to comparative effectiveness research, and many have emphasized the importance of including observational studies in this effort. The rationale for using observational studies to assess comparative effectiveness is based on concerns that randomized controlled trials (RCTs) are not "real world" because they enroll homogeneous patient populations, measure study outcomes that are not important to patients, use protocols that are overly complex, are conducted in specialized centers, and use study treatments that are not consistent with usual care, and that RCTs are not always feasible because of a lack of equipoise, the need to assess delayed endpoints, and concerns that they take years to complete and are expensive. This essay questions the validity of each of these proposed limitations, summarizes concerns raised about the accuracy of results generated by observational studies, provides some examples of discrepancies between results of observational studies and RCTs that pertain to pulmonary and critical care, and suggests that using observational studies for comparative effectiveness research may increase rather than decrease the cost of health care and may harm patients.

Development of a quality assessment tool for systematic reviews of observational studies (QATSO) of HIV prevalence in men having sex with men and associated risk behaviours

PubMed Central

Wong, William CW; Cheung, Catherine SK; Hart, Graham J

2008-01-01

Background Systematic reviews based on the critical appraisal of observational and analytic studies on HIV prevalence and risk factors for HIV transmission among men having sex with men are very useful for health care decisions and planning. Such appraisal is particularly difficult, however, as the quality assessment tools available for use with observational and analytic studies are poorly established. Methods We reviewed the existing quality assessment tools for systematic reviews of observational studies and developed a concise quality assessment checklist to help standardise decisions regarding the quality of studies, with careful consideration of issues such as external and internal validity. Results A pilot version of the checklist was developed based on epidemiological principles, reviews of study designs, and existing checklists for the assessment of observational studies. The Quality Assessment Tool for Systematic Reviews of Observational Studies (QATSO) Score consists of five items: External validity (1 item), reporting (2 items), bias (1 item) and confounding factors (1 item). Expert opinions were sought and it was tested on manuscripts that fulfil the inclusion criteria of a systematic review. Like all assessment scales, QATSO may oversimplify and generalise information yet it is inclusive, simple and practical to use, and allows comparability between papers. Conclusion A specific tool that allows researchers to appraise and guide study quality of observational studies is developed and can be modified for similar studies in the future. PMID:19014686

Basic concepts and development of an all-purpose computer interface for ROC/FROC observer study.

PubMed

Shiraishi, Junji; Fukuoka, Daisuke; Hara, Takeshi; Abe, Hiroyuki

2013-01-01

In this study, we initially investigated various aspects of requirements for a computer interface employed in receiver operating characteristic (ROC) and free-response ROC (FROC) observer studies which involve digital images and ratings obtained by observers (radiologists). Secondly, by taking into account these aspects, an all-purpose computer interface utilized for these observer performance studies was developed. Basically, the observer studies can be classified into three paradigms, such as one rating for one case without an identification of a signal location, one rating for one case with an identification of a signal location, and multiple ratings for one case with identification of signal locations. For these paradigms, display modes on the computer interface can be used for single/multiple views of a static image, continuous viewing with cascade images (i.e., CT, MRI), and dynamic viewing of movies (i.e., DSA, ultrasound). Various functions on these display modes, which include windowing (contrast/level), magnifications, and annotations, are needed to be selected by an experimenter corresponding to the purpose of the research. In addition, the rules of judgment for distinguishing between true positives and false positives are an important factor for estimating diagnostic accuracy in an observer study. We developed a computer interface which runs on a Windows operating system by taking into account all aspects required for various observer studies. This computer interface requires experimenters to have sufficient knowledge about ROC/FROC observer studies, but allows its use for any purpose of the observer studies. This computer interface will be distributed publicly in the near future.

Cautionary tales in the interpretation of observational studies of effects of clinical interventions.

PubMed

Scott, I A; Attia, J

2017-02-01

Observational studies of the effectiveness of clinical interventions are proliferating as more 'real-world' clinical data (so called 'big data') are gathered from clinical registries, administrative datasets and electronic health records. While well-conducted randomised controlled trials (RCT) remain the scientific standard in assessing the efficacy of clinical interventions, well-designed observational studies may add to the evidence base of effectiveness in situations where RCT are of limited value or very difficult to perform. Rather than dismissing observational studies, we need to determine what circumstances may justify doing an observational study and when the study is sufficiently rigorous to be considered reasonably trustworthy. This article proposes criteria by which users of the literature might make such determinations. © 2016 Royal Australasian College of Physicians.

Use of benzodiazepine and risk of cancer: A meta-analysis of observational studies.

PubMed

Kim, Hong-Bae; Myung, Seung-Kwon; Park, Yon Chul; Park, Byoungjin

2017-02-01

Several observational epidemiological studies have reported inconsistent results on the association between the use of benzodiazepine and the risk of cancer. We investigated the association by using a meta-analysis. We searched PubMed, EMBASE, and the bibliographies of relevant articles to locate additional publications in January 2016. Three evaluators independently reviewed and selected eligible studies based on predetermined selection criteria. Of 796 articles meeting our initial criteria, a total of 22 observational epidemiological studies with 18 case-control studies and 4 cohort studies were included in the final analysis. Benzodiazepine use was significantly associated with an increased risk of cancer (odds ratio [OR] or relative risk [RR] 1.19; 95% confidence interval 1.16-1.21) in a random-effects meta-analysis of all studies. Subgroup meta-analyses by various factors such as study design, type of case-control study, study region, and methodological quality of study showed consistent findings. Also, a significant dose-response relationship was observed between the use of benzodiazepine and the risk of cancer (p for trend <0.01). The current meta-analysis of observational epidemiological studies suggests that benzodiazepine use is associated with an increased risk of cancer. © 2016 UICC.

Bias in Observational Studies of Prevalent Users: Lessons for Comparative Effectiveness Research From a Meta-Analysis of Statins

PubMed Central

Danaei, Goodarz; Tavakkoli, Mohammad; Hernán, Miguel A.

2012-01-01

Randomized clinical trials (RCTs) are usually the preferred strategy with which to generate evidence of comparative effectiveness, but conducting an RCT is not always feasible. Though observational studies and RCTs often provide comparable estimates, the questioning of observational analyses has recently intensified because of randomized-observational discrepancies regarding the effect of postmenopausal hormone replacement therapy on coronary heart disease. Reanalyses of observational data that excluded prevalent users of hormone replacement therapy led to attenuated discrepancies, which begs the question of whether exclusion of prevalent users should be generally recommended. In the current study, the authors evaluated the effect of excluding prevalent users of statins in a meta-analysis of observational studies of persons with cardiovascular disease. The pooled, multivariate-adjusted mortality hazard ratio for statin use was 0.77 (95% confidence interval (CI): 0.65, 0.91) in 4 studies that compared incident users with nonusers, 0.70 (95% CI: 0.64, 0.78) in 13 studies that compared a combination of prevalent and incident users with nonusers, and 0.54 (95% CI: 0.45, 0.66) in 13 studies that compared prevalent users with nonusers. The corresponding hazard ratio from 18 RCTs was 0.84 (95% CI: 0.77, 0.91). It appears that the greater the proportion of prevalent statin users in observational studies, the larger the discrepancy between observational and randomized estimates. PMID:22223710

Physiotherapists use a small number of behaviour change techniques when promoting physical activity: A systematic review comparing experimental and observational studies.

PubMed

Kunstler, Breanne E; Cook, Jill L; Freene, Nicole; Finch, Caroline F; Kemp, Joanne L; O'Halloran, Paul D; Gaida, James E

2018-06-01

Physiotherapists promote physical activity as part of their practice. This study reviewed the behaviour change techniques physiotherapists use when promoting physical activity in experimental and observational studies. Systematic review of experimental and observational studies. Twelve databases were searched using terms related to physiotherapy and physical activity. We included experimental studies evaluating the efficacy of physiotherapist-led physical activity interventions delivered to adults in clinic-based private practice and outpatient settings to individuals with, or at risk of, non-communicable diseases. Observational studies reporting the techniques physiotherapists use when promoting physical activity were also included. The behaviour change techniques used in all studies were identified using the Behaviour Change Technique Taxonomy. The behaviour change techniques appearing in efficacious and inefficacious experimental interventions were compared using a narrative approach. Twelve studies (nine experimental and three observational) were retained from the initial search yield of 4141. Risk of bias ranged from low to high. Physiotherapists used seven behaviour change techniques in the observational studies, compared to 30 behaviour change techniques in the experimental studies. Social support (unspecified) was the most frequently identified behaviour change technique across both settings. Efficacious experimental interventions used more behaviour change techniques (n=29) and functioned in more ways (n=6) than did inefficacious experimental interventions (behaviour change techniques=10 and functions=1). Physiotherapists use a small number of behaviour change techniques. Less behaviour change techniques were identified in observational studies compared to experimental studies, suggesting physiotherapists use less BCTs clinically than experimentally. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Real-world research and the role of observational data in the field of gynaecology - a practical review.

PubMed

Heikinheimo, Oskari; Bitzer, Johannes; García Rodríguez, Luis

2017-08-01

In the context of women's health, we examine (1) the role that observational ('real-world') studies have in overcoming limitations of randomised clinical trials, (2) the relative advantages and disadvantages of different study designs, (3) the importance of outcome data from observational studies when making health-economic or clinical decisions, and (4) provide insights into changing perceptions of observational clinical data. PubMed and internet searches were used to identify (i) guidance and expert commentary on designing, conducting, analysing, and reporting clinical trials or observational studies, (ii) supporting evidence of the rapid growth of observational ('real world') studies and publications since the turn of millennium in the fields of contraception, reproductive health, obstetrics or gynaecology. The rapidly growing use and validation of large, computerised medical records and related databases (e.g., health insurance or national registries) have played a major part in changing perceptions of observational data among researchers and clinicians. In the past 10 years, a distinct increase in the number of observational studies published tends to confirm their growing acceptance, appreciation and use. Observational studies can provide information that is impossible or infeasible to obtain otherwise (e.g., impractical, very expensive, or ethically unacceptable). Greater understanding, dissemination, uptake and use of observational data might be expected to drive ongoing evolution of research, data collection, analysis, and validation, in turn improving quality and therefore credibility, utility, and further application by clinicians.

Observational studies: a valuable source for data on the true value of RA therapies.

PubMed

van Vollenhoven, Ronald F; Severens, Johan L

2011-03-01

The validity of observational studies is sometimes questioned because of the limitations of non-randomly assigned controls, various biases such as channeling bias, confounding by indication, and other pitfalls. Yet, (post-marketing) observational data can provide important information regarding not only drug safety but also the effectiveness and appropriate use of agents in the real world, outside of clinical trials. Observational studies also provide data regarding the wider value of these agents in terms of, for example, reducing the need for surgical procedures, reducing absenteeism and increasing productivity. Importantly, data from some observational registry studies have subsequently been confirmed by clinical trials, supporting the overall validity of the registry-based approach. Observational studies also allow measures such as health assessment questionnaire scores, disease activity scores, and glucocorticoid use over time to be monitored for longer periods. Furthermore, observational data in real, less strictly selected patients without the constraints of formal study populations may produce findings not observed in clinical trials but that warrant further investigation in a controlled trial environment. For example, recent data from the Stockholm tumor necrosis factor follow-up registry in Sweden showed increases in the time people worked after initiation of biologics that, surprisingly, continued into the fourth and fifth years of treatment--a finding not observed with standardized outcomes. Observational studies are truly an underappreciated and valuable source of data on the real value of anti-rheumatic therapies, and these data are essential for making sound decisions regarding coverage and reimbursement.

Untapped Potential of Observational Research to Inform Clinical Decision Making: American Society of Clinical Oncology Research Statement.

PubMed

Visvanathan, Kala; Levit, Laura A; Raghavan, Derek; Hudis, Clifford A; Wong, Sandra; Dueck, Amylou; Lyman, Gary H

2017-06-01

ASCO believes that high-quality observational studies can advance evidence-based practice for cancer care and are complementary to randomized controlled trials (RCTs). Observational studies can generate hypotheses by evaluating novel exposures or biomarkers and by revealing patterns of care and relationships that might not otherwise be discovered. Researchers can then test these hypotheses in RCTs. Observational studies can also answer or inform questions that either have not been or cannot be answered by RCTs. In addition, observational studies can be used for postmarketing surveillance of new cancer treatments, particularly in vulnerable populations. The incorporation of observational research as part of clinical decision making is consistent with the position of many leading institutions. ASCO identified five overarching recommendations to enhance the role of observational research in clinical decision making: (1) improve the quality of electronic health data available for research, (2) improve interoperability and the exchange of electronic health information, (3) ensure the use of rigorous observational research methodologies, (4) promote transparent reporting of observational research studies, and (5) protect patient privacy.

Association between carbohydrate quality and inflammatory markers: systematic review of observational and interventional studies.

PubMed

Buyken, Anette E; Goletzke, Janina; Joslowski, Gesa; Felbick, Anna; Cheng, Guo; Herder, Christian; Brand-Miller, Jennie C

2014-04-01

Chronic low-grade inflammation is a likely intermediary between quality of carbohydrate and chronic disease risk. We conducted a systematic literature search to evaluate the relevance of carbohydrate quality on inflammatory markers in observational and intervention studies. MEDLINE, EMBASE, and the Cochrane Library were searched for studies on associations between glycemic index (GI), glycemic load (GL), dietary fiber or fiber supplements or whole grain intake, and high-sensitivity C-reactive protein (hsCRP) or interleukin 6 (IL-6). Included studies had to be conducted on adults (healthy, overweight, with type 2 diabetes or metabolic syndrome features, but without inflammatory disease) with ≥20 participants and a 3-wk duration. In total, 22 of the 60 studies that met our inclusion criteria examined GI/GL: 5 of 9 observational studies reported lower concentrations of hsCRP or IL-6 among persons with a lower dietary GI/GL; 3 of 13 intervention studies showed significant antiinflammatory effects of a low-GI/GL diet, and 4 further studies suggested beneficial effects (trends or effects in a subgroup). For fiber intake, 13 of 16 observational studies reported an inverse relation with hsCRP or IL-6, but only 1 of 11 intervention studies showed a significant antiinflammatory effect of fiber intake, and a further trial reported a beneficial trend. For whole-grain intake, 6 of 7 observational studies observed an inverse association with inflammatory markers, but only 1 of 7 intervention studies reported significant antiinflammatory effects, 1 further study was suggestive (in a subgroup) of such, and another study found an adverse effect (trend only). Evidence from intervention studies for antiinflammatory benefits is less consistent for higher-fiber or whole-grain diets than for low-GI/GL diets. Benefits of higher fiber and whole-grain intakes suggested by observational studies may reflect confounding.

Observational methods in comparative effectiveness research.

PubMed

Concato, John; Lawler, Elizabeth V; Lew, Robert A; Gaziano, J Michael; Aslan, Mihaela; Huang, Grant D

2010-12-01

Comparative effectiveness research (CER) may be defined informally as an assessment of available options for treating specific medical conditions in selected groups of patients. In this context, the most prominent features of CER are the various patient populations, medical ailments, and treatment options involved in any particular project. Yet, each research investigation also has a corresponding study design or "architecture," and in patient-oriented research a common distinction used to describe such designs are randomized controlled trials (RCTs) versus observational studies. The purposes of this overview, with regard to CER, are to (1) understand how observational studies can provide accurate results, comparable to RCTs; (2) recognize strategies used in selected newer methods for conducting observational studies; (3) review selected observational studies from the Veterans Health Administration; and (4) appreciate the importance of fundamental methodological principles when conducting or evaluating individual studies. Published by Elsevier Inc.

Comparative effectiveness research in cancer with observational data.

PubMed

Giordano, Sharon H

2015-01-01

Observational studies are increasingly being used for comparative effectiveness research. These studies can have the greatest impact when randomized trials are not feasible or when randomized studies have not included the population or outcomes of interest. However, careful attention must be paid to study design to minimize the likelihood of selection biases. Analytic techniques, such as multivariable regression modeling, propensity score analysis, and instrumental variable analysis, also can also be used to help address confounding. Oncology has many existing large and clinically rich observational databases that can be used for comparative effectiveness research. With careful study design, observational studies can produce valid results to assess the benefits and harms of a treatment or intervention in representative real-world populations.

Evaluation of observational research reports published in Turkish nursing journals.

PubMed

Karaçam, Z; Şen, E; Yildirim, B

2015-09-01

The aim of this literature-based descriptive study was to examine the reporting of the observational research studies published in peer-reviewed nursing journals in Turkey. Eleven peer-reviewed nursing journals printed on a regular basis in Turkey between 2007 and 2012 were selected. These journals were searched for observational research studies, and 502 studies were selected and examined by using the Strengthening the Reporting of Observational Studies in Epidemiology Statement. Of the 502 studies, 495 were cross-sectional, 3 were cohort, and 4 were case controlled. Summary and introduction and aim sections were sufficient in most of the studies. The methods sections of the reports were mostly not reported: 64.3% of the reports did not indicate eligibility/inclusion criteria; sampling method, 67.0%; possible sources of bias, 99.2%; ways to reach sample size, 92.6%. In the results section, the number of individuals participating in each stage of the studies (44.0%) and in other analyses made (39.2%) was not reported. In the discussion section, a main comment about research findings was partly made (97.4%), and limitations of the studies and possible sources of bias were not written in 99.0% of the studies. This study clearly revealed that the observational research studies published in nursing journals in Turkey did not fulfil the important criteria and needed to be improved. Information obtained from this study can contribute to improvement of the quality of reporting observational studies in nursing and thus using obtained findings in practice. © 2015 International Council of Nurses.

Applying a social network analysis (SNA) approach to understanding radiologists' performance in reading mammograms

NASA Astrophysics Data System (ADS)

Tavakoli Taba, Seyedamir; Hossain, Liaquat; Heard, Robert; Brennan, Patrick; Lee, Warwick; Lewis, Sarah

2017-03-01

Rationale and objectives: Observer performance has been widely studied through examining the characteristics of individuals. Applying a systems perspective, while understanding of the system's output, requires a study of the interactions between observers. This research explains a mixed methods approach to applying a social network analysis (SNA), together with a more traditional approach of examining personal/ individual characteristics in understanding observer performance in mammography. Materials and Methods: Using social networks theories and measures in order to understand observer performance, we designed a social networks survey instrument for collecting personal and network data about observers involved in mammography performance studies. We present the results of a study by our group where 31 Australian breast radiologists originally reviewed 60 mammographic cases (comprising of 20 abnormal and 40 normal cases) and then completed an online questionnaire about their social networks and personal characteristics. A jackknife free response operating characteristic (JAFROC) method was used to measure performance of radiologists. JAFROC was tested against various personal and network measures to verify the theoretical model. Results: The results from this study suggest a strong association between social networks and observer performance for Australian radiologists. Network factors accounted for 48% of variance in observer performance, in comparison to 15.5% for the personal characteristics for this study group. Conclusion: This study suggest a strong new direction for research into improving observer performance. Future studies in observer performance should consider social networks' influence as part of their research paradigm, with equal or greater vigour than traditional constructs of personal characteristics.

75 FR 3237 - Proposed Collection; Comment Request; Women's Health Initiative Observational Study

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-20

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Proposed Collection; Comment Request; Women's Health Initiative Observational Study SUMMARY: In compliance with the requirement of... Initiative (WHI) Observational Study. Type of Information Collection Request: Revision OMB 0925- 0414. Need...

The utility of observational studies in clinical decision making: lessons learned from statin trials.

PubMed

Foody, JoAnne M; Mendys, Phillip M; Liu, Larry Z; Simpson, Ross J

2010-05-01

Contemporary clinical decision making is well supported by a wide variety of information sources, including clinical practice guidelines, position papers, and insights from randomized controlled trials (RCTs). Much of our fundamental understanding of cardiovascular risk factors is based on multiple observations from major epidemiologic studies, such as The Seven Country Studies and the US-based Framingham Heart Study. These studies provided the framework for the development of clinical practice guidelines, including the National Cholesterol Education Program Adult Treatment Panel series. The objective of this article is to highlight the value of observational studies as a complement to clinical trial data for clinical decision making in real-world practice. Although RCTs are still the benchmark for assessing clinical efficacy and safety of a specific therapeutic approach, they may be of limited utility to practitioners who must then adapt the lessons learned from the trial into the patient care environment. The use of well-structured observational studies can improve our understanding of the translation of clinical trials into clinical practice, as demonstrated here with the example of statins. Although such studies have their own limitations, improved techniques for design and analysis have reduced the impact of bias and confounders. The introduction of the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines has provided more uniformity for such studies. When used together with RCTs, observational studies can enhance our understanding of effectiveness and utility in real-world clinical practice. In the examples of statin observational studies, the results suggest that relative effectiveness of different statins and potential impact of switching statins should be carefully considered in treating individual patients by practicing physicians.

Observer Use of Standardized Observation Protocols in Consequential Observation Systems

ERIC Educational Resources Information Center

Bell, Courtney A.; Yi, Qi; Jones, Nathan D.; Lewis, Jennifer M.; McLeod, Monica; Liu, Shuangshuang

2014-01-01

Evidence from a handful of large-scale studies suggests that although observers can be trained to score reliably using observation protocols, there are concerns related to initial training and calibration activities designed to keep observers scoring accurately over time (e.g., Bell, et al, 2012; BMGF, 2012). Studies offer little insight into how…

Active-comparator design and new-user design in observational studies

PubMed Central

Yoshida, Kazuki; Solomon, Daniel H.; Kim, Seoyoung C.

2015-01-01

SUMMARY Over the past decade, an increasing number of observational studies have examined the effectiveness or safety of rheumatoid arthritis treatments. However, unlike randomized controlled trials (RCTs), observational studies of drug effects face methodological challenges including confounding by indication. Two design principles - active comparator design and new user design can help mitigate such challenges in observational studies. To improve validity of study findings, observational studies should be designed in such a way that makes them more closely approximate RCTs. The active comparator design compares the drug of interest to another commonly used agent for the same indication, rather than a ‘non-user’ group. This principle helps select treatment groups similar in treatment indications (both measured and unmeasured characteristics). The new user design includes a cohort of patients from the time of treatment initiation, so that it can assess patients’ pretreatment characteristics and capture all events occurring anytime during follow-up. PMID:25800216

Assessment of Interobserver Reliability in Nutrition Studies that Use Direct Observation of School Meals

PubMed Central

BAGLIO, MICHELLE L.; BAXTER, SUZANNE DOMEL; GUINN, CAROLINE H.; THOMPSON, WILLIAM O.; SHAFFER, NICOLE M.; FRYE, FRANCESCA H. A.

2005-01-01

This article (a) provides a general review of interobserver reliability (IOR) and (b) describes our method for assessing IOR for items and amounts consumed during school meals for a series of studies regarding the accuracy of fourth-grade children's dietary recalls validated with direct observation of school meals. A widely used validation method for dietary assessment is direct observation of meals. Although many studies utilize several people to conduct direct observations, few published studies indicate whether IOR was assessed. Assessment of IOR is necessary to determine that the information collected does not depend on who conducted the observation. Two strengths of our method for assessing IOR are that IOR was assessed regularly throughout the data collection period and that IOR was assessed for foods at the item and amount level instead of at the nutrient level. Adequate agreement among observers is essential to the reasoning behind using observation as a validation tool. Readers are encouraged to question the results of studies that fail to mention and/or to include the results for assessment of IOR when multiple people have conducted observations. PMID:15354155

A concealed observational study of infection control and safe injection practices in Jordanian governmental hospitals.

PubMed

Al-Rawajfah, Omar M; Tubaishat, Ahmad

2017-10-01

The recognized international organizations on infection prevention recommend using an observational method as the gold standard procedure for assessing health care professional's compliance with standard infection control practices. However, observational studies are rarely used in Jordanian infection control studies. This study aimed to evaluate injection practices among nurses working in Jordanian governmental hospitals. A cross-sectional concealed observational design is used for this study. A convenience sampling technique was used to recruit a sample of nurses working in governmental hospitals in Jordan. Participants were unaware of the time and observer during the observation episode. A total of 384 nurses from 9 different hospitals participated in the study. A total of 835 injections events were observed, of which 73.9% were performed without handwashing, 64.5% without gloving, and 27.5% were followed by needle recapping. Handwashing rate was the lowest (18.9%) when injections were performed by beginner nurses. Subcutaneous injections were associated with the lowest rate (26.7%) of postinjection handwashing compared with other routes. This study demonstrates the need for focused and effective infection control educational programs in Jordanian hospitals. Future studies should consider exploring the whole infection control practices related to waste disposal and the roles of the infection control nurse in this process in Jordanian hospitals. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Assessing validity of observational intervention studies - the Benchmarking Controlled Trials.

PubMed

Malmivaara, Antti

2016-09-01

Benchmarking Controlled Trial (BCT) is a concept which covers all observational studies aiming to assess impact of interventions or health care system features to patients and populations. To create and pilot test a checklist for appraising methodological validity of a BCT. The checklist was created by extracting the most essential elements from the comprehensive set of criteria in the previous paper on BCTs. Also checklists and scientific papers on observational studies and respective systematic reviews were utilized. Ten BCTs published in the Lancet and in the New England Journal of Medicine were used to assess feasibility of the created checklist. The appraised studies seem to have several methodological limitations, some of which could be avoided in planning, conducting and reporting phases of the studies. The checklist can be used for planning, conducting, reporting, reviewing, and critical reading of observational intervention studies. However, the piloted checklist should be validated in further studies. Key messages Benchmarking Controlled Trial (BCT) is a concept which covers all observational studies aiming to assess impact of interventions or health care system features to patients and populations. This paper presents a checklist for appraising methodological validity of BCTs and pilot-tests the checklist with ten BCTs published in leading medical journals. The appraised studies seem to have several methodological limitations, some of which could be avoided in planning, conducting and reporting phases of the studies. The checklist can be used for planning, conducting, reporting, reviewing, and critical reading of observational intervention studies.

Observational studies and the difficult quest for causality: lessons from vaccine effectiveness and impact studies.

PubMed

Lipsitch, Marc; Jha, Ayan; Simonsen, Lone

2016-12-01

Although randomized placebo-controlled trials (RCT) are critical to establish efficacy of vaccines at the time of licensure, important remaining questions about vaccine effectiveness (VE)-used here to include individual-level measures and population-wide impact of vaccine programmes-can only be answered once the vaccine is in use, from observational studies. However, such studies are inherently at risk for bias. Using a causal framework and illustrating with examples, we review newer approaches to detecting and avoiding confounding and selection bias in three major classes of observational study design: cohort, case-control and ecological studies. Studies of influenza VE, especially in seniors, are an excellent demonstration of the challenges of detecting and reducing such bias, and so we use influenza VE as a running example. We take a fresh look at the time-trend studies often dismissed as 'ecological'. Such designs are the only observational study design that can measure the overall effect of a vaccination programme [indirect (herd) as well as direct effects], and are in fact already an important part of the evidence base for several vaccines currently in use. Despite the great strides towards more robust observational study designs, challenges lie ahead for evaluating best practices for achieving robust unbiased results from observational studies. This is critical for evaluation of national and global vaccine programme effectiveness. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

Issues of reporting in observational studies in veterinary medicine.

PubMed

Sargeant, Jan M; O'Connor, Annette M

2014-02-15

Observational studies are common in veterinary medicine; the results may be used to inform decision-making, future research, or as inputs to systematic reviews or risk assessment. To be of use, the results must be published, all of the outcomes that were assessed must be included in the publication, and the research (methods and results) must be reported in sufficient detail that the reader can evaluate the internal and external validity. In human healthcare, concerns about the completeness of reporting - and evidence that poor reporting is associated with study results - have led to the creation of reporting guidelines; these include the STROBE statement for observational studies. There is evidence from a limited body of research that there also are reporting inadequacies in veterinary observational studies. There are differences between human and veterinary observational studies that might be relevant to recommendations for reporting. Such differences include: the use of observational studies in animal populations for simultaneously estimating disease frequency and risk-factor identification; the distinction between the animal owners who consent to participate and the animals that are the study subjects; and the complexity of organizational levels inherent in animal research (in particular, for studies in livestock species). In veterinary medicine, it is common to have clustering within outcomes (due to animal grouping) and clustering of predictor variables. We argue that there is a compelling need for the scientific community involved in veterinary observational studies to use the STROBE statement, use an amended version of STROBE, or to develop and use reporting guidelines that are specific to veterinary medicine to improve reporting of these studies. Copyright © 2013 Elsevier B.V. All rights reserved.

Observational studies are complementary to randomized controlled trials.

PubMed

Grootendorst, Diana C; Jager, Kitty J; Zoccali, Carmine; Dekker, Friedo W

2010-01-01

Randomized controlled trials (RCTs) are considered the gold standard study design to investigate the effect of health interventions, including treatment. However, in some situations, it may be unnecessary, inappropriate, impossible, or inadequate to perform an RCT. In these special situations, well-designed observational studies, including cohort and case-control studies, may provide an alternative to doing nothing in order to obtain estimates of treatment effect. It should be noted that such studies should be performed with caution and correctly. The aims of this review are (1) to explain why RCTs are considered the optimal study design to evaluate treatment effects, (2) to describe the situations in which an RCT is not possible and observational studies are an adequate alternative, and (3) to explain when randomization is not needed and can be approximated in observational studies. Examples from the nephrology literature are used for illustration. Copyright 2009 S. Karger AG, Basel.

Ultraviolet Imaging Telescope (UIT) observations of galaxies

NASA Technical Reports Server (NTRS)

Neff, S. G.

1993-01-01

Ultraviolet images of several galaxies were obtained during the ASTRO-1 shuttle mission in December, 1990. The images have a FWHM angular resolution of approximately 3 arcsecond and are of circular fields approximately 40 arcminutes in diameter. Most galaxies were observed in at least two and sometimes as many as four broad bands. A very few fields were observed with narrower band filters. The most basic result of these observations is that most systems look dramatically different in the UV from their well-known optical appearances. Preliminary results of these studies will be presented. Information will be available on fields observed by the UTI during the ASTRO 1 mission; when that data becomes public it can be obtained from the NSSDC. The ASTRO observatory is expected to fly again in 1994 with approximately half of the observing time from that mission devoted to guest observers. The Ultraviolet Imaging telescope is extremely well suited for galaxy studies, and the UIT term is interested in encouraging a wide range of scientific studies by guest observers. Ultraviolet Imaging telescope is extremely well suited for galaxy studies, and the UIT team is interested in encouraging a wide range of scientific studies by guest observers.

Observational evidence and strength of evidence domains: case examples

PubMed Central

2014-01-01

Background Systematic reviews of healthcare interventions most often focus on randomized controlled trials (RCTs). However, certain circumstances warrant consideration of observational evidence, and such studies are increasingly being included as evidence in systematic reviews. Methods To illustrate the use of observational evidence, we present case examples of systematic reviews in which observational evidence was considered as well as case examples of individual observational studies, and how they demonstrate various strength of evidence domains in accordance with current Agency for Healthcare Research and Quality (AHRQ) Evidence-based Practice Center (EPC) methods guidance. Results In the presented examples, observational evidence is used when RCTs are infeasible or raise ethical concerns, lack generalizability, or provide insufficient data. Individual study case examples highlight how observational evidence may fulfill required strength of evidence domains, such as study limitations (reduced risk of selection, detection, performance, and attrition); directness; consistency; precision; and reporting bias (publication, selective outcome reporting, and selective analysis reporting), as well as additional domains of dose-response association, plausible confounding that would decrease the observed effect, and strength of association (magnitude of effect). Conclusions The cases highlighted in this paper demonstrate how observational studies may provide moderate to (rarely) high strength evidence in systematic reviews. PMID:24758494

Alcohol Intake and Risk of Thyroid Cancer: A Meta-Analysis of Observational Studies.

PubMed

Hong, Seung-Hee; Myung, Seung-Kwon; Kim, Hyeon Suk

2017-04-01

The purpose of this study was to assess whether alcohol intake is associated with the risk of thyroid cancer by a meta-analysis of observational studies. We searched PubMed and EMBASE in June of 2015 to locate eligible studies. We included observational studies such as cross-sectional studies, case-control studies, and cohort studies reporting odd ratios (ORs) or relative risk (RRs) with 95% confidence intervals (CIs). We included 33 observational studies with two cross-sectional studies, 20 case-controls studies, and 11 cohort studies, which involved a total of 7,725 thyroid cancer patients and 3,113,679 participants without thyroid cancer in the final analysis. In the fixed-effect model meta-analysis of all 33 studies, we found that alcohol intake was consistently associated with a decreased risk of thyroid cancer (OR or RR, 0.74; 95% CI, 0.67 to 0.83; I 2 =38.6%). In the subgroup meta-analysis by type of study, alcohol intake also decreased the risk of thyroid cancer in both case-control studies (OR, 0.77; 95% CI, 0.65 to 0.92; I 2 =29.5%; n=20) and cohort studies (RR, 0.70; 95% CI, 0.60 to 0.82; I 2 =0%; n=11). Moreover, subgroup meta-analyses by type of thyroid cancer, gender, amount of alcohol consumed, and methodological quality of study showed that alcohol intake was significantly associated with a decreased risk of thyroid cancer. The current meta-analysis of observational studies found that, unlike most of other types of cancer, alcohol intake decreased the risk of thyroid cancer.

Sample size considerations for paired experimental design with incomplete observations of continuous outcomes.

PubMed

Zhu, Hong; Xu, Xiaohan; Ahn, Chul

2017-01-01

Paired experimental design is widely used in clinical and health behavioral studies, where each study unit contributes a pair of observations. Investigators often encounter incomplete observations of paired outcomes in the data collected. Some study units contribute complete pairs of observations, while the others contribute either pre- or post-intervention observations. Statistical inference for paired experimental design with incomplete observations of continuous outcomes has been extensively studied in literature. However, sample size method for such study design is sparsely available. We derive a closed-form sample size formula based on the generalized estimating equation approach by treating the incomplete observations as missing data in a linear model. The proposed method properly accounts for the impact of mixed structure of observed data: a combination of paired and unpaired outcomes. The sample size formula is flexible to accommodate different missing patterns, magnitude of missingness, and correlation parameter values. We demonstrate that under complete observations, the proposed generalized estimating equation sample size estimate is the same as that based on the paired t-test. In the presence of missing data, the proposed method would lead to a more accurate sample size estimate comparing with the crude adjustment. Simulation studies are conducted to evaluate the finite-sample performance of the generalized estimating equation sample size formula. A real application example is presented for illustration.

Analysis of Spatial Autocorrelation for Optimal Observation Network in Korea

NASA Astrophysics Data System (ADS)

Park, S.; Lee, S.; Lee, E.; Park, S. K.

2016-12-01

Many studies for improving prediction of high-impact weather have been implemented, such as THORPEX (The Observing System Research and Predictability Experiment), FASTEX (Fronts and Atlantic Storm-Track Experiment), NORPEX (North Pacific Experiment), WSR/NOAA (Winter Storm Reconnaissance), and DOTSTAR (Dropwindsonde Observations for Typhoon Surveillance near the TAiwan Region). One of most important objectives in these studies is to find effects of observation on forecast, and to establish optimal observation network. However, there are lack of such studies on Korea, although Korean peninsula exhibits a highly complex terrain so it is difficult to predict its weather phenomena. Through building the future optimal observation network, it is necessary to increase utilization of numerical weather prediction and improve monitoring·tracking·prediction skills of high-impact weather in Korea. Therefore, we will perform preliminary study to understand the spatial scale for an expansion of observation system through Spatial Autocorrelation (SAC) analysis. In additions, we will develop a testbed system to design an optimal observation network. Analysis is conducted with Automatic Weather System (AWS) rainfall data, global upper air grid observation (i.e., temperature, pressure, humidity), Himawari satellite data (i.e., water vapor) during 2013-2015 of Korea. This study will provide a guideline to construct observation network for not only improving weather prediction skill but also cost-effectiveness.

[Registration of observational studies: it is time to comply with the Declaration of Helsinki requirement].

PubMed

Dal-Ré, Rafael; Delgado, Miguel; Bolumar, Francisco

2015-01-01

Publication bias is a serious deficiency in the current system of disseminating the results of human research studies. Clinical investigators know that, from an ethical standpoint, they should prospectively register clinical trials in a public registry before starting them. In addition, it is believed that this approach will help to reduce publication bias. However, most studies conducted in humans are observational rather than experimental. It is estimated that less than 2% out of 2 million concluded or ongoing observational studies have been registered. The 2013 revision of the Declaration of Helsinki requires registration of any type of research study involving humans or identifiable samples or data. It is proposed that funding agencies, such as the Fondo de Investigaciones Sanitarias, as well as private companies, require preregistration of observational studies before providing funding. It is also proposed that Research Ethics Committees which, following Spanish regulation, have been using the Declaration as the framework for assessing the ethics of clinical trials with medicines since 1990, should follow the same provisions for the assessment of health-related observational studies: therefore, they should require prospective registration of studies before granting their final approval. This would allow observational study investigators to be educated in complying with an ethical requirement recently introduced in the most important ethical code for research involving humans. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

The Association between Observed Parental Emotion Socialization and Adolescent Self-Medication

ERIC Educational Resources Information Center

Hersh, Matthew A.; Hussong, Andrea M.

2009-01-01

The current study examined the moderating influence of observed parental emotion socialization (PES) on self-medication in adolescents. Strengths of the study include the use of a newly developed observational coding system further extending the study of PES to adolescence, the use of an experience sampling method to assess the daily covariation…

Observational Learning among Older Adults Living in Nursing Homes

ERIC Educational Resources Information Center

Story, Colleen D.

2010-01-01

The purpose of this study was to evaluate learning by older adults living in nursing homes through observational learning based on Bandura's (1977) social learning theory. This quantitative study investigated if older adults could learn through observation. The nursing homes in the study were located in the midwestern United States. The…

The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: guidelines for reporting observational studies.

PubMed

von Elm, Erik; Altman, Douglas G; Egger, Matthias; Pocock, Stuart J; Gøtzsche, Peter C; Vandenbroucke, Jan P

2014-12-01

Much biomedical research is observational. The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Initiative developed recommendations on what should be included in an accurate and complete report of an observational study. We defined the scope of the recommendations to cover three main study designs: cohort, case-control, and cross-sectional studies. We convened a 2-day workshop in September 2004, with methodologists, researchers, and journal editors to draft a checklist of items. This list was subsequently revised during several meetings of the coordinating group and in e-mail discussions with the larger group of STROBE contributors, taking into account empirical evidence and methodological considerations. The workshop and the subsequent iterative process of consultation and revision resulted in a checklist of 22 items (the STROBE Statement) that relate to the title, abstract, introduction, methods, results, and discussion sections of articles. 18 items are common to all three study designs and four are specific for cohort, case-control, or cross-sectional studies. A detailed Explanation and Elaboration document is published separately and is freely available on the Web sites of PLoS Medicine, Annals of Internal Medicine, and Epidemiology. We hope that the STROBE Statement will contribute to improving the quality of reporting of observational studies. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Media coverage of medical journals: do the best articles make the news?

PubMed

Selvaraj, Senthil; Borkar, Durga S; Prasad, Vinay

2014-01-01

News coverage of medical research is followed closely by many Americans and affects the practice of medicine and influence of scientific research. Prior work has examined the quality of media coverage, but no investigation has characterized the choice of stories covered in a controlled manner. We examined whether the media systematically covers stories of weaker study design. We compared study characteristics of 75 clinically-oriented journal articles that received coverage in the top five newspapers by circulation against 75 clinically-oriented journal articles that appeared in the top five medical journals by impact factor over a similar timespan. Subgroup analysis was performed to determine whether differences between investigations from both sources varied by study type (randomized controlled trial [RCT] or observational study). Investigations receiving coverage from newspapers were less likely to be RCTs (17% vs. 35%, p = 0.016) and more likely to be observational studies (75% vs. 47%, p<0.001). No difference was observed in number of people studied (median: 1034 vs. 1901, p = 0.14) or length of follow-up (median: 1.80 vs. 1.00 years, p = 0.22). In subgroup analysis, observational studies from the media used smaller sample sizes (median: 1984 vs. 21136, p = 0.029) and were more likely to be cross-sectional (71% vs. 31%, p<0.001), while no differences were observed for RCTs. Newspapers were more likely to cover observational studies and less likely to cover RCTs than high impact journals. Additionally, when the media does cover observational studies, they select articles of inferior quality. Newspapers preferentially cover medical research with weaker methodology.

Methods to systematically review and meta-analyse observational studies: a systematic scoping review of recommendations.

PubMed

Mueller, Monika; D'Addario, Maddalena; Egger, Matthias; Cevallos, Myriam; Dekkers, Olaf; Mugglin, Catrina; Scott, Pippa

2018-05-21

Systematic reviews and meta-analyses of observational studies are frequently performed, but no widely accepted guidance is available at present. We performed a systematic scoping review of published methodological recommendations on how to systematically review and meta-analyse observational studies. We searched online databases and websites and contacted experts in the field to locate potentially eligible articles. We included articles that provided any type of recommendation on how to conduct systematic reviews and meta-analyses of observational studies. We extracted and summarised recommendations on pre-defined key items: protocol development, research question, search strategy, study eligibility, data extraction, dealing with different study designs, risk of bias assessment, publication bias, heterogeneity, statistical analysis. We summarised recommendations by key item, identifying areas of agreement and disagreement as well as areas where recommendations were missing or scarce. The searches identified 2461 articles of which 93 were eligible. Many recommendations for reviews and meta-analyses of observational studies were transferred from guidance developed for reviews and meta-analyses of RCTs. Although there was substantial agreement in some methodological areas there was also considerable disagreement on how evidence synthesis of observational studies should be conducted. Conflicting recommendations were seen on topics such as the inclusion of different study designs in systematic reviews and meta-analyses, the use of quality scales to assess the risk of bias, and the choice of model (e.g. fixed vs. random effects) for meta-analysis. There is a need for sound methodological guidance on how to conduct systematic reviews and meta-analyses of observational studies, which critically considers areas in which there are conflicting recommendations.

Methods and Processes of Developing the Strengthening the Reporting of Observational Studies in Epidemiology-Veterinary (STROBE-Vet) Statement.

PubMed

Sargeant, J M; O'Connor, A M; Dohoo, I R; Erb, H N; Cevallos, M; Egger, M; Ersbøll, A K; Martin, S W; Nielsen, L R; Pearl, D L; Pfeiffer, D U; Sanchez, J; Torrence, M E; Vigre, H; Waldner, C; Ward, M P

2016-12-01

Reporting of observational studies in veterinary research presents challenges that often are not addressed in published reporting guidelines. Our objective was to develop an extension of the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement that addresses unique reporting requirements for observational studies in veterinary medicine related to health, production, welfare, and food safety. We conducted a consensus meeting with 17 experts in Mississauga, Canada. Experts completed a premeeting survey about whether items in the STROBE statement should be modified or added to address unique issues related to observational studies in animal species with health, production, welfare, or food safety outcomes. During the meeting, each STROBE item was discussed to determine whether or not rewording was recommended, and whether additions were warranted. Anonymous voting was used to determine consensus. Six items required no modifications or additions. Modifications or additions were made to the STROBE items 1 (title and abstract), 3 (objectives), 5 (setting), 6 (participants), 7 (variables), 8 (data sources and measurement), 9 (bias), 10 (study size), 12 (statistical methods), 13 (participants), 14 (descriptive data), 15 (outcome data), 16 (main results), 17 (other analyses), 19 (limitations), and 22 (funding). The methods and processes used were similar to those used for other extensions of the STROBE statement. The use of this STROBE statement extension should improve reporting of observational studies in veterinary research by recognizing unique features of observational studies involving food-producing and companion animals, products of animal origin, aquaculture, and wildlife.

Prospective observational studies to assess comparative effectiveness: the ISPOR good research practices task force report.

PubMed

Berger, Marc L; Dreyer, Nancy; Anderson, Fred; Towse, Adrian; Sedrakyan, Art; Normand, Sharon-Lise

2012-01-01

In both the United States and Europe there has been an increased interest in using comparative effectiveness research of interventions to inform health policy decisions. Prospective observational studies will undoubtedly be conducted with increased frequency to assess the comparative effectiveness of different treatments, including as a tool for "coverage with evidence development," "risk-sharing contracting," or key element in a "learning health-care system." The principle alternatives for comparative effectiveness research include retrospective observational studies, prospective observational studies, randomized clinical trials, and naturalistic ("pragmatic") randomized clinical trials. This report details the recommendations of a Good Research Practice Task Force on Prospective Observational Studies for comparative effectiveness research. Key issues discussed include how to decide when to do a prospective observational study in light of its advantages and disadvantages with respect to alternatives, and the report summarizes the challenges and approaches to the appropriate design, analysis, and execution of prospective observational studies to make them most valuable and relevant to health-care decision makers. The task force emphasizes the need for precision and clarity in specifying the key policy questions to be addressed and that studies should be designed with a goal of drawing causal inferences whenever possible. If a study is being performed to support a policy decision, then it should be designed as hypothesis testing-this requires drafting a protocol as if subjects were to be randomized and that investigators clearly state the purpose or main hypotheses, define the treatment groups and outcomes, identify all measured and unmeasured confounders, and specify the primary analyses and required sample size. Separate from analytic and statistical approaches, study design choices may strengthen the ability to address potential biases and confounding in prospective observational studies. The use of inception cohorts, new user designs, multiple comparator groups, matching designs, and assessment of outcomes thought not to be impacted by the therapies being compared are several strategies that should be given strong consideration recognizing that there may be feasibility constraints. The reasoning behind all study design and analytic choices should be transparent and explained in study protocol. Execution of prospective observational studies is as important as their design and analysis in ensuring that results are valuable and relevant, especially capturing the target population of interest, having reasonably complete and nondifferential follow-up. Similar to the concept of the importance of declaring a prespecified hypothesis, we believe that the credibility of many prospective observational studies would be enhanced by their registration on appropriate publicly accessible sites (e.g., clinicaltrials.gov and encepp.eu) in advance of their execution. Copyright © 2012 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Assessing treatment effects in older breast cancer patients: systematic review of observational research methods.

PubMed

de Glas, N A; Kiderlen, M; de Craen, A J M; Hamaker, M E; Portielje, J E A; van de Velde, C J H; Liefers, G J; Bastiaannet, E

2015-03-01

Solid evidence of treatment effects in older women with breast cancer is lacking, as they are generally underrepresented in randomized clinical trials on which guideline recommendations are based. An alternative way to study treatment effects in older patients could be to use data from observational studies. However, using appropriate methods in analyzing observational data is a key condition in order to draw valid conclusions, as directly comparing treatments generally results in biased estimates due to confounding by indication. The aim of this systematic review was to investigate the methods that have been used in observational studies that assessed the effects of breast cancer treatment on survival, breast cancer survival and recurrence in older patients (aged 65 years and older). Studies were identified through systematic review of the literature published between January 1st 2009 and December 13th 2013 in the PubMed database and EMBASe. Finally, 31 studies fulfilled the inclusion criteria. Of these, 22 studies directly compared two treatments. Fifteen out of these 22 studies addressed the problem of confounding by indication, while seven studies did not. Nine studies used some form of instrumental variable analysis. In conclusion, the vast majority of observational studies that investigate treatment effects in older breast cancer patients compared treatments directly. These studies are therefore likely to be biased. Observational research will be essential to improve treatment and outcome of older breast cancer patients, but the use of accurate methods is essential to draw valid conclusions from this type of data. Copyright © 2015 Elsevier Ltd. All rights reserved.

Metformin and the Risk of Cancer

PubMed Central

Suissa, Samy; Azoulay, Laurent

2012-01-01

OBJECTIVE Time-related biases in observational studies of drug effects have been described extensively in different therapeutic areas but less so in diabetes. Immortal time bias, time-window bias, and time-lag bias all tend to greatly exaggerate the benefits observed with a drug. RESEARCH DESIGN AND METHODS These time-related biases are described and shown to be prominent in observational studies that have associated metformin with impressive reductions in the incidence of and mortality from cancer. As a consequence, metformin received much attention as a potential anticancer agent; these observational studies sparked the conduction of randomized, controlled trials of metformin as cancer treatment. However, the spectacular effects reported in these studies are compatible with time-related biases. RESULTS We found that 13 observational studies suffered from immortal time bias; 9 studies had not considered time-window bias, whereas other studies did not consider inherent time-lagging issues when comparing the first-line treatment metformin with second- or third-line treatments. These studies, subject to time-related biases that are avoidable with proper study design and data analysis, led to illusory extraordinarily significant effects, with reductions in cancer risk with metformin ranging from 20 to 94%. Three studies that avoided these biases reported no effect of metformin use on cancer incidence. CONCLUSIONS Although observational studies are important to better understand the effects of drugs, their proper design and analysis is essential to avoid major time-related biases. With respect to metformin, the scientific evidence of its potential beneficial effects on cancer would need to be reassessed critically before embarking on further long and expensive trials. PMID:23173135

Terminal illness and the increased mortality risk of conventional antipsychotics in observational studies: a systematic review.

PubMed

Luijendijk, Hendrika J; de Bruin, Niels C; Hulshof, Tessa A; Koolman, Xander

2016-02-01

Numerous large observational studies have shown an increased risk of mortality in elderly users of conventional antipsychotics. Health authorities have warned against use of these drugs. However, terminal illness is a potentially strong confounder of the observational findings. So, the objective of this study was to systematically assess whether terminal illness may have biased the observational association between conventional antipsychotics and risk of mortality in elderly patients. Studies were searched in PubMed, CINAHL, Embase, the references of selected studies and articles referring to selected studies (Web of Science). Inclusion criteria were (i) observational studies that estimated (ii) the risk of all-cause mortality in (iii) new elderly users of (iv) conventional antipsychotics compared with atypical antipsychotics or no use. Two investigators assessed the characteristics of the exposure and reference groups, main results, measured confounders and methods used to adjust for unmeasured confounders. We identified 21 studies. All studies were based on administrative medical and pharmaceutical databases. Sicker and older patients received conventional antipsychotics more often than new antipsychotics. The risk of dying was especially high in the first month of use, and when haloperidol was administered per injection or in high doses. Terminal illness was not measured in any study. Instrumental variables that were used were also confounded by terminal illness. We conclude that terminal illness has not been adjusted for in observational studies that reported an increased risk of mortality risk in elderly users of conventional antipsychotics. As the validity of the evidence is questionable, so is the warning based on it. Copyright © 2015 John Wiley & Sons, Ltd.

Assessing validity of observational intervention studies – the Benchmarking Controlled Trials

PubMed Central

Malmivaara, Antti

2016-01-01

Abstract Background: Benchmarking Controlled Trial (BCT) is a concept which covers all observational studies aiming to assess impact of interventions or health care system features to patients and populations. Aims: To create and pilot test a checklist for appraising methodological validity of a BCT. Methods: The checklist was created by extracting the most essential elements from the comprehensive set of criteria in the previous paper on BCTs. Also checklists and scientific papers on observational studies and respective systematic reviews were utilized. Ten BCTs published in the Lancet and in the New England Journal of Medicine were used to assess feasibility of the created checklist. Results: The appraised studies seem to have several methodological limitations, some of which could be avoided in planning, conducting and reporting phases of the studies. Conclusions: The checklist can be used for planning, conducting, reporting, reviewing, and critical reading of observational intervention studies. However, the piloted checklist should be validated in further studies.Key messagesBenchmarking Controlled Trial (BCT) is a concept which covers all observational studies aiming to assess impact of interventions or health care system features to patients and populations.This paper presents a checklist for appraising methodological validity of BCTs and pilot-tests the checklist with ten BCTs published in leading medical journals. The appraised studies seem to have several methodological limitations, some of which could be avoided in planning, conducting and reporting phases of the studies.The checklist can be used for planning, conducting, reporting, reviewing, and critical reading of observational intervention studies. PMID:27238631

Surface Layer Processes And Nocturnal Low Level Jet Development--An Observational Study During Pecan

DTIC Science & Technology

2016-12-01

PROCESSES AND NOCTURNAL LOW-LEVEL JET DEVELOPMENT—AN OBSERVATIONAL STUDY DURING PECAN by Michael K. Beall December 2016 Thesis Advisor... OBSERVATIONAL STUDY DURING PECAN 5. FUNDING NUMBERS 6. AUTHOR(S) Michael K. Beall 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate... research project and collected high-resolution stable boundary layer data as it evolved through the night. The objective of this study was to use this

Alcohol Intake and Risk of Thyroid Cancer: A Meta-Analysis of Observational Studies

PubMed Central

Hong, Seung-Hee; Myung, Seung-Kwon; Kim, Hyeon Suk

2017-01-01

Purpose The purpose of this study was to assess whether alcohol intake is associated with the risk of thyroid cancer by a meta-analysis of observational studies. Materials and Methods We searched PubMed and EMBASE in June of 2015 to locate eligible studies. We included observational studies such as cross-sectional studies, case-control studies, and cohort studies reporting odd ratios (ORs) or relative risk (RRs) with 95% confidence intervals (CIs). Results We included 33 observational studies with two cross-sectional studies, 20 case-controls studies, and 11 cohort studies, which involved a total of 7,725 thyroid cancer patients and 3,113,679 participants without thyroid cancer in the final analysis. In the fixed-effect model meta-analysis of all 33 studies, we found that alcohol intake was consistently associated with a decreased risk of thyroid cancer (OR or RR, 0.74; 95% CI, 0.67 to 0.83; I2=38.6%). In the subgroup meta-analysis by type of study, alcohol intake also decreased the risk of thyroid cancer in both case-control studies (OR, 0.77; 95% CI, 0.65 to 0.92; I2=29.5%; n=20) and cohort studies (RR, 0.70; 95% CI, 0.60 to 0.82; I2=0%; n=11). Moreover, subgroup meta-analyses by type of thyroid cancer, gender, amount of alcohol consumed, and methodological quality of study showed that alcohol intake was significantly associated with a decreased risk of thyroid cancer. Conclusion The current meta-analysis of observational studies found that, unlike most of other types of cancer, alcohol intake decreased the risk of thyroid cancer. PMID:27456949

Clinical Research Methodology 2: Observational Clinical Research.

PubMed

Sessler, Daniel I; Imrey, Peter B

2015-10-01

Case-control and cohort studies are invaluable research tools and provide the strongest feasible research designs for addressing some questions. Case-control studies usually involve retrospective data collection. Cohort studies can involve retrospective, ambidirectional, or prospective data collection. Observational studies are subject to errors attributable to selection bias, confounding, measurement bias, and reverse causation-in addition to errors of chance. Confounding can be statistically controlled to the extent that potential factors are known and accurately measured, but, in practice, bias and unknown confounders usually remain additional potential sources of error, often of unknown magnitude and clinical impact. Causality-the most clinically useful relation between exposure and outcome-can rarely be definitively determined from observational studies because intentional, controlled manipulations of exposures are not involved. In this article, we review several types of observational clinical research: case series, comparative case-control and cohort studies, and hybrid designs in which case-control analyses are performed on selected members of cohorts. We also discuss the analytic issues that arise when groups to be compared in an observational study, such as patients receiving different therapies, are not comparable in other respects.

In-Hospital Recruitment to Observational Studies of Stroke

ERIC Educational Resources Information Center

Pickering, Ruth M.; Kunkel, Dorit; Fitton, Carolyn; Ashburn, Ann; Jenkinson, Damian

2010-01-01

The objective of this study was to examine recruitment in three observational follow-up studies of patients with stroke, focusing on reasons for nonparticipation and the role of potential factors in explaining recruitment rates. It comprised secondary analysis of the three studies. Recruitment rates varied between the studies. Between 10 and 50%…

Regulatory considerations in the design of comparative observational studies using propensity scores.

PubMed

Yue, Lilly Q

2012-01-01

In the evaluation of medical products, including drugs, biological products, and medical devices, comparative observational studies could play an important role when properly conducted randomized, well-controlled clinical trials are infeasible due to ethical or practical reasons. However, various biases could be introduced at every stage and into every aspect of the observational study, and consequently the interpretation of the resulting statistical inference would be of concern. While there do exist statistical techniques for addressing some of the challenging issues, often based on propensity score methodology, these statistical tools probably have not been as widely employed in prospectively designing observational studies as they should be. There are also times when they are implemented in an unscientific manner, such as performing propensity score model selection for a dataset involving outcome data in the same dataset, so that the integrity of observational study design and the interpretability of outcome analysis results could be compromised. In this paper, regulatory considerations on prospective study design using propensity scores are shared and illustrated with hypothetical examples.

International Halley watch amateur observers' manual for scientific comet studies. Part 1: Methods

NASA Technical Reports Server (NTRS)

Edberg, S. J.

1983-01-01

The International Halley Watch is described as well as comets and observing techniques. Information on periodic Comet Halley's apparition for its 1986 perihelion passage is provided. Instructions are given for observation projects valuable to the International Halley Watch in six areas of study: (1) visual observations; (2) photography; (3) astrometry; (4) spectroscopic observations; (5) photoelectric photometry; and (6) meteor observations.

Visual-search models for location-known detection tasks

NASA Astrophysics Data System (ADS)

Gifford, H. C.; Karbaschi, Z.; Banerjee, K.; Das, M.

2017-03-01

Lesion-detection studies that analyze a fixed target position are generally considered predictive of studies involving lesion search, but the extent of the correlation often goes untested. The purpose of this work was to develop a visual-search (VS) model observer for location-known tasks that, coupled with previous work on localization tasks, would allow efficient same-observer assessments of how search and other task variations can alter study outcomes. The model observer featured adjustable parameters to control the search radius around the fixed lesion location and the minimum separation between suspicious locations. Comparisons were made against human observers, a channelized Hotelling observer and a nonprewhitening observer with eye filter in a two-alternative forced-choice study with simulated lumpy background images containing stationary anatomical and quantum noise. These images modeled single-pinhole nuclear medicine scans with different pinhole sizes. When the VS observer's search radius was optimized with training images, close agreement was obtained with human-observer results. Some performance differences between the humans could be explained by varying the model observer's separation parameter. The range of optimal pinhole sizes identified by the VS observer was in agreement with the range determined with the channelized Hotelling observer.

A Tale of Two Settings: The Lab and the Classroom

DTIC Science & Technology

1991-08-08

employed in this study were intensive and extensive classroom observation and repeated extended interviews with students and teachers. Classroom observers...instruction were observed during both years of the study, resulting in a very large data base gathered during almost 500 hours of classroom observation . With

Media Coverage of Medical Journals: Do the Best Articles Make the News?

PubMed Central

Selvaraj, Senthil; Borkar, Durga S.; Prasad, Vinay

2014-01-01

Background News coverage of medical research is followed closely by many Americans and affects the practice of medicine and influence of scientific research. Prior work has examined the quality of media coverage, but no investigation has characterized the choice of stories covered in a controlled manner. We examined whether the media systematically covers stories of weaker study design. Methods We compared study characteristics of 75 clinically-oriented journal articles that received coverage in the top five newspapers by circulation against 75 clinically-oriented journal articles that appeared in the top five medical journals by impact factor over a similar timespan. Subgroup analysis was performed to determine whether differences between investigations from both sources varied by study type (randomized controlled trial [RCT] or observational study). Results Investigations receiving coverage from newspapers were less likely to be RCTs (17% vs. 35%, p = 0.016) and more likely to be observational studies (75% vs. 47%, p<0.001). No difference was observed in number of people studied (median: 1034 vs. 1901, p = 0.14) or length of follow-up (median: 1.80 vs. 1.00 years, p = 0.22). In subgroup analysis, observational studies from the media used smaller sample sizes (median: 1984 vs. 21136, p = 0.029) and were more likely to be cross-sectional (71% vs. 31%, p<0.001), while no differences were observed for RCTs. Conclusions Newspapers were more likely to cover observational studies and less likely to cover RCTs than high impact journals. Additionally, when the media does cover observational studies, they select articles of inferior quality. Newspapers preferentially cover medical research with weaker methodology. PMID:24465543

Observational Study Designs for Comparative Effectiveness Research: An Alternative Approach to Close Evidence Gaps in Head-and-Neck Cancer

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

Goulart, Bernardo H.L., E-mail: bhg@uw.edu; University of Washington, Seattle, Washington; Ramsey, Scott D.

Comparative effectiveness research (CER) has emerged as an approach to improve quality of care and patient outcomes while reducing healthcare costs by providing evidence to guide healthcare decisions. Randomized controlled trials (RCTs) have represented the ideal study design to support treatment decisions in head-and-neck (H and N) cancers. In RCTs, formal chance (randomization) determines treatment allocation, which prevents selection bias from distorting the measure of treatment effects. Despite this advantage, only a minority of patients qualify for inclusion in H and N RCTs, which limits the validity of their results to the broader H and N cancer patient population seenmore » in clinical practice. Randomized controlled trials often do not address other knowledge gaps in the management of H and N cancer, including treatment comparisons for rare types of H and N cancers, monitoring of rare or late toxicity events (eg, osteoradionecrosis), or in some instances an RCT is simply not feasible. Observational studies, or studies in which treatment allocation occurs independently of investigators' choice or randomization, may address several of these gaps in knowledge, thereby complementing the role of RCTs. This critical review discusses how observational CER studies complement RCTs in generating the evidence to inform healthcare decisions and improve the quality of care and outcomes of H and N cancer patients. Review topics include a balanced discussion about the strengths and limitations of both RCT and observational CER study designs; a brief description of design and analytic techniques to handle selection bias in observational studies; examples of observational studies that inform current clinical practices and management of H and N cancers; and suggestions for relevant CER questions that could be addressed by an observational study design.« less

Observational study designs for comparative effectiveness research: an alternative approach to close evidence gaps in head-and-neck cancer.

PubMed

Goulart, Bernardo H L; Ramsey, Scott D; Parvathaneni, Upendra

2014-01-01

Comparative effectiveness research (CER) has emerged as an approach to improve quality of care and patient outcomes while reducing healthcare costs by providing evidence to guide healthcare decisions. Randomized controlled trials (RCTs) have represented the ideal study design to support treatment decisions in head-and-neck (H&N) cancers. In RCTs, formal chance (randomization) determines treatment allocation, which prevents selection bias from distorting the measure of treatment effects. Despite this advantage, only a minority of patients qualify for inclusion in H&N RCTs, which limits the validity of their results to the broader H&N cancer patient population seen in clinical practice. Randomized controlled trials often do not address other knowledge gaps in the management of H&N cancer, including treatment comparisons for rare types of H&N cancers, monitoring of rare or late toxicity events (eg, osteoradionecrosis), or in some instances an RCT is simply not feasible. Observational studies, or studies in which treatment allocation occurs independently of investigators' choice or randomization, may address several of these gaps in knowledge, thereby complementing the role of RCTs. This critical review discusses how observational CER studies complement RCTs in generating the evidence to inform healthcare decisions and improve the quality of care and outcomes of H&N cancer patients. Review topics include a balanced discussion about the strengths and limitations of both RCT and observational CER study designs; a brief description of design and analytic techniques to handle selection bias in observational studies; examples of observational studies that inform current clinical practices and management of H&N cancers; and suggestions for relevant CER questions that could be addressed by an observational study design. Copyright © 2014 Elsevier Inc. All rights reserved.

Fourth-grade children's dietary recall accuracy for energy intake at school meals differs by social desirability and body mass index percentile in a study concerning retention interval.

PubMed

Guinn, Caroline H; Baxter, Suzanne D; Royer, Julie A; Hardin, James W; Mackelprang, Alyssa J; Smith, Albert F

2010-05-01

Data from a study concerning retention interval and school-meal observation on children's dietary recalls were used to investigate relationships of social desirability score (SDS) and body mass index percentile (BMI%) to recall accuracy for energy for observed (n = 327) children, and to reported energy for observed and unobserved (n = 152) children. Report rates (reported/observed) correlated negatively with SDS and BMI%. Correspondence rates (correctly reported/observed) correlated negatively with SDS. Inflation ratios (overreported/observed) correlated negatively with BMI%. The relationship between reported energy and each of SDS and BMI% did not depend on observation status. Studies utilizing children's dietary recalls should assess SDS and BMI%.

Practices Middle School Principals in Large School Divisions Located within the Commonwealth of Virginia Employ during the Supervisory Process

ERIC Educational Resources Information Center

Hitchman, Ryan Patrick

2015-01-01

The purpose of this study was to examine the practices middle school principals employed during the supervisory process. The qualitative study focused on practices middle school principals followed during the pre-observation process, observation process, and post observation process. The study also detailed how the data collected from formal…

What Works Clearinghouse Quick Review: "Gathering Feedback for Teachers: Combining High-Quality Observations with Student Surveys and Achievement Gains"

ERIC Educational Resources Information Center

What Works Clearinghouse, 2012

2012-01-01

This study examined five instruments used to assess the effectiveness of teacher practices based on classroom observations. The study first examined whether observers could reliably assess teachers with each instrument, and then examined how well each instrument, along with other information, predicted student achievement. The study reported that,…

Development of Creative Behavior Observation Form: A Study on Validity and Reliability

ERIC Educational Resources Information Center

Dere, Zeynep; Ömeroglu, Esra

2018-01-01

This study, Creative Behavior Observation Form was developed to assess creativity of the children. While the study group on the reliability and validity of Creative Behavior Observation Form was being developed, 257 children in total who were at the ages of 5-6 were used as samples with stratified sampling method. Content Validity Index (CVI) and…

Reporting quality of statistical methods in surgical observational studies: protocol for systematic review.

PubMed

Wu, Robert; Glen, Peter; Ramsay, Tim; Martel, Guillaume

2014-06-28

Observational studies dominate the surgical literature. Statistical adjustment is an important strategy to account for confounders in observational studies. Research has shown that published articles are often poor in statistical quality, which may jeopardize their conclusions. The Statistical Analyses and Methods in the Published Literature (SAMPL) guidelines have been published to help establish standards for statistical reporting.This study will seek to determine whether the quality of statistical adjustment and the reporting of these methods are adequate in surgical observational studies. We hypothesize that incomplete reporting will be found in all surgical observational studies, and that the quality and reporting of these methods will be of lower quality in surgical journals when compared with medical journals. Finally, this work will seek to identify predictors of high-quality reporting. This work will examine the top five general surgical and medical journals, based on a 5-year impact factor (2007-2012). All observational studies investigating an intervention related to an essential component area of general surgery (defined by the American Board of Surgery), with an exposure, outcome, and comparator, will be included in this systematic review. Essential elements related to statistical reporting and quality were extracted from the SAMPL guidelines and include domains such as intent of analysis, primary analysis, multiple comparisons, numbers and descriptive statistics, association and correlation analyses, linear regression, logistic regression, Cox proportional hazard analysis, analysis of variance, survival analysis, propensity analysis, and independent and correlated analyses. Each article will be scored as a proportion based on fulfilling criteria in relevant analyses used in the study. A logistic regression model will be built to identify variables associated with high-quality reporting. A comparison will be made between the scores of surgical observational studies published in medical versus surgical journals. Secondary outcomes will pertain to individual domains of analysis. Sensitivity analyses will be conducted. This study will explore the reporting and quality of statistical analyses in surgical observational studies published in the most referenced surgical and medical journals in 2013 and examine whether variables (including the type of journal) can predict high-quality reporting.

How Many Classroom Observations Are Sufficient? Empirical Findings in the Context of a Longitudinal Study

ERIC Educational Resources Information Center

Shih, Jeffrey C.; Ing, Marsha; Tarr, James E.

2013-01-01

One method to investigate classroom quality is for a person to observe what is happening in the classroom. However, this method raises practical and technical concerns such as how many observations to collect, when to collect these observations and who should collect these observations. The purpose of this study is to provide empirical evidence to…

Reporting of methodological features in observational studies of pre-harvest food safety.

PubMed

Sargeant, Jan M; O'Connor, Annette M; Renter, David G; Kelton, David F; Snedeker, Kate; Wisener, Lee V; Leonard, Erin K; Guthrie, Alessia D; Faires, Meredith

2011-02-01

Observational studies in pre-harvest food safety may be useful for identifying risk factors and for evaluating potential mitigation strategies to reduce foodborne pathogens. However, there are no structured reporting guidelines for these types of study designs in livestock species. Our objective was to evaluate the reporting of observational studies in the pre-harvest food safety literature using guidelines modified from the human healthcare literature. We identified 100 pre-harvest food safety studies published between 1999 and 2009. Each study was evaluated independently by two reviewers using a structured checklist. Of the 38 studies that explicitly stated the observational study design, 27 were described as cross-sectional studies, eight as case-control studies, and three as cohort studies. Study features reported in over 75% of the selected studies included: description of the geographic location of the studies, definitions and sources of data for outcomes, organizational level and source of data for independent variables, description of statistical methods and results, number of herds enrolled in the study and included in the analysis, and sources of study funding. However, other features were not consistently reported, including details related to eligibility criteria for groups (such as barn, room, or pen) and individuals, numbers of groups and individuals included in various stages of the study, identification of primary outcomes, the distinction between putative risk factors and confounding variables, the identification of a primary exposure variable, the referent level for evaluation of categorical variable associations, methods of controlling confounding variables and missing variables, model fit, details of subset analysis, demographic information at the sampling unit level, and generalizability of the study results. Improvement in reporting of observational studies of pre-harvest food safety will aid research readers and reviewers in interpreting and evaluating the results of such studies. Copyright © 2010 Elsevier B.V. All rights reserved.

Serum uric acid levels and multiple health outcomes: umbrella review of evidence from observational studies, randomised controlled trials, and Mendelian randomisation studies.

PubMed

Li, Xue; Meng, Xiangrui; Timofeeva, Maria; Tzoulaki, Ioanna; Tsilidis, Konstantinos K; Ioannidis, John PA; Campbell, Harry; Theodoratou, Evropi

2017-06-07

Objective  To map the diverse health outcomes associated with serum uric acid (SUA) levels. Design  Umbrella review. Data sources  Medline, Embase, Cochrane Database of Systematic Reviews, and screening of citations and references. Eligibility criteria  Systematic reviews and meta-analyses of observational studies that examined associations between SUA level and health outcomes, meta-analyses of randomised controlled trials that investigated health outcomes related to SUA lowering treatment, and Mendelian randomisation studies that explored the causal associations of SUA level with health outcomes. Results  57 articles reporting 15 systematic reviews and144 meta-analyses of observational studies (76 unique outcomes), 8 articles reporting 31 meta-analyses of randomised controlled trials (20 unique outcomes), and 36 articles reporting 107 Mendelian randomisation studies (56 unique outcomes) met the eligibility criteria. Across all three study types, 136 unique health outcomes were reported. 16 unique outcomes in meta-analyses of observational studies had P<10 -6 , 8 unique outcomes in meta-analyses of randomised controlled trials had P<0.001, and 4 unique outcomes in Mendelian randomisation studies had P<0.01. Large between study heterogeneity was common (80% and 45% in meta-analyses of observational studies and of randomised controlled trials, respectively). 42 (55%) meta-analyses of observational studies and 7 (35%) meta-analyses of randomised controlled trials showed evidence of small study effects or excess significance bias. No associations from meta-analyses of observational studies were classified as convincing; five associations were classified as highly suggestive (increased risk of heart failure, hypertension, impaired fasting glucose or diabetes, chronic kidney disease, coronary heart disease mortality with high SUA levels). Only one outcome from randomised controlled trials (decreased risk of nephrolithiasis recurrence with SUA lowering treatment) had P<0.001, a 95% prediction interval excluding the null, and no large heterogeneity or bias. Only one outcome from Mendelian randomisation studies (increased risk of gout with high SUA levels) presented convincing evidence. Hypertension and chronic kidney disease showed concordant evidence in meta-analyses of observational studies, and in some (but not all) meta-analyses of randomised controlled trials with respective intermediate or surrogate outcomes, but they were not statistically significant in Mendelian randomisation studies. Conclusion  Despite a few hundred systematic reviews, meta-analyses, and Mendelian randomisation studies exploring 136 unique health outcomes, convincing evidence of a clear role of SUA level only exists for gout and nephrolithiasis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

The epistemological function of Hill's criteria.

PubMed

Bird, Alexander

2011-10-01

This article outlines an epistemological framework for understanding how Hill's criteria may aid us in establishing a causal hypothesis (A causes B) in an observational study. We consider Hill's criteria in turn with respect to their ability or otherwise to exclude alternative hypotheses (B causes A; there is a common cause of A and B; there is no causal connection between A and B). We may classify Hill's criteria according to which of the alternative hypotheses they are able to exclude, and also on the basis of whether they relate to (a) evidence from within observational study or (b) evidence independent of that study. It is noted that no criterion is able to exclude the common cause hypothesis in a systematic way. Observational studies are typically weaker than experimental studies, since the latter can systematically exclude competing hypotheses, whereas observational studies lack a systematic way of ruling out the common cause hypothesis. Copyright © 2011 Elsevier Inc. All rights reserved.

Washington's "free" 300-station microscale weather network

Treesearch

Thomas Blackburn

1977-01-01

This article is intended to encourage those planning to conduct meso- or microscale weather studies to supplement their sophisticated observing techniques and equipment- with low-cost observations taken by volunteers. Such observations can often show high benefits per unit costs in expanding the geographical area of study, increasing the density of observations, or in...

Quantum Observables and Effect Algebras

NASA Astrophysics Data System (ADS)

Dvurečenskij, Anatolij

2018-03-01

We study observables on monotone σ-complete effect algebras. We find conditions when a spectral resolution implies existence of the corresponding observable. We characterize sharp observables of a monotone σ-complete homogeneous effect algebra using its orthoalgebraic skeleton. In addition, we study compatibility in orthoalgebras and we show that every orthoalgebra satisfying RIP is an orthomodular poset.

The Classroom Observations of Vietnamese Teachers: Mediating Underlying Values to Understand Student Learning

ERIC Educational Resources Information Center

Tsukui, Atsushi; Saito, Eisuke; Sato, Masaaki; Michiyama, Megumi; Murase, Masatsugu

2017-01-01

This study uses the grounded theory approach (GTA) to investigate the value and characteristics of teacher observations, when used to understand student learning. Earlier studies have analysed the act of observation, defining it as a combination of joint observation and interpretation activities. By contrast, this analysis of 28 primary school…

Elementary School English Teachers' Professional Learning from Teaching Demonstrations as Professional Development

ERIC Educational Resources Information Center

Chien, Chin-Wen

2017-01-01

This study used interviews, observations and documentary evidence to analyze the professional learning of sixteen elementary school English teachers and two expert teachers during the pre-observation conference, observation, and post-observation conference from three-step teaching demonstrations. This study has the following major findings. First,…

Evaluation of Multiclass Model Observers in PET LROC Studies

NASA Astrophysics Data System (ADS)

Gifford, H. C.; Kinahan, P. E.; Lartizien, C.; King, M. A.

2007-02-01

A localization ROC (LROC) study was conducted to evaluate nonprewhitening matched-filter (NPW) and channelized NPW (CNPW) versions of a multiclass model observer as predictors of human tumor-detection performance with PET images. Target localization is explicitly performed by these model observers. Tumors were placed in the liver, lungs, and background soft tissue of a mathematical phantom, and the data simulation modeled a full-3D acquisition mode. Reconstructions were performed with the FORE+AWOSEM algorithm. The LROC study measured observer performance with 2D images consisting of either coronal, sagittal, or transverse views of the same set of cases. Versions of the CNPW observer based on two previously published difference-of-Gaussian channel models demonstrated good quantitative agreement with human observers. One interpretation of these results treats the CNPW observer as a channelized Hotelling observer with implicit internal noise

Osteoporosis therapies: evidence from health-care databases and observational population studies.

PubMed

Silverman, Stuart L

2010-11-01

Osteoporosis is a well-recognized disease with severe consequences if left untreated. Randomized controlled trials are the most rigorous method for determining the efficacy and safety of therapies. Nevertheless, randomized controlled trials underrepresent the real-world patient population and are costly in both time and money. Modern technology has enabled researchers to use information gathered from large health-care or medical-claims databases to assess the practical utilization of available therapies in appropriate patients. Observational database studies lack randomization but, if carefully designed and successfully completed, can provide valuable information that complements results obtained from randomized controlled trials and extends our knowledge to real-world clinical patients. Randomized controlled trials comparing fracture outcomes among osteoporosis therapies are difficult to perform. In this regard, large observational database studies could be useful in identifying clinically important differences among therapeutic options. Database studies can also provide important information with regard to osteoporosis prevalence, health economics, and compliance and persistence with treatment. This article describes the strengths and limitations of both randomized controlled trials and observational database studies, discusses considerations for observational study design, and reviews a wealth of information generated by database studies in the field of osteoporosis.

Meta-analyses including data from observational studies.

PubMed

O'Connor, Annette M; Sargeant, Jan M

2014-02-15

Observational studies represent a wide group of studies where the disease or condition of interest is naturally occurring and the investigator does not control allocation to interventions or exposures. Observational studies are used to test hypotheses about the efficacy of interventions or about exposure-disease relationships, to estimate incidence or prevalence of conditions, and to assess the sensitivity and specificity of diagnostic assays. Experimental-study designs and randomized controlled trials (RCTs) can also contribute to the body of evidence about such questions. Meta-analyses (either with or without systematic reviews) aim to combine information from primary research studies to better describe the entire body of work. The aim of meta-analyses may be to obtain a summary effect size, or to understand factors that affect effect sizes. In this paper, we discuss the role of observational studies in meta-analysis questions and some factors to consider when deciding whether a meta-analysis should include results from such studies. Our suggestion is that one should only include studies that are not at high risk of inherent bias when calculating a summary effect size. Study design however can be a meaningful variable in assessment of outcome heterogeneity. Copyright © 2013 Elsevier B.V. All rights reserved.

An Observational Measure of Children's Behavioural Style: Evidence Supporting a Multi-Method Approach to Studying Temperament

ERIC Educational Resources Information Center

Karp, Jennifer; Serbin, Lisa A.; Stack, Dale M.; Schwartzman, Alex E.

2004-01-01

This study demonstrates the potential utility of the Behavioural Style Observational System (BSOS) as a new observational measure of children's behavioural style. The BSOS is an objective, short and easy to use measure that can be readily adapted to a variety of home and laboratory situations. In the present study, 160 mother-child dyads from the…

Resuscitative Hyperkalemia in Noncrush Trauma: A Prospective, Observational Study

DTIC Science & Technology

2006-12-01

Resuscitative Hyperkalemia in Noncrush Trauma: A Prospective, Observational Study Robert M. Perkins,*† Matthew C. Aboudara,* Kevin C. Abbott,*† and...Surgical Research, San Antonio, Texas The trauma patient is exposed to physiologic processes and life-saving interventions that predispose to hyperkalemia ...in the care of the massively traumatized patient may or may not increase the risk for hyperkalemia . This prospective, observational study was

User-friendly tools on handheld devices for observer performance study

NASA Astrophysics Data System (ADS)

Matsumoto, Takuya; Hara, Takeshi; Shiraishi, Junji; Fukuoka, Daisuke; Abe, Hiroyuki; Matsusako, Masaki; Yamada, Akira; Zhou, Xiangrong; Fujita, Hiroshi

2012-02-01

ROC studies require complex procedures to select cases from many data samples, and to set confidence levels in each selected case to generate ROC curves. In some observer performance studies, researchers have to develop software with specific graphical user interface (GUI) to obtain confidence levels from readers. Because ROC studies could be designed for various clinical situations, it is difficult task for preparing software corresponding to every ROC studies. In this work, we have developed software for recording confidence levels during observer studies on tiny personal handheld devices such as iPhone, iPod touch, and iPad. To confirm the functions of our software, three radiologists performed observer studies to detect lung nodules by using public database of chest radiograms published by Japan Society of Radiological Technology. The output in text format conformed to the format for the famous ROC kit from the University of Chicago. Times required for the reading each case was recorded very precisely.

Prosocial Conformity: Prosocial Norms Generalize Across Behavior and Empathy.

PubMed

Nook, Erik C; Ong, Desmond C; Morelli, Sylvia A; Mitchell, Jason P; Zaki, Jamil

2016-08-01

Generosity is contagious: People imitate others' prosocial behaviors. However, research on such prosocial conformity focuses on cases in which people merely reproduce others' positive actions. Hence, we know little about the breadth of prosocial conformity. Can prosocial conformity cross behavior types or even jump from behavior to affect? Five studies address these questions. In Studies 1 to 3, participants decided how much to donate to charities before learning that others donated generously or stingily. Participants who observed generous donations donated more than those who observed stingy donations (Studies 1 and 2). Crucially, this generalized across behaviors: Participants who observed generous donations later wrote more supportive notes to another participant (Study 3). In Studies 4 and 5, participants observed empathic or non-empathic group responses to vignettes. Group empathy ratings not only shifted participants' own empathic feelings (Study 4), but they also influenced participants' donations to a homeless shelter (Study 5). These findings reveal the remarkable breadth of prosocial conformity. © 2016 by the Society for Personality and Social Psychology, Inc.

Integrating data from randomized controlled trials and observational studies to predict the response to pregabalin in patients with painful diabetic peripheral neuropathy.

PubMed

Alexander, Joe; Edwards, Roger A; Savoldelli, Alberto; Manca, Luigi; Grugni, Roberto; Emir, Birol; Whalen, Ed; Watt, Stephen; Brodsky, Marina; Parsons, Bruce

2017-07-20

More patient-specific medical care is expected as more is learned about variations in patient responses to medical treatments. Analytical tools enable insights by linking treatment responses from different types of studies, such as randomized controlled trials (RCTs) and observational studies. Given the importance of evidence from both types of studies, our goal was to integrate these types of data into a single predictive platform to help predict response to pregabalin in individual patients with painful diabetic peripheral neuropathy (pDPN). We utilized three pivotal RCTs of pregabalin (398 North American patients) and the largest observational study of pregabalin (3159 German patients). We implemented a hierarchical cluster analysis to identify patient clusters in the Observational Study to which RCT patients could be matched using the coarsened exact matching (CEM) technique, thereby creating a matched dataset. We then developed autoregressive moving average models (ARMAXs) to estimate weekly pain scores for pregabalin-treated patients in each cluster in the matched dataset using the maximum likelihood method. Finally, we validated ARMAX models using Observational Study patients who had not matched with RCT patients, using t tests between observed and predicted pain scores. Cluster analysis yielded six clusters (287-777 patients each) with the following clustering variables: gender, age, pDPN duration, body mass index, depression history, pregabalin monotherapy, prior gabapentin use, baseline pain score, and baseline sleep interference. CEM yielded 1528 unique patients in the matched dataset. The reduction in global imbalance scores for the clusters after adding the RCT patients (ranging from 6 to 63% depending on the cluster) demonstrated that the process reduced the bias of covariates in five of the six clusters. ARMAX models of pain score performed well (R 2 : 0.85-0.91; root mean square errors: 0.53-0.57). t tests did not show differences between observed and predicted pain scores in the 1955 patients who had not matched with RCT patients. The combination of cluster analyses, CEM, and ARMAX modeling enabled strong predictive capabilities with respect to pain scores. Integrating RCT and Observational Study data using CEM enabled effective use of Observational Study data to predict patient responses.

Visual-search model observer for assessing mass detection in CT

NASA Astrophysics Data System (ADS)

Karbaschi, Zohreh; Gifford, Howard C.

2017-03-01

Our aim is to devise model observers (MOs) to evaluate acquisition protocols in medical imaging. To optimize protocols for human observers, an MO must reliably interpret images containing quantum and anatomical noise under aliasing conditions. In this study of sampling parameters for simulated lung CT, the lesion-detection performance of human observers was compared with that of visual-search (VS) observers, a channelized nonprewhitening (CNPW) observer, and a channelized Hoteling (CH) observer. Scans of a mathematical torso phantom modeled single-slice parallel-hole CT with varying numbers of detector pixels and angular projections. Circular lung lesions had a fixed radius. Twodimensional FBP reconstructions were performed. A localization ROC study was conducted with the VS, CNPW and human observers, while the CH observer was applied in a location-known ROC study. Changing the sampling parameters had negligible effect on the CNPW and CH observers, whereas several VS observers demonstrated a sensitivity to sampling artifacts that was in agreement with how the humans performed.

Solar system exploration from the Moon: Synoptic and comparative study of bodies in our Planetary system

NASA Technical Reports Server (NTRS)

Bruston, P.; Mumma, M. J.

1994-01-01

An observational approach to Planetary Sciences and exploration from Earth applies to a quite limited number of targets, but most of these are spatially complex, and exhibit variability and evolution on a number of temporal scales which lie within the scope of possible observations. Advancing our understanding of the underlying physics requires the study of interactions between the various elements of such systems, and also requires study of the comparative response of both a given object to various conditions and of comparable objects to similar conditions. These studies are best conducted in 'campaigns', i.e. comprehensive programs combining simultaneous coherent observations of every interacting piece of the puzzle. The requirements include both imaging and spectroscopy over a wide spectral range, from UV to IR. While temporal simultaneity of operation in various modes is a key feature, these observations are also conducted over extended periods of time. The moon is a prime site offering long unbroken observation times and high positional stability, observations at small angular separation from the sun, comparative studies of planet Earth, and valuable technical advantages. A lunar observatory should become a central piece of any coherent set of planetary missions, supplying in-situ explorations with the synoptic and comparative data necessary for proper advance planning, correlative observations during the active exploratory phase, and follow-up studies of the target body or of related objects.

Fourth-grade children’s dietary recall accuracy for energy intake at school meals differs by social desirability and body mass index percentile in a study concerning retention interval

PubMed Central

Guinn, Caroline H.; Baxter, Suzanne D.; Royer, Julie A.; Hardin, James W.; Mackelprang, Alyssa J.; Smith, Albert F.

2010-01-01

Data from a study concerning retention interval and school-meal observation on children’s dietary recalls were used to investigate relationships of social desirability score (SDS) and body mass index percentile (BMI%) to recall accuracy for energy for observed (n=327) children, and to reported energy for observed and unobserved (n=152) children. Report rates (reported/observed) correlated negatively with SDS and BMI%. Correspondence rates (correctly reported/observed) correlated negatively with SDS. Inflation ratios (overreported/observed) correlated negatively with BMI%. The relationship between reported energy and each of SDS and BMI% did not depend on observation status. Studies utilizing children’s dietary recalls should assess SDS and BMI%. PMID:20460407

PPB | What is a Clinical Study

Cancer.gov

The Pleuropulmonary blastoma (PPB) DICER1 Syndrome Study ‹an observational clinical research study‹is enrolling children with PPB and their families. In an observational study, investigators assess health outcomes in groups of participants according to a protocol or research plan.

Does observability affect prosociality?

PubMed

Bradley, Alex; Lawrence, Claire; Ferguson, Eamonn

2018-03-28

The observation of behaviour is a key theoretical parameter underlying a number of models of prosociality. However, the empirical findings showing the effect of observability on prosociality are mixed. In this meta-analysis, we explore the boundary conditions that may account for this variability, by exploring key theoretical and methodological moderators of this link. We identified 117 papers yielding 134 study level effects (total n = 788 164) and found a small but statistically significant, positive association between observability and prosociality ( r = 0.141, 95% confidence interval = 0.106, 0.175). Moderator analysis showed that observability produced stronger effects on prosociality: (i) in the presence of passive observers (i.e. people whose role was to only observe participants) versus perceptions of being watched, (ii) when participants' decisions were consequential (versus non-consequential), (iii) when the studies were performed in the laboratory (as opposed to in the field/online), (iv) when the studies used repeated measures (instead of single games), and (v) when the studies involved social dilemmas (instead of bargaining games). These effects show the conditions under which observability effects on prosociality will be maximally observed. We describe the theoretical and practical significance of these results. © 2018 The Authors.

Does observability affect prosociality?

PubMed Central

Lawrence, Claire

2018-01-01

The observation of behaviour is a key theoretical parameter underlying a number of models of prosociality. However, the empirical findings showing the effect of observability on prosociality are mixed. In this meta-analysis, we explore the boundary conditions that may account for this variability, by exploring key theoretical and methodological moderators of this link. We identified 117 papers yielding 134 study level effects (total n = 788 164) and found a small but statistically significant, positive association between observability and prosociality (r = 0.141, 95% confidence interval = 0.106, 0.175). Moderator analysis showed that observability produced stronger effects on prosociality: (i) in the presence of passive observers (i.e. people whose role was to only observe participants) versus perceptions of being watched, (ii) when participants’ decisions were consequential (versus non-consequential), (iii) when the studies were performed in the laboratory (as opposed to in the field/online), (iv) when the studies used repeated measures (instead of single games), and (v) when the studies involved social dilemmas (instead of bargaining games). These effects show the conditions under which observability effects on prosociality will be maximally observed. We describe the theoretical and practical significance of these results. PMID:29593114

Assessment of reporting quality of conference abstracts in sports injury prevention according to CONSORT and STROBE criteria and their subsequent publication rate as full papers.

PubMed

Yoon, Uzung; Knobloch, Karsten

2012-04-11

The preliminary results of a study are usually presented as an abstract in conference meetings. The reporting quality of those abstracts and the relationship between their study designs and full paper publication rate is unknown. We hypothesized that randomized controlled trials are more likely to be published as full papers than observational studies. 154 oral abstracts presented at the World Congress of Sports Injury Prevention 2005 Oslo and the corresponding full paper publication were identified and analysed. The main outcome measures were frequency of publication, time to publication, impact factor, CONSORT (for Consolidated Standards of Reporting Trials) score, STROBE (for Strengthening the Reporting of Observational Studies in Epidemiology) score, and minor and major inconsistencies between the abstract and the full paper publication. Overall, 76 of the 154 (49%) presented abstracts were published as full papers in a peer-reviewed journal with an impact factor of 1.946 ± 0.812. No significant difference existed between the impact factor for randomized controlled trials (2.122 ± 1.015) and observational studies (1.913 ± 0.765, p = 0.469). The full papers for the randomized controlled trials were published after an average (SD) of 17 months (± 13 months); for observational studies, the average (SD) was 12 months (± 14 months) (p = 0.323). A trend was observed in this study that a higher percentage of randomized controlled trial abstracts were published as full papers (71% vs. 47%, p = 0.078) than observational trials. The reporting quality of abstracts, published as full papers, significantly increased compared to conference abstracts both in randomized control studies ( 5.7 ± 0.7 to 7.2 ± 1.3; p = 0.018, CI -2.7 to -0.32) and in observational studies (STROBE: 8.2 ± 1.3 to 8.6 ± 1.4; p = 0.007, CI -0.63 to -0.10). All of the published abstracts had at least one minor inconsistency (title, authors, research center, outcome presentation, conclusion), while 65% had at least major inconsistencies (study objective, hypothesis, study design, primary outcome measures, sample size, statistical analysis, results, SD/CI). Comparing the results of conference and full paper; results changed in 90% vs. 68% (randomized, controlled studies versus observational studies); data were added (full paper reported more result data) in 60% vs. 30%, and deleted (full paper reported fewer result data) in 40% vs. 30%. No significant differences with respect to type of study (randomized controlled versus observational), impact factor, and time to publication existed for the likelihood that a World Congress of Sports Injury conference abstract could be published as a full paper.

Meta-analyses of Adverse Effects Data Derived from Randomised Controlled Trials as Compared to Observational Studies: Methodological Overview

PubMed Central

Golder, Su; Loke, Yoon K.; Bland, Martin

2011-01-01

Background There is considerable debate as to the relative merits of using randomised controlled trial (RCT) data as opposed to observational data in systematic reviews of adverse effects. This meta-analysis of meta-analyses aimed to assess the level of agreement or disagreement in the estimates of harm derived from meta-analysis of RCTs as compared to meta-analysis of observational studies. Methods and Findings Searches were carried out in ten databases in addition to reference checking, contacting experts, citation searches, and hand-searching key journals, conference proceedings, and Web sites. Studies were included where a pooled relative measure of an adverse effect (odds ratio or risk ratio) from RCTs could be directly compared, using the ratio of odds ratios, with the pooled estimate for the same adverse effect arising from observational studies. Nineteen studies, yielding 58 meta-analyses, were identified for inclusion. The pooled ratio of odds ratios of RCTs compared to observational studies was estimated to be 1.03 (95% confidence interval 0.93–1.15). There was less discrepancy with larger studies. The symmetric funnel plot suggests that there is no consistent difference between risk estimates from meta-analysis of RCT data and those from meta-analysis of observational studies. In almost all instances, the estimates of harm from meta-analyses of the different study designs had 95% confidence intervals that overlapped (54/58, 93%). In terms of statistical significance, in nearly two-thirds (37/58, 64%), the results agreed (both studies showing a significant increase or significant decrease or both showing no significant difference). In only one meta-analysis about one adverse effect was there opposing statistical significance. Conclusions Empirical evidence from this overview indicates that there is no difference on average in the risk estimate of adverse effects of an intervention derived from meta-analyses of RCTs and meta-analyses of observational studies. This suggests that systematic reviews of adverse effects should not be restricted to specific study types. Please see later in the article for the Editors' Summary PMID:21559325

Comparison between treatment effects in a randomised controlled trial and an observational study using propensity scores in primary care.

PubMed

Stuart, Beth L; Grebel, Louise En; Butler, Christopher C; Hood, Kerenza; Verheij, Theo J M; Little, Paul

2017-09-01

Although randomised controlled trials (RCTs) are considered 'gold standard' evidence, they are not always feasible or appropriate, and may represent a select population. Observational studies provide a useful alternative to enhance applicability, but results can be biased due to confounding. To explore the utility of propensity scores for causal inference in an observational study. Comparison of the effect of amoxicillin on key outcomes in an international RCT and observational study of lower respiratory tract infections. Propensity scores were calculated and applied as probability weights in the analyses. The adjusted results were compared with the effects reported in the RCT. Groups were well balanced in the RCT but significantly imbalanced in the observational study, with evidence of confounding by indication: patients receiving antibiotics tended to be older and more unwell at baseline consultation. In the trial duration of symptoms (hazard ratio 1.06, 95% CI = 0.96 to 1.18) and symptom severity (-0.07, 95% CI = -0.15 to 0.007) did not differ between groups. Weighting by propensity score in the observational study resulted in very similar estimates of effect: duration of symptoms (hazard ratio 1.06, 95% CI = 0.80 to 1.40) and difference for symptom severity (-0.07, 95% CI = -0.34 to 0.20). The observational study, after conditioning on propensity score, echoed the trial results. Provided that detailed information is available on potential sources of confounding, effects of interventions can probably be assessed reasonably well in observational datasets, allowing them to be more directly compared with the results of RCTs. © British Journal of General Practice 2017.

Preliminary Checklist for Reporting Observational Studies in Sports Areas: Content Validity.

PubMed

Chacón-Moscoso, Salvador; Sanduvete-Chaves, Susana; Anguera, M Teresa; Losada, José L; Portell, Mariona; Lozano-Lozano, José A

2018-01-01

Observational studies are based on systematic observation, understood as an organized recording and quantification of behavior in its natural context. Applied to the specific area of sports, observational studies present advantages when comparing studies based on other designs, such as the flexibility for adapting to different contexts and the possibility of using non-standardized instruments as well as a high degree of development in specific software and data analysis. Although the importance and usefulness of sports-related observational studies have been widely shown, there is no checklist to report these studies. Consequently, authors do not have a guide to follow in order to include all of the important elements in an observational study in sports areas, and reviewers do not have a reference tool for assessing this type of work. To resolve these issues, this article aims to develop a checklist to measure the quality of sports-related observational studies based on a content validity study. The participants were 22 judges with at least 3 years of experience in observational studies, sports areas, and methodology. They evaluated a list of 60 items systematically selected and classified into 12 dimensions. They were asked to score four aspects of each item on 5-point Likert scales to measure the following dimensions: representativeness, relevance, utility, and feasibility. The judges also had an open-format section for comments. The Osterlind index was calculated for each item and for each of the four aspects. Items were considered appropriate when obtaining a score of at least 0.5 in the four assessed aspects. After considering these inclusion criteria and all of the open-format comments, the resultant checklist consisted of 54 items grouped into the same initial 12 dimensions. Finally, we highlight the strengths of this work. We also present its main limitation: the need to apply the resultant checklist to obtain data and, thus, increase quality indicators of its psychometric properties. For this reason, as relevant actions for further development, we encourage expert readers to use it and provide feedback; we plan to apply it to different sport areas.

Preliminary Checklist for Reporting Observational Studies in Sports Areas: Content Validity

PubMed Central

Chacón-Moscoso, Salvador; Sanduvete-Chaves, Susana; Anguera, M. Teresa; Losada, José L.; Portell, Mariona; Lozano-Lozano, José A.

2018-01-01

Observational studies are based on systematic observation, understood as an organized recording and quantification of behavior in its natural context. Applied to the specific area of sports, observational studies present advantages when comparing studies based on other designs, such as the flexibility for adapting to different contexts and the possibility of using non-standardized instruments as well as a high degree of development in specific software and data analysis. Although the importance and usefulness of sports-related observational studies have been widely shown, there is no checklist to report these studies. Consequently, authors do not have a guide to follow in order to include all of the important elements in an observational study in sports areas, and reviewers do not have a reference tool for assessing this type of work. To resolve these issues, this article aims to develop a checklist to measure the quality of sports-related observational studies based on a content validity study. The participants were 22 judges with at least 3 years of experience in observational studies, sports areas, and methodology. They evaluated a list of 60 items systematically selected and classified into 12 dimensions. They were asked to score four aspects of each item on 5-point Likert scales to measure the following dimensions: representativeness, relevance, utility, and feasibility. The judges also had an open-format section for comments. The Osterlind index was calculated for each item and for each of the four aspects. Items were considered appropriate when obtaining a score of at least 0.5 in the four assessed aspects. After considering these inclusion criteria and all of the open-format comments, the resultant checklist consisted of 54 items grouped into the same initial 12 dimensions. Finally, we highlight the strengths of this work. We also present its main limitation: the need to apply the resultant checklist to obtain data and, thus, increase quality indicators of its psychometric properties. For this reason, as relevant actions for further development, we encourage expert readers to use it and provide feedback; we plan to apply it to different sport areas. PMID:29568280

Methods and Processes of Developing the Strengthening the Reporting of Observational Studies in Epidemiology - Veterinary (STROBE-Vet) Statement.

PubMed

Sargeant, J M; O'Connor, A M; Dohoo, I R; Erb, H N; Cevallos, M; Egger, M; Ersbøll, A K; Martin, S W; Nielsen, L R; Pearl, D L; Pfeiffer, D U; Sanchez, J; Torrence, M E; Vigre, H; Waldner, C; Ward, M P

2016-11-01

Reporting of observational studies in veterinary research presents challenges that often are not addressed in published reporting guidelines. To develop an extension of the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement that addresses unique reporting requirements for observational studies in veterinary medicine related to health, production, welfare, and food safety. Consensus meeting of experts. Mississauga, Canada. Seventeen experts from North America, Europe, and Australia. Experts completed a pre-meeting survey about whether items in the STROBE statement should be modified or added to address unique issues related to observational studies in animal species with health, production, welfare, or food safety outcomes. During the meeting, each STROBE item was discussed to determine whether or not rewording was recommended and whether additions were warranted. Anonymous voting was used to determine consensus. Six items required no modifications or additions. Modifications or additions were made to the STROBE items 1 (title and abstract), 3 (objectives), 5 (setting), 6 (participants), 7 (variables), 8 (data sources/measurement), 9 (bias), 10 (study size), 12 (statistical methods), 13 (participants), 14 (descriptive data), 15 (outcome data), 16 (main results), 17 (other analyses), 19 (limitations), and 22 (funding). The methods and processes used were similar to those used for other extensions of the STROBE statement. The use of this STROBE statement extension should improve reporting of observational studies in veterinary research by recognizing unique features of observational studies involving food-producing and companion animals, products of animal origin, aquaculture, and wildlife. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Strengthening the Reporting of Observational Studies in Epidemiology—Nutritional Epidemiology (STROBE-nut): An Extension of the STROBE Statement

PubMed Central

Hawwash, Dana; Ocké, Marga C.; Berg, Christina; Forsum, Elisabet; Sonestedt, Emily; Wirfält, Elisabet; Åkesson, Agneta; Kolsteren, Patrick; Byrnes, Graham; De Keyzer, Willem; Van Camp, John; Slimani, Nadia; Cevallos, Myriam; Egger, Matthias; Huybrechts, Inge

2016-01-01

Background Concerns have been raised about the quality of reporting in nutritional epidemiology. Research reporting guidelines such as the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement can improve quality of reporting in observational studies. Herein, we propose recommendations for reporting nutritional epidemiology and dietary assessment research by extending the STROBE statement into Strengthening the Reporting of Observational Studies in Epidemiology—Nutritional Epidemiology (STROBE-nut). Methods and Findings Recommendations for the reporting of nutritional epidemiology and dietary assessment research were developed following a systematic and consultative process, coordinated by a multidisciplinary group of 21 experts. Consensus on reporting guidelines was reached through a three-round Delphi consultation process with 53 external experts. In total, 24 recommendations for nutritional epidemiology were added to the STROBE checklist. Conclusion When used appropriately, reporting guidelines for nutritional epidemiology can contribute to improve reporting of observational studies with a focus on diet and health. PMID:27270749

Space observations for global and regional studies of the biosphere

NASA Technical Reports Server (NTRS)

Cihlar, J.; Li, Z.; Chen, J.; Sellers, P.; Hall, F.

1994-01-01

The capability to make space-based measurements of Earth at high spatial and temporal resolutions, which would not otherwise be economically or practically feasible, became available just in time to contribute to scientific understanding of the interactive processes governing the total Earth system. Such understanding has now become essential in order to take practical steps which would counteract or mitigate the pervasive impact of the growing human population on the future habitability of the Earth. The paper reviews the rationale for using space observations for studies of climate and terrestrial ecosystems at global and regional scales, as well as the requirements for such observations for studies of climate and ecosystem dynamics. The present status of these developments is reported along with initiatives under way to advance the use of satellite observations for Earth system studies. The most important contribution of space observations is the provision of physical or biophysical parameters for models representing various components of the Earth system. Examples of such parameters are given for climatic and ecosystem studies.

Teacher Supervision and Evaluation: A Case Study of Administrators' and Teachers' Perceptions of Mini Observations

ERIC Educational Resources Information Center

Campbell, Thomas F.

2013-01-01

This case study will investigate teachers' and administrators' perceptions of the relationship between mini observations and teacher performance to understand what effect, if any, a system of mini observations has on teacher performance, and if mini observations influences a teacher's pedagogical practice differently than a…

Clinical research on postoperative trauma care: has the position of observational studies changed?

PubMed

Smeeing, D P J; Houwert, R M; Kruyt, M C; van der Meijden, O A J; Hietbrink, F

2017-02-01

The postoperative care regimes of ankle fractures are studied for over 30 years and recommendations have shifted only slightly in the last decades. However, study methodology might have evolved. The aim of this study was to evaluate the changes in time in the design, quality and outcome measures of studies investigating the postoperative care of ankle fractures. The MEDLINE and EMBASE database were searched for both RCTs and cohort studies. The original studies were divided into decades of publication over the last 30 years. The methodological quality of the studies was assessed using the 'traditional' risk of bias assessment tool provided by The Cochrane Collaboration and the 'newer' MINORS criteria. The percentage of RCTs on this subject declined from 67 to 38 % in the last decades. According to the Cochrane tool, the reported quality of RCTs has improved in the last three decades whereas the reported quality of observational studies has remained unchanged. However, when quality was evaluated with the MINORS criteria, equal improvement was observed for both RCTs and observational studies. In the 80s, 67 % of all studies used the range of motion as the primary outcome measure, which decreased to 45 % in the 90s. In the 00s, none of the studies used the range of motion as the primary outcome. For postoperative care of ankle fractures, results of this study showed a relative decrease in the published number of RCTs. The overall quality of the published articles did not decline. In addition, a gradual shift from physician measured to patient-reported outcome variables was observed. However, it should be borne in mind that the findings are based on a small sample (n = 25).

Theoretical and Observational Studies of Meteor Interactions with the Ionosphere

DTIC Science & Technology

2006-06-01

within an order of magnitude. The histograms of scattering mass, calculated from data collected at the ALTAIR rada are contained in Figure 1 . These...RTO-MP-IST-056 12 - 1 UNCLASSIFIED/UNLIMITED UNCLASSIFIED/UNLIMITED Theoretical and Observational Studies of Meteor Interactions with the...Observational Studies of Meteor Interactions with the Ionosphere. In Characterising the Ionosphere (pp. 12- 1 – 12-12). Meeting Proceedings RTO-MP-IST-056

Investigation of nuclear stopping observable in heavy ion collisions

NASA Astrophysics Data System (ADS)

Deepshikha; Kumar, Suneel

2018-07-01

Detailed analysis has been made on nuclear stopping using various observable. Transport model, isospin dependent quantum molecular dynamics model (IQMD) has been used to study stopping over the whole mass range at incident energies between 10 MeV/nucleon and 1000 MeV/nucleon. Our study proves that ratio of width of transverse to longitudinal rapidity distribution i.e., < varxz > is the most suitable parameter to study nuclear stopping. Also, it has been observed that light mass fragments (LMF's) emitted from participant region can be used as barometer to study nuclear stopping.

Luminosities of Radio Pulsars

NASA Astrophysics Data System (ADS)

Bagchi, Manjari

2013-08-01

Luminosity is an intrinsic property of radio pulsars related to the properties of the magnetospheric plasma and the beam geometry, and inversely proportional to the observing frequency. In traditional models, luminosity has been considered as a function of the spin parameters of pulsars. On the other hand, parameter independent models like power law and lognormal have been also used to fit the observed luminosities. Some of the older studies on pulsar luminosities neglected observational biases, but all of the recent studies tried to model observational effects as accurately as possible. Luminosities of pulsars in globular clusters (GCs) and in the Galactic disk have been studied separately. Older studies concluded that these two categories of pulsars have different luminosity distributions, but the most recent study concluded that those are the same. This paper reviews all significant works on pulsar luminosities and discusses open questions.

Vaccine Effectiveness - How Well Does the Seasonal Flu Vaccine Work?

MedlinePlus

... to determine the benefits of flu vaccination are “observational studies.” “Observational studies” compare the occurrence of flu illness in ... randomized. The measurement of vaccine effects in an observational study is referred to as “effectiveness.” Top of ...

Literacy and Text Reading in Middle and High School Social Studies and English Language Arts Classrooms

ERIC Educational Resources Information Center

Swanson, Elizabeth; Wanzek, Jeanne; McCulley, Lisa; Stillman-Spisak, Stephanie; Vaughn, Sharon; Simmons, Deborah; Fogarty, Melissa; Hairrell, Angela

2016-01-01

This study reports vocabulary and reading comprehension instructional practices implemented in middle and high school social studies and language arts classrooms. It also describes text reading practices. We conducted 137 observations of 11 social studies and 9 language arts teachers over the course of 1 academic year. We observed instructional…

Behavioral Response Research Evaluation Workshop (BRREW)

DTIC Science & Technology

2015-09-30

future research directions, focusing on controlled exposure experiments ( captive and free-ranging animals) and observational studies. OBJECTIVES...in key areas including controlled exposure experiments ( captive and free-ranging animals) and observational studies on real Navy exercises; 2...include response to simulated sources of Navy sonar (BRS and captive studies), response to real Navy sources (BRS studies, M3R), incidental response

Understanding Electrochemistry Concepts Using the Predict-Observe-Explain Strategy

ERIC Educational Resources Information Center

Karamustafaoglu, Sevilay; Mamlok-Naaman, Rachel

2015-01-01

The current study deals with freshman students who study at the Department of Science at the Faculty of Education. The aim of the study was to investigate the effect of teaching electrochemistry concepts using Predict-Observe-Explain (POE) strategy. The study was quasi-experimental design using 20 students each in the experimental group (EG) and…

Bearing-based localization for leader-follower formation control

PubMed Central

Han, Qing; Ren, Shan; Lang, Hao; Zhang, Changliang

2017-01-01

The observability of the leader robot system and the leader-follower formation control are studied. First, the nonlinear observability is studied for when the leader robot observes landmarks. Second, the system is shown to be completely observable when the leader robot observes two different landmarks. When the leader robot system is observable, multi-robots can rapidly form and maintain a formation based on the bearing-only information that the follower robots observe from the leader robot. Finally, simulations confirm the effectiveness of the proposed formation control. PMID:28426706

Application of seemingly unrelated regression in medical data with intermittently observed time-dependent covariates.

PubMed

Keshavarzi, Sareh; Ayatollahi, Seyyed Mohammad Taghi; Zare, Najaf; Pakfetrat, Maryam

2012-01-01

BACKGROUND. In many studies with longitudinal data, time-dependent covariates can only be measured intermittently (not at all observation times), and this presents difficulties for standard statistical analyses. This situation is common in medical studies, and methods that deal with this challenge would be useful. METHODS. In this study, we performed the seemingly unrelated regression (SUR) based models, with respect to each observation time in longitudinal data with intermittently observed time-dependent covariates and further compared these models with mixed-effect regression models (MRMs) under three classic imputation procedures. Simulation studies were performed to compare the sample size properties of the estimated coefficients for different modeling choices. RESULTS. In general, the proposed models in the presence of intermittently observed time-dependent covariates showed a good performance. However, when we considered only the observed values of the covariate without any imputations, the resulted biases were greater. The performances of the proposed SUR-based models in comparison with MRM using classic imputation methods were nearly similar with approximately equal amounts of bias and MSE. CONCLUSION. The simulation study suggests that the SUR-based models work as efficiently as MRM in the case of intermittently observed time-dependent covariates. Thus, it can be used as an alternative to MRM.

Characterizing Musculoskeletal Injury among Aeromedical Evacuation Personnel: An Observational Study

DTIC Science & Technology

2016-09-28

three phases: a sampling study, laboratory observations, and field observations. In Phase I, 43 active duty AECMs volunteered to complete a...was administered via SurveyMonkey to volunteers from the USAFSAM Education and Training Department and the four active duty AE squadrons. The

Study of mastoid canals and grooves in north karnataka human skulls.

PubMed

Hadimani, Gavishiddappa Andanappa; Bagoji, Ishwar Basavantappa

2013-08-01

This study was undertaken to observe the frequency of mastoid canals and grooves in north Karnataka dry human skulls. 100 dry human skulls of unknown age and sex from the department of Anatomy were selected and observed for the present study. The mastoid regions of dry skulls were observed for the presence of mastoid canals and grooves, if any. A metallic wire was passed through the canal for its confirmation and then the length was measured. The Mastoid canals were present in 53% of the total 100 skulls observed either bilaterally or unilaterally. Mastoid grooves were present in 18% of the total skulls (100) observed. Double mastoid canal was found in 01% of total skull studied and both Mastoid canals & Mastoid grooves together were present in 02% of the total skulls (100) observed. The knowledge of mastoid canals and grooves is very important for otolaryngologists and neurosurgeons. Because they contain an arterial branch of occipital artery with its accompanying vein which is liable to injury resulting into severe bleeding.

Evidence Synthesis in Harm Assessment of Medicines Using the Example of Rosiglitazone and Myocardial Infarction.

PubMed

Rietbergen, Charlotte; Stefansdottir, Gudrun; Leufkens, Hubert G; Knol, Mirjam J; De Bruin, Marie L; Klugkist, Irene

2017-01-01

The current system of harm assessment of medicines has been criticized for relying on intuitive expert judgment. There is a call for more quantitative approaches and transparency in decision-making. Illustrated with the case of cardiovascular safety concerns for rosiglitazone, we aimed to explore a structured procedure for the collection, quality assessment, and statistical modeling of safety data from observational and randomized studies. We distinguished five stages in the synthesis process. In Stage I, the general research question, population and outcome, and general inclusion and exclusion criteria are defined and a systematic search is performed. Stage II focusses on the identification of sub-questions examined in the included studies and the classification of the studies into the different categories of sub-questions. In Stage III, the quality of the identified studies is assessed. Coding and data extraction are performed in Stage IV. Finally, meta-analyses on the study results per sub-question are performed in Stage V. A Pubmed search identified 30 randomized and 14 observational studies meeting our search criteria. From these studies, we identified 4 higher level sub-questions and 4 lower level sub-questions. We were able to categorize 29 individual treatment comparisons into one or more of the sub-question categories, and selected study duration as an important covariate. We extracted covariate, outcome, and sample size information at the treatment arm level of the studies. We extracted absolute numbers of myocardial infarctions from the randomized study, and adjusted risk estimates with 95% confidence intervals from the observational studies. Overall, few events were observed in the randomized studies that were frequently of relatively short duration. The large observational studies provided more information since these were often of longer duration. A Bayesian random effects meta-analysis on these data showed no significant increase in risk of rosiglitazone for any of the sub-questions. The proposed procedure can be of additional value for drug safety assessment because it provides a stepwise approach that guides the decision-making in increasing process transparency. The procedure allows for the inclusion of results from both randomized an observational studies, which is especially relevant for this type of research.

What Principals Do to Improve Teaching and Learning: Comparing the Use of Informal Classroom Observations in Two School Districts

ERIC Educational Resources Information Center

Ing, Marsha

2013-01-01

Informally observing classrooms is one way that principals can help improve teaching and learning. This study describes the variability of principals' classroom observations across schools and identifies the conditions under which observations relate to the instructional climate in some schools and not others. Data for this study come from…

Observation and Coding Manual for the Longitudinal Study of Reading Comprehension and Science Concept Acquisition (Third Edition). Technical Report No. L-1.

ERIC Educational Resources Information Center

Meyer, Linda A.; And Others

This manual describes the model--specifically the observation procedures and coding systems--used in a longitudinal study of how children learn to comprehend what they read, with particular emphasis on science texts. Included are procedures for the following: identifying students; observing--recording observations and diagraming the room; writing…

Seeing beyond monitors-Critical care nurses' multiple skills in patient observation: Descriptive qualitative study.

PubMed

Alastalo, Mika; Salminen, Leena; Lakanmaa, Riitta-Liisa; Leino-Kilpi, Helena

2017-10-01

The aim of this study was to provide a comprehensive description of multiple skills in patient observation in critical care nursing. Data from semi-structured interviews were analysed using thematic analysis. Experienced critical care nurses (n=20) from three intensive care units in two university hospitals in Finland. Patient observation skills consist of: information gaining skills, information processing skills, decision-making skills and co-operation skills. The first three skills are integrated in the patient observation process, in which gaining information is a prerequisite for processing information that precedes making decisions. Co-operation has a special role as it occurs throughout the process. This study provided a comprehensive description of patient observation skills related to the three-phased patient observation process. The findings contribute to clarifying this part of the competence. The description of patient observation skills may be applied in both clinical practice and education as it may serve as a framework for orientation, ensuring clinical skills and designing learning environments. Based on this study, patient observation skills can be recommended to be included in critical care nursing education, orientation and as a part of critical care nurses' competence evaluation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ten Years of Gamma-Ray Bursts Observations with BATSE

NASA Technical Reports Server (NTRS)

Fishman, Gerald J.; Rose, M. Franklin (Technical Monitor)

2000-01-01

The observed gamma-ray temporal, spectral, intensity and spatial distribution characteristics of GRBs from data obtained from BATSE/Compton Observatory, will be described. The talk will concentrate on recent studies of burst properties, correlations of GRB parameters and other statistical studies that have only recently come to light with the unprecedented sample of over 2700 GRBS. Recent studies of possible observational biases, un-triggered GRBs and threshold calculations for BATSE will also be described.

A QUESTIONNAIRE TO ASSESS THE RELEVANCE AND CREDIBILITY OF OBSERVATIONAL STUDIES TO INFORM HEALTH CARE DECISION MAKING: AN ISPOR-AMCP-NPC GOOD PRACTICE TASK FORCE REPORT

PubMed Central

Berger, Marc L; Martin, Bradley C; Husereau, Don; Worley, Karen; Allen, Dan; Yang, Winnie; Mullins, C. Daniel; Kahler, Kristijan; Quon, Nicole C.; Devine, Scott; Graham, John; Cannon, Eric; Crown, William

2014-01-01

Evidence-based healthcare decisions are best informed by comparisons of all relevant interventions used to treat conditions in specific patient populations. Observational studies are being performed to help fill evidence gaps. However, widespread adoption of evidence from observational studies has been limited due to a variety of factors, including the lack of consensus regarding accepted principles for their evaluation and interpretation. Two Task Forces were formed to develop questionnaires to assist decision makers in evaluating observational studies, with one Task Force addressing retrospective research and the other prospective research. The intent was to promote a structured approach to reduce the potential for subjective interpretation of evidence and drive consistency in decision-making. Separately developed questionnaires were combined into a single questionnaire consisting of 33 items. These were divided into two domains: relevance and credibility. Relevance addresses the extent to which findings, if accurate, apply to the setting of interest to the decision maker. Credibility addresses the extent to which the study findings accurately answer the study question. The questionnaire provides a guide for assessing the degree of confidence that should be placed from observational studies and promotes awareness of the subtleties involved in evaluating those. PMID:24636373

Statistical analysis of mixed recurrent event data with application to cancer survivor study

PubMed Central

Zhu, Liang; Tong, Xingwei; Zhao, Hui; Sun, Jianguo; Srivastava, Deo Kumar; Leisenring, Wendy; Robison, Leslie L.

2014-01-01

Event history studies occur in many fields including economics, medical studies and social science. In such studies concerning some recurrent events, two types of data have been extensively discussed in the literature. One is recurrent event data that arise if study subjects are monitored or observed continuously. In this case, the observed information provides the times of all occurrences of the recurrent events of interest. The other is panel count data, which occur if the subjects are monitored or observed only periodically. This can happen if the continuous observation is too expensive or not practical and in this case, only the numbers of occurrences of the events between subsequent observation times are available. In this paper, we discuss a third type of data, which is a mixture of recurrent event and panel count data and for which there exists little literature. For regression analysis of such data, a marginal mean model is presented and we propose an estimating equation-based approach for estimation of regression parameters. A simulation study is conducted to assess the finite sample performance of the proposed methodology and indicates that it works well for practical situations. Finally it is applied to a motivating study on childhood cancer survivors. PMID:23139023

Using non-specialist observers in 4AFC human observer studies

NASA Astrophysics Data System (ADS)

Elangovan, Premkumar; Mackenzie, Alistair; Dance, David R.; Young, Kenneth C.; Wells, Kevin

2017-03-01

Virtual clinical trials (VCTs) are an emergent approach for rapid evaluation and comparison of various breast imaging technologies and techniques using computer-based modeling tools. Increasingly 4AFC (Four alternative forced choice) virtual clinical trials are used to compare detection performances of different breast imaging modalities. Most prior studies have used physicists and/or radiologists and physicists interchangeably. However, large scale use of statistically significant 4AFC observer studies is challenged by the individual time commitment and cost of such observers, often drawn from a limited local pool of specialists. This work aims to investigate whether non-specialist observers can be used to supplement such studies. A team of five specialist observers (medical physicists) and five non-specialists participated in a 4AFC study containing simulated 2D-mammography and DBT (digital breast tomosynthesis) images, produced using the OPTIMAM toolbox for VCTs. The images contained 4mm irregular solid masses and 4mm spherical targets at a range of contrast levels embedded in a realistic breast phantom background. There was no statistically significant difference between the detection performance of medical physicists and non-specialists (p>0.05). However, non-specialists took longer to complete the study than their physicist counterparts, which was statistically significant (p<0.05). Overall, the results from both observer groups indicate that DBT has a lower detectable threshold contrast than 2D-mammography for both masses and spheres, and both groups found spheres easier to detect than irregular solid masses.

STRengthening Analytical Thinking for Observational Studies: the STRATOS initiative

PubMed Central

Sauerbrei, Willi; Abrahamowicz, Michal; Altman, Douglas G; le Cessie, Saskia; Carpenter, James

2014-01-01

The validity and practical utility of observational medical research depends critically on good study design, excellent data quality, appropriate statistical methods and accurate interpretation of results. Statistical methodology has seen substantial development in recent times. Unfortunately, many of these methodological developments are ignored in practice. Consequently, design and analysis of observational studies often exhibit serious weaknesses. The lack of guidance on vital practical issues discourages many applied researchers from using more sophisticated and possibly more appropriate methods when analyzing observational studies. Furthermore, many analyses are conducted by researchers with a relatively weak statistical background and limited experience in using statistical methodology and software. Consequently, even ‘standard’ analyses reported in the medical literature are often flawed, casting doubt on their results and conclusions. An efficient way to help researchers to keep up with recent methodological developments is to develop guidance documents that are spread to the research community at large. These observations led to the initiation of the strengthening analytical thinking for observational studies (STRATOS) initiative, a large collaboration of experts in many different areas of biostatistical research. The objective of STRATOS is to provide accessible and accurate guidance in the design and analysis of observational studies. The guidance is intended for applied statisticians and other data analysts with varying levels of statistical education, experience and interests. In this article, we introduce the STRATOS initiative and its main aims, present the need for guidance documents and outline the planned approach and progress so far. We encourage other biostatisticians to become involved. PMID:25074480

Online Studies on Variation in Orthopedic Surgery: Computed Tomography in MPEG4 Versus DICOM Format.

PubMed

Mellema, Jos J; Mallee, Wouter H; Guitton, Thierry G; van Dijk, C Niek; Ring, David; Doornberg, Job N

2017-10-01

The purpose of this study was to compare the observer participation and satisfaction as well as interobserver reliability between two online platforms, Science of Variation Group (SOVG) and Traumaplatform Study Collaborative, for the evaluation of complex tibial plateau fractures using computed tomography in MPEG4 and DICOM format. A total of 143 observers started with the online evaluation of 15 complex tibial plateau fractures via either the SOVG or Traumaplatform Study Collaborative websites using MPEG4 videos or a DICOM viewer, respectively. Observers were asked to indicate the absence or presence of four tibial plateau fracture characteristics and to rate their satisfaction with the evaluation as provided by the respective online platforms. The observer participation rate was significantly higher in the SOVG (MPEG4 video) group compared to that in the Traumaplatform Study Collaborative (DICOM viewer) group (75 and 43%, respectively; P < 0.001). The median observer satisfaction with the online evaluation was seven (range, 0-10) using MPEG4 video compared to six (range, 1-9) using DICOM viewer (P = 0.11). The interobserver reliability for recognition of fracture characteristics in complex tibial plateau fractures was higher for the evaluation using MPEG4 video. In conclusion, observer participation and interobserver reliability for the characterization of tibial plateau fractures was greater with MPEG4 videos than with a standard DICOM viewer, while there was no difference in observer satisfaction. Future reliability studies should account for the method of delivering images.

Public availability of results of observational studies evaluating an intervention registered at ClinicalTrials.gov.

PubMed

Baudart, Marie; Ravaud, Philippe; Baron, Gabriel; Dechartres, Agnes; Haneef, Romana; Boutron, Isabelle

2016-01-28

Observational studies are essential for assessing safety. The aims of this study were to evaluate whether results of observational studies evaluating an intervention with safety outcome(s) registered at ClinicalTrials.gov were published and, if not, whether they were available through posting on ClinicalTrials.gov or the sponsor website. We identified a cohort of observational studies with safety outcome(s) registered on ClinicalTrials.gov after October 1, 2007, and completed between October 1, 2007, and December 31, 2011. We systematically searched PubMed for a publication, as well as ClinicalTrials.gov and the sponsor website for results. The main outcomes were the time to the first publication in journals and to the first public availability of the study results (i.e. published or posted on ClinicalTrials.gov or the sponsor website). For all studies with results publicly available, we evaluated the completeness of reporting (i.e. reported with the number of events per arm) of safety outcomes. We identified 489 studies; 334 (68%) were partially or completely funded by industry. Results for only 189 (39%, i.e. 65% of the total target number of participants) were published at least 30 months after the study completion. When searching other data sources, we obtained the results for 53% (n = 158; i.e. 93% of the total target number of participants) of unpublished studies; 31% (n = 94) were posted on ClinicalTrials.gov and 21% (n = 64) on the sponsor website. As compared with non-industry-funded studies, industry-funded study results were less likely to be published but not less likely to be publicly available. Of the 242 studies with a primary outcome recorded as a safety issue, all these outcomes were adequately reported in 86% (114/133) when available in a publication, 91% (62/68) when available on ClinicalTrials.gov, and 80% (33/41) when available on the sponsor website. Only 39% of observational studies evaluating an intervention with safety outcome(s) registered at ClinicalTrials.gov had their results published at least 30 months after study completion. The registration of these observational studies allowed searching other sources (results posted at ClinicalTrials.gov and sponsor website) and obtaining results for half of unpublished studies and 93% of the total target number of participants.

Magic Mirror, On the Wall-Which Is the Right Study Design of Them All?-Part II.

PubMed

Vetter, Thomas R

2017-07-01

The assessment of a new or existing treatment or other intervention typically answers 1 of 3 central research-related questions: (1) "Can it work?" (efficacy); (2) "Does it work?" (effectiveness); or (3) "Is it worth it?" (efficiency or cost-effectiveness). There are a number of study designs that, on a situational basis, are appropriate to apply in conducting research. These study designs are generally classified as experimental, quasiexperimental, or observational, with observational studies being further divided into descriptive and analytic categories. This second of a 2-part statistical tutorial reviews these 3 salient research questions and describes a subset of the most common types of observational study designs. Attention is focused on the strengths and weaknesses of each study design to assist in choosing which is appropriate for a given study objective and hypothesis as well as the particular study setting and available resources and data. Specific studies and papers are highlighted as examples of a well-chosen, clearly stated, and properly executed study design type.

NASA/University Joint Venture (JOVE) Program

NASA Technical Reports Server (NTRS)

Magee-Sauer, Karen P.

1999-01-01

Hale-Bopp observations at the NASA IRTF concluded in September 1997. For the post Hale-Bopp period, telescope time was awarded to study comet Giacobini-Zinner in October 1998 at the NASA IRTF. A total of 6 nights were awarded to our team to study the comet where 2 of those 6 nights were awarded to Magee-Sauer as the principal investigator. Other observing trips were awarded to study YSOs (October 1998) and Mars (spring 1999) were Magee-Sauer was a co-investigator. An observing run from July 4 -7 1999 included study of Mars and YSOS. Our group has started to use the NIRSPEC instrument on the Keck II telescope. In collaboration with the development team from UCLA, we obtained images of comet Lee in August 1999. Telescope proposals are submitted each semester for targeted comet observations when a comet is bright enough to observe.

From pattern to process: The strategy of the Earth Observing System: Volume 2: EOS Science Steering Committee report

NASA Technical Reports Server (NTRS)

1987-01-01

The Earth Observing System (EOS) represents a new approach to the study of the Earth. It consists of remotely sensed and correlative in situ observations designed to address important, interrelated global-scale processes. There is an urgent need to study the Earth as a complete, integrated system in order to understand and predict changes caused by human activities and natural processes. The EOS approach is based on an information system concept and designed to provide a long-term study of the Earth using a variety of measurement methods from both operational and research satellite payloads and continuing ground-based Earth science studies. The EOS concept builds on the foundation of the earlier, single-discipline space missions designed for relatively short observation periods. Continued progress in our understanding of the Earth as a system will come from EOS observations spanning several decades using a variety of contemporaneous measurements.

Dynamic Modulation of Human Motor Activity When Observing Actions

PubMed Central

Press, Clare; Cook, Jennifer; Blakemore, Sarah-Jayne; Kilner, James

2012-01-01

Previous studies have demonstrated that when we observe somebody else executing an action many areas of our own motor systems are active. It has been argued that these motor activations are evidence that we motorically simulate observed actions; this motoric simulation may support various functions such as imitation and action understanding. However, whether motoric simulation is indeed the function of motor activations during action observation is controversial, due to inconsistency in findings. Previous studies have demonstrated dynamic modulations in motor activity when we execute actions. Therefore, if we do motorically simulate observed actions, our motor systems should also be modulated dynamically, and in a corresponding fashion, during action observation. Using magnetoencephalography, we recorded the cortical activity of human participants while they observed actions performed by another person. Here, we show that activity in the human motor system is indeed modulated dynamically during action observation. The finding that activity in the motor system is modulated dynamically when observing actions can explain why studies of action observation using functional magnetic resonance imaging have reported conflicting results, and is consistent with the hypothesis that we motorically simulate observed actions. PMID:21414901

Transabdominal amnioinfusion for preterm premature rupture of membranes: a systematic review and metaanalysis of randomized and observational studies.

PubMed

Porat, Shay; Amsalem, Hagai; Shah, Prakesh S; Murphy, Kellie E

2012-11-01

The purpose of this study was to review systematically the efficacy of transabdominal amnioinfusion (TA) in early preterm premature rupture of membranes (PPROM). We conducted a literature search of EMBASE, MEDLINE, and ClinicalTrials.gov databases and identified studies in which TA was used in cases of proven PPROM and oligohydramnios. Risk of bias was assessed for observational studies and randomized controlled trials. Primary outcomes were latency period and perinatal mortality rates. Four observational studies (n = 147) and 3 randomized controlled trials (n = 165) were eligible. Pooled latency period was 14.4 (range, 8.2-20.6) and 11.41 (range -3.4 to 26.2) days longer in the TA group in the observational and the randomized controlled trials, respectively. Perinatal mortality rates were reduced among the treatment groups in both the observational studies (odds ratio, 0.12; 95% confidence interval, 0.02-0.61) and the randomized controlled trials (odds ratio, 0.33; 95% confidence interval, 0.10-1.12). Serial TA for early PPROM may improve early PPROM-associated morbidity and mortality rates. Additional adequately powered randomized control trials are needed. Copyright © 2012 Mosby, Inc. All rights reserved.

Observational Studies on Evaluating the Safety and Adverse Effects of Traditional Chinese Medicine

PubMed Central

Tang, Jin-Ling; Wang, Jung-Der

2013-01-01

Background. This study aims to share our experiences when carrying out observational studies of traditional Chinese medicine (TCM). Methods. We have proactively monitored the safety profiles of Duhuo Jisheng Tang (DJT), Suan Zao Ren Tang (SZRT), and TMN-1. A list of adverse events (AEs), complete blood counts, and liver and kidney function tests were obtained from the participants during their scheduled hospital visits. Retrospective observational studies were conducted based on the reimbursement database of the National Health Insurance system, Taiwan, to explore the relationship between the use of TCM that have been adulterated by aristolochic acid and the risk from both nephrotoxins and carcinogens. Results. A total of 221, 287, and 203 AEs were detected after SZRT, DJT, and TMN-1 had been taken, respectively. Dizziness, headache, stomach ache, and diarrhea were judged to be probably related to SZRT treatment. Retrospective observational studies found an association between the consumption of aristolochic acid-containing Chinese formulae such as Mu Tong and an increased risk of CKD, ESRD, and urinary tract cancer. Conclusion. Prospective and retrospective observational studies seem to have specific advantages when investigating the safety and adverse effects of TCM therapies, as well as possibly other alternative/complementary therapies. PMID:24159351

Observing Parent Behavior: Reconciling Theoretical Concepts with Empirical Reality.

ERIC Educational Resources Information Center

Ge, Xiaojia

Using data from the Iowa Youth and Families Project, this longitudinal study investigated the predictive validity of different dimensions of observed parent behavior on adolescent externalizing (aggression, hostility) and internalizing (depression, anxiety) problems over a 2-year period. In addition, the study examined how observer ratings…

Propensity Score Estimation With Boosted Regression for Evaluating Causal Effects in Observational Studies

ERIC Educational Resources Information Center

McCaffrey, Daniel F.; Ridgeway, Greg; Morral, Andrew R.

2004-01-01

Causal effect modeling with naturalistic rather than experimental data is challenging. In observational studies participants in different treatment conditions may also differ on pretreatment characteristics that influence outcomes. Propensity score methods can theoretically eliminate these confounds for all observed covariates, but accurate…

Polarization observables in few nucleon systems with CLAS

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

Zachariou, Nicholas

The CEBAF Large Acceptance Spectrometer (CLAS), housed in Hall-B at the Thomas Jefferson National Accelerator Facility provides us with the experimental tools to study strongly-interacting matter and its dynamics in the transition from hadronic to partonic degrees of freedom in nuclear interactions. In this paper we discuss the progress made in understanding the relevant degrees of freedom using polarisation observables of deuteron photodisintegration in the few-GeV photon-energy region. We also address progress made in studying the interaction between Hyperons and Nucleons via polarisation observables, utilising high-statistics experiments that provided us with the large data samples needed to study final-state interactions,more » as well as perform detailed studies on initial-state effects. The polarisation observables presented here provide us with unique experimental tools to study the underlying dynamics of both initial and final-state interactions, as well as the information needed to disentangle signal from background contributions.« less

Polarization observables in few nucleon systems with CLAS

DOE PAGES

Zachariou, Nicholas

2017-12-01

The CEBAF Large Acceptance Spectrometer (CLAS), housed in Hall-B at the Thomas Jefferson National Accelerator Facility provides us with the experimental tools to study strongly-interacting matter and its dynamics in the transition from hadronic to partonic degrees of freedom in nuclear interactions. In this paper we discuss the progress made in understanding the relevant degrees of freedom using polarisation observables of deuteron photodisintegration in the few-GeV photon-energy region. We also address progress made in studying the interaction between Hyperons and Nucleons via polarisation observables, utilising high-statistics experiments that provided us with the large data samples needed to study final-state interactions,more » as well as perform detailed studies on initial-state effects. The polarisation observables presented here provide us with unique experimental tools to study the underlying dynamics of both initial and final-state interactions, as well as the information needed to disentangle signal from background contributions.« less

Observational Research Rigor Alone Does Not Justify Causal Inference

PubMed Central

Ejima, Keisuke; Li, Peng; Smith, Daniel L.; Nagy, Tim R.; Kadish, Inga; van Groen, Thomas; Dawson, John A.; Yang, Yongbin; Patki, Amit; Allison, David B.

2016-01-01

Background Differing opinions exist on whether associations obtained in observational studies can be reliable indicators of a causal effect if the observational study is sufficiently well controlled and executed. Materials and methods To test this, we conducted two animal observational studies that were rigorously controlled and executed beyond what is achieved in studies of humans. In study 1, we randomized 332 genetically identical C57BL/6J mice into three diet groups with differing food energy allotments and recorded individual self-selected daily energy intake and lifespan. In study 2, 60 male mice (CD1) were paired and divided into two groups for a 2-week feeding regimen. We evaluated the association between weight gain and food consumption. Within each pair, one animal was randomly assigned to an S group in which the animals had free access to food. The second paired animal (R group) was provided exactly the same diet that their S partner ate the day before. Results In study 1, across all three groups, we found a significant negative effect of energy intake on lifespan. However, we found a positive association between food intake and lifespan among the ad libitum feeding group: 29.99 (95% CI: 8.2 to 51.7) days per daily kcal. In study 2, we found a significant (P=0.003) group (randomized vs self-selected)-by-food consumption interaction effect on weight gain. Conclusions At least in nutrition research, associations derived from observational studies may not be reliable indicators of causal effects, even with the most rigorous study designs achievable. PMID:27711975

Antidepressant use and risk of coronary heart disease: meta-analysis of observational studies

PubMed Central

Oh, Seung-Won; Kim, Joonseok; Myung, Seung-Kwon; Hwang, Seung-Sik; Yoon, Dae-Hyun

2014-01-01

Aims Our goal was to evaluate the association between antidepressant use and the risk of coronary heart disease (CHD) among subjects with no history of coronary heart disease. Methods A search of Medline, EMBASE, PsycINFO and the Cochrane Library was performed in January 2013. Two authors independently reviewed and selected eligible observational studies, based on predetermined selection criteria. Pooled relative risks (RRs) with confidence intervals (CIs) were calculated using random-effects or fixed-effects models. Results Sixteen observational studies (seven case–control studies and nine cohort studies) were included in the final analysis. There was no association between selective serotonin reuptake inhibitor use and the risk of CHD overall [odds ratio (OR), 0.93; 95% CI, 0.65–1.33] or in subgroup meta-analysis of case–control studies (OR, 0.91; 95% CI, 0.60–1.37) and cohort studies (RR, 0.96; 95% CI, 0.59–1.55). The use of tricyclic antidepressant was associated with an increased risk of CHD overall (OR, 1.51; 95% CI, 1.07–2.12), but it was observed only in case–control studies (OR, 1.56; 95% CI, 1.24–1.96) and low-quality studies (OR, 1.49; 95% CI, 1.20–1.85) in the subgroup meta-analyses. Conclusions This meta-analysis of observational studies in subjects with no history of CHD suggests that neither selective serotonin reuptake inhibitor nor tricyclic antidepressant use is associated with an increased risk of CHD. PMID:24646010

Embedding clinical interventions into observational studies

PubMed Central

Newman, Anne B.; Avilés-Santa, M. Larissa; Anderson, Garnet; Heiss, Gerardo; Howard, Wm. James; Krucoff, Mitchell; Kuller, Lewis H.; Lewis, Cora E.; Robinson, Jennifer G.; Taylor, Herman; Treviño, Roberto P.; Weintraub, William

2017-01-01

Novel approaches to observational studies and clinical trials could improve the cost-effectiveness and speed of translation of research. Hybrid designs that combine elements of clinical trials with observational registries or cohort studies should be considered as part of a long-term strategy to transform clinical trials and epidemiology, adapting to the opportunities of big data and the challenges of constrained budgets. Important considerations include study aims, timing, breadth and depth of the existing infrastructure that can be leveraged, participant burden, likely participation rate and available sample size in the cohort, required sample size for the trial, and investigator expertise. Community engagement and stakeholder (including study participants) support are essential for these efforts to succeed. PMID:26611435

UHV-TEM-REM Studies of Si(111) Surfaces

NASA Astrophysics Data System (ADS)

Yagi, K.; Yamanaka, A.; Sato, H.; Shima, M.; Ohse, H.; Ozawa, S.; Tanishiro, Y.

Recent progresses of ultra-high vacuum transmission and reflection electron microscope studies of clean Si(111) surfaces are described. Anisotropy of surface atomic steps such as step energy, bunching of steps, are studied. Out of phase boundaries are observed in transmission mode and its energy relative to the step energy is studied. The phase transition between the 1 × 1 and the 7 × 7 structures around 830°C, studied previously is re-examined under various conditions. Contraction strains of the 7 × 7 structure and adatom density on terraces play important role during the transition. Diffuse scattering observed by LEED and RHEED above the transition temperature is not observed in teh TED pattern from a thin film.

A Case Study on Teaching of Energy as a Subject for 9th Graders

ERIC Educational Resources Information Center

Bezen, Sevim; Bayrak, Celal; Aykutlu, Isil

2017-01-01

This study aims to describe how energy subject is taught in 9th grades. The study is designed as a descriptive case study with the participation of 3 physics teachers and 85 students. Data were obtained through observation, interviews, and documents, and they were analyzed through descriptive analysis method. In the observations made at the…

New Insights into the Management of Hypertension and Cardiovascular Risk with Angiotensin Receptor Blockers: Observational Studies Help Us?

PubMed Central

Goudev, Assen

2014-01-01

Post-marketing observational studies are valuable for establishing the real-world effectiveness of treatment regimens in routine clinical practice as they typically monitor a diverse population of patients over many months. This article reviews recent observational studies of angiotensin receptor blockers (ARBs) for the management of hypertension: the 6-month eprosartan POWER study (n~29,400), the 3-month valsartan translational research programme (n~19,500), the 9-month irbesartan Treat to Target study (n=14,200), the 6-month irbesartan DO-IT survey (n~3300) and the 12-week candesartan CHILI survey programme (n=4600). Reduction in blood pressure with ARBs reported across these studies appears to be comparable for the different agents, although direct comparisons between studies cannot be made owing to different treatment durations and baseline patient demographics. Of these studies, the eprosartan POWER study, 2 of the 7 studies in the valsartan translational research programme, and the candesartan CHILI Triple T study measured total cardiovascular risk, as recommended in the 2013 European Society of Cardiology-European Society of Hypertension guidelines. The POWER study confirmed the value of the Systemic Coronary Risk Evaluation (SCORE) to accurately assess total cardiovascular risk. With the advent of new healthcare practices, such as the use of electronic health records (EHRs), observational studies in larger patient populations will become possible. In the future, algorithms embedded in EHR systems could evolve as decision support tools to inform on patient care. PMID:24847388

Evaluating the Impact of Database Heterogeneity on Observational Study Results

PubMed Central

Madigan, David; Ryan, Patrick B.; Schuemie, Martijn; Stang, Paul E.; Overhage, J. Marc; Hartzema, Abraham G.; Suchard, Marc A.; DuMouchel, William; Berlin, Jesse A.

2013-01-01

Clinical studies that use observational databases to evaluate the effects of medical products have become commonplace. Such studies begin by selecting a particular database, a decision that published papers invariably report but do not discuss. Studies of the same issue in different databases, however, can and do generate different results, sometimes with strikingly different clinical implications. In this paper, we systematically study heterogeneity among databases, holding other study methods constant, by exploring relative risk estimates for 53 drug-outcome pairs and 2 widely used study designs (cohort studies and self-controlled case series) across 10 observational databases. When holding the study design constant, our analysis shows that estimated relative risks range from a statistically significant decreased risk to a statistically significant increased risk in 11 of 53 (21%) of drug-outcome pairs that use a cohort design and 19 of 53 (36%) of drug-outcome pairs that use a self-controlled case series design. This exceeds the proportion of pairs that were consistent across databases in both direction and statistical significance, which was 9 of 53 (17%) for cohort studies and 5 of 53 (9%) for self-controlled case series. Our findings show that clinical studies that use observational databases can be sensitive to the choice of database. More attention is needed to consider how the choice of data source may be affecting results. PMID:23648805

Teacher Effectiveness and Causal Inference in Observational Studies

ERIC Educational Resources Information Center

Rose, Roderick A.

2013-01-01

An important target of education policy is to improve overall teacher effectiveness using evidence-based policies. Randomized control trials (RCTs), which randomly assign study participants or groups of participants to treatment and control conditions, are not always practical or possible and observational studies using rigorous quasi-experimental…

Stroke prevention in atrial fibrillation: re-defining 'real-world data' within the broader data universe.

PubMed

Fanaroff, Alexander C; Steffel, Jan; Alexander, John H; Lip, Gregory Y H; Califf, Robert M; Lopes, Renato D

2018-04-23

Real-world data (RWD) has been defined as data generated outside of traditional randomized clinical trials (RCTs). Though RWD has received increasing attention from regulatory authorities and professional societies, dividing evidence into that derived from 'real-world' vs. 'non-real-world' sources provides only one element of a much larger framework for evidence evaluation. Evidence should be evaluated on the source of the data, the method of treatment allocation (whether any intervention being evaluated was assigned or simply observed as used in practice) and the context in which the evidence was generated (overall study design). Under this framework, RWD refers only to data source, and a study incorporates RWD when it primarily uses data collected for non-research purposes, such as insurance claims data or the electronic health record, regardless of study design. Separation of study design, data source, and context enables parallel evaluation of two critical elements: (i) whether a study can support claims of causal inference, which can be assured with a high degree of confidence only in studies where patients are assigned treatments by protocol; and (ii) whether the study population and clinical context mirror clinical practice, a strength of observational studies using data from clinical practice or administrative claims. In this review, we describe the strengths and weaknesses of observational and non-observational studies, and studies involving RWD and non-RWD, through the lens of anticoagulation for atrial fibrillation (AF). Observational studies employing RWD are useful for describing how oral anticoagulants are used in clinical practice, but generally cannot be used to make claims regarding comparative treatment effects. Questions regarding treatment effect generally are best answered through an RCT, and additional pragmatic RCTs are needed to compare different antithrombotic agents for the prevention of thrombotic events in AF.

Clinical profile, predisposing factors, and associated co-morbidities of children with cerebral palsy in South India

PubMed Central

Gowda, Vykuntaraju K.; Kumar, Anil; Shivappa, Sanjay K.; Srikanteswara, Praveen Kumar; Shivananda; Mahadeviah, M. S.; Govindraj, M.; Ramaswamy, Premalatha

2015-01-01

Introduction: Cerebral palsy (CP) is the most common physical disorder of children. Causes like jaundice and birth injury though are decreasing; complications resulting from the survival of low birth weight babies are replacing some of the older etiologies. Hence, this study was planned. Objectives: The objective was to study the clinical patterns, predisposing factors, and co-morbidities in children with CP. Materials and Methods: The present study is a hospital based prospective study conducted from January 2012 to January 2013 in children presenting to neurodevelopmental clinic at a tertiary care teaching hospital in India. Hundred cases with clinical features suggestive of CP were included in the study. Cases were evaluated by history, clinical examination, and necessary investigations. Results: Results of the study showed 81% of spastic, 12% of hypotonic, 5% of dystonic, and 2% of mixed CP cases. The mean age of presentation was 2 year, 2 month, and male to female ratio of 1:2. Pregnancy-induced hypertension (PIH) was the most common antenatal complication observed in 6%. Four percent had neonatal sepsis and 19% were born premature. Associated co-morbidities were mental retardation (55%), seizure disorder (46%), visual problems (26%), hearing problems (19%), and failure to thrive (47%). Discussion: Sex distribution observed in our study was male to female ratio of 1.2, which was comparable with a multicenter study in Europe. PIH was observed in 6% of cases, which was comparable with prior studies. Birth asphyxia was observed in 43% of cases. Eighty-one percent of the cases constituted a spastic variety of CP which was comparable to other studies. Conclusion: Perinatal asphyxia was the important etiological factor. We found preventable intranatal causes (60%) and antenatal causes (20%) forming a significant proportion. Co-morbidities were significantly observed in our study. PMID:26167210

NASA Satellite Observations: A Unique Asset for the Study of the Environment and Implications for Public Health

NASA Technical Reports Server (NTRS)

Estes Sue M.

2010-01-01

This slide presentation highlights how satellite observation systems are assets for studying the environment in relation to public health. It includes information on current and future satellite observation systems, NASA's public health and safety research, surveillance projects, and NASA's public health partners.

Empirical Performance of Covariates in Education Observational Studies

ERIC Educational Resources Information Center

Wong, Vivian C.; Valentine, Jeffrey C.; Miller-Bains, Kate

2017-01-01

This article summarizes results from 12 empirical evaluations of observational methods in education contexts. We look at the performance of three common covariate-types in observational studies where the outcome is a standardized reading or math test. They are: pretest measures, local geographic matching, and rich covariate sets with a strong…

Evolution of Observation: Implementing Programmatic Change

ERIC Educational Resources Information Center

Bender-Slack, Delane A.; Young, Teresa

2013-01-01

In the study reported, we examine the evolution of preservice teacher observation, focusing on the essential nature of observation to preservice teachers' learning about teaching while in the field. The study was 3 years long, and it involved 79 preservice teachers during semester-long language arts methods courses in early childhood and…

Short-Term Temporal Stability in Observed Retail Food Characteristics

ERIC Educational Resources Information Center

Zenk, Shannon N.; Grigsby-Toussaint, Diana S.; Curry, Susan J.; Berbaum, Michael; Schneider, Linda

2010-01-01

Objective: Use of direct observation to characterize neighborhood retail food environments is increasing, but to date most studies have relied on a single observation. If food availability, prices, and quality vary over short time periods, repeated measures may be needed to portray these food characteristics. This study evaluated short-term…

Observation and Recording Effects on Group Therapy Client Behaviors.

ERIC Educational Resources Information Center

Berman, Alan L.; Decker, Robert E.

This study assesses the effect of visual versus audio observation/recording on both client and therapist verbal and non-verbal behavior in ongoing therapy. Three co-led, therapy groups were studied over six weekly sessions under counterbalanced observation conditions. Measures of verbal behavior, verbal productivity, and non-verbal behavior were…

Explanation and Elaboration Document for the STROBE-Vet Statement: Strengthening the Reporting of Observational Studies in Epidemiology-Veterinary Extension.

PubMed

O'Connor, A M; Sargeant, J M; Dohoo, I R; Erb, H N; Cevallos, M; Egger, M; Ersbøll, A K; Martin, S W; Nielsen, L R; Pearl, D L; Pfeiffer, D U; Sanchez, J; Torrence, M E; Vigre, H; Waldner, C; Ward, M P

2016-11-01

The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement was first published in 2007 and again in 2014. The purpose of the original STROBE was to provide guidance for authors, reviewers, and editors to improve the comprehensiveness of reporting; however, STROBE has a unique focus on observational studies. Although much of the guidance provided by the original STROBE document is directly applicable, it was deemed useful to map those statements to veterinary concepts, provide veterinary examples, and highlight unique aspects of reporting in veterinary observational studies. Here, we present the examples and explanations for the checklist items included in the STROBE-Vet statement. Thus, this is a companion document to the STROBE-Vet statement methods and process document (JVIM_14575 "Methods and Processes of Developing the Strengthening the Reporting of Observational Studies in Epidemiology-Veterinary (STROBE-Vet) Statement" undergoing proofing), which describes the checklist and how it was developed. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Analysis of Critical Earth Observation Priorities for Societal Benefit

NASA Astrophysics Data System (ADS)

Zell, E. R.; Huff, A. K.; Carpenter, A. T.; Friedl, L.

2011-12-01

To ensure that appropriate near real-time (NRT) and historical Earth observation data are available to benefit society and meet end-user needs, the Group on Earth Observations (GEO) sponsored a multi-disciplinary study to identify a set of critical and common Earth observations associated with 9 Societal Benefit Areas (SBAs): Agriculture, Biodiversity, Climate, Disasters, Ecosystems, Energy, Health, Water, and Weather. GEO is an intergovernmental organization working to improve the availability, access, and use of Earth observations to benefit society through a Global Earth Observation System of Systems (GEOSS). The study, overseen by the GEO User Interface Committee, focused on the "demand" side of Earth observation needs: which users need what types of data, and when? The methodology for the study was a meta-analysis of over 1,700 publicly available documents addressing Earth observation user priorities, under the guidance of expert advisors from around the world. The result was a ranking of 146 Earth observation parameters that are critical and common to multiple SBAs, based on an ensemble of 4 statistically robust methods. Within the results, key details emerged on NRT observations needed to serve a broad community of users. The NRT observation priorities include meteorological parameters, vegetation indices, land cover and soil property observations, water body and snow cover properties, and atmospheric composition. The results of the study and examples of NRT applications will be presented. The applications are as diverse as the list of priority parameters. For example, NRT meteorological and soil moisture information can support monitoring and forecasting for more than 25 infectious diseases, including epidemic diseases, such as malaria, and diseases of major concern in the U.S., such as Lyme disease. Quickly evolving events that impact forests, such as fires and insect outbreaks, can be monitored and forecasted with a combination of vegetation indices, fuel moisture content, burn scars, and meteorological parameters. Impacts to public health and livelihoods due to food insecurity, algal blooms, and air pollution can be addressed through NRT monitoring of specific events utilizing land cover, atmospheric composition, water quality, and meteorological observations. More broadly, the assessment of water availability for drinking and agriculture and the development of floods and storms rely on continuous feeds of NRT meteorological and atmospheric composition observations. Overall, this multi-disciplinary study of user needs for NRT data and products can inform the design and operation of NRT data systems. Follow-on work for this study will also be presented, focusing on the availability of current and future satellite measurements (including NRT) of the 30 most critical Earth observation priorities, as well as a detailed analysis of users' needs for precipitation data. The results of this study summarize the priorities for critical Earth observations utilized globally for societal benefit.

Optical observational programs at the Indian Institute of Astrophysics

NASA Astrophysics Data System (ADS)

Singh, Jagdev; Ravindra, B.

The Indian Institute of Astrophysics has been making optical observations of the sun for more than a century by taking images of the sun in continuum to study the photosphere, Ca-K line and H-alpha line in order to study the chromosphere by using the same instruments which are used to study the long term variations of the magnetic fields on the sun. The digitizers have been developed using uniform light sources, imaging optics without any vignetting in the required FOV and large format 4K×4K CCD cameras to digitize the data for scientific studies. At the Solar Tower Telescope we have performed very high resolution spectroscopic observations around Ca-K line to investigate the variations and delineate the contribution of various features to the solar cycle variations. Solar coronal studies have been done during the occurrence of total solar eclipses and with a coronagraph to study the coronal heating. Here we discuss the systematic temporal variations observed in the green and red emission profiles using high spectral and temporal observations during the 2006, 2009 and 2010 total solar eclipses. The TWIN telescope a new facility has been fabricated and installed at Kodaikanal observatory to continue the synoptic observations of the sun and a space-based coronagraph is also being designed and fabricated in collaboration with various laboratories of ISRO (LEOS, ISAC and SAC) and USO. In this article we present the summary of results of optical observational programs carried out at Kodaikanal Observatory and during the eclipse expeditions where authors have played a leading role. Furthermore, this review is not complete in all respects of all the observational programs carried out at the Kodaikanal observatory.

Behavioral and TMS Markers of Action Observation Might Reflect Distinct Neuronal Processes.

PubMed

Hétu, Sébastien; Taschereau-Dumouchel, Vincent; Meziane, Hadj Boumediene; Jackson, Philip L; Mercier, Catherine

2016-01-01

Transcranial magnetic stimulation (TMS) studies have shown that observing an action induces muscle-specific changes in corticospinal excitability. From a signal detection theory standpoint, this pattern can be related to sensitivity, which here would measure the capacity to distinguish between two action observation conditions. In parallel to these TMS studies, action observation has also been linked to behavioral effects such as motor priming and interference. It has been hypothesized that behavioral markers of action observation could be related to TMS markers and thus represent a potentially cost-effective mean of assessing the functioning of the action-perception system. However, very few studies have looked at possible relationships between these two measures. The aim of this study was to investigate if individual differences in sensitivity to action observation could be related to the behavioral motor priming and interference effects produced by action observation. To this end, 14 healthy participants observed index and little finger movements during a TMS task and a stimulus-response compatibility task. Index muscle displayed sensitivity to action observation, and action observation resulted in significant motor priming+interference, while no significant effect was observed for the little finger in both task. Nevertheless, our results indicate that the sensitivity measured in TMS was not related to the behavioral changes measured in the stimulus-response compatibility task. Contrary to a widespread assumption, the current results indicate that individual differences in physiological and behavioral markers of action observation may be unrelated. This could have important impacts on the potential use of behavioral markers in place of more costly physiological markers of action observation in clinical settings.

A Study of Pulse Shape Evolution and X-Ray Reprocessing in Her X-1

NASA Technical Reports Server (NTRS)

Cushman, Paula P.

1998-01-01

This study focused on the pulse shape evolution and spectral properties of the X-ray binary Her X-1 with regard to the well known 35-day cycle of Her X-1. A follow-up set of RXTE observations has been conducted in RXTE AO-2 phase and the two observation sets are being analyzed together. We presented results of early analysis of pulse shape evolution in "Proceedings of the Fourth Compton Symposium". More advanced analysis was presented at the HEAD meeting in November, 1997 in Estes Park, Colorado. A related study of the 35-day cycle using RXTE/ASM data, which laid out the overall picture within which the more detailed PCA observations could be placed has also been conducted. The results of this study have been published. A pair of papers on the detailed pulse evolution and the spectral/color evolution are currently being prepared for publication. Some of the significant results of this study have been a confirmation of the detailed pulse profile changes at the end of the Main High state in HerX-1 first observed by GINGA, observations of the pulse evolution in several Short High states which agree with the pulse evolution pattern predicted using a disk occultation model, observation of a systematic lengthening of the eclipse egress during the Main High state of the 35-day phase and observation of a new type of extended eclipse ingress during which pulsations cease to observed during the Short High state.

Consolidated RXTE Observing Grants on Observation of Neutron Stars and Black Holes in Binaries

NASA Technical Reports Server (NTRS)

Prince, Thomas A.; Vaughan, Brian A.

1998-01-01

This final report is a study of neutron stars and black holes in binaries. The activities focused on observation made with the Rossi X-ray Timing Explorer. The following areas were covered: long term observations of accreting binary pulsars with the All-Sky Monitor (ASM); observations of Centaurus X-3 with the Proportional Counter Array (PCA) and the High-Energy X-ray Timing Experiment (HEXTE); observations of accreting pulsars with the PCA and HEXTE; studies of quasi-periodic oscillations (QPO); and investigations of accreting black-hole candidates.

Methods and processes of developing the strengthening the reporting of observational studies in epidemiology - veterinary (STROBE-Vet) statement.

PubMed

Sargeant, J M; O'Connor, A M; Dohoo, I R; Erb, H N; Cevallos, M; Egger, M; Ersbøll, A K; Martin, S W; Nielsen, L R; Pearl, D L; Pfeiffer, D U; Sanchez, J; Torrence, M E; Vigre, H; Waldner, C; Ward, M P

2016-11-01

The reporting of observational studies in veterinary research presents many challenges that often are not adequately addressed in published reporting guidelines. To develop an extension of the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement that addresses unique reporting requirements for observational studies in veterinary medicine related to health, production, welfare, and food safety. A consensus meeting of experts was organized to develop an extension of the STROBE statement to address observational studies in veterinary medicine with respect to animal health, animal production, animal welfare, and food safety outcomes. Consensus meeting May 11-13, 2014 in Mississauga, Ontario, Canada. Seventeen experts from North America, Europe, and Australia attended the meeting. The experts were epidemiologists and biostatisticians, many of whom hold or have held editorial positions with relevant journals. Prior to the meeting, 19 experts completed a survey about whether they felt any of the 22 items of the STROBE statement should be modified and if items should be added to address unique issues related to observational studies in animal species with health, production, welfare, or food safety outcomes. At the meeting, the participants were provided with the survey responses and relevant literature concerning the reporting of veterinary observational studies. During the meeting, each STROBE item was discussed to determine whether or not re-wording was recommended, and whether additions were warranted. Anonymous voting was used to determine whether there was consensus for each item change or addition. The consensus was that six items needed no modifications or additions. Modifications or additions were made to the STROBE items numbered: 1 (title and abstract), 3 (objectives), 5 (setting), 6 (participants), 7 (variables), 8 (data sources/measurement), 9 (bias), 10 (study size), 12 (statistical methods), 13 (participants), 14 (descriptive data), 15 (outcome data), 16 (main results), 17 (other analyses), 19 (limitations), and 22 (funding). Published literature was not always available to support modification to, or inclusion of, an item. The methods and processes used in the development of this statement were similar to those used for other extensions of the STROBE statement. The use of this extension to the STROBE statement should improve the reporting of observational studies in veterinary research related to animal health, production, welfare, or food safety outcomes by recognizing the unique features of observational studies involving food-producing and companion animals, products of animal origin, aquaculture, and wildlife. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Observational Learning of Academic and Social Behaviors during Small-Group Direct Instruction

ERIC Educational Resources Information Center

Ledford, Jennifer R.; Wolery, Mark

2015-01-01

Many studies have shown that small-group direct instruction is effective and efficient for teaching students with and without disabilities, although relatively few studies have been conducted with heterogeneous groups of preschool participants. In addition, previous studies have primarily assessed whether observational learning occurred for…

How Questionnaires and Multimedia Measurements collected in the U.S. EPA’s Observational Human Exposure Measurement Studies Inform Exposures

EPA Science Inventory

In the last decade, the U.S. EPA has conducted and/or funded numerous observational humanexposure measurement studies where questionnaires were administered to the study participants in addition tothe collection of multimedia measurements. Questionnaire responses provide ancillar...

Using Multiple Control Groups and Matching to Address Unobserved Biases in Comparative Effectiveness Research: An Observational Study of the Effectiveness of Mental Health Parity.

PubMed

Yoon, Frank B; Huskamp, Haiden A; Busch, Alisa B; Normand, Sharon-Lise T

2011-06-21

Studies of large policy interventions typically do not involve randomization. Adjustments, such as matching, can remove the bias due to observed covariates, but residual confounding remains a concern. In this paper we introduce two analytical strategies to bolster inferences of the effectiveness of policy interventions based on observational data. First, we identify how study groups may differ and then select a second comparison group on this source of difference. Second, we match subjects using a strategy that finely balances the distributions of key categorical covariates and stochastically balances on other covariates. An observational study of the effect of parity on the severely ill subjects enrolled in the Federal Employees Health Benefits (FEHB) Program illustrates our methods.

Applications of propensity score methods in observational comparative effectiveness and safety research: where have we come and where should we go?

PubMed

Borah, Bijan J; Moriarty, James P; Crown, William H; Doshi, Jalpa A

2014-01-01

Propensity score (PS) methods have proliferated in recent years in observational studies in general and in observational comparative effectiveness research (CER) in particular. PS methods are an important set of tools for estimating treatment effects in observational studies, enabling adjustment for measured confounders in an easy-to-understand and transparent way. This article demonstrates how PS methods have been used to address specific CER questions from 2001 through to 2012 by identifying six impactful studies from this period. This article also discusses areas for improvement, including data infrastructure, and a unified set of guidelines in terms of PS implementation and reporting, which will boost confidence in evidence generated through observational CER using PS methods.

Quantifying ADHD classroom inattentiveness, its moderators, and variability: a meta-analytic review.

PubMed

Kofler, Michael J; Rapport, Mark D; Alderson, R Matt

2008-01-01

Most classroom observation studies have documented significant deficiencies in the classroom attention of children with attention-deficit/hyperactivity disorder (ADHD) compared to their typically developing peers. The magnitude of these differences, however, varies considerably and may be influenced by contextual, sampling, diagnostic, and observational differences. Meta-analysis of 23 between-group classroom observation studies using weighted regression, publication bias, goodness of fit, best case, and original metric analyses. Across studies, a large effect size (ES = .73) was found prior to consideration of potential moderators. Weighted regression, best case, and original metric estimation indicate that this effect may be an underestimation of the classroom visual attention deficits of children with ADHD. Several methodological factors-classroom environment, sample characteristics, diagnostic procedures, and observational coding schema-differentially affect observed rates of classroom attentive behavior for children with ADHD and typically developing children. After accounting for these factors, children with ADHD were on-task approximately 75% of the time compared to 88% for their classroom peers (ES = 1.40). Children with ADHD were also more variable in their attentive behavior across studies. The present study confirmed that children with ADHD exhibit deficient and more variable visual attending to required stimuli in classroom settings and provided an aggregate estimation of the magnitude of these deficits at the group level. It also demonstrated the impact of situational, sampling, diagnostic, and observational variables on observed rates of on-task behavior.

Reconstruction of the right ventricular outflow tract with a bovine jugular vein graft fixed with a naturally occurring crosslinking agent (genipin) in a canine model.

PubMed

Chang, Y; Tsai, C C; Liang, H C; Sung, H W

2001-12-01

This study was designed to evaluate a newly developed biologic valved conduit fixed with genipin used to reconstruct the right ventricular outflow tract in a canine model. Fresh bovine jugular veins with a retained native valve procured from a slaughterhouse were used as raw materials to fabricate the valved conduits. A naturally occurring crosslinking agent, genipin, was used to fix the procured jugular veins. The glutaraldehyde-fixed counterpart was used as a control. A canine model was used in the study. Echocardiography revealed that the motion of the valvular leaflets in both the glutaraldehyde- and genipin-fixed conduits was satisfactory. The transvalvular pressure gradients of both studied groups were minimal. No endothelium-like cells were observed on the luminal surface of the conduit and the valvular leaflet for the glutaraldehyde-fixed group throughout the entire course of the study. In contrast, endothelium-like cells were observed on the entire surface of the genipin-fixed valved conduit retrieved at 6 months postoperatively in all the cases studied. There was no evidence of luminal fibrous peel in any the valved conduits studied. Degradation of valvular leaflet in one of the glutaraldehyde-fixed conduits was observed. In this particular case, thrombus formation was also observed on the surface of the valvular leaflet. On the other hand, no apparent degradation or thrombus formation was observed on the surfaces of the genipin-fixed valvular leaflet and conduit. A significantly more severe inflammatory reaction was observed for the glutaraldehyde-fixed conduit than for its genipin-fixed counterpart throughout the entire course of the study. The calcium contents of the samples before implantation and those retrieved at distinct implantation duration were minimal for both the glutaraldehyde- and genipin-fixed tissues. Although further studies are necessary, the genipin-fixed valved conduit appears to have great potential in helping mitigate the complications observed in the commercially available conduits.

Interpreting febrile neutropenia rates from randomized, controlled trials for consideration of primary prophylaxis in the real world: a systematic review and meta-analysis.

PubMed

Truong, J; Lee, E K; Trudeau, M E; Chan, K K W

2016-04-01

Guidelines recommend primary prophylaxis (PP) with granulocyte-colony-stimulating factors (G-CSF) for patients above a febrile neutropenia (FN) risk threshold of 20%. Practitioners often use FN rates of regimens based on data from randomized, controlled trials (RCTs), which are often comprised of highly selected patients. Patients in the community setting may be at higher risk of FN. A systematic literature search was conducted for full-length articles reporting FN rates for breast cancer-related chemotherapies between January 1996 and February 2014. A regimen was included if there was at least one RCT and one observational study. Meta-regression was used to model the odds of FN. 130 studies involving 29 regimens and 50 069 patients were identified. Sixty-five observational study (n = 7812) and 110 RCT (n = 42 257) cohorts were included. The unadjusted FN rate was 11.7% in observational and 7.9% in RCT cohorts. The univariable odds ratio (OR) for FN in the observational study compared with RCT cohorts was 1.58 [95% confidence interval (CI) 1.09-2.28; P = 0.017]. The FN rates remained significantly higher in the observational study compared with RCT cohorts (OR = 1.74; 95% CI 1.15-2.62; P = 0.012) after adjusting for age, chemotherapy intent, and regimen; this meant that a 13% (95% CI 8.7% to 17.9%) FN rate in RCT would translate into 20% FN rate in observational study. FN rates in the observational studies are significantly higher than suggested by RCTs. Guidelines should clarify how FN rates from RCTs should be applied in clinical practice. Large population-based studies are needed to confirm FN rates in the real world. © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Evaluation of Quality of Lower Limb Arthroplasty Observational Studies Using the Assessment of Quality in Lower Limb Arthroplasty (AQUILA) Checklist.

PubMed

Cowan, James B; Mlynarek, Ryan A; Nelissen, Rob G H H; Pijls, Bart G C W; Gagnier, Joel J

2015-09-01

This study used the assessment of quality in lower limb arthroplasty (AQUILA) checklist to assess the quality of lower limb arthroplasty observational studies. Among 132 studies the mean reporting quality score was 5.4 (SD=1.2) out of 8 possible points. Most studies adequately reported reasons for revisions (98%) and prosthesis brand and fixation (95%) in sufficient detail. Only 3% of studies adequately reported the number of patients unwilling to participate, 15% stated a clear primary research question or hypothesis, 11% reported a worst-case analysis or competing risk analysis for endpoints, and 42% reported more than 5% of patients were lost to follow-up. There is significant room for improvement in the reporting and methodology of lower limb arthroplasty observational studies. Level III. Copyright © 2015 Elsevier Inc. All rights reserved.

STRengthening analytical thinking for observational studies: the STRATOS initiative.

PubMed

Sauerbrei, Willi; Abrahamowicz, Michal; Altman, Douglas G; le Cessie, Saskia; Carpenter, James

2014-12-30

The validity and practical utility of observational medical research depends critically on good study design, excellent data quality, appropriate statistical methods and accurate interpretation of results. Statistical methodology has seen substantial development in recent times. Unfortunately, many of these methodological developments are ignored in practice. Consequently, design and analysis of observational studies often exhibit serious weaknesses. The lack of guidance on vital practical issues discourages many applied researchers from using more sophisticated and possibly more appropriate methods when analyzing observational studies. Furthermore, many analyses are conducted by researchers with a relatively weak statistical background and limited experience in using statistical methodology and software. Consequently, even 'standard' analyses reported in the medical literature are often flawed, casting doubt on their results and conclusions. An efficient way to help researchers to keep up with recent methodological developments is to develop guidance documents that are spread to the research community at large. These observations led to the initiation of the strengthening analytical thinking for observational studies (STRATOS) initiative, a large collaboration of experts in many different areas of biostatistical research. The objective of STRATOS is to provide accessible and accurate guidance in the design and analysis of observational studies. The guidance is intended for applied statisticians and other data analysts with varying levels of statistical education, experience and interests. In this article, we introduce the STRATOS initiative and its main aims, present the need for guidance documents and outline the planned approach and progress so far. We encourage other biostatisticians to become involved. © 2014 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd.

Hierarchy of evidence: where observational studies fit in and why we need them.

PubMed

Hoppe, Daniel J; Schemitsch, Emil H; Morshed, Saam; Tornetta, Paul; Bhandari, Mohit

2009-05-01

Although randomized controlled designs are considered the so-called gold standard in medical trials and sit atop the hierarchy of evidence in evidence-based medicine, there are situations in which they are impractical or unethical to undertake, especially in surgical trials. Then, observational studies often provide the best source of information. In this paper, we use examples from the literature to explain the importance of observational studies in furthering the boundaries of orthopaedic surgery and knowledge of musculoskeletal disorders.

Transparency of the 2 μm window on Titan studied with observations made by VIMS

NASA Astrophysics Data System (ADS)

Rannou, P.; Lemouélic, S.; Sotin, C.; Brown, R. H.

2012-09-01

The study of Titan properties with remote sensing relies on a good knowledge of the atmosphere properties. The in-situ observations made by Huygens combined with recent advances in the definition of methane properties enable to model and interpret observations with a very good accuracy. However, intensity at some wavelengths are poorly modeled because additional opacities must be studied. We focus here on the case of the 2 μm window, which is essential to determined cloud and surface properties.

Coordination and management of multicenter clinical studies in trauma: Experience from the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) Study.

PubMed

Rahbar, Mohammad H; Fox, Erin E; del Junco, Deborah J; Cotton, Bryan A; Podbielski, Jeanette M; Matijevic, Nena; Cohen, Mitchell J; Schreiber, Martin A; Zhang, Jiajie; Mirhaji, Parsa; Duran, Sarah J; Reynolds, Robert J; Benjamin-Garner, Ruby; Holcomb, John B

2012-04-01

Early death due to hemorrhage is a major consequence of traumatic injury. Transfusion practices differ among hospitals and it is unknown which transfusion practices improve survival. This report describes the experience of the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) Study Data Coordination Center in designing and coordinating a study to examine transfusion practices at ten Level 1 trauma centers in the US. PROMMTT was a multisite prospective observational study of severely injured transfused trauma patients. The clinical sites collected real-time information on the timing and amounts of blood product infusions as well as colloids and crystalloids, vital signs, initial diagnostic and clinical laboratory tests, life saving interventions and other clinical care data. Between July 2009 and October 2010, PROMMTT screened 12,561 trauma admissions and enrolled 1245 patients who received one or more blood transfusions within 6h of Emergency Department (ED) admission. A total of 297 massive transfusions were observed over the course of the study at a combined rate of 5.0 massive transfusion patients/week. PROMMTT is the first multisite study to collect real-time prospective data on trauma patients requiring transfusion. Support from the Department of Defense and collaborative expertise from the ten participating centers helped to demonstrate the feasibility of prospective trauma transfusion studies. The observational data collected from this study will be an invaluable resource for research in trauma surgery and it will guide the design and conduct of future randomized trials. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Media Coverage, Journal Press Releases and Editorials Associated with Randomized and Observational Studies in High-Impact Medical Journals: A Cohort Study.

PubMed

Wang, Michael T M; Bolland, Mark J; Gamble, Greg; Grey, Andrew

2015-01-01

Publication of clinical research findings in prominent journals influences health beliefs and medical practice, in part by engendering news coverage. Randomized controlled trials (RCTs) should be most influential in guiding clinical practice. We determined whether study design of clinical research published in high-impact journals influences media coverage. We compared the incidence and amount of media coverage of RCTs with that of observational studies published in the top 7 medical journals between 1 January 2013 and 31 March 2013. We specifically assessed media coverage of the most rigorous RCTs, those with >1000 participants that reported 'hard' outcomes. There was no difference between RCTs and observational studies in coverage by major newspapers or news agencies, or in total number of news stories generated (all P>0.63). Large RCTs reporting 'hard' outcomes did not generate more news coverage than small RCTs that reported surrogate outcomes and observational studies (all P>0.32). RCTs were more likely than observational studies to attract a journal editorial (70% vs 46%, P = 0.003), but less likely to be the subject of a journal press release (17% vs 50%, P<0.001). Large RCTs that reported 'hard' outcomes did not attract an editorial more frequently than other studies (61% vs 58%, P>0.99), nor were they more likely to be the subject of a journal press release (14% vs 38%, P = 0.14). The design of clinical studies whose results are published in high-impact medical journals is not associated with the likelihood or amount of ensuing news coverage.

Effects of the Non-Nutritive Sweeteners on Glucose Metabolism and Appetite Regulating Hormones: Systematic Review of Observational Prospective Studies and Clinical Trials

PubMed Central

Romo-Romo, Alonso; Aguilar-Salinas, Carlos A.; Brito-Córdova, Griselda X.; Gómez Díaz, Rita A.; Vilchis Valentín, David

2016-01-01

Background The effects of non-nutritive sweeteners (NNS) on glucose metabolism and appetite regulating hormones are not clear. There is an ongoing debate concerning NNS use and deleterious changes in metabolism. Objectives The aim of this review is to analyze the scientific available evidence regarding the effects of NNS on glucose metabolism and appetite regulating hormones. Data Sources and Study Eligibility Criteria We identified human observational studies evaluating the relation between NNS consumption and obesity, diabetes, and metabolic syndrome, in addition to clinical trials evaluating the effects of NNS in glucose metabolism and appetite regulating hormones. Results Fourteen observational studies evaluating the association between NNS consumption and the development of metabolic diseases and twenty-eight clinical trials studying the effects of NNS on metabolism were included. Finally, two meta-analyses evaluating the association between the consumption of NNS-containing beverages and the development of type 2 diabetes were identified. Conclusions Some observational studies suggest an association between NNS consumption and development of metabolic diseases; however, adiposity is a confounder frequently found in observational studies. The effects of the NNS on glucose metabolism are not clear. The results of the identified clinical trials are contradictory and are not comparable because of the major existing differences between them. Studies evaluating specific NNS, with an adequate sample size, including a homogeneous study group, identifying significant comorbidities, with an appropriate control group, with an appropriate exposure time, and considering adjustment for confounder variables such as adiposity are needed. PMID:27537496

Coordination and management of multicenter clinical studies in trauma: Experience from the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) Study

PubMed Central

Rahbar, Mohammad H.; Fox, Erin E.; del Junco, Deborah J.; Cotton, Bryan A.; Podbielski, Jeanette M.; Matijevic, Nena; Cohen, Mitchell J.; Schreiber, Martin A.; Zhang, Jiajie; Mirhaji, Parsa; Duran, Sarah; Reynolds, Robert J.; Benjamin-Garner, Ruby; Holcomb, John B.

2011-01-01

Aim Early death due to hemorrhage is a major consequence of traumatic injury. Transfusion practices differ among hospitals and it is unknown which transfusion practices improve survival. This report describes the experience of the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) Study Data Coordination Center in designing and coordinating a study to examine transfusion practices at ten Level 1 trauma centers in the U.S. Methods PROMMTT was a multisite prospective observational study of severely injured transfused trauma patients. The clinical sites collected real-time information on the timing and amounts of blood product infusions as well as colloids and crystalloids, vital signs, initial diagnostic and clinical laboratory tests, life saving interventions and other clinical care data. Results Between July 2009 and October 2010, PROMMTT screened 12,561 trauma admissions and enrolled 1,245 patients who received one or more blood transfusions within 6 hours of ED admission. A total of 297 massive transfusions were observed over the course of the study at a combined rate of 5.0 massive transfusion patients/week. Conclusion PROMMTT is the first multisite study to collect real-time prospective data on trauma patients requiring transfusion. Support from the Department of Defense and collaborative expertise from the ten participating centers helped to demonstrate the feasibility of prospective trauma transfusion studies. The observational data collected from this study will be an invaluable resource for research in trauma surgery and it will guide the design and conduct of future randomized trials. PMID:22001613

Assessment of prostate cancer detection with a visual-search human model observer

NASA Astrophysics Data System (ADS)

Sen, Anando; Kalantari, Faraz; Gifford, Howard C.

2014-03-01

Early staging of prostate cancer (PC) is a significant challenge, in part because of the small tumor sizes in- volved. Our long-term goal is to determine realistic diagnostic task performance benchmarks for standard PC imaging with single photon emission computed tomography (SPECT). This paper reports on a localization receiver operator characteristic (LROC) validation study comparing human and model observers. The study made use of a digital anthropomorphic phantom and one-cm tumors within the prostate and pelvic lymph nodes. Uptake values were consistent with data obtained from clinical In-111 ProstaScint scans. The SPECT simulation modeled a parallel-hole imaging geometry with medium-energy collimators. Nonuniform attenua- tion and distance-dependent detector response were accounted for both in the imaging and the ordered-subset expectation-maximization (OSEM) iterative reconstruction. The observer study made use of 2D slices extracted from reconstructed volumes. All observers were informed about the prostate and nodal locations in an image. Iteration number and the level of postreconstruction smoothing were study parameters. The results show that a visual-search (VS) model observer correlates better with the average detection performance of human observers than does a scanning channelized nonprewhitening (CNPW) model observer.

A questionnaire to assess the relevance and credibility of observational studies to inform health care decision making: an ISPOR-AMCP-NPC Good Practice Task Force report.

PubMed

Berger, Marc L; Martin, Bradley C; Husereau, Don; Worley, Karen; Allen, J Daniel; Yang, Winnie; Quon, Nicole C; Mullins, C Daniel; Kahler, Kristijan H; Crown, William

2014-03-01

Evidence-based health care decisions are best informed by comparisons of all relevant interventions used to treat conditions in specific patient populations. Observational studies are being performed to help fill evidence gaps. Widespread adoption of evidence from observational studies, however, has been limited because of various factors, including the lack of consensus regarding accepted principles for their evaluation and interpretation. Two task forces were formed to develop questionnaires to assist decision makers in evaluating observational studies, with one Task Force addressing retrospective research and the other Task Force addressing prospective research. The intent was to promote a structured approach to reduce the potential for subjective interpretation of evidence and drive consistency in decision making. Separately developed questionnaires were combined into a single questionnaire consisting of 33 items. These were divided into two domains: relevance and credibility. Relevance addresses the extent to which findings, if accurate, apply to the setting of interest to the decision maker. Credibility addresses the extent to which the study findings accurately answer the study question. The questionnaire provides a guide for assessing the degree of confidence that should be placed from observational studies and promotes awareness of the subtleties involved in evaluating those. Copyright © 2014 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Bias reduction in repeated-measures observational studies by the use of propensity score: the case of enteral sedation for critically ill patients.

PubMed

Umbrello, Michele; Mistraletti, Giovanni; Corbella, Davide; Cigada, Marco; Salini, Silvia; Morabito, Alberto; Iapichino, Gaetano

2012-12-01

Within the evidence-based medicine paradigm, randomized controlled trials represent the "gold standard" to produce reliable evidence. Indeed, planning and implementing randomized controlled trials in critical care medicine presents limitations because of intrinsic and structural problems. As a consequence, observational studies still occur frequently. In these cases, propensity score (PS) (probability of receiving a treatment conditional on observed covariates) is an increasingly used technique to adjust the results. Few studies addressed the specific issue of a PS correction of repeated-measures designs. Three techniques for correcting the analysis of nonrandomized designs (matching, stratification, regression adjustment) are presented in a tutorial form and applied to a real case study: the comparison between intravenous and enteral sedative therapy in the intensive care unit setting. After showing the results before and after the use of PS, we suggest that such a tool allows to partially overcoming the bias associated with the observational nature of the study. It permits to correct the estimates for any observed covariate, while unobserved confounders cannot be controlled for. Propensity score represents a useful additional tool to estimate the effects of treatments in nonrandomized studies. In the case study, an enteral sedation approach was equally effective to an intravenous regime, allowing for a lower level of sedation and spare of resources. Copyright © 2012 Elsevier Inc. All rights reserved.

An Observational Study of Print Literacy in Canadian Preschool Classrooms

ERIC Educational Resources Information Center

Lynch, Jacqueline

2011-01-01

The purpose of this study was to examine the role of print literacy in preschool classrooms. There were seven preschool teachers working in central Canada who were observed over three sessions. The process of analytic induction was used to formulate categories based on interviews, classroom observations and documents. The following categories were…

An Observational Analysis of Coaching Behaviors for Career Development Event Teams: A Mixed Methods Study

ERIC Educational Resources Information Center

Ball, Anna L.; Bowling, Amanda M.; Sharpless, Justin D.

2016-01-01

School Based Agricultural Education (SBAE) teachers can use coaching behaviors, along with their agricultural content knowledge to help their Career Development Event (CDE) teams succeed. This mixed methods, collective case study observed three SBAE teachers preparing multiple CDEs throughout the CDE season. The teachers observed had a previous…

Goethe's Theory of Color and Scientific Intuition

ERIC Educational Resources Information Center

Zajonc, Arthur G.

1976-01-01

Summarizes Goethe's color studies and his methods of study. It is proposed that the act of accurate qualitative observation creates the capability in the observer for an intuitive understanding of the physical laws underlying the phenomena under observation. The use of such a method as a basis for laboratory instruction is discussed. (Author/CP)

Observed Parenting Practices of First-Generation Latino Families

ERIC Educational Resources Information Center

Domenech Rodriguez, Melanie; Davis, Melissa R.; Rodriguez, Jesus; Bates, Scott C.

2006-01-01

This study used an established behavioral observation methodology to examine the parenting practices of first-generation Latino parents of children 4 to 9 years of age. The study had three central aims, to examine: (1) the feasibility of using a behavioral observation methodology with Spanish-speaking immigrant families, (2) the utility of the…

On measuring bird habitat: influence of observer variability and sample size

Treesearch

William M. Block; Kimberly A. With; Michael L. Morrison

1987-01-01

We studied the effects of observer variability when estimating vegetation characteristics at 75 0.04-ha bird plots. Observer estimates were significantly different for 31 of 49 variables. Multivariate analyses showed significant interobserver differences for five of the seven classes of variables studied. Variable classes included the height, number, and diameter of...

Examining the Validity of Behavioral Self-Regulation Tools in Predicting Preschoolers' Academic Achievement

ERIC Educational Resources Information Center

Schmitt, Sara A.; Pratt, Megan E.; McClelland, Megan M.

2014-01-01

The current study investigated the predictive utility among teacher-rated, observed, and directly assessed behavioral self-regulation skills to academic achievement in preschoolers. Specifically, this study compared how a teacher report, the Child Behavior Rating Scale, an observer report, the Observed Child Engagement Scale, and a direct…

Examining the Validity of Behavioral Self-Regulation Tools in Predicting Preschoolers' Academic Achievement

ERIC Educational Resources Information Center

Schmitt, Sara A.; Pratt, Megan E.; McClelland, Megan M.

2014-01-01

Research Findings: The current study investigated the predictive utility of teacher-rated, observed, and directly assessed behavioral self-regulation skills to academic achievement in preschoolers. Specifically, this study compared how a teacher report (the Child Behavior Rating Scale), an observer report (the Observed Child Engagement Scale), and…

Intergenerational Transmission of Familial Boundary Dissolution: Observations and Psychosocial Outcomes in Adolescence

ERIC Educational Resources Information Center

Shaffer, Anne; Egeland, Byron

2011-01-01

This study investigated the transmission of boundary dissolution (BD) in parent-child relationships from parental behaviors observed in early childhood to adolescent behaviors observed at age 13 and relations to adolescent psychosocial adaptation. The goals of the study are (a) to examine the developmental relation of early childhood BD to several…

Demonstration for Social Change: An Experiment in Local Control.

ERIC Educational Resources Information Center

Gittell, Marilyn; And Others

This evaluative history of New York City's recent experiments in public education documents three projects: Ocean Hill-Brownsville, IS 201, and Two Bridges. This study employs a process oriented and a qualitative methodology which relies most on field observation and participant-observers. The Institute study observed the new community boards,…

An Observational Study of Skilled Memory in Waitresses.

ERIC Educational Resources Information Center

Stevens, Joy

A two-phase study about skilled memory as it is used by waitresses included a participant-observer phase and an observational phase. Participants were three experienced waitresses who had worked at a midtown Manhattan restaurant for 14, 7, and 3 years respectively and a team of 5 confederate customers. Waitresses and customers wore microphones.…

Embedding clinical interventions into observational studies.

PubMed

Newman, Anne B; Avilés-Santa, M Larissa; Anderson, Garnet; Heiss, Gerardo; Howard, Wm James; Krucoff, Mitchell; Kuller, Lewis H; Lewis, Cora E; Robinson, Jennifer G; Taylor, Herman; Treviño, Roberto P; Weintraub, William

2016-01-01

Novel approaches to observational studies and clinical trials could improve the cost-effectiveness and speed of translation of research. Hybrid designs that combine elements of clinical trials with observational registries or cohort studies should be considered as part of a long-term strategy to transform clinical trials and epidemiology, adapting to the opportunities of big data and the challenges of constrained budgets. Important considerations include study aims, timing, breadth and depth of the existing infrastructure that can be leveraged, participant burden, likely participation rate and available sample size in the cohort, required sample size for the trial, and investigator expertise. Community engagement and stakeholder (including study participants) support are essential for these efforts to succeed. Copyright © 2015. Published by Elsevier Inc.

Study of Mastoid Canals and Grooves in North Karnataka Human Skulls

PubMed Central

Hadimani, Gavishiddappa Andanappa; Bagoji, Ishwar Basavantappa

2013-01-01

Introduction: This study was undertaken to observe the frequency of mastoid canals and grooves in north Karnataka dry human skulls. 100 dry human skulls of unknown age and sex from the department of Anatomy were selected and observed for the present study. Material and Methods: The mastoid regions of dry skulls were observed for the presence of mastoid canals and grooves, if any. A metallic wire was passed through the canal for its confirmation and then the length was measured. Results: The Mastoid canals were present in 53% of the total 100 skulls observed either bilaterally or unilaterally. Mastoid grooves were present in 18% of the total skulls (100) observed. Double mastoid canal was found in 01% of total skull studied and both Mastoid canals & Mastoid grooves together were present in 02% of the total skulls (100) observed. Conclusion: The knowledge of mastoid canals and grooves is very important for otolaryngologists and neurosurgeons. Because they contain an arterial branch of occipital artery with its accompanying vein which is liable to injury resulting into severe bleeding. PMID:24086832

Observational research rigour alone does not justify causal inference.

PubMed

Ejima, Keisuke; Li, Peng; Smith, Daniel L; Nagy, Tim R; Kadish, Inga; van Groen, Thomas; Dawson, John A; Yang, Yongbin; Patki, Amit; Allison, David B

2016-12-01

Differing opinions exist on whether associations obtained in observational studies can be reliable indicators of a causal effect if the observational study is sufficiently well controlled and executed. To test this, we conducted two animal observational studies that were rigorously controlled and executed beyond what is achieved in studies of humans. In study 1, we randomized 332 genetically identical C57BL/6J mice into three diet groups with differing food energy allotments and recorded individual self-selected daily energy intake and lifespan. In study 2, 60 male mice (CD1) were paired and divided into two groups for a 2-week feeding regimen. We evaluated the association between weight gain and food consumption. Within each pair, one animal was randomly assigned to an S group in which the animals had free access to food. The second paired animal (R group) was provided exactly the same diet that their S partner ate the day before. In study 1, across all three groups, we found a significant negative effect of energy intake on lifespan. However, we found a positive association between food intake and lifespan among the ad libitum feeding group: 29·99 (95% CI: 8·2-51·7) days per daily kcal. In study 2, we found a significant (P = 0·003) group (randomized vs. self-selected)-by-food consumption interaction effect on weight gain. At least in nutrition research, associations derived from observational studies may not be reliable indicators of causal effects, even with the most rigorous study designs achievable. © 2016 Stichting European Society for Clinical Investigation Journal Foundation. Published by John Wiley & Sons Ltd.

Assessing the reporting of categorised quantitative variables in observational epidemiological studies.

PubMed

Mabikwa, Onkabetse V; Greenwood, Darren C; Baxter, Paul D; Fleming, Sarah J

2017-03-14

One aspect to consider when reporting results of observational studies in epidemiology is how quantitative risk factors are analysed. The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines recommend that researchers describe how they handle quantitative variables when analysing data. For categorised quantitative variables, the authors are required to provide reasons and justifications informing their practice. We investigated and assessed the practices and reporting of categorised quantitative variables in epidemiology. The assessment was based on five medical journals that publish epidemiological research. Observational studies published between April and June 2015 and investigating the relationships between quantitative exposures (or risk factors) and the outcomes were considered for assessment. A standard form was used to collect the data, and the reporting patterns amongst eligible studies were quantified and described. Out of 61 articles assessed for eligibility, 23 observational studies were included in the assessment. Categorisation of quantitative exposures occurred in 61% of these studies and reasons informing the practice were rarely provided. Only one article explained the choice of categorisation in the analysis. Transformation of quantitative exposures into four or five groups was common and dominant amongst studies using equally spaced categories. Dichotomisation was not popular; the practice featured in one article. Overall, the majority (86%) of the studies preferred ordered or arbitrary group categories. Other criterions used to decide categorical boundaries were based on established guidelines such as consensus statements and WHO standards. Categorisation of continuous variables remains a dominant practice in epidemiological studies. The reasons informing the practice of categorisation within published work are limited and remain unknown in most articles. The existing STROBE guidelines could provide stronger recommendations on reporting quantitative risk factors in epidemiology.

Nature versus intensity of intoxication: Co-ingestion of alcohol and energy drinks and the effect on objective and subjective intoxication.

PubMed

Forward, Jessica; Akhurst, Jane; Bruno, Raimondo; Leong, Xiao; VanderNiet, Amelia; Bromfield, Holly; Erny, Jacqueline; Bellamy, Tessa; Peacock, Amy

2017-11-01

We report a series of studies examining the effect of alcohol mixed with energy drinks (AmEDs) versus alcohol on objective intoxication (breath alcohol concentration; BrAC), intensity, and nature of intoxication. We also aimed to disentangle the role of energy drink (ED) ingredients in any effects. Three within-subject double-blind placebo-controlled studies measured BrAC, subjective intoxication and impairment ('intensity of intoxication'), stimulation and sedation ('nature of intoxication') following administration of ED, Cola, Caffeine+Sugar, and Placebo with alcohol (Study 1, n=18); ED, Caffeine-only, Sugar-only and Placebo with alcohol (Study 2, n=20); and ED and Placebo with alcohol (Study 3, n=27). Significant moderate-to-large magnitude BrAC decrements and delayed time to peak BrAC were observed after ED administration versus Placebo. However, no meaningful BrAC differences between ED and other active conditions were observed in Study 1 and 2. After BrAC adjustment, moderate-to-large magnitude reductions in intoxication and impairment ratings were observed after ED versus Placebo on the ascending limb in all studies and at peak in Study 2 and 3. No meaningful differences were observed in intoxication and impairment ratings between ED and Caffeine+Sugar and Cola conditions (Study 1); ratings were lower after ED versus Sugar-only (Study 2). Stimulation and sedation ratings did not differ between ED and Placebo. Reductions in objective intoxication and perceived intensity of intoxication, but not nature of intoxication, were observed after AmED consumption. However, effects may be common to alcohol mixers containing sugars (objective intoxication) and caffeine (intensity of intoxication) and specific to a laboratory setting. Copyright © 2017. Published by Elsevier B.V.

Creation of an ensemble of simulated cardiac cases and a human observer study: tools for the development of numerical observers for SPECT myocardial perfusion imaging

NASA Astrophysics Data System (ADS)

O'Connor, J. Michael; Pretorius, P. Hendrik; Gifford, Howard C.; Licho, Robert; Joffe, Samuel; McGuiness, Matthew; Mehurg, Shannon; Zacharias, Michael; Brankov, Jovan G.

2012-02-01

Our previous Single Photon Emission Computed Tomography (SPECT) myocardial perfusion imaging (MPI) research explored the utility of numerical observers. We recently created two hundred and eighty simulated SPECT cardiac cases using Dynamic MCAT (DMCAT) and SIMIND Monte Carlo tools. All simulated cases were then processed with two reconstruction methods: iterative ordered subset expectation maximization (OSEM) and filtered back-projection (FBP). Observer study sets were assembled for both OSEM and FBP methods. Five physicians performed an observer study on one hundred and seventy-nine images from the simulated cases. The observer task was to indicate detection of any myocardial perfusion defect using the American Society of Nuclear Cardiology (ASNC) 17-segment cardiac model and the ASNC five-scale rating guidelines. Human observer Receiver Operating Characteristic (ROC) studies established the guidelines for the subsequent evaluation of numerical model observer (NO) performance. Several NOs were formulated and their performance was compared with the human observer performance. One type of NO was based on evaluation of a cardiac polar map that had been pre-processed using a gradient-magnitude watershed segmentation algorithm. The second type of NO was also based on analysis of a cardiac polar map but with use of a priori calculated average image derived from an ensemble of normal cases.

Quality standards for real-world research. Focus on observational database studies of comparative effectiveness.

PubMed

Roche, Nicolas; Reddel, Helen; Martin, Richard; Brusselle, Guy; Papi, Alberto; Thomas, Mike; Postma, Dirjke; Thomas, Vicky; Rand, Cynthia; Chisholm, Alison; Price, David

2014-02-01

Real-world research can use observational or clinical trial designs, in both cases putting emphasis on high external validity, to complement the classical efficacy randomized controlled trials (RCTs) with high internal validity. Real-world research is made necessary by the variety of factors that can play an important a role in modulating effectiveness in real life but are often tightly controlled in RCTs, such as comorbidities and concomitant treatments, adherence, inhalation technique, access to care, strength of doctor-caregiver communication, and socio-economic and other organizational factors. Real-world studies belong to two main categories: pragmatic trials and observational studies, which can be prospective or retrospective. Focusing on comparative database observational studies, the process aimed at ensuring high-quality research can be divided into three parts: preparation of research, analyses and reporting, and discussion of results. Key points include a priori planning of data collection and analyses, identification of appropriate database(s), proper outcomes definition, study registration with commitment to publish, bias minimization through matching and adjustment processes accounting for potential confounders, and sensitivity analyses testing the robustness of results. When these conditions are met, observational database studies can reach a sufficient level of evidence to help create guidelines (i.e., clinical and regulatory decision-making).

Scientific and Ethical Approaches for Observational Exposure ...

EPA Pesticide Factsheets

Researchers conduct observational human exposure studies to understand how and the extent to which people come into contact with chemicals and environmental stressors in their everyday lives, through the air they breathe, the food and liquids they consume, and the things they touch. The U.S. Environmental Protection Agency’s (EPA’s) National Exposure Research Laboratory (NERL) has conducted observational human exposure studies for several decades and uses the information and data from these studies to improve the Agency’s understanding of human exposures to chemicals and other stressors and ultimately to support efforts to improve public health. Because these studies involve people as research participants, they are complex and raise numerous scientific and ethical issues that have to be addressed prior to and during their design and implementation. To ensure that EPA’s research continues to be based on the most up-to-date science and the highest ethical standards, the Agency has developed this document that contains state-of-the-science approaches for conducting observational human exposure studies. This document is not meant to represent an official Agency “guidance document” but, rather, serves as a resource tool and source of information for NERL and other researchers on which to rely as they develop and conduct observational human exposure studies.

Using video-based observation research methods in primary care health encounters to evaluate complex interactions.

PubMed

Asan, Onur; Montague, Enid

2014-01-01

The purpose of this paper is to describe the use of video-based observation research methods in primary care environment and highlight important methodological considerations and provide practical guidance for primary care and human factors researchers conducting video studies to understand patient-clinician interaction in primary care settings. We reviewed studies in the literature which used video methods in health care research, and we also used our own experience based on the video studies we conducted in primary care settings. This paper highlighted the benefits of using video techniques, such as multi-channel recording and video coding, and compared "unmanned" video recording with the traditional observation method in primary care research. We proposed a list that can be followed step by step to conduct an effective video study in a primary care setting for a given problem. This paper also described obstacles, researchers should anticipate when using video recording methods in future studies. With the new technological improvements, video-based observation research is becoming a promising method in primary care and HFE research. Video recording has been under-utilised as a data collection tool because of confidentiality and privacy issues. However, it has many benefits as opposed to traditional observations, and recent studies using video recording methods have introduced new research areas and approaches.

A Quasi-experimental outcomes analysis of a psychoeducation intervention for pregnant women with abuse-related posttraumatic stress.

PubMed

Rowe, Heather; Sperlich, Mickey; Cameron, Heather; Seng, Julia

2014-01-01

To test the effectiveness of a trauma-specific, psychoeducational intervention for pregnant women with a history of childhood maltreatment on six intrapartum and postpartum psychological outcomes. Quasi-experimental study comparing women from a single-group, pretest-posttest pilot intervention study with women matched from a prospective observational study. Rural and university-based prenatal clinics. Pregnant women entered the study by responding to an advertisement or by referral from a maternity care provider. Women could take part whether or not they met posttraumatic stress disorder diagnostic criteria. Outcomes data exist for 17 pilot intervention study participants and 43 matched observational study participants. Participants in the observational study received usual care. Participants in the pilot intervention study received usual care plus the intervention, a fully manualized, self-study program supported by weekly phone tutoring sessions with a health professional. The National Women's Study PTSD Module, the Peritraumatic Dissociation Experience Questionnaire, the Perception of Care Questionnaire, the Postpartum Depression Screening Scale, the Postpartum Bonding Questionnaire, and a semantic differential appraisal of the labor experience. Participants in the intervention study had better scores on all measures. Differences in means between participants in the intervention study and participants in the observational study equated to medium effect sized for dissociation during labor, rating of labor experience, and perception of care in labor and small effect sizes for postpartum posttraumatic stress disorder (PTSD) symptoms, postpartum depression symptoms, and motherinfant bonding. This trauma-specific intervention reaches and benefits pregnant women with a history of childhood maltreatment. © 2014 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

A quasi-experimental outcomes analysis of a psychoeducation intervention for pregnant women with abuse-related posttraumatic stress

PubMed Central

Rowe, Heather; Sperlich, Mickey; Seng, Julia S.

2015-01-01

Objective To test the effectiveness of a trauma-specific psycho-educational intervention for pregnant women with a history of childhood maltreatment on six intrapartum and postpartum psychological outcomes. Design Quasi-experimental study comparing women from a single-group pretest-posttest pilot intervention study with women matched from a prospective observational study. Setting Rural and university-based prenatal clinics. Participants Pregnant women entered the study by responding to an advertisement or by referral from a maternity care provider. Women could take part whether or not they met posttraumatic stress disorder diagnostic criteria. Outcomes data exist for 17 pilot intervention study participants and 43 matched observational study participants. Interventions Participants in the observational study received usual care. Participants in the pilot intervention study received usual care plus the intervention, a fully manualized self-study program supported by weekly phone tutoring sessions with a health professional. Main Outcome Measures The National Women’s Study PTSD Module; The Peritraumatic Dissociation Experience Questionnaire); The Perception of Care Questionnaire; The Postpartum Depression Screening Scale; The Postpartum Bonding Questionnaire; and a semantic differential appraisal of the labor experience. Results Participants in the intervention study had better scores on all measures. Differences in means between participants in the intervention study and participants in the observational study equated to medium effect sized for dissociation during labor, rating of labor experience, and perception of care in labor, and small effect sizes for postpartum PTSD symptoms, postpartum depression symptoms, and mother-infant bonding. Conclusion This trauma-specific intervention reaches and benefits pregnant women with a history of childhood maltreatment. PMID:24754455

Design and implementation of observational studies to measure disease burden with a focus on stroke.

PubMed

Howard, George; Howard, Virginia J

2018-02-01

Observational epidemiological studies have the dual goals of measuring disease burden and assessing the association between exposures and outcomes. This report focuses on the first of these goals and provides an overview of design considerations of commonly used approaches, specifically community surveillance studies, cross-sectional studies, and longitudinal cohort studies. Each of these designs has strengths and weaknesses, with no study design being superior in all cases. Rather, these designs are complementary to achieve a better understanding of the burden of stroke.

Amateur boxing and risk of chronic traumatic brain injury: systematic review of observational studies

PubMed Central

Knowles, Charles H; Whyte, Greg P

2007-01-01

Objective To evaluate the risk of chronic traumatic brain injury from amateur boxing. Setting Secondary research performed by combination of sport physicians and clinical academics. Design, data sources, and methods Systematic review of observational studies in which chronic traumatic brain injury was defined as any abnormality on clinical neurological examination, psychometric testing, neuroimaging studies, and electroencephalography. Studies were identified through database (1950 to date) and bibliographic searches without language restrictions. Two reviewers extracted study characteristics, quality, and data, with adherence to a protocol developed from a widely recommended method for systematic review of observational studies (MOOSE). Results 36 papers had relevant extractable data (from a detailed evaluation of 93 studies of 943 identified from the initial search). Quality of evidence was generally poor. The best quality studies were those with a cohort design and those that used psychometric tests. These yielded the most negative results: only four of 17 (24%) better quality studies found any indication of chronic traumatic brain injury in a minority of boxers studied. Conclusion There is no strong evidence to associate chronic traumatic brain injury with amateur boxing. PMID:17916811

Amateur boxing and risk of chronic traumatic brain injury: systematic review of observational studies.

PubMed

Loosemore, Mike; Knowles, Charles H; Whyte, Greg P

2007-10-20

To evaluate the risk of chronic traumatic brain injury from amateur boxing. Secondary research performed by combination of sport physicians and clinical academics. DESIGN, DATA SOURCES, AND METHODS: Systematic review of observational studies in which chronic traumatic brain injury was defined as any abnormality on clinical neurological examination, psychometric testing, neuroimaging studies, and electroencephalography. Studies were identified through database (1950 to date) and bibliographic searches without language restrictions. Two reviewers extracted study characteristics, quality, and data, with adherence to a protocol developed from a widely recommended method for systematic review of observational studies (MOOSE). 36 papers had relevant extractable data (from a detailed evaluation of 93 studies of 943 identified from the initial search). Quality of evidence was generally poor. The best quality studies were those with a cohort design and those that used psychometric tests. These yielded the most negative results: only four of 17 (24%) better quality studies found any indication of chronic traumatic brain injury in a minority of boxers studied. There is no strong evidence to associate chronic traumatic brain injury with amateur boxing.

Antioxidants and cancer therapy: a systematic review.

PubMed

Ladas, Elena J; Jacobson, Judith S; Kennedy, Deborah D; Teel, Katherine; Fleischauer, Aaron; Kelly, Kara M

2004-02-01

Many patients with cancer take antioxidant nutritional supplements during cancer treatment to alleviate treatment toxicities and to improve long-term outcomes, but little is known about the efficacy and safety of antioxidant use during cancer treatment. We reviewed English-language manuscripts published in the biomedical literature, reporting the results of observational studies of antioxidant status and cancer outcomes and of intervention trials of antioxidants among patients receiving chemotherapy with or without radiation for various malignancies. We searched the Medline database and the bibliographies of the retrieved manuscripts, reviews, and books on antioxidants and cancer. The retrieved studies are grouped by study design, malignancy, and end points. More than 100 citations were retrieved; 52 met our criteria, 31 were observational studies, and 21 were intervention trials. The studies varied in study design, timing of observation/intervention, intervention protocol, malignancy, and anticancer regimen. These inconsistencies preclude a definitive conclusion as to the effect of chemotherapy on antioxidant status in patients undergoing anticancer therapy. However, our review suggests that total antioxidant status (measured by total radical antioxidant parameter) declines during cancer treatment. Adequately powered trials or observational studies among patients with a specific cancer diagnosis receiving a specific treatment regimen are needed to address patients' and physicians' concerns regarding these associations.

An Ethnographic Case Study of the Administrative Organization, Processes, and Behavior in a Model Comprehensive High School.

ERIC Educational Resources Information Center

Zimman, Richard N.

Using ethnographic case study methodology (involving open-ended interviews, participant observation, and document analysis) theories of administrative organization, processes, and behavior were tested during a three-week observation of a model comprehensive (experimental) high school. Although the study is limited in its general application, it…

Reading Instruction for Students with Learning Disabilities: An Observation Study Synthesis (1980-2014)

ERIC Educational Resources Information Center

Walker, Melodee A.; Stevens, Elizabeth A.

2017-01-01

This article synthesizes observation studies investigating reading instruction for students with learning disabilities (LD) in Grades K-12. A systematic search of the literature between 1980 and 2014 resulted in the identification of 25 studies. In addition to replicating and extending E. A. Swanson's synthesis, the research questions of studies…

Dietary patterns are associated with disease risk among participants in the women's health initiative observational study

USDA-ARS?s Scientific Manuscript database

Coronary heart disease (CHD) is the leading cause of death in women. A nested case-control study tested whether dietary patterns predicted CHD events among 1224 participants in the Women’s Health Initiative-Observational Study (WHI-OS) with centrally confirmed CHD, fatal or nonfatal myocardial infar...

Using and Experiencing the Academic Library: A Multisite Observational Study of Space and Place

ERIC Educational Resources Information Center

May, Francine; Swabey, Alice

2015-01-01

This study examines how students are using academic library spaces and the role these spaces are playing in the campus community. Data were collected on five campuses (two community colleges, two undergraduate universities, and one technical institute) via observational seating sweeps and questionnaires. The study found remarkably similar usage…

Comparison of Observational Methods and Their Relation to Ratings of Engagement in Young Children

ERIC Educational Resources Information Center

Wood, Brenna K.; Hojnoski, Robin L.; Laracy, Seth D.; Olson, Christopher L.

2016-01-01

Although, collectively, results of earlier direct observation studies suggest momentary time sampling (MTS) may offer certain technical advantages over whole-interval (WIR) and partial-interval (PIR) recording, no study has compared these methods for measuring engagement in young children in naturalistic environments. This study compared direct…

A Naturalistic Observational Study of Informal Segregation: Seating Patterns in Lectures

ERIC Educational Resources Information Center

Koen, Jennifer; Durrheim, Kevin

2010-01-01

In spite of the removal of legislated racial segregation, a number of observational studies in South Africa and elsewhere have shown that "informal," nonlegislated segregation persists in spaces of everyday interaction. Most of these have been case studies of segregation at single sites. The authors seek to quantify segregation in a…

Teaching the Poor in Turkey: A Phenomenological Insight

ERIC Educational Resources Information Center

Ömür, Yunus Emre

2018-01-01

The purpose of this study was to analyze how primary school classroom teachers experienced teaching poor students. This study was designed in a phenomenological approach. To fulfill the aim of the study, in-depth and focus group interviews were held as well as classroom observations. The data gathered through interviews and observations was…

A Phenomenological Case Study: Teacher Bias Effects on Early Education Assessments

ERIC Educational Resources Information Center

Reynolds, Rebecca Jeannine

2012-01-01

This qualitative phenomenological case study explored the lived experiences of a purposive sample of 20 current and past early education teachers who have experience in assessing children through observational assessment. The purpose of this study was to determine if bias affects the documentation of observational assessment and the implementation…

Digital spatial data for observed, predicted, and misclassification errors for observations in the training dataset for nitrate and arsenic concentrations in basin-fill aquifers in the Southwest Principal Aquifers study area

USGS Publications Warehouse

McKinney, Tim S.; Anning, David W.

2012-01-01

This product "Digital spatial data for observed, predicted, and misclassification errors for observations in the training dataset for nitrate and arsenic concentrations in basin-fill aquifers in the Southwest Principal Aquifers study area" is a 1:250,000-scale point spatial dataset developed as part of a regional Southwest Principal Aquifers (SWPA) study (Anning and others, 2012). The study examined the vulnerability of basin-fill aquifers in the southwestern United States to nitrate contamination and arsenic enrichment. Statistical models were developed by using the random forest classifier algorithm to predict concentrations of nitrate and arsenic across a model grid that represents local- and basin-scale measures of source, aquifer susceptibility, and geochemical conditions.

Topical Review: Integrating Findings on Direct Observation of Family Communication in Studies Comparing Pediatric Chronic Illness and Typically Developing Samples.

PubMed

Murphy, Lexa K; Murray, Caitlin B; Compas, Bruce E

2017-01-01

To review research on observed family communication in families with children with chronic illnesses compared with families with healthy, typically developing children, and to integrate findings utilizing a unifying family communication framework. Topical review of studies that have directly observed family communication in pediatric populations and included a typically developing comparison group. Initial findings from 14 studies with diverse approaches to quantifying observed family communication suggest that families with children with chronic illnesses may demonstrate lower levels of warm and structured communication and higher levels of hostile/intrusive and withdrawn communication compared with families with healthy, typically developing children. An integrative framework of family communication may be used in future studies that examine the occurrence, correlates, and mechanisms of family communication in pediatric populations.

EMC Aspects of Turbulence Heating ObserveR (THOR) Spacecraft

NASA Astrophysics Data System (ADS)

Soucek, J.; Ahlen, L.; Bale, S.; Bonnell, J.; Boudin, N.; Brienza, D.; Carr, C.; Cipriani, F.; Escoubet, C. P.; Fazakerley, A.; Gehler, M.; Genot, V.; Hilgers, A.; Hanock, B.; Jannet, G.; Junge, A.; Khotyaintsev, Y.; De Keyser, J.; Kucharek, H.; Lan, R.; Lavraud, B.; Leblanc, F.; Magnes, W.; Mansour, M.; Marcucci, M. F.; Nakamura, R.; Nemecek, Z.; Owen, C.; Phal, Y.; Retino, A.; Rodgers, D.; Safrankova, J.; Sahraoui, F.; Vainio, R.; Wimmer-Schweingruber, R.; Steinhagen, J.; Vaivads, A.; Wielders, A.; Zaslavsky, A.

2016-05-01

Turbulence Heating ObserveR (THOR) is a spacecraft mission dedicated to the study of plasma turbulence in near-Earth space. The mission is currently under study for implementation as a part of ESA Cosmic Vision program. THOR will involve a single spinning spacecraft equipped with state of the art instruments capable of sensitive measurements of electromagnetic fields and plasma particles. The sensitive electric and magnetic field measurements require that the spacecraft- generated emissions are restricted and strictly controlled; therefore a comprehensive EMC program has been put in place already during the study phase. The THOR study team and a dedicated EMC working group are formulating the mission EMC requirements already in the earliest phase of the project to avoid later delays and cost increases related to EMC. This article introduces the THOR mission and reviews the current state of its EMC requirements.

Strategies to Make Ramadan Fasting Safer in Type 2 Diabetics: A Systematic Review and Network Meta-analysis of Randomized Controlled Trials and Observational Studies.

PubMed

Lee, Shaun Wen Huey; Lee, Jun Yang; Tan, Christina San San; Wong, Chee Piau

2016-01-01

Ramadan is the holy month for Muslims whereby they fast from predawn to after sunset and is observed by all healthy Muslim adults as well as a large population of type 2 diabetic Muslims.To determine the comparative effectiveness of various strategies that have been used for type 2 diabetic Muslim who fast during Ramadan.A systematic review and network meta-analysis of randomized controlled studies (RCT) as well as observational studies for patients with type 2 diabetes who fasted during Ramadan was conducted. Eight databases were searched from January 1980 through October 2015 for relevant studies. Two reviewers independently screened and assessed study for eligibility, assessed the risk of bias, and extracted relevant data. A network meta-analysis for each outcome was fitted separately, combining direct and indirect evidence for each comparison.Twenty-nine studies, 16 RCTs and 13 observational studies each met the inclusion criteria. The most common strategy used was drug changes during the Ramadan period, which found that the use of DPP-4 (Dipeptidyl peptidase inhibitor -4) inhibitors were associated with a reduction in incidence of experiencing hypoglycemia during Ramadan in both RCTs (pooled relative risk: 0.56; 95% confidence interval: 0.44-0.72) as well as in observational studies (pooled relative risk: 0.27; 0.09-0.75). Ramadan-focused education was shown to be beneficial in reducing hypoglycemia in observational studies but not RCTs (0.25 versus 1.00). Network meta-analyses suggest that incretin mimetics can reduce the risk of hypoglycemia by nearly 1.5 times.The newer antidiabetic agents appear to lower the risk of hypoglycemia and improved glycemic control when compared with sulfonylureas. Ramadan-focused education shows to be a promising strategy but more rigorous examination from RCTs are required.

[Patients' perspective and economic variables as objectives in clinical trials: added value to clinical parameters].

PubMed

Bovaira-García, M J; Soler-Company, E

2012-01-01

Patient-reported outcome (PRO) measures complement traditional biomedical outcome measures. The purpose of this study was to evaluate the use of PRO measures including health-related quality of life (HRQoL) questionnaires as a measurement of efficacy and the frequency of inclusion of economic variables related to direct and indirect costs in the design of clinical trials and phase IV observational studies. Moreover, for the trials quality score were measured, and if there were any relationship between the quality study design score and the PRO inclusion. Retrospective observational study of the clinical trials and phase IV observational studies approved by a Clinical Research Ethics Committee (2008-2010). We gathered data concerning general aspects including medical specialty, pathology, methodological quality based on Jadad scale (0-5), inclusion of PRO and economic variables. For clinical trials including HRQoL measurements, we analysed the type of questionnaire in use. Where there were no HRQoL measurements, we analysed if their inclusion would have been proper or not. A total of 70 protocols (59 CTs and 11 phase IV observational studies) were analysed; 37 (52.8%) included PRO measures, and 3 protocols (4.3%) used them as a primary endpoint. Data analysis by therapeutic area showed that PRO measures were most commonly studied in the fields of endocrinology, neurology, digestive diseases, and cardiology. The average quality score for the trials was 2.8. The trials with more PRO inclusion in their end points had a significantly higher quality score. Only 13 (22%) clinical trials and 2 (18.2%) phase IV observational studies included economic variables. The emergence of economic variables in clinical trials and phase IV observational studies evaluated was low, however, more than half of the revised protocols have included PRO measures, reflecting the importance of these parameters in the assessment of the effectiveness of drug treatments, although its use is still not systematic. Copyright © 2011 SECA. Published by Elsevier Espana. All rights reserved.

Evaluation of a rule-based method for epidemiological document classification towards the automation of systematic reviews.

PubMed

Karystianis, George; Thayer, Kristina; Wolfe, Mary; Tsafnat, Guy

2017-06-01

Most data extraction efforts in epidemiology are focused on obtaining targeted information from clinical trials. In contrast, limited research has been conducted on the identification of information from observational studies, a major source for human evidence in many fields, including environmental health. The recognition of key epidemiological information (e.g., exposures) through text mining techniques can assist in the automation of systematic reviews and other evidence summaries. We designed and applied a knowledge-driven, rule-based approach to identify targeted information (study design, participant population, exposure, outcome, confounding factors, and the country where the study was conducted) from abstracts of epidemiological studies included in several systematic reviews of environmental health exposures. The rules were based on common syntactical patterns observed in text and are thus not specific to any systematic review. To validate the general applicability of our approach, we compared the data extracted using our approach versus hand curation for 35 epidemiological study abstracts manually selected for inclusion in two systematic reviews. The returned F-score, precision, and recall ranged from 70% to 98%, 81% to 100%, and 54% to 97%, respectively. The highest precision was observed for exposure, outcome and population (100%) while recall was best for exposure and study design with 97% and 89%, respectively. The lowest recall was observed for the population (54%), which also had the lowest F-score (70%). The generated performance of our text-mining approach demonstrated encouraging results for the identification of targeted information from observational epidemiological study abstracts related to environmental exposures. We have demonstrated that rules based on generic syntactic patterns in one corpus can be applied to other observational study design by simple interchanging the dictionaries aiming to identify certain characteristics (i.e., outcomes, exposures). At the document level, the recognised information can assist in the selection and categorization of studies included in a systematic review. Copyright © 2017 Elsevier Inc. All rights reserved.

A Puzzle Unsolved: Failure to Observe Different Effects of God and Religion Primes on Intergroup Attitudes

PubMed Central

Ramsay, Jonathan E.; Tong, Eddie M. W.; Pang, Joyce S.; Chowdhury, Avijit

2016-01-01

Religious priming has been found to have both positive and negative consequences, and recent research suggests that the activation of God-related and community-related religious cognitions may cause outgroup prosociality and outgroup derogation respectively. The present research sought to examine whether reminders of God and religion have different effects on attitudes towards ingroup and outgroup members. Over two studies, little evidence was found for different effects of these two types of religious primes. In study 1, individuals primed with the words “religion”, “God” and a neutral control word evaluated both ingroup and outgroup members similarly, although a marginal tendency towards more negative evaluations of outgroup members by females exposed to religion primes was observed. In study 2, no significant differences in attitudes towards an outgroup member were observed between the God, religion, and neutral priming conditions. Furthermore, the gender effect observed in study 1 did not replicate in this second study. Possible explanations for these null effects are discussed. PMID:26812526

A Puzzle Unsolved: Failure to Observe Different Effects of God and Religion Primes on Intergroup Attitudes.

PubMed

Ramsay, Jonathan E; Tong, Eddie M W; Pang, Joyce S; Chowdhury, Avijit

2016-01-01

Religious priming has been found to have both positive and negative consequences, and recent research suggests that the activation of God-related and community-related religious cognitions may cause outgroup prosociality and outgroup derogation respectively. The present research sought to examine whether reminders of God and religion have different effects on attitudes towards ingroup and outgroup members. Over two studies, little evidence was found for different effects of these two types of religious primes. In study 1, individuals primed with the words "religion", "God" and a neutral control word evaluated both ingroup and outgroup members similarly, although a marginal tendency towards more negative evaluations of outgroup members by females exposed to religion primes was observed. In study 2, no significant differences in attitudes towards an outgroup member were observed between the God, religion, and neutral priming conditions. Furthermore, the gender effect observed in study 1 did not replicate in this second study. Possible explanations for these null effects are discussed.

On the Numerical Study of Heavy Rainfall in Taiwan

NASA Technical Reports Server (NTRS)

Tao, Wei-Kuo; Chen, Ching-Sen; Chen, Yi-Leng; Jou, Ben Jong-Dao; Lin, Pay-Liam; Starr, David OC. (Technical Monitor)

2001-01-01

Heavy rainfall events are frequently observed over the western side of the CMR (central mountain range), which runs through Taiwan in a north-south orientation, in a southwesterly flow regime and over the northeastern side of the CMR in a northeasterly flow regime. Previous studies have revealed the mechanisms by which the heavy rainfall events are formed. Some of them have examined characteristics of the heavy rainfall via numerical simulations. In this paper, some of the previous numerical studies on heavy rainfall events around Taiwan during the Mei-Yu season (May and June), summer (non-typhoon cases) and autumn will be reviewed. Associated mechanisms proposed from observational studies will be reviewed first, and then characteristics of numerically simulated heavy rainfall events will be presented. The formation mechanisms of heavy rainfall from simulated results and from observational analysis are then compared and discussed. Based on these previous modeling studies, we will also discuss what are the major observations and modeling processes which will be needed for understanding the heavy precipitation in the future.

Radar studies of bird migration

NASA Technical Reports Server (NTRS)

Williams, T. C.; Williams, J. M.

1974-01-01

Observations of bird migration with NASA radars were made at Wallops Island, Va. Simultaneous observations were made at a number of radar sites in the North Atlantic Ocean in an effort to discover what happened to those birds that were observed leaving the coast of North America headed toward Bermuda, the Caribbean and South America. Transatlantic migration, utilizing observations from a large number of radars is discussed. Detailed studies of bird movements at Wallops Island are presented.

The Relationship Between Observations and Measures of Oral and Pharyngeal Residue from Videofluorography and Scintigraphy

PubMed Central

Logemann, Jeri A.; Williams, Rohan B.; Rademaker, Alfred; Pauloski, Barbara Roa; Lazarus, Cathy L.; Cook, Ian

2006-01-01

We examined measures of oral and pharyngeal residues from scintigraphic studies and estimates/observations from videofluorographic (modified barium swallow) studies taken on the same day but not concurrently in 16 dysphagic patients of varying etiologies presenting with oral and/or pharyngeal dysphagia. Oral and pharyngeal residuals following the swallow were quantified scintigraphically and were then compared with measures of residuals obtained from the modified barium swallow. Estimates of oral and pharyngeal residues from the modified barium swallows were generated by a trained observer who was blinded to the scintigraphic data. Positive and significant Spearman correlations between oral and pharyngeal residue measures from scintigraphy and observations of oral and pharyngeal residues from modified barium swallows were found. This supports the validity of observations of oral and pharyngeal residues in clinical studies. Limitations of these observations are discussed. PMID:16362511

Radiation energy budget studies using collocated AVHRR and ERBE observations

NASA Technical Reports Server (NTRS)

Ackerman, Steven A.; Inoue, Toshiro

1994-01-01

Changes in the energy balance at the top of the atmosphere are specified as a function of atmospheric and surface properties using observations from the Advanced Very High Resolution Radiometer (AVHRR) and the Earth Radiation Budget Experiment (ERBE) scanner. By collocating the observations from the two instruments, flown on NOAA-9, the authors take advantage of the remote-sensing capabilities of each instrument. The AVHRR spectral channels were selected based on regions that are strongly transparent to clear sky conditions and are therefore useful for characterizing both surface and cloud-top conditions. The ERBE instruments make broadband observations that are important for climate studies. The approach of collocating these observations in time and space is used to study the radiative energy budget of three geographic regions: oceanic, savanna, and desert.

Observer Agreement for Measurements in Videolaryngostroboscopy.

PubMed

Brunings, Jan Wouter; Vanbelle, Sophie; Akkermans, Annemarie; Heemskerk, Nienke M M; Kremer, Bernd; Stokroos, Robert J; Baijens, Laura W J

2017-11-06

This study evaluated the levels of intraobserver and interobserver agreement for measurements of visuoperceptual variables in videolaryngostroboscopic examinations and compared the observers' behavior during independent versus consensus panel rating. This is a retrospective study. This study was conducted in a single-center tertiary care facility. Sixty-four patients with dysphonia of heterogeneous etiology were included. All subjects underwent a standardized videolaryngostroboscopic examination. Two experienced and trained observers scored exactly the same examinations, first independently and then on a consensus panel. Specific visuoperceptual variables and the clinical diagnosis (as recommended by the Committee on Phoniatrics and the Phonosurgery Committee of the European Laryngological Society and advised by the American Speech-Language-Hearing Association) were scored. Descriptive and kappa statistics were used. In general, intraobserver agreement was better than agreement between observers for measurements of several variables. The intrapanel observer agreement levels were slightly higher than the intraobserver agreement levels on the independent rating task. When rating on the consensus panel, the observers deviated considerably from the scores they had previously given on the independent rating task. Observer agreement in videolaryngostroboscopic assessment has important implications not only for the diagnosis and treatment of dysphonic patients but also for the interpretation of the results of scientific studies using videolaryngostroboscopic outcome parameters. The identification of factors that can influence the levels of observer agreement can provide a better understanding of the rating process and its limitations. The results of this study suggest that future research could achieve better agreement levels by rating the visuoperceptual variables in a panel setting. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Observed Sensitivity during Family Interactions and Cumulative Risk: A Study of Multiple Dyads per Family

ERIC Educational Resources Information Center

Browne, Dillon T.; Leckie, George; Prime, Heather; Perlman, Michal; Jenkins, Jennifer M.

2016-01-01

The present study sought to investigate the family, individual, and dyad-specific contributions to observed cognitive sensitivity during family interactions. Moreover, the influence of cumulative risk on sensitivity at the aforementioned levels of the family was examined. Mothers and 2 children per family were observed interacting in a round robin…

Peer Observation, Feedback and Reflection for Development of Practice in Synchronous Online Teaching

ERIC Educational Resources Information Center

Jones, Mark H.; Gallen, Anne-Marie

2016-01-01

Peer observation of teaching is an established developmental tool in face-to-face settings. While there have been studies into peer observation as applied to asynchronous online teaching, less is known about its application to teaching online using synchronous communication systems. We describe a small-scale study of an online peer observation…

The Validity of Observational Measures in Detecting Optimal Maternal Communication Styles: Evidence from European Americans and Latinos

ERIC Educational Resources Information Center

Nadeem, Erum; Romo, Laura F.; Sigman, Marian; Lefkowitz, Eva S.; Au, Terry K.

2007-01-01

This study examined the sensitivity of an observational coding system for assessing positive and negative maternal behaviors of Latino and European American mothers toward their adolescent children. Ninety Latino (54 Spanish speaking and 35 English speaking) and 20 European American mother-adolescent dyads participated in an observational study of…

A Classroom Observational Study of Qatar's Independent Schools: Instruction and School Reform

ERIC Educational Resources Information Center

Palmer, Douglas J.; Sadiq, Hissa M.; Lynch, Patricia; Parker, Dawn; Viruru, Radhika; Knight, Stephanie; Waxman, Hersh; Alford, Beverly; Brown, Danielle Bairrington; Rollins, Kayla; Stillisano, Jacqueline; Abu-Tineh, Abdullah M. Hamdan; Nasser, Ramzi; Allen, Nancy; Al-Binali, Hessa; Ellili, Maha; Al-Kateeb, Haithem; Al-Kubaisi, Huda

2016-01-01

Qatar initiated a K-12 national educational reform in 2001. However, there is limited information on the instructional practices of the teachers in the reform schools. This project was an observational study of classrooms with a stratified random sample of the first six cohorts of reform schools. Specifically, 156 classrooms were observed in 29…

An Introduction to Propensity Score Methods for Reducing the Effects of Confounding in Observational Studies

ERIC Educational Resources Information Center

Austin, Peter C.

2011-01-01

The propensity score is the probability of treatment assignment conditional on observed baseline characteristics. The propensity score allows one to design and analyze an observational (nonrandomized) study so that it mimics some of the particular characteristics of a randomized controlled trial. In particular, the propensity score is a balancing…

A Sociocultural-Theory-Based Study of the Impact of Mediation during Post- Observation Conferences on Language Teacher Learning

ERIC Educational Resources Information Center

Harvey, Jane

2011-01-01

The post-observation conference offers a potentially fecund context for promoting language teacher learning, but very little research has been conducted into how this actually happens. Taking Vygotskian sociocultural theory as its theoretical framework, this study examined the mediational discourse of a series of post-observation conferences…

Alternative Observation Tools for the Scope of Contemporary Education Supervision: An Action Research

ERIC Educational Resources Information Center

Kuru Cetin, Saadet

2018-01-01

In this study, in-class lesson observations were made with volunteer teachers working in primary and secondary schools using alternative observation tools regarding the scope of contemporary educational supervision. The study took place during the fall and spring semesters of the 2015-2016 and 2016-2017 academic years and the class observations…

The reporting of observational research studies in dermatology journals: a literature-based study.

PubMed

Langan, Sinéad; Schmitt, Jochen; Coenraads, Pieter-Jan; Svensson, Ake; von Elm, Erik; Williams, Hywel

2010-05-01

To assess the quality of reporting in observational studies in dermatology. Five dermatology journals-the Archives of Dermatology, the British Journal of Dermatology, the Journal of the American Academy of Dermatology, the Journal of Investigative Dermatology, and Acta Dermato-Venereologica. Cohort, case-control, and cross-sectional studies published as original articles during the period January 2005 through December 2007. Studies were identified with a literature search of PubMed combining the journal title and the term epidemiological studies (free text) and by hand searching all of the issues of each journal to identify relevant articles. All articles were extracted by 2 reviewers independently using standardized checklists based on the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations. The number and proportion of reported STROBE items were analyzed for each article. The proportion of studies with good reporting for each item was also assessed. A total of 138 articles were included and analyzed. Reporting quality was very mixed. Key areas that were infrequently reported included sample size calculations (n = 10 [7%]), missing data (n = 8 [6%]), losses to follow-up (n = 17 [12%]), and statistical methods (n = 19 [14%]). Only 13 studies (9%) explained the role of funders in the research. The quality of reporting was similar across study designs for "critical" questions with the exception of reporting of participant details, which was better reported in cohort studies (96%) compared with cross-sectional (80%) and case-control (70%) studies. It is difficult to judge the quality of dermatological research unless it is reported well. This study has identified a clear need to improve the quality of reporting of observational studies in dermatology. We recommend that dermatology journals adopt the STROBE criteria.

[Quality analysis of observational studies on pelvic organ prolapse in China].

PubMed

Wang, Y T; Tao, L Y; He, H J; Han, J S

2017-06-25

Objective: To evaluate the quality of observational studies on pelvic organ prolapse in China. Methods: The checklist of strengthening the reporting of observational studies in epidemiology (STROBE) statement was applied to evaluate the observational studies. The articles were searched in the SinoMed database using the terms: prolapse, uterine prolapse, cystocele, rectal prolapse and pelvic floor; limited to Chinese core journals in obstetrics and gynecology from January 1996 to December 2015. With two 10-year groups (1996-2005 and 2006-2015), the χ(2) test was used to evaluate inter-group differences. Results: (1) A total of 386 observational studies were selected, including 15.5%(60/386) of case-control studies, 80.6%(311/386) of cohort studies and 3.9% (15/386) of cross-sectional studies. (2) There were totally 22 items including 34 sub-items in the checklist. There were 17 sub-items (50.0%, 17/34) had a reporting ratio less than 50% in all of aticles, including: 1a (study's design) 3.9% (15/386), 6a (participants) 24.6% (95/386), 6b (matched studies) 0 (0/386), 9 (bias) 8.3% (32/386), 10 (study size) 3.9%, 11 (quantitative variables) 41.2% (159/386), 12b-12e (statistical methods in detail) 0-2.6% (10/386), 13a (numbers of individuals at each stage of study) 18.9% (73/386), 13b (reasons for non-participation at each stage) 18.9%, 13c (flow diagram) 0, 16b and 16c (results of category boundaries and relative risk) 9.6% (37/386) and 0, 19 (limitations) 31.6% (122/386), 22 (funding) 20.5% (79/386). (3) The quality of articles published in the two decades (1996-2005 and 2006-2015) were compared, and 38.2%(13/34) of sub-items had been significantly improved in the second 10-year (all P< 0.05). The improved items were as follows: 1b (integrity of abstract), 2 (background/rationale), 6a (participants), 7 (variables), 8 (data sources/measurement), 9 (bias), 11 (quantitative variables), 12a (statistical methods), 17 (other analyses), 18 (key results), 19 (limitations), 21 (generalisability), 22 (funding). Conclusions: The quality of observational studies on POP in China is suboptimal in half of evaluation items. However, the quality of articles published in the second 10-year have significantly improved.

Does Digital Game Interactivity Always Promote Self-Efficacy?

PubMed

Lee, Yu-Hao

2015-11-01

Interactive digital games can promote self-efficacy by engaging players in enactive and observational learning. However, interactivity does not always lead to greater self-efficacy. Important constructs in social cognitive theory, such as performance outcome and perceived similarity, are often not accounted for in studies that have tested the effect of digital game interactivity on self-efficacy. This study assessed the effects of interactive digital games compared with passive digital games based on video comparison, a common experimental design used to test the effect of digital game interactivity on self-efficacy. In addition, this study also evaluated player performance and measured perceived similarity to the observed player. Findings suggested that in general, digital game interactivity predicted higher self-efficacy compared with noninteractive passive games. However, in the noninteractive conditions, the effects of performance on self-efficacy were moderated by perceived similarity between the observer and the observed player. When the observed player was perceived to be similar to the observer, the effects of performance on self-efficacy were comparable to the interactive game, but when the observed player was perceived as dissimilar to the observer, observing the dissimilar player failed to increase observer self-efficacy. Implications for interactivity manipulations and game developers are discussed.

Observation and Modeling of the Generation Mechanism of Ion Upflow during Sudden Commencement

NASA Astrophysics Data System (ADS)

Zou, S.; Ozturk, D. S.; Li, C.; Varney, R. H.; Reimer, A.

2017-12-01

Sudden commencement (SC) induced by solar wind pressure enhancement can produce significant global impact on the coupled magnetosphere-ionosphere (MI) system, and its effects have been studied extensively using ground magnetometers and coherent scatter radars. However, very limited observations have been reported about the effects of SC on the ionospheric plasma. We study the ionosphere response to the SC using the Poker Flat incoherent scatter radar (PFISR) and numerical simulations. A detailed case study of SC during the 17 March 2015 storm was conducted. PFISR observed lifting of the F region ionosphere, transient field-aligned ion upflow, prompt but short-lived ion temperature increase, subsequent F region density decrease, and persistent electron temperature increase. A global magnetohydrodynamic (MHD) simulation has been carried out to characterize the SC-induced current, convection, and magnetic perturbations. Simulated magnetic perturbations at Poker Flat show a satisfactory agreement with observations. The simulation provides a global context for linking localized PFISR observations to large-scale dynamic processes in the MI system. Following the case study, we also perform a statistical study of the effects of SC on the ionosphere focusing on the magnetic local time and latitudinal asymmetries using PFISR and GPS TEC.

Testing the Reliability of Cluster Mass Indicators with a Systematics Limited Dataset

NASA Technical Reports Server (NTRS)

Juett, Adrienne M.; Davis, David S.; Mushotzky, Richard

2009-01-01

We present the mass X-ray observable scaling relationships for clusters of galaxies using the XMM-Newton cluster catalog of Snowden et al. Our results are roughly consistent with previous observational and theoretical work, with one major exception. We find 2-3 times the scatter around the best fit mass scaling relationships as expected from cluster simulations or seen in other observational studies. We suggest that this is a consequence of using hydrostatic mass, as opposed to virial mass, and is due to the explicit dependence of the hydrostatic mass on the gradients of the temperature and gas density profiles. We find a larger range of slope in the cluster temperature profiles at radii 500 than previous observational studies. Additionally, we find only a weak dependence of the gas mass fraction on cluster mass, consistent with a constant. Our average gas mass fraction results also argue for a closer study of the systematic errors due to instrumental calibration and modeling method variations between analyses. We suggest that a more careful study of the differences between various observational results and with cluster simulations is needed to understand sources of bias and scatter in cosmological studies of galaxy clusters.

Does Helicobacter pylori infection play a role in iron deficiency anemia? A meta-analysis

PubMed Central

Qu, Xin-Hua; Huang, Xiao-Lu; Xiong, Ping; Zhu, Cui-Ying; Huang, You-Liang; Lu, Lun-Gen; Sun, Xu; Rong, Lan; Zhong, Liang; Sun, Da-Yu; Lin, Hai; Cai, Ming-Ci; Chen, Zhi-Wei; Hu, Bing; Wu, Lian-Ming; Jiang, Yi-Bin; Yan, Wei-Li

2010-01-01

AIM: To perform a meta-analysis of observational studies and randomized controlled trials (RCTs) on the association between Helicobacter pylori (H. pylori) and iron deficiency anemia (IDA). METHODS: A defined search strategy was used to search Medline, Embase, the Cochrane Library, Clinical Trials, Cochrane Central Register of Controlled Trials, Premedline and Healthstar. Odds ratio (OR) was used to evaluate observational epidemiology studies, and weighted mean difference (WMD) was used to demonstrate the difference between control and intervention groups. RESULTS: Fifteen observational studies and 5 RCTs were identified and used for calculation. The pooled OR for observational studies was 2.22 (95% CI: 1.52-3.24, P < 0.0001). The WMD for hemoglobin (HB) was 4.06 g/L (95% CI: -2.57-10.69, P = 0.01), and the WMD for serum ferritin (SF) was 9.47 μg/L (95% CI: -0.50-19.43, P < 0.0001). Results were heterogeneous for all comparisons. CONCLUSION: This meta-analysis on observational studies suggests an association between H. pylori and IDA. In RCTs, eradication of H. pylori can improve HB and SF levels but not significantly. PMID:20143469

The spatial and temporal domains of modern ecology.

PubMed

Estes, Lyndon; Elsen, Paul R; Treuer, Timothy; Ahmed, Labeeb; Caylor, Kelly; Chang, Jason; Choi, Jonathan J; Ellis, Erle C

2018-05-01

To understand ecological phenomena, it is necessary to observe their behaviour across multiple spatial and temporal scales. Since this need was first highlighted in the 1980s, technology has opened previously inaccessible scales to observation. To help to determine whether there have been corresponding changes in the scales observed by modern ecologists, we analysed the resolution, extent, interval and duration of observations (excluding experiments) in 348 studies that have been published between 2004 and 2014. We found that observational scales were generally narrow, because ecologists still primarily use conventional field techniques. In the spatial domain, most observations had resolutions ≤1 m 2 and extents ≤10,000 ha. In the temporal domain, most observations were either unreplicated or infrequently repeated (>1 month interval) and ≤1 year in duration. Compared with studies conducted before 2004, observational durations and resolutions appear largely unchanged, but intervals have become finer and extents larger. We also found a large gulf between the scales at which phenomena are actually observed and the scales those observations ostensibly represent, raising concerns about observational comprehensiveness. Furthermore, most studies did not clearly report scale, suggesting that it remains a minor concern. Ecologists can better understand the scales represented by observations by incorporating autocorrelation measures, while journals can promote attentiveness to scale by implementing scale-reporting standards.

Investigating the relationship between two home numeracy measures: A questionnaire and observations during Lego building and book reading.

PubMed

Mutaf Yildiz, Belde; Sasanguie, Delphine; De Smedt, Bert; Reynvoet, Bert

2018-06-01

Home numeracy has been defined as the parent-child interactions that include experiences with numerical content in daily-life settings. Previous studies have commonly operationalized home numeracy either via questionnaires or via observational methods. These studies have shown that both types of measures are positively related to variability in children's mathematical skills. This study investigated whether these distinctive data collection methods index the same aspect of home numeracy. The frequencies of home numeracy activities and parents' opinions about their children's mathematics education were assessed via a questionnaire. The amount of home numeracy talk was observed via two semi-structured videotaped parent-child activity sessions (Lego building and book reading). Children's mathematical skills were examined with two calculation subtests. We observed that parents' reports and number of observed numeracy interactions were not related to each other. Interestingly, parents' reports of numeracy activities were positively related to children's calculation abilities, whereas the observed home numeracy talk was negatively related to children's calculation abilities. These results indicate that these two methods tap on different aspects of home numeracy. Statement of contribution What is already known on this subject? Home numeracy, that is, parent-child interactions that include experiences with numerical content, is supposed to have a positive impact on calculation or mathematical ability in general. Despite many positive results, some studies have failed to find such an association. Home numeracy has been assessed with questionnaires on the frequency of numerical experiences and observations of parent-child interactions; however, those two measures of home numeracy have never been compared directly. What does this study add? This study assessed home numeracy through questionnaires and observations in the 44 parent-child dyads and showed that home numeracy measures derived from questionnaires and observations are not related. Moreover, the relation between the reported frequency of home numeracy activities and calculation on the one hand, and parent-child number talk (derived from observations) and calculation on the other hand is in opposite directions; the frequency of activities is positively related to calculation performance; and the amount of number talk is negatively related to calculation. This study shows that both measures tap into different aspects of home numeracy and can be an important factor explaining inconsistencies in literature. © 2018 The British Psychological Society.

Observing Protein & Energy Nutrition (OPEN) Study

Cancer.gov

The Observing Protein and Energy Nutrition (OPEN) Study was designed to assess dietary measurement error by comparing results from self-reported dietary intake data with four dietary biomarkers: doubly labeled water and urinary nitrogen, sodium, and potassium.

Community Engagement in Observational Human Exposure Studies

EPA Science Inventory

Although observational human exposure studies do not deliberately expose participants to chemicals or environmental conditions, merely involving people as research participants and conducting research inside homes raises ethical issues. Community engagement offers a promising st...

Effectiveness, safety and health-related quality of life of multiple sclerosis patients treated with fingolimod: results from a 12-month, real-world, observational PERFORMS study in the Middle East.

PubMed

Achiron, Anat; Aref, Hany; Inshasi, Jihad; Harb, Mohamad; Alroughani, Raed; Bijarnia, Mahendra; Cooke, Kathryn; Yuksel, Ozgur

2017-08-07

Evidence on the use of fingolimod in real-world clinical practice and data on patient-reported health-related quality of life (HRQoL) in countries such as the Middle East are sparse. The Prospective Evaluation of Treatment with Fingolimod for Multiple Sclerosis (PERFORMS) study assessed HRQoL and effectiveness and safety of fingolimod in patients with relapsing-remitting multiples sclerosis (RRMS), primarily in Middle Eastern countries. This 12-month, observational, multicentre, prospective, real-world study was conducted in patients with RRMS who initiated fingolimod or another approved disease-modifying treatment (DMT) within 4 weeks before study entry. Patients were enrolled in a 2:1 ratio to obtain more data in fingolimod and parallel in other DMTs cohort by physicians during routine medical care. Key study outcomes included HRQoL assessed using MS International QoL (MusiQoL), MS relapses and disability. Safety was assessed throughout the study period. Due to the observational nature of the study, no neuroimaging assessments were mandated and central reading was not performed. Of 249 enrolled patients, 247 were included in the analysis (fingolimod cohort 172; other DMTs cohort 75). Overall, the mean age of patients was 36.5 years, 64.4% were women and ~90% were Caucasians. At baseline, mean MS duration since diagnosis was 7.2 years in the fingolimod and 4.8 years in the other DMTs cohorts. Overall, mean changes in MusiQoL index scores were -2.1 in the fingolimod cohort and -0.7 in the other DMTs cohort at Month 12, but improvement was not significant vs. baseline in both cohorts. Proportion of relapse-free patients increased significantly during the study vs. 0-12 months before the study in the fingolimod cohort (80.2% vs. 24.4%; p < 0.0001). Proportion of patients free from disability progression was 86.5% in the fingolimod cohort. The incidences of AEs were 59.9% and 50.6% in the fingolimod and other DMTs cohorts, respectively. First-dose monitoring of fingolimod observed no cases of symptomatic bradyarrhythmia. Three cases of bradycardia were reported in the fingolimod cohort: one after the first dose and two during the study. No cases of macular oedema were observed during the study. Fingolimod treatment maintained QoL over 12 months and was effective in reducing relapse rate and disability progression. No new safety findings were observed in this real-world observational study in Middle Eastern countries.

Night Shift Work and Risk of Depression: Meta-analysis of Observational Studies.

PubMed

Lee, Aeyoung; Myung, Seung Kwon; Cho, Jung Jin; Jung, Yu Jin; Yoon, Jong Lull; Kim, Mee Young

2017-07-01

This study aimed to assess whether night shift work is associated with the risk of depression by using a meta-analysis of observational studies. We searched PubMed and EMBASE in August, 2016 to locate eligible studies and investigated the association between night shift work and the risk of depression, reporting outcome measures with adjusted odds ratios (ORs) or relative risks (RRs) and 95% confidence intervals (CIs). In the meta-analysis of a total of 11 observational studies with 9 cross-sectional study, 1 longitudinal study, and 1 cohort study, night shift work was significantly associated with an increased risk of depression (OR/RR, 1.43; 95% CI, 1.24-1.64; I² = 78.0%). Also, subgroup meta-analyses by gender, night shift work duration, type of occupation, continent, and type of publication showed that night shift work was consistently associated with the increased risk of depression. The current meta-analysis suggests that night shift work is associated with the increased risk of depression. However, further large prospective cohort studies are needed to confirm this association. © 2017 The Korean Academy of Medical Sciences.

Night Shift Work and Risk of Depression: Meta-analysis of Observational Studies

PubMed Central

2017-01-01

This study aimed to assess whether night shift work is associated with the risk of depression by using a meta-analysis of observational studies. We searched PubMed and EMBASE in August, 2016 to locate eligible studies and investigated the association between night shift work and the risk of depression, reporting outcome measures with adjusted odds ratios (ORs) or relative risks (RRs) and 95% confidence intervals (CIs). In the meta-analysis of a total of 11 observational studies with 9 cross-sectional study, 1 longitudinal study, and 1 cohort study, night shift work was significantly associated with an increased risk of depression (OR/RR, 1.43; 95% CI, 1.24–1.64; I2 = 78.0%). Also, subgroup meta-analyses by gender, night shift work duration, type of occupation, continent, and type of publication showed that night shift work was consistently associated with the increased risk of depression. The current meta-analysis suggests that night shift work is associated with the increased risk of depression. However, further large prospective cohort studies are needed to confirm this association. PMID:28581264

Single-Incision Multiport/Single Port Laparoscopic Abdominal Surgery (SILAP): A Prospective Multicenter Observational Quality Study.

PubMed

Mantke, Rene; Diener, Markus; Kropf, Siegfried; Otto, Ronny; Manger, Thomas; Vestweber, Boris; Mirow, Lutz; Winde, Günther; Lippert, Hans

2016-09-07

Increasing experience with minimally invasive surgery and the development of new instruments has resulted in a tendency toward reducing the number of abdominal skin incisions. Retrospective and randomized prospective studies could show the feasibility of single-incision surgery without any increased risk to the patient. However, large prospective multicenter observational datasets do not currently exist. This prospective multicenter observational quality study will provide a relevant dataset reflecting the feasibility and safety of single-incision surgery. This study focuses on external validity, clinical relevance, and the patients' perspective. Accordingly, the single-incision multiport/single port laparoscopic abdominal surgery (SILAP) study will supplement the existing evidence, which does not currently allow evidence-based surgical decision making. The SILAP study is an international prospective multicenter observational quality study. Mortality, morbidity, complications during surgery, complications postoperatively, patient characteristics, and technical aspects will be monitored. We expect more than 100 surgical centers to participate with 5000 patients with abdominal single-incision surgery during the study period. Funding was obtained in 2012. Enrollment began on January 01, 2013, and will be completed on December 31, 2018. As of January 2016, 2119 patients have been included, 106 German centers are registered, and 27 centers are very active (>5 patients per year). This prospective multicenter observational quality study will provide a relevant dataset reflecting the feasibility and safety of single-incision surgery. An international enlargement and recruitment of centers outside of Germany is meaningful. German Clinical Trials Register: DRKS00004594; https://drks-neu.uniklinik-freiburg.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00004594 (Archived by WebCite at http://www.webcitation.org/6jK6ZVyUs).

Media Coverage, Journal Press Releases and Editorials Associated with Randomized and Observational Studies in High-Impact Medical Journals: A Cohort Study

PubMed Central

Wang, Michael T. M.; Bolland, Mark J.; Gamble, Greg; Grey, Andrew

2015-01-01

Background Publication of clinical research findings in prominent journals influences health beliefs and medical practice, in part by engendering news coverage. Randomized controlled trials (RCTs) should be most influential in guiding clinical practice. We determined whether study design of clinical research published in high-impact journals influences media coverage. Methods and Findings We compared the incidence and amount of media coverage of RCTs with that of observational studies published in the top 7 medical journals between 1 January 2013 and 31 March 2013. We specifically assessed media coverage of the most rigorous RCTs, those with >1000 participants that reported ‘hard’ outcomes. There was no difference between RCTs and observational studies in coverage by major newspapers or news agencies, or in total number of news stories generated (all P>0.63). Large RCTs reporting ‘hard’ outcomes did not generate more news coverage than small RCTs that reported surrogate outcomes and observational studies (all P>0.32). RCTs were more likely than observational studies to attract a journal editorial (70% vs 46%, P = 0.003), but less likely to be the subject of a journal press release (17% vs 50%, P<0.001). Large RCTs that reported ‘hard’ outcomes did not attract an editorial more frequently than other studies (61% vs 58%, P>0.99), nor were they more likely to be the subject of a journal press release (14% vs 38%, P = 0.14). Conclusions The design of clinical studies whose results are published in high-impact medical journals is not associated with the likelihood or amount of ensuing news coverage. PMID:26701758

Consumer food handling in the home: a review of food safety studies.

PubMed

Redmond, Elizabeth C; Griffith, Christopher J

2003-01-01

Epidemiological data from Europe, North America, Australia, and New Zealand indicate that a substantial proportion of foodborne disease is attributable to improper food preparation practices in consumers' homes. International concern about consumer food safety has prompted considerable research to evaluate domestic food-handling practices. The majority of consumer food safety studies in the last decade have been conducted in the United Kingdom and Northern Ireland (48%) and in the United States (42%). Surveys (questionnaires and interviews), the most frequent means of data collection, were used in 75% of the reviewed studies. Focus groups and observational studies have also been used. One consumer food safety study examined the relationship between pathogenic microbial contamination from raw chicken and observed food-handling behaviors, and the results of this study indicated extensive Campylobacter cross-contamination during food preparation sessions. Limited information about consumers' attitudes and intentions with regard to safe food-handling behaviors has been obtained, although a substantial amount of information about consumer knowledge and self-reported practices is available. Observation studies suggest that substantial numbers of consumers frequently implement unsafe food-handling practices. Knowledge, attitudes, intentions, and self-reported practices did not correspond to observed behaviors, suggesting that observational studies provide a more realistic indication of the food hygiene actions actually used in domestic food preparation. An improvement in consumer food-handling behavior is likely to reduce the risk and incidence of foodborne disease. The need for the development and implementation of food safety education strategies to improve specific food safety behaviors is reviewed in this paper.

Diagnostic inaccuracy and subject exclusions render placebo and observational studies of acute otitis media inconclusive.

PubMed

Pichichero, Michael E; Casey, Janet R

2008-11-01

Diagnostic accuracy and appropriate inclusion/exclusion criteria representative of children at greatest risk is of paramount importance in trials to evaluate placebo or observation as an option for acute otitis media (AOM) management. Twelve observational studies spanning the time frame 1958-2005 and 13 natural history studies spanning the time frame 1968-2006 were evaluated for the diagnostic criteria, inclusion criteria, and exclusion criteria applied within the study design. Although a bulging or full tympanic membrane (TM) with effusion is the best indication of a diagnosis of bacterial AOM based on tympanocentesis findings, few observational and natural history studies required a bulging TM. Examination of subject inclusion criteria showed that many subjects did not have AOM but rather had no middle ear disease at all or they had otitis media with effusion. Exclusion criteria of subjects were also remarkable. Frequently children <2 years old were excluded; mean age among the studies reflected an older age group, unlike the true epidemiology of AOM. Otitis prone children, those with severe disease, with a bulging TM, with fever, with a definite need for antibiotics, with recent antibiotic treatment, with recent AOM, or with perforation of the TM were often excluded. Guidelines and some authorities have overlooked or discounted the importance of the issues of inaccurate diagnosis on study entry, broad inclusion criteria, and the creation of bias in exclusion criteria among placebo/natural history trials in AOM. The current data favoring observation of children with AOM should be reconsidered until better studies are conducted.

The use of dogs as second species in regulatory testing of pesticides. Part II: Subacute, subchronic and chronic studies in the dog.

PubMed

Spielmann, H; Gerbracht, U

2001-03-01

Data on 172 pesticides (fungicides, herbicides, insecticides and other pesticides) submitted for regulatory purposes during the past 40 years to the German Federal Institute for the Health Protection of Consumers and Veterinary Medicine (BgVV) were analysed to determine whether chronic studies in dogs (52/104 weeks) provide essential additional specific toxicological compared with subchronic (13 weeks) or subacute (4 weeks) studies in the same species. Comparison of the lowest observed effect levels (LOELs) in dogs revealed no significant differences between subchronic and chronic studies but a significant difference between subacute studies and subchronic or chronic studies. Moreover, there was a significant correlation between the LOELs determined in subchronic studies and those determined in chronic studies in dogs (r = 0.78-0.84). The distribution of target organ toxicity determined in chronic studies in dogs was not significantly different from the distribution determined in subchronic studies, except for effects on the spleen in studies on herbicides which were only observed in chronic studies and in combined subchronic/chronic studies, but never in subchronic studies. Organ-specific effects that were observed in chronic studies but not in subchronic studies were found in 30 of 55 studies on fungicides, in 25 of 44 on herbicides, in 17 of 38 on insecticides and in 10 of 16 on other pesticides. Compared with 26-week studies, additional organ-specific toxic effects were found in three of five, in three of four, in one of three and in one of one 52/104-week studies on fungicides, of herbicides, of insecticides and other pesticides, respectively. The organ-specific effects that were seen only in the chronic dog studies were evaluated according to their severity, e.g. significant damage to organs versus changes in enzyme activities that do not affect organ function or histology. Such effects were not considered to be specific for dogs in chronic studies if similar effects were also found in chronic studies in rodents (rat or mouse). In 15 of 141 studies in dogs serious side effects were observed in chronic studies that were not observed in subchronic studies. Furthermore, for 9 of 172 pesticides significant new effects were seen in 52/104-week studies when compared with 4- or 13-week studies and in 7 of 141 52/104-week studies when compared with 13-week studies. Analysis of the severity of organ-specific toxic effects of pesticides revealed that chronic long-term studies (52/104 weeks) in dogs do not provide specific additional information to 26-week studies in the same species.

Case Study: Interventions for an ADHD Student

ERIC Educational Resources Information Center

Hartlep, Nicholas Daniel

2009-01-01

This case study was done in partial fulfillment of a Master of Science in Education (M.S.Ed.) Graduate Course the participant-observer was completing. The participant-observer learned a lot about Dmitrov, the child in this study. Dmitrov was a 2nd-grade student who was diagnosed (late in the school year) with Attention Deficit Hyperactivity…

Prosocial Behaviors in Context: Examining the Role of Children's Social Companions

ERIC Educational Resources Information Center

de Guzman, Maria Rosario T.; Carlo, Gustavo; Edwards, Carolyn Pope

2008-01-01

This study examines the role of immediate social companions in the prosocial behaviors of children from two cultural communities from the USA and the Philippines. Materials for this study comprised behavioral observations drawn from the Six Cultures Study--with 612 five-minute observations of 23 children (12 girls, 11 boys) from Orchard Town, MA…

An Expressive Bodily Movement Repertoire for Marimba Performance, Revealed through Observers' Laban Effort-Shape Analyses, and Allied Musical Features: Two Case Studies.

PubMed

Broughton, Mary C; Davidson, Jane W

2016-01-01

Musicians' expressive bodily movements can influence observers' perception of performance. Furthermore, individual differences in observers' music and motor expertise can shape how they perceive and respond to music performance. However, few studies have investigated the bodily movements that different observers of music performance perceive as expressive, in order to understand how they might relate to the music being produced, and the particular instrument type. In this paper, we focus on marimba performance through two case studies-one solo and one collaborative context. This study aims to investigate the existence of a core repertoire of marimba performance expressive bodily movements, identify key music-related features associated with the core repertoire, and explore how observers' perception of expressive bodily movements might vary according to individual differences in their music and motor expertise. Of the six professional musicians who observed and analyzed the marimba performances, three were percussionists and experienced marimba players. Following training, observers implemented the Laban effort-shape movement analysis system to analyze marimba players' bodily movements that they perceived as expressive in audio-visual recordings of performance. Observations that were agreed by all participants as being the same type of action at the same location in the performance recording were examined in each case study, then across the two studies. A small repertoire of bodily movements emerged that the observers perceived as being expressive. Movements were primarily allied to elements of the music structure, technique, and expressive interpretation, however, these elements appeared to be interactive. A type of body sway movement and more localized sound generating actions were perceived as expressive. These movements co-occurred and also appeared separately. Individual participant data revealed slightly more variety in the types and locations of actions observed, with judges revealing preferences for observing particular types of expressive bodily movements. The particular expressive bodily movements that are produced and perceived in marimba performance appear to be shaped by music-related and sound generating features, musical context, and observer music and motor expertise. With an understanding of bodily movements that are generated and perceived as expressive, embodied music performance training programs might be developed to enhance expressive performer-audience communication.

Observer detection of image degradation caused by irreversible data compression processes

NASA Astrophysics Data System (ADS)

Chen, Ji; Flynn, Michael J.; Gross, Barry; Spizarny, David

1991-05-01

Irreversible data compression methods have been proposed to reduce the data storage and communication requirements of digital imaging systems. In general, the error produced by compression increases as an algorithm''s compression ratio is increased. We have studied the relationship between compression ratios and the detection of induced error using radiologic observers. The nature of the errors was characterized by calculating the power spectrum of the difference image. In contrast with studies designed to test whether detected errors alter diagnostic decisions, this study was designed to test whether observers could detect the induced error. A paired-film observer study was designed to test whether induced errors were detected. The study was conducted with chest radiographs selected and ranked for subtle evidence of interstitial disease, pulmonary nodules, or pneumothoraces. Images were digitized at 86 microns (4K X 5K) and 2K X 2K regions were extracted. A full-frame discrete cosine transform method was used to compress images at ratios varying between 6:1 and 60:1. The decompressed images were reprinted next to the original images in a randomized order with a laser film printer. The use of a film digitizer and a film printer which can reproduce all of the contrast and detail in the original radiograph makes the results of this study insensitive to instrument performance and primarily dependent on radiographic image quality. The results of this study define conditions for which errors associated with irreversible compression cannot be detected by radiologic observers. The results indicate that an observer can detect the errors introduced by this compression algorithm for compression ratios of 10:1 (1.2 bits/pixel) or higher.

Randomized Trials Built on Sand: Examples from COPD, Hormone Therapy, and Cancer

PubMed Central

Suissa, Samy

2012-01-01

The randomized controlled trial is the fundamental study design to evaluate the effectiveness of medications and receive regulatory approval. Observational studies, on the other hand, are essential to address post-marketing drug safety issues but have also been used to uncover new indications or new benefits for already marketed drugs. Hormone replacement therapy (HRT) for instance, effective for menopausal symptoms, was reported in several observational studies during the 1980s and 1990s to also significantly reduce the incidence of coronary heart disease. This claim was refuted in 2002 by the large-scale Women’s Health Initiative randomized trial. An example of a new indication for an old drug is that of metformin, an anti-diabetic medication, which is being hailed as a potential anti-cancer agent, primarily on the basis of several recent observational studies that reported impressive reductions in cancer incidence and mortality with its use. These observational studies have now sparked the conduct of large-scale randomized controlled trials currently ongoing in cancer. We show in this paper that the spectacular effects on new indications or new outcomes reported in many observational studies in chronic obstructive pulmonary disease (COPD), HRT, and cancer are the result of time-related biases, such as immortal time bias, that tend to seriously exaggerate the benefits of a drug and that eventually disappear with the proper statistical analysis. In all, while observational studies are central to assess the effects of drugs, their proper design and analysis are essential to avoid bias. The scientific evidence on the potential beneficial effects in new indications of existing drugs will need to be more carefully assessed before embarking on long and expensive unsubstantiated trials. PMID:23908838

Patent foramen ovale closure and medical treatments for secondary stroke prevention: a systematic review of observational and randomized evidence.

PubMed

Kitsios, Georgios D; Dahabreh, Issa J; Abu Dabrh, Abd Moain; Thaler, David E; Kent, David M

2012-02-01

Patients discovered to have a patent foramen ovale in the setting of a cryptogenic stroke may be treated with percutaneous closure, antiplatelet therapy, or anticoagulants. A recent randomized trial (CLOSURE I) did not detect any benefit of closure over medical treatment alone; the optimal medical therapy is also unknown. We synthesized the available evidence on secondary stroke prevention in patients with patent foramen ovale and cryptogenic stroke. A MEDLINE search was performed for finding longitudinal studies investigating medical treatment or closure, meta-analysis of incidence rates (IR), and IR ratios of recurrent cerebrovascular events. Fifty-two single-arm studies and 7 comparative nonrandomized studies and the CLOSURE I trial were reviewed. The summary IR of recurrent stroke was 0.36 events (95% confidence interval [CI], 0.24-0.56) per 100 person-years with closure versus 2.53 events (95% CI, 1.91-3.35) per 100 person-years with medical therapy. In comparative observational studies, closure was superior to medical therapy (IR ratio=0.19; 95% CI, 0.07-0.54). The IR for the closure arm of the CLOSURE I trial was higher than the summary estimate from observational studies; there was no significant benefit of closure over medical treatment (P=0.002 comparing efficacy estimates between observational studies and the trial). Observational and randomized data (9 studies) comparing medical therapies were consistent and suggested that anticoagulants are superior to antiplatelets for preventing stroke recurrence (IR ratio=0.42; 95% CI, 0.18-0.98). Although further randomized trial data are needed to precisely determine the effects of closure on stroke recurrence, the results of CLOSURE I challenge the credibility of a substantial body of observational evidence strongly favoring mechanical closure over medical therapy.

Studies in occultation astronomy

NASA Technical Reports Server (NTRS)

Veverka, J.

1980-01-01

Major scientific results are summarized for the following studies: (1) observations of the 8 April 1976 occultation of epsilon Geminorum by Mars; (2) studies in occultation techniques; and (3) the March 1974 occultation of Saturn by the Moon. A re-analysis of the 1974 lunar occultation of the Titan indicates that Titan is strongly limb darkened, with D approximately greater than 5800km; there is internal evidence in the data that Titan's atmosphere is inhomogeneous; and that observations are inconsistent with any sample homogeneous model atmosphere which matches the P (lambda) and Beta (lambda) observations of Titan.

Observance of Patient's Rights: A Survey on the Views of Patients, Nurses, and Physicians.

PubMed

Parsapoor, A; Mohammad, K; Malek Afzali, H; Ala'eddini, F; Larijani, B

2012-01-01

Assessment of patients' views about the observance of patients' rights in the health system is of great importance for evaluation of such systems. Comparing views of patients (recipients of health services) and physicians and nurses (health care providers) regarding the observance of various aspects of patients' rights at three hospitals representing three models of medical service provision (teaching, private, and public) is the main objective of this study. This was a cross-sectional descriptive and analytical study, and the information needed was gathered through questionnaires. They were filled out by an interviewer for patients, but self administered by physicians and nurses. The field of study consisted of three hospitals including a general teaching hospital, a private hospital, and a public hospital, all located in Tehran. The questionnaires contained some general questions regarding demographic information and 21 questions concerning the necessity of observing patient's rights. The questionnaires were initially filled out by a total of 143 patients, and then consigned to 143 nurses (response rate = 61.3%) and 82 physicians (response rate = 27.5%) to be completed. The rate of observance of each right was measured on a Likert scale ranging from zero (non-observance) to 10 (full observance). Considering abnormal distribution of the information, it was analyzed with non-parametrical tests using SPSS 11.5 software package. The results of this study showed that the study groups had different views about how well different aspects of patients' rights were observed. The highest level of disagreement was related to the right of choosing and deciding by the patients, which was not satisfactory in the teaching hospital. According to the results, it seems that healthcare providers, especially physicians, should be better informed of patients' right of access to information and right of choosing and deciding. Based on the observed disagreement between the views of the patients and those of the physicians in the present study, it can be asserted that the patients thought that the level of observance of these rights was lower in comparison with what the physicians thought.

The burden of responsibility: Interpersonal costs of high self-control.

PubMed

Koval, Christy Zhou; vanDellen, Michelle R; Fitzsimons, Gráinne M; Ranby, Krista W

2015-05-01

The psychological literature on self-control has illustrated the many benefits experienced by people with high self-control, who are more successful both personally and interpersonally. In the current research, we explore the possibility that having high self-control also may have some interpersonal costs, leading individuals to become burdened by others' reliance. In Studies 1 and 2, we examined the effects of actors' self-control on observers' performance expectations and found that observers had higher performance expectations for actors with high (vs. low) self-control. In Study 3, we tested the effect of actors' self-control on work assigned to actors and found that observers assigned greater workloads to actors with high (vs. low) self-control. In Study 4, we examined how actors and observers differed in their assessments of the effort expended by high and low self-control actors and found that observers (but not actors) reported that high self-control actors expended less effort than low self-control actors. Finally, we found that people high (vs. low) in self-control reported greater burden from the reliance of coworkers (Study 5) and romantic partners (Study 6), and this tendency led them to feel less satisfied with their relationships (Study 6). Together, results from these studies provide novel evidence that individuals' self-control affects others' attitudes and behaviors toward them, and suggest that these interpersonal dynamics can have negative consequences for high self-control individuals. (c) 2015 APA, all rights reserved).

Intraseasonal sea surface warming in the western Indian Ocean by oceanic equatorial Rossby waves

DTIC Science & Technology

2017-05-09

using observational and reanalysis products , respectively. In the heat budget, horizontal advection is the leading contributor to warming, in part due to...warming and cooling in these studies . SST is observed to maximize just ahead of MJO convection. After convection begins, SST rapidly cools and reaches a...minimum ~5 days later. However, several studies have observed a certain class of MJO events that deviate from the previously observed relationship of

Stress and social behaviors of maternally deprived captive giraffes (Giraffa camelopardalis).

PubMed

Siciliano-Martina, Leila; Martina, Jason P

2018-03-01

Maternal deprivation can cause long-term behavioral changes in captive mammals. Studies regarding captive ungulates have also indicated behavioral shifts in the presence of the animal keeping staff; however, little is known about these effects in captive giraffes (Giraffa camelopardalis). To examine this, we observed a population of reticulated giraffes composed of maternally raised and maternally deprived individuals by direct and camera observations at Binder Park Zoo, Battle Creek, Michigan. We conducted observations using a unique ethogram with special regard for behaviors that might indicate stress or anti-social tendencies. Several variables can interact to create behavioral changes; to account for this, our study design examined the interactive effects of observation technique, raising style, and temperature on giraffe behavior. The results of these observations showed a significant increase in the rate of stereotypic and antisocial behaviors resulting from the interaction of observation technique and raising style. Stereotypic behaviors in particular showed a marked increased during cooler temperatures among giraffes of all raising style. Likewise, raising style, observation technique, and their interaction significantly impacted the time spent rubbing the enclosure. The findings of this study suggest that captive giraffe behavior can be a complex response to multiple factors and studies only examining single factors might oversimplify behavioral shifts. © 2018 Wiley Periodicals, Inc.

Risk of bias and confounding of observational studies of Zika virus infection: A scoping review of research protocols.

PubMed

Reveiz, Ludovic; Haby, Michelle M; Martínez-Vega, Ruth; Pinzón-Flores, Carlos E; Elias, Vanessa; Smith, Emma; Pinart, Mariona; Broutet, Nathalie; Becerra-Posada, Francisco; Aldighieri, Sylvain; Van Kerkhove, Maria D

2017-01-01

Given the severity and impact of the current Zika virus (ZIKV) outbreak in the Americas, numerous countries have rushed to develop research studies to assess ZIKV and its potential health consequences. In an effort to ensure that studies are comprehensive, both internally and externally valid, and with reliable results, the World Health Organization, the Pan American Health Organization, Institut Pasteur, the networks of Fiocruz, the Consortia for the Standardization of Influenza Seroepidemiology (CONSISE) and the International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) have generated six standardized clinical and epidemiological research protocols and questionnaires to address key public health questions on ZIKV. We conducted a systematic search of ongoing study protocols related to ZIKV research. We analyzed the content of protocols of 32 cohort studies and 13 case control studies for systematic bias that could produce erroneous results. Additionally we aimed to characterize the risks of bias and confounding in observational studies related to ZIKV and to propose ways to minimize them, including the use of six newly standardized research protocols. Observational studies of ZIKV face an array of challenges, including measurement of exposure and outcomes (microcephaly and Guillain-Barré Syndrome). Potential confounders need to be measured where known and controlled for in the analysis. Selection bias due to non-random selection is a significant issue, particularly in the case-control design, and losses to follow-up is equally important for the cohort design. Observational research seeking to answer key questions on the ZIKV should consider these restrictions and take precautions to minimize bias in an effort to provide reliable and valid results. Utilization of the standardized research protocols developed by the WHO, PAHO, Institut Pasteur, and CONSISE will harmonize the key methodological aspects of each study design to minimize bias at different stages of the study. Biases need to be considered by researchers implementing the standardized protocols as well as by users of observational epidemiological studies of ZIKV.

Doctors or mid-level providers for abortion.

PubMed

Barnard, Sharmani; Kim, Caron; Park, Min Hae; Ngo, Thoai D

2015-07-27

The World Health Organization recommends that abortion can be provided at the lowest level of the healthcare system. Training mid-level providers, such as midwives, nurses and other non-physician providers, to conduct first trimester aspiration abortions and manage medical abortions has been proposed as a way to increase women's access to safe abortion procedures. To assess the safety and effectiveness of abortion procedures administered by mid-level providers compared to doctors. We searched the CENTRAL Issue 7, MEDLINE and POPLINE databases for comparative studies of doctor and mid-level providers of abortion services. We searched for studies published in any language from January 1980 until 15 August 2014. Randomised controlled trials (RCTs) (clustered or not clustered), prospective cohort studies or observational studies that compared the safety or effectiveness (or both) of any type of first trimester abortion procedure, administered by any type of mid-level provider or doctors, were eligible for inclusion in the review. Two independent review authors screened abstracts for eligibility and double-extracted data from the included studies using a pre-tested form. We meta-analysed primary outcome data using both fixed-effect and random-effects models to obtain pooled risk ratios (RR) with 95% confidence intervals (CIs). We carried out separate analyses by study design (RCT or cohort) and type of abortion procedure (medical versus surgical). Eight studies involving 22,018 participants met our eligibility criteria. Five studies (n = 18,962) assessed the safety and effectiveness of surgical abortion procedures administered by mid-level providers compared to doctors. Three studies (n = 3056) assessed the safety and effectiveness of medical abortion procedures. The surgical abortion studies (one RCT and four cohort studies) were carried out in the United States, India, South Africa and Vietnam. The medical abortion studies (two RCTs and one cohort study) were carried out in India, Sweden and Nepal. The studies included women with gestational ages up to 14 weeks for surgical abortion and nine weeks for medical abortion.Risk of selection bias was considered to be low in the three RCTs, unclear in four observational studies and high in one observational study. Concealment bias was considered to be low in the three RCTs and high in all five observational studies. Although none of the eight studies performed blinding of the participants to the provider type, we considered the performance bias to be low as this is part of the intervention. Detection bias was considered to be high in all eight studies as none of the eight studies preformed blinding of the outcome assessment. Attrition bias was low in seven studies and high in one, with over 20% attrition. We considered six studies to have unclear risk of selective reporting bias as their protocols had not been published. The remaining two studies had published their protocols. Few other sources of bias were found.Based on an analysis of three cohort studies, the risk of surgical abortion failure was significantly higher when provided by mid-level providers than when procedures were administered by doctors (RR 2.25, 95% CI 1.38 to 3.68), however the quality of evidence for this outcome was deemed to be very low. For surgical abortion procedures, we found no significant differences in the risk of complications between mid-level providers and doctors (RR 0.99, 95% CI 0.17 to 5.70 from RCTs; RR 1.38, 95% CI 0.70 to 2.72 from observational studies). When we combined the data for failure and complications for surgical abortion we found no significant differences between mid-level providers and doctors in both the observational study analysis (RR 1.36, 95% CI 0.86 to 2.14) and the RCT analysis (RR 3.07, 95% CI 0.16 to 59.08). The quality of evidence of the outcome for RCT studies was considered to be low and for observational studies very low. For medical abortion procedures the risk of failure was not different for mid-level providers or doctors (RR 0.81, 95% CI 0.48 to 1.36 from RCTs; RR 1.09, 95% CI 0.63 to 1.88 from observational studies). The quality of evidence of this outcome for the RCT analysis was considered to be high, although the quality of evidence of the observational studies was considered to be very low. There were no complications reported in the three medical abortion studies. There was no statistically significant difference in the risk of failure for medical abortions performed by mid-level providers compared with doctors. Observational data indicate that there may be a higher risk of abortion failure for surgical abortion procedures administered by mid-level providers, but the number of studies is small and more robust data from controlled trials are needed. There were no statistically significant differences in the risk of complications for first trimester surgical abortions performed by mid-level providers compared with doctors.

A Numerical Climate Observing Network Design Study

NASA Technical Reports Server (NTRS)

Stammer, Detlef

2003-01-01

This project was concerned with three related questions of an optimal design of a climate observing system: 1. The spatial sampling characteristics required from an ARGO system. 2. The degree to which surface observations from ARGO can be used to calibrate and test satellite remote sensing observations of sea surface salinity (SSS) as it is anticipated now. 3. The more general design of an climate observing system as it is required in the near future for CLIVAR in the Atlantic. An important question in implementing an observing system is that of the sampling density required to observe climate-related variations in the ocean. For that purpose this project was concerned with the sampling requirements for the ARGO float system, but investigated also other elements of a climate observing system. As part of this project we studied the horizontal and vertical sampling characteristics of a global ARGO system which is required to make it fully complementary to altimeter data with the goal to capture climate related variations on large spatial scales (less thanAttachment: 1000 km). We addressed this question in the framework of a numerical model study in the North Atlantic with an 1/6 horizontal resolution. The advantage of a numerical design study is the knowledge of the full model state. Sampled by a synthetic float array, model results will therefore allow to test and improve existing deployment strategies with the goal to make the system as optimal and cost-efficient as possible. Attachment: "Optimal observations for variational data assimilation".

Explanation and Elaboration Document for the STROBE-Vet Statement: Strengthening the Reporting of Observational Studies in Epidemiology - Veterinary Extension.

PubMed

O'Connor, A M; Sargeant, J M; Dohoo, I R; Erb, H N; Cevallos, M; Egger, M; Ersbøll, A K; Martin, S W; Nielsen, L R; Pearl, D L; Pfeiffer, D U; Sanchez, J; Torrence, M E; Vigre, H; Waldner, C; Ward, M P

2016-12-01

The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement was first published in 2007 and again in 2014. The purpose of the original STROBE was to provide guidance for authors, reviewers and editors to improve the comprehensiveness of reporting; however, STROBE has a unique focus on observational studies. Although much of the guidance provided by the original STROBE document is directly applicable, it was deemed useful to map those statements to veterinary concepts, provide veterinary examples and highlight unique aspects of reporting in veterinary observational studies. Here, we present the examples and explanations for the checklist items included in the STROBE-Vet Statement. Thus, this is a companion document to the STROBE-Vet Statement Methods and process document, which describes the checklist and how it was developed. © 2016 The Authors. Zoonoses and Public Health published by Blackwell Verlag GmbH.

Studying RR Lyrae Stars in M4 with K2

NASA Astrophysics Data System (ADS)

Kuehn, Charles A.; Drury, Jason; Moskalik, Pawel

2017-01-01

Observations by Kepler/K2 have revolutionized the study of RR Lyrae stars by allowing the detection of new phenomena, such as low amplitude additional modes and period doubling, which had not previously been seen from the ground. During its campaign 2, K2 observed the globular cluster M4, providing the first opportunity to study a sizeable group of RR Lyrae stars that belong to a single population; the other RR Lyrae stars that have been observed from space are field stars in the galactic halo and thus belong to an assortment of populations. We present the results of our study of the RR Lyrae variables in M4 from K2 photometry. We have identified additional, low amplitude pulsation modes in the two observed RRc stars. In three RRab stars we have found the Blazhko effect with periods of 16.6 days, 22.4 days, and 44.5 days.

Identification of potential hazards associated with new residential construction.

PubMed

Methner, M M

2000-02-01

There were several advantages and limitations of this observational study. The most important advantage of this study was the opportunity to observe residential construction workers performing their jobs. By observing work practices, valuable information was gathered about specific trades and their potential exposure to various chemical and physical agents. This information will be useful in guiding subsequent exposure assessments. Probably the greatest limitation of this study was the lack of participation by homebuilders. Ideally, observations of construction processes would have been more objective if the study included the participation of more than one homebuilder. Aside from one worker who was observed to wear safety glasses, leather gloves, and a dust mask, virtually no personal protective equipment (PPE) was observed onsite. Often small contractors do not have the financial resources necessary to procure the appropriate PPE and issue these items to the workers. Based on hazard prevalence, professional judgement, and the degree of hazardous product use, potential exposures that warrant quantitative sampling efforts during Phase 2 of this study are: bulldozer/backhoe operators--noise, vibration, diesel exhaust; concrete workers--naphtha, mineral spirits, Portland cement; asphalt workers--petroleum hydrocarbons, asphalt, mineral spirits; plumbers--methylethyl ketone, acetone, tetrahydrofuran, cyclohexanone; drywall finishers--total and respirable dust, hexane, acetone; painters--ethylene glycol, VOCs; masons--dust (during the preparation of mortar); floor preparation technicians--total and respirable dust; and ceramic tile installers--toluene, naphtha, silica (from grout powder).

Magnetic resonance imaging versus computed tomography to plan hemilaminectomies in chondrodystrophic dogs with intervertebral disc extrusion.

PubMed

Noyes, Julie A; Thomovsky, Stephanie A; Chen, Annie V; Owen, Tina J; Fransson, Boel A; Carbonneau, Kira J; Matthew, Susan M

2017-10-01

To determine the influence of preoperative computed tomography (CT) versus magnetic resonance (MR) on hemilaminectomies planned to treat thoracolumbar (TL) intervertebral disc (IVD) extrusions in chondrodystrophic dogs. Prospective clinical study. Forty chondrodystrophic dogs with TL IVD extrusion and preoperative CT and MR studies. MR and CT images were randomized and reviewed by 4 observers masked to the dog's identity and corresponding imaging studies. Observers planned the location along the spine, side, and extent (number of articular facets to be removed) based on individual reviews of CT and MR studies. Intra-observer agreement was determined between overall surgical plan, location, side, and size of the hemilaminectomy planned on CT versus MR of the same dog. Similar surgical plans were developed based on MR versus CT in 43.5%-66.6% of dogs, depending on the observer. Intra-observer agreement in location, side, and size of the planned hemilaminectomy based on CT versus MR ranged between 48.7%-66.6%, 87%-92%, and 51.2%-71.7% of dogs, respectively. Observers tended to plan larger laminectomy defects based on MR versus CT of the same dog. Findings from this study indicated considerable differences in hemilaminectomies planned on preoperative MR versus CT imaging. Surgical location and size varied the most; the side of planned hemilaminectomies was most consistent between imaging modalities. © 2017 The American College of Veterinary Surgeons.

Randomized controlled trials vs. observational studies: why not just live together?

PubMed

Faraoni, David; Schaefer, Simon Thomas

2016-10-21

Randomized controlled trials (RCTs) are considered the gold standard for clinical research, thus having a high impact on clinical guidelines and our daily patients' care. However, various treatment strategies which we consider "evidence based" have never been subject to a prospective RCT, as we would rate it unethical to withheld an established treatment to individuals in an placebo controlled trial.In a recent BMC Anesthesiology publication, Trentino et al. analyzed the usefulness of observational studies in assessing benefit and risk of different transfusion strategies. The authors nicely reviewed and summarized similarities and differences, advantages and limitations, between different study types frequently used in transfusion medicine. In this interesting article, the authors conclude, that 'when comparing the results of observational studies with RCTs assessing transfusion outcomes, it is important that one consider not only the study method, but also the key elements of the study design'. Thus, in this commentary we now discuss the pro's and con's of different study types, even irrespective of transfusion medicine.

Validation of an Instructional Observation Instrument for Teaching English as a Foreign Language in Spain

ERIC Educational Resources Information Center

Gomez-Garcia, Maria

2011-01-01

The design and validation of a classroom observation instrument to provide formative feedback for teachers of EFL in Spain is the overarching purpose of this study. This study proposes that a valid and reliable classroom observation instrument, based on effective practice in teaching EFL, can be developed and used in Spain to enable teachers to…

An Observational Study for Evaluating the Effects of Interpersonal Problem-Solving Skills Training on Behavioural Dimensions

ERIC Educational Resources Information Center

Anliak, Sakire; Sahin, Derya

2010-01-01

The present observational study was designed to evaluate the effectiveness of the I Can Problem Solve (ICPS) programme on behavioural change from aggression to pro-social behaviours by using the DECB rating scale. Non-participant observation method was used to collect data in pretest-training-posttest design. It was hypothesised that the ICPS…

The Effect of Using More than One Type of Teacher Observation System in the Same Study.

ERIC Educational Resources Information Center

Marston, Paul T.; Zimmerer, Linda K.

The multiple use of several classroom observation instruments was investigated to determine its influence upon the way an observer records behavior, since such an influence may cause discrepancies in findings between studies. Twenty-four volunteer students were divided into three groups and trained to use one or more of three classroom observation…

Diagnosing Pre-Service Science Teachers' Understanding of Chemistry Concepts by Using Computer-Mediated Predict-Observe-Explain Tasks

ERIC Educational Resources Information Center

Sesn, Burcin Acar

2013-01-01

The purpose of this study was to investigate pre-service science teachers' understanding of surface tension, cohesion and adhesion forces by using computer-mediated predict-observe-explain tasks. 22 third-year pre-service science teachers participated in this study. Three computer-mediated predict-observe-explain tasks were developed and applied…

The Divided Self: Overcoming the Internal Divisions in the Ethnographic Participant/Observer Role.

ERIC Educational Resources Information Center

Narney, Pam

A composition scholar conducted a study of peer response groups in a freshmen composition course to determine what leads to conflict among students in these groups. In the course of her study, however, she found herself deeply perplexed by conflicting roles she had to play as a participant/observer. The ethnographer as a participant/observer is,…

Assessing the Accuracy of Classwide Direct Observation Methods: Two Analyses Using Simulated and Naturalistic Data

ERIC Educational Resources Information Center

Dart, Evan H.; Radley, Keith C.; Briesch, Amy M.; Furlow, Christopher M.; Cavell, Hannah J.; Briesch, Amy M.

2016-01-01

Two studies investigated the accuracy of eight different interval-based group observation methods that are commonly used to assess the effects of classwide interventions. In Study 1, a Microsoft Visual Basic program was created to simulate a large set of observational data. Binary data were randomly generated at the student level to represent…

Ideology and gender: observers' system justification and targets' gender as interactive predictors of citizenship expectations.

PubMed

Chiaburu, Dan S; Harris, T Brad; Smith, Troy A

2014-01-01

We integrate system justification and social role theory to explain how observers' system justification and target employees' gender interact to predict observers' expectations of targets' sportsmanship citizenship behaviors. In contrast with social role theory predictions, observers did not expect greater levels of sportsmanship from women compared to men. Yet observers expected more sportsmanship from women (a) when observers were ideologically motivated by gender-specific beliefs (gender-specific system justification; Study 1) and (b) when system justification was cued experimentally (Study 2). A heretofore-unexamined aspect, observers' ideology, modifies their expectations of sportsmanship citizenship across target genders. This has implications for system justification, social role, and organizational citizenship theoretical perspectives.

Characteristics of Type I PSCs Derived from POAM Observations

NASA Technical Reports Server (NTRS)

Strawa, Anthony W.; Drdla, Katja; Bokarius, Konstantin; Fromm, Michael D.; Alfred, Jerome M.

2004-01-01

The characteristics of Polar Ozone and Aerosol Measurement III (POAM 3) observations of Type I Arctic Polar Stratospheric Clouds (PSCs) from 1998 to 2003 are studied using a scheme that discriminates Type la from Ib PSCs. The PSCs observed in these years are studied simultaneously by aligning the day in each year when the temperature associated with a POAM observation first reaches T(sub NAT). It is observed that PSC formation occurs within days of the minimum observation temperature reaching T(sub NAT) and that the majority of these first PSCs are Type Ia. Our observations support the hypothesis that heterogeneous freezing contributes at least in part to the freezing of solid phase PSCs.

A global logrank test for adaptive treatment strategies based on observational studies.

PubMed

Li, Zhiguo; Valenstein, Marcia; Pfeiffer, Paul; Ganoczy, Dara

2014-02-28

In studying adaptive treatment strategies, a natural question that is of paramount interest is whether there is any significant difference among all possible treatment strategies. When the outcome variable of interest is time-to-event, we propose an inverse probability weighted logrank test for testing the equivalence of a fixed set of pre-specified adaptive treatment strategies based on data from an observational study. The weights take into account both the possible selection bias in an observational study and the fact that the same subject may be consistent with more than one treatment strategy. The asymptotic distribution of the weighted logrank statistic under the null hypothesis is obtained. We show that, in an observational study where the treatment selection probabilities need to be estimated, the estimation of these probabilities does not have an effect on the asymptotic distribution of the weighted logrank statistic, as long as the estimation of the parameters in the models for these probabilities is n-consistent. Finite sample performance of the test is assessed via a simulation study. We also show in the simulation that the test can be pretty robust to misspecification of the models for the probabilities of treatment selection. The method is applied to analyze data on antidepressant adherence time from an observational database maintained at the Department of Veterans Affairs' Serious Mental Illness Treatment Research and Evaluation Center. Copyright © 2013 John Wiley & Sons, Ltd.

Using video-based observation research methods in primary care health encounters to evaluate complex interactions

PubMed Central

Asan, Onur; Montague, Enid

2015-01-01

Objective The purpose of this paper is to describe the use of video-based observation research methods in primary care environment and highlight important methodological considerations and provide practical guidance for primary care and human factors researchers conducting video studies to understand patient-clinician interaction in primary care settings. Methods We reviewed studies in the literature which used video methods in health care research and, we also used our own experience based on the video studies we conducted in primary care settings. Results This paper highlighted the benefits of using video techniques such as multi-channel recording and video coding and compared “unmanned” video recording with the traditional observation method in primary care research. We proposed a list, which can be followed step by step to conduct an effective video study in a primary care setting for a given problem. This paper also described obstacles researchers should anticipate when using video recording methods in future studies. Conclusion With the new technological improvements, video-based observation research is becoming a promising method in primary care and HFE research. Video recording has been under-utilized as a data collection tool because of confidentiality and privacy issues. However, it has many benefits as opposed to traditional observations, and recent studies using video recording methods have introduced new research areas and approaches. PMID:25479346

Many participants in inpatient rehabilitation can quantify their exercise dosage accurately: an observational study.

PubMed

Scrivener, Katharine; Sherrington, Catherine; Schurr, Karl; Treacy, Daniel

2011-01-01

Are inpatients undergoing rehabilitation who appear able to count exercises able to quantify accurately the amount of exercise they undertake? Observational study. Inpatients in an aged care rehabilitation unit and a neurological rehabilitation unit, who appeared able to count their exercises during a 1-2 min observation by their treating physiotherapist. Participants were observed for 30 min by an external observer while they exercised in the physiotherapy gymnasium. Both the participants and the observer counted exercise repetitions with a hand-held tally counter and the two tallies were compared. Of the 60 people admitted for aged care rehabilitation during the study period, 49 (82%) were judged by their treating therapist to be able to count their own exercise repetitions accurately. Of the 30 people admitted for neurological rehabilitation during the study period, 20 (67%) were judged by their treating therapist to be able to count their repetitions accurately. Of the 69 people judged to be accurate, 40 underwent observation while exercising. There was excellent agreement between these participants' counts of their exercise repetitions and the observers' counts, ICC (3,1) of 0.99 (95% CI 0.98 to 0.99). Eleven participants (28%) were in complete agreement with the observer. A further 19 participants (48%) varied from the observer by less than 10%. Therapists were able to identify a group of rehabilitation participants who were accurate in counting their exercise repetitions. Counting of exercise repetitions by therapist-selected patients is a valid means of quantifying exercise dosage during inpatient rehabilitation. Copyright © 2011 Australian Physiotherapy Association. Published by .. All rights reserved.

Evaluation of internal noise methods for Hotelling observers

NASA Astrophysics Data System (ADS)

Zhang, Yani; Pham, Binh T.; Eckstein, Miguel P.

2005-04-01

Including internal noise in computer model observers to degrade model observer performance to human levels is a common method to allow for quantitatively comparisons of human and model performance. In this paper, we studied two different types of methods for injecting internal noise to Hotelling model observers. The first method adds internal noise to the output of the individual channels: a) Independent non-uniform channel noise, b) Independent uniform channel noise. The second method adds internal noise to the decision variable arising from the combination of channel responses: a) internal noise standard deviation proportional to decision variable's standard deviation due to the external noise, b) internal noise standard deviation proportional to decision variable's variance caused by the external noise. We tested the square window Hotelling observer (HO), channelized Hotelling observer (CHO), and Laguerre-Gauss Hotelling observer (LGHO). The studied task was detection of a filling defect of varying size/shape in one of four simulated arterial segment locations with real x-ray angiography backgrounds. Results show that the internal noise method that leads to the best prediction of human performance differs across the studied models observers. The CHO model best predicts human observer performance with the channel internal noise. The HO and LGHO best predict human observer performance with the decision variable internal noise. These results might help explain why previous studies have found different results on the ability of each Hotelling model to predict human performance. Finally, the present results might guide researchers with the choice of method to include internal noise into their Hotelling models.

Biases and systematics in the observational derivation of galaxy properties: comparing different techniques on synthetic observations of simulated galaxies

NASA Astrophysics Data System (ADS)

Guidi, Giovanni; Scannapieco, Cecilia; Walcher, C. Jakob

2015-12-01

We study the sources of biases and systematics in the derivation of galaxy properties from observational studies, focusing on stellar masses, star formation rates, gas and stellar metallicities, stellar ages, magnitudes and colours. We use hydrodynamical cosmological simulations of galaxy formation, for which the real quantities are known, and apply observational techniques to derive the observables. We also analyse biases that are relevant for a proper comparison between simulations and observations. For our study, we post-process the simulation outputs to calculate the galaxies' spectral energy distributions (SEDs) using stellar population synthesis models and also generate the fully consistent far-UV-submillimetre wavelength SEDs with the radiative transfer code SUNRISE. We compared the direct results of simulations with the observationally derived quantities obtained in various ways, and found that systematic differences in all studied galaxy properties appear, which are caused by: (1) purely observational biases, (2) the use of mass-weighted and luminosity-weighted quantities, with preferential sampling of more massive and luminous regions, (3) the different ways of constructing the template of models when a fit to the spectra is performed, and (4) variations due to different calibrations, most notably for gas metallicities and star formation rates. Our results show that large differences can appear depending on the technique used to derive galaxy properties. Understanding these differences is of primary importance both for simulators, to allow a better judgement of similarities and differences with observations, and for observers, to allow a proper interpretation of the data.

Comparison of the medical students' perceived self-efficacy and the evaluation of the observers and patients.

PubMed

Ammentorp, Jette; Thomsen, Janus Laust; Jarbøl, Dorte Ejg; Holst, René; Øvrehus, Anne Lindebo Holm; Kofoed, Poul-Erik

2013-04-08

The accuracy of self-assessment has been questioned in studies comparing physicians' self-assessments to observed assessments; however, none of these studies used self-efficacy as a method for self-assessment. The aim of the study was to investigate how medical students' perceived self-efficacy of specific communication skills corresponds to the evaluation of simulated patients and observers. All of the medical students who signed up for an Objective Structured Clinical Examination (OSCE) were included. As a part of the OSCE, the student performance in the "parent-physician interaction" was evaluated by a simulated patient and an observer at one of the stations. After the examination the students were asked to assess their self-efficacy according to the same specific communication skills. The Calgary Cambridge Observation Guide formed the basis for the outcome measures used in the questionnaires. A total of 12 items was rated on a Likert scale from 1-5 (strongly disagree to strongly agree). We used extended Rasch models for comparisons between the groups of responses of the questionnaires. Comparisons of groups were conducted on dichotomized responses. Eighty-four students participated in the examination, 87% (73/84) of whom responded to the questionnaire. The response rate for the simulated patients and the observers was 100%. Significantly more items were scored in the highest categories (4 and 5) by the observers and simulated patients compared to the students (observers versus students: -0.23; SE:0.112; p=0.002 and patients versus students:0.177; SE:0.109; p=0.037). When analysing the items individually, a statistically significant difference only existed for two items. This study showed that students scored their communication skills lower compared to observers or simulated patients. The differences were driven by only 2 of 12 items. The results in this study indicate that self-efficacy based on the Calgary Cambridge Observation guide seems to be a reliable tool.

Evaluation of reporting quality for observational studies using routinely collected health data in pharmacovigilance.

PubMed

Nie, Xiaolu; Zhang, Ying; Wu, Zehao; Jia, Lulu; Wang, Xiaoling; Langan, Sinéad M; Benchimol, Eric I; Peng, Xiaoxia

2018-06-01

To appraise the reporting quality of studies which concerned linezolid related thrombocytopenia referring to REporting of studies Conducted using Observational Routinely-collected health Data (RECORD) statement. Medline, Embase, Cochrane library and clinicaltrial.gov were searched for observational studies concerning linezolid related thrombocytopenia using routinely collected health data from 2000 to 2017. Two reviewers screened potential eligible articles and extracted data independently. Finally, reporting quality assessment was performed by two senior researchers using RECORD statement. Of 25 included studies, 11 (44.0%) mentioned the type of data in the title and/or abstract. In 38 items derived from RECORD statement, the median number of items reported in the included studies was 22 (interquartile range (IQR) 18 to 27). Inadequate reporting issues were discovered in the following aspects: validation studies of the codes or algorithms, study size estimation, quantitative variables, subgroup statistical methods, missing data, follow-up/matching or sampling strategy, sensitivity analysis and cleaning methods, funding and role of funders and accessibility of protocol, raw data. This study provides the evidence that the reporting quality of post-marketing safety evaluation studies conducted using routinely collected health data was often insufficient. Future stakeholders are encouraged to endorse the RECORD guidelines in pharmacovigilance.

Individual and social learning processes involved in the acquisition and generalization of tool use in macaques

PubMed Central

Macellini, S.; Maranesi, M.; Bonini, L.; Simone, L.; Rozzi, S.; Ferrari, P. F.; Fogassi, L.

2012-01-01

Macaques can efficiently use several tools, but their capacity to discriminate the relevant physical features of a tool and the social factors contributing to their acquisition are still poorly explored. In a series of studies, we investigated macaques' ability to generalize the use of a stick as a tool to new objects having different physical features (study 1), or to new contexts, requiring them to adapt the previously learned motor strategy (study 2). We then assessed whether the observation of a skilled model might facilitate tool-use learning by naive observer monkeys (study 3). Results of study 1 and study 2 showed that monkeys trained to use a tool generalize this ability to tools of different shape and length, and learn to adapt their motor strategy to a new task. Study 3 demonstrated that observing a skilled model increases the observers' manipulations of a stick, thus facilitating the individual discovery of the relevant properties of this object as a tool. These findings support the view that in macaques, the motor system can be modified through tool use and that it has a limited capacity to adjust the learnt motor skills to a new context. Social factors, although important to facilitate the interaction with tools, are not crucial for tool-use learning. PMID:22106424

Eating under observation: a systematic review and meta-analysis of the effect that heightened awareness of observation has on laboratory measured energy intake.

PubMed

Robinson, Eric; Hardman, Charlotte A; Halford, Jason C G; Jones, Andrew

2015-08-01

Laboratory paradigms are commonly used to study human energy intake. However, the extent to which participants believe their eating behavior is being measured may affect energy intake and is a methodologic factor that has received little consideration. Our main objective was to examine available evidence for the effect that heightened awareness of observation has on energy intake in a laboratory setting. We systematically reviewed laboratory studies that allowed for experimental examination of the effect that heightened awareness of observation has on energy intake. From these experimental studies we combined effect estimates using inverse variance meta-analysis, calculating the standardized mean difference (SMD) in energy intake between heightened-awareness and control conditions and qualitatively synthesized potential moderators of this effect. Nine studies, providing 22 comparisons, were eligible for inclusion. These studies largely sampled young women and examined the energy intake of energy-dense snack foods. Evidence indicated that heightened awareness of observation was associated with reduced energy intake when compared with the control condition (random-effects SMD: 0.45; 95% CI: 0.25, 0.66; P < 0.0001). We found little evidence that the type of experimental manipulation used to heighten awareness moderated the overall effect. The available evidence to date suggests that heightened awareness of observation reduces energy intake in a laboratory setting. These findings suggest that laboratory studies should attempt to minimize the degree to which participants are aware that their eating behavior is being measured. © 2015 American Society for Nutrition.

Potential Pitfalls of Reporting and Bias in Observational Studies With Propensity Score Analysis Assessing a Surgical Procedure: A Methodological Systematic Review.

PubMed

Lonjon, Guillaume; Porcher, Raphael; Ergina, Patrick; Fouet, Mathilde; Boutron, Isabelle

2017-05-01

To describe the evolution of the use and reporting of propensity score (PS) analysis in observational studies assessing a surgical procedure. Assessing surgery in randomized controlled trials raises several challenges. Observational studies with PS analysis are a robust alternative for comparative effectiveness research. In this methodological systematic review, we identified all PubMed reports of observational studies with PS analysis that evaluated a surgical procedure and described the evolution of their use over time. Then, we selected a sample of articles published from August 2013 to July 2014 and systematically appraised the quality of reporting and potential bias of the PS analysis used. We selected 652 reports of observational studies with PS analysis. The publications increased over time, from 1 report in 1987 to 198 in 2013. Among the 129 reports assessed, 20% (n = 24) did not detail the covariates included in the PS and 77% (n = 100) did not report a justification for including these covariates in the PS. The rate of missing data for potential covariates was reported in 9% of articles. When a crossover by conversion was possible, only 14% of reports (n = 12) mentioned this issue. For matched analysis, 10% of articles reported all 4 key elements that allow for reproducibility of a PS-matched analysis (matching ratio, method to choose the nearest neighbors, replacement and method for statistical analysis). Observational studies with PS analysis in surgery are increasing in frequency, but specific methodological issues and weaknesses in reporting exist.

The role of vitamin D in the prevention of late-life depression.

PubMed

Okereke, Olivia I; Singh, Ankura

2016-07-01

In this article, we review current evidence regarding potential benefits of vitamin D for improving mood and reducing depression risk in older adults. We summarize gaps in knowledge and describe future efforts that may clarify the role of vitamin D in late-life depression prevention. MEDLINE and PsychINFO databases were searched for all articles on vitamin D and mood that had been published up to and including May 2015. Observational studies and randomized trials with 50 or more participants were included. We excluded studies that involved only younger adults and/or exclusively involved persons with current depression. Twenty observational (cross-sectional and prospective) studies and 10 randomized trials (nine were randomized placebo-controlled trials [RCTs]; one was a randomized blinded comparison trial) were reviewed. Inverse associations of vitamin D blood level or vitamin D intake with depression were found in 13 observational studies; three identified prospective relations. Results from all but one of the RCTs showed no statistically significant differences in depression outcomes between vitamin D and placebo groups. Observational studies were mostly cross-sectional and frequently lacked adequate control of confounding. RCTs often featured low treatment doses, suboptimal post-intervention changes in biochemical levels of vitamin D, and/or short trial durations. Vitamin D level-mood associations were observed in most, but not all, observational studies; results indicated that vitamin D deficiency may be a risk factor for late-life depression. However, additional data from well-designed RCTs are required to determine the impact of vitamin D in late-life depression prevention. Copyright © 2016 Elsevier B.V. All rights reserved.

WRF nested large-eddy simulations of deep convection during SEAC4RS

NASA Astrophysics Data System (ADS)

Heath, Nicholas K.; Fuelberg, Henry E.; Tanelli, Simone; Turk, F. Joseph; Lawson, R. Paul; Woods, Sarah; Freeman, Sean

2017-04-01

Large-eddy simulations (LES) and observations are often combined to increase our understanding and improve the simulation of deep convection. This study evaluates a nested LES method that uses the Weather Research and Forecasting (WRF) model and, specifically, tests whether the nested LES approach is useful for studying deep convection during a real-world case. The method was applied on 2 September 2013, a day of continental convection that occurred during the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaign. Mesoscale WRF output (1.35 km grid length) was used to drive a nested LES with 450 m grid spacing, which then drove a 150 m domain. Results reveal that the 450 m nested LES reasonably simulates observed reflectivity distributions and aircraft-observed in-cloud vertical velocities during the study period. However, when examining convective updrafts, reducing the grid spacing to 150 m worsened results. We find that the simulated updrafts in the 150 m run become too diluted by entrainment, thereby generating updrafts that are weaker than observed. Lastly, the 450 m simulation is combined with observations to study the processes forcing strong midlevel cloud/updraft edge downdrafts that were observed on 2 September. Results suggest that these strong downdrafts are forced by evaporative cooling due to mixing and by perturbation pressure forces acting to restore mass continuity around neighboring updrafts. We conclude that the WRF nested LES approach, with further development and evaluation, could potentially provide an effective method for studying deep convection in real-world cases.

Fourth-Grade Children are Less Accurate in Reporting School Breakfast than School Lunch during 24-Hour Dietary Recalls

PubMed Central

Baxter, Suzanne Domel; Royer, Julie A.; Hardin, James W.; Guinn, Caroline H.; Smith, Albert F.

2008-01-01

Objective To compare reporting accuracy for breakfast and lunch in two studies. Design Children were observed eating school meals and interviewed the following morning about the previous day. Study 1 – 104 children were each interviewed one to three times with ≥25 days separating any two interviews. Study 2 – 121 children were each interviewed once in forward (morning-to-evening) and once in reverse (evening-to-morning) order, separated by ≥29 days. Setting 12 schools. Participants Fourth-grade children. Main Outcome Measures For each meal: food-item variables – observed number, reported number, omission rate, intrusion rate, total inaccuracy; kilocalorie variables – observed, reported, correspondence rate, inflation ratio. Analysis General linear mixed-models. Results For each study, observed and reported numbers of items and kilocalories, and correspondence rate (reporting accuracy), were greater for lunch than breakfast; omission rate, intrusion rate, and inflation ratio (measures of reporting error) were greater for breakfast than lunch. Study 1 – for each meal over interviews, total inaccuracy decreased and correspondence rate increased. Study 2 – for each meal for boys for reverse and girls for forward order, omission rate was lower and correspondence rate was higher. Conclusions and Implications Breakfast was reported less accurately than lunch. Despite improvement over interviews (Study 1) and differences for order × sex (Study 2), reporting accuracy was low for breakfast and lunch. PMID:17493562

Registration practices for observational studies on ClinicalTrials.gov indicated low adherence.

PubMed

Boccia, Stefania; Rothman, Kenneth J; Panic, Nikola; Flacco, Maria Elena; Rosso, Annalisa; Pastorino, Roberta; Manzoli, Lamberto; La Vecchia, Carlo; Villari, Paolo; Boffetta, Paolo; Ricciardi, Walter; Ioannidis, John P A

2016-02-01

The study aims to assess the status of registration of observational studies. We identified studies on cancer research with prospective recruitment of participants that were registered from February 2000 to December 2011 in ClinicalTrials.gov. We recorded the dates of registration and start of recruitment, outcomes, and description of statistical method. We searched for publications corresponding to the registered studies through May 31, 2014. One thousand one hundred nine registered studies were eligible. Primary and secondary outcomes were reported in 809 (73.0%) and 464 (41.8%) of them. The date of registration preceded the month of the study start in 145 (13.8%) and coincided in 205 (19.5%). A total of 151 publications from 120 (10.8%) registered studies were identified. In 2 (33.3%) of the 6 publications where ClinicalTrials.gov reported that the study started recruitment after registration, and in 9 (50.0%) of 18 publications where ClinicalTrials.gov reported the same date for registration and start of recruitment, the articles showed that the study had actually started recruiting before registration. During the period reviewed, few observational studies have been registered. Registration usually occurred after the study started, and prespecification of outcomes and statistical analysis rarely occurred. Copyright © 2016 Elsevier Inc. All rights reserved.

Environmental and psychosocial factors affecting seat belt use among Turkish front-seat occupants in Ankara: two observation studies.

PubMed

Simşekoğlu, Ozlem; Lajunen, Timo

2008-01-01

Low seat belt use rate among car occupants is one of the main problems contributing to low driver and passenger safety in Turkey, where injury and fatality rates of car occupants are very high in traffic crashes. The present article consists of two observation studies, which were conducted in Ankara. The first study aimed at investigating environmental factors and occupant characteristics affecting seat belt use among front-seat occupants, and the objective of the second study was to investigate the relationship between driver and front-seat passenger seat belt use. In the first study, 4, 227 front-seat occupants (drivers or front seat passengers) were observed on four different road sides and, in the second study 1, 398 front seat occupants were observed in car parks of five different shopping centers in Ankara. In both observations, front-seat occupants' seat bet use (yes, no), sex (male, female), and age (< 30 years, 30-50 years, > 50 years) were recorded. The data were analyzed using chi-square statistics and binary logistic regression techniques. Results of the first study showed that seat belt use proportion among observed front seat occupants was very low (25%). Being female and traveling on intercity roads were two main factors positively related to use a seat belt among front-seat occupants. High correlations between seat belt use of the drivers and front-seat passengers were found in the second study. Overall, low seat belt use rate (25%) among the front-seat occupants should be increased urgently for an improved driver and passenger safety in Turkey. Seat belt campaigns especially tailored for male front-seat occupants and for the front-seat occupants traveling on city roads are needed to increase seat belt use rates among them. Also, both drivers and passengers may have an important role in enforcing seat belt use among themselves.

Implementation Evaluation Study: Flipped Classroom Professional Development with Faculty Members to Enhance Students' Engagement in Higher Education

ERIC Educational Resources Information Center

Alebrahim, Fatimah Hussain

2016-01-01

The purpose of this qualitative study was to explore student engagement in higher education by evaluating training provided by experienced faculty members for those faculty desiring to implement a flipped classroom. A case study was utilized; data were collected in the form of online observation, in-class observation, student focus group…

Sex Differences in Learned Helplessness: II. The Contingencies of Evaluative Feedback in the Classroom and III. An Experimental Analysis.

ERIC Educational Resources Information Center

Dweck, Carol S.; And Others

1978-01-01

In Study I, teachers' work-related feedback to boys and girls was observed in a classroom situation. In Study II, the different contingencies of work-related criticism observed for boys and girls in the first study were programed in an experimental situation and the children's attributions for failure feedback were assessed. (JMB)

Direct Instruction in Language and Speaking: A Study of Mother-Child Discourse in a Working-Class Community.

ERIC Educational Resources Information Center

Miller, Peggy

A naturalistic-observational study of three inner-city, working-class mother-infant pairs was conducted to study early language development and maternal teaching styles. The subjects were three white 2-year-olds and their mothers. Observations were made under everyday conditions as the infants interacted with their mothers and other family members…

Prevention of metabolic diseases: fruits (including fruit sugars) vs. vegetables.

PubMed

Kuzma, Jessica N; Schmidt, Kelsey A; Kratz, Mario

2017-07-01

To discuss recent evidence from observational and intervention studies on the relationship between fruit and vegetable (F&V) consumption and metabolic disease. Observational studies have consistently demonstrated a modest inverse association between the intake of fruit and leafy green vegetables, but not total vegetables, and biomarkers of metabolic disease as well as incident type 2 diabetes mellitus. This is in contrast to limited evidence from recently published randomized controlled dietary intervention trials, which - in sum - suggests little to no impact of increased F&V consumption on biomarkers of metabolic disease. Evidence from observational studies that fruit and leafy green vegetable intake is associated with lower type 2 diabetes risk and better metabolic health could not be confirmed by dietary intervention trials. It is unclear whether this discrepancy is because of limitations inherent in observational studies (e.g., subjective dietary assessment methods, residual confounding) or due to limitations in the few available intervention studies (e.g., short duration of follow-up, interventions combining whole fruit and fruit juice, or lack of compliance). Future studies that attempt to address these limitations are needed to provide more conclusive insight into the impact of F&V consumption on metabolic health.

The Pfirrmann classification of lumbar intervertebral disc degeneration: an independent inter- and intra-observer agreement assessment.

PubMed

Urrutia, Julio; Besa, Pablo; Campos, Mauricio; Cikutovic, Pablo; Cabezon, Mario; Molina, Marcelo; Cruz, Juan Pablo

2016-09-01

Grading inter-vertebral disc degeneration (IDD) is important in the evaluation of many degenerative conditions, including patients with low back pain. Magnetic resonance imaging (MRI) is considered the best imaging instrument to evaluate IDD. The Pfirrmann classification is commonly used to grade IDD; the authors describing this classification showed an adequate agreement using it; however, there has been a paucity of independent agreement studies using this grading system. The aim of this study was to perform an independent inter- and intra-observer agreement study using the Pfirrmann classification. T2-weighted sagittal images of 79 patients consecutively studied with lumbar spine MRI were classified using the Pfirrmann grading system by six evaluators (three spine surgeons and three radiologists). After a 6-week interval, the 79 cases were presented to the same evaluators in a random sequence for repeat evaluation. The intra-class correlation coefficient (ICC) and the weighted kappa (wκ) were used to determine the inter- and intra-observer agreement. The inter-observer agreement was excellent, with an ICC = 0.94 (0.93-0.95) and wκ = 0.83 (0.74-0.91). There were no differences between spine surgeons and radiologists. Likewise, there were no differences in agreement evaluating the different lumbar discs. Most differences among observers were only of one grade. Intra-observer agreement was also excellent with ICC = 0.86 (0.83-0.89) and wκ = 0.89 (0.85-0.93). In this independent study, the Pfirrmann classification demonstrated an adequate agreement among different observers and by the same observer on separate occasions. Furthermore, it allows communication between radiologists and spine surgeons.

Mixed methods study on the use of and attitudes towards safety checklists in interventional radiology.

PubMed

Munn, Zachary; Giles, Kristy; Aromataris, Edoardo; Deakin, Anita; Schultz, Timothy; Mandel, Catherine; Peters, Micah Dj; Maddern, Guy; Pearson, Alan; Runciman, William

2018-02-01

The use of safety checklists in interventional radiology is an intervention aimed at reducing mortality and morbidity. Currently there is little known about their practical use in Australian radiology departments. The primary aim of this mixed methods study was to evaluate how safety checklists (SC) are used and completed in radiology departments within Australian hospitals, and attitudes towards their use as described by Australian radiologists. A mixed methods approach employing both quantitative and qualitative techniques was used for this study. Direct observations of checklist use during radiological procedures were performed to determine compliance. Medical records were also audited to investigate whether there was any discrepancy between practice (actual care measured by direct observation) and documentation (documented care measured by an audit of records). A focus group with Australian radiologists was conducted to determine attitudes towards the use of checklists. Among the four participating radiology departments, overall observed mean completion of the components of the checklist was 38%. The checklist items most commonly observed to be addressed by the operating theatre staff as noted during observations were correct patient (80%) and procedure (60%). Findings from the direct observations conflicted with the medical record audit, where there was a higher percentage of completion (64% completion) in comparison to the 38% observed. The focus group participants spoke of barriers to the use of checklists, including the culture of radiology departments. This is the first study of safety checklist use in radiology within Australia. Overall completion was low across the sites included in this study. Compliance data collected from observations differed markedly from reported compliance in medical records. There remain significant barriers to the proper use of safety checklists in Australian radiology departments. © 2017 The Royal Australian and New Zealand College of Radiologists.

Observational study of the extent of driving while suspended for alcohol-impaired driving

DOT National Transportation Integrated Search

2002-09-01

A study was undertaken to determine the proportion of first-time alcohol-impaired driving offenders who drive while suspended and the circumstances and motivations for driving. Systematic, unobtrusive observations were conducted by surveillance profe...

Multispectral observations complementary to the study of high-energy solar phenomena

NASA Technical Reports Server (NTRS)

Walker, Arthur B. C., Jr.

1988-01-01

Multispectral observations of phenomena associated with nonthermal events on the sun and characterized by the transient acceleration of electrons and ions to energies ranging from several keV to tens of GeV are discussed. It is shown that observations of the thermal and quasi-thermal phenomena preceeding, coinciding with, and following the impulsive acceleration and heating event itself can be used to study the evolution of magnetic structures in the solar convection zone and atmosphere. Observational techniques are discussed in detail.

Observing outer planet satellites (except Titan) with JWST: Science justification and observational requirements

USGS Publications Warehouse

Kestay, Laszlo P.; Grundy, Will; Stansberry, John; Sivaramakrishnan, Anand; Thatte, Deepashri; Gudipati, Murthy; Tsang, Constantine; Greenbaum, Alexandra; McGruder, Chima

2016-01-01

The James Webb Space Telescope (JWST) will allow observations with a unique combination of spectral, spatial, and temporal resolution for the study of outer planet satellites within our Solar System. We highlight the infrared spectroscopy of icy moons and temporal changes on geologically active satellites as two particularly valuable avenues of scientific inquiry. While some care must be taken to avoid saturation issues, JWST has observation modes that should provide excellent infrared data for such studies.

Bleeding risk under selective serotonin reuptake inhibitor (SSRI) antidepressants: A meta-analysis of observational studies.

PubMed

Laporte, Silvy; Chapelle, Céline; Caillet, Pascal; Beyens, Marie-Noëlle; Bellet, Florelle; Delavenne, Xavier; Mismetti, Patrick; Bertoletti, Laurent

2017-04-01

Selective serotonin reuptake inhibitors (SSRIs) have been reported to be potentially associated with an increased risk of bleeding. A meta-analysis of observational studies was conducted to quantify this risk. Case-control and cohort studies investigating bleeding risk under SSRI therapy were retrieved by searching the Medline, Pascal, Google Scholar and Scopus databases. Case-control studies were included if they reported bleeding incidents with and without the use of SSRIs and cohort studies were included if they reported the rate of bleeds among SSRI users and non-users. The main outcome was severe bleeding, whatever the site. Only data concerning SSRI belonging to the ATC class N06AB were used. For both case-control and cohort studies, we recorded the adjusted effect estimates and their 95% confidence intervals (CI). Pooled adjusted odds ratio (OR) estimates were computed for case-control and cohort studies using an inverse-variance model. Meta-analysis of the adjusted ORs of 42 observational studies showed a significant association between SSRI use and the risk of bleeding [OR 1.41 (95% CI 1.27-1.57), random effect model, p<0.0001]. The association was found for the 31 case-control studies (1,255,073 patients), with an increased risk of 41% of bleeding [OR 1.41 (95% CI 1.25-1.60)], as well as for the 11 cohort studies including 187,956 patients [OR 1.36 (95% CI 1.12-1.64)]. Subgroup analyses showed that the association remained constant whatever the characteristics of studies. This meta-analysis shows an increased risk of bleeding of at least 36% (from 12% to 64%) based on the high-level of observational studies with SSRIs use. Copyright © 2016 Elsevier Ltd. All rights reserved.

Does design matter? Systematic evaluation of the impact of analytical choices on effect estimates in observational studies

PubMed Central

Ryan, Patrick B.; Schuemie, Martijn

2013-01-01

Background: Clinical studies that use observational databases, such as administrative claims and electronic health records, to evaluate the effects of medical products have become commonplace. These studies begin by selecting a particular study design, such as a case control, cohort, or self-controlled design, and different authors can and do choose different designs for the same clinical question. Furthermore, published papers invariably report the study design but do not discuss the rationale for the specific choice. Studies of the same clinical question with different designs, however, can generate different results, sometimes with strikingly different implications. Even within a specific study design, authors make many different analytic choices and these too can profoundly impact results. In this paper, we systematically study heterogeneity due to the type of study design and due to analytic choices within study design. Methods and findings: We conducted our analysis in 10 observational healthcare databases but mostly present our results in the context of the GE Centricity EMR database, an electronic health record database containing data for 11.2 million lives. We considered the impact of three different study design choices on estimates of associations between bisphosphonates and four particular health outcomes for which there is no evidence of an association. We show that applying alternative study designs can yield discrepant results, in terms of direction and significance of association. We also highlight that while traditional univariate sensitivity analysis may not show substantial variation, systematic assessment of all analytical choices within a study design can yield inconsistent results ranging from statistically significant decreased risk to statistically significant increased risk. Our findings show that clinical studies using observational databases can be sensitive both to study design choices and to specific analytic choices within study design. Conclusion: More attention is needed to consider how design choices may be impacting results and, when possible, investigators should examine a wide array of possible choices to confirm that significant findings are consistently identified. PMID:25083251

Radar studies of gravity waves and tides in the middle atmosphere - A review

NASA Technical Reports Server (NTRS)

Rastogi, P. K.

1981-01-01

A review is presented of recent radar studies of gravity waves and tides in the middle atmosphere (over regions of approximately 10-30 and 60-90 km). The techniques used for monitoring the motions are outlined and their limitations are pointed out. The radars provide observations of short-period (1 min-1 h) gravity waves and tides at selected height intervals, depending on the radar frequency and the observation technique. The following contributions to the study of the midatmosphere are included in the discussion: (1) buoyancy oscillations and short-period (less than 10 min) acoustic-gravity waves have been observed in the troposphere and stratosphere and, in several cases, their generation and propagation near critical levels has been reconciled with theoretical models; (2) excitation of stratospheric waves by penetrative convection associated with thunderstorms has been established; (3) stratospheric and mesospheric tides at diurnal and semidiurnal periods have been observed; and (4) long-period (approximately 2 to 5 days) waves have been observed in the mesosphere. It is noted that more comprehensive data bases need to be obtained for further tidal and wave studies.

An observational clinical study of the efficacy and tolerability of donepezil in the treatment of Alzheimer's disease.

PubMed

Hager, Klaus; Calabrese, Pasquale; Frölich, Lutz; Göbel, Claus; Berger, Frank M

2003-01-01

An open-label, observational Post-Marketing Surveillance (PMS) study was undertaken in Germany to examine the efficacy and tolerability of donepezil in routine clinical practice. Alzheimer's disease (AD) patients were treated with donepezil (5 or 10 mg once daily) and observed for a period of approximately 3 months. Study assessments included the Mini-Mental State Examination (MMSE), the Nurses' Observation Scale for Geriatric Patients (NOSGER), and adverse events (AEs). A total of 2,092 patients (mean age 73.0 years; mean +/- SD MMSE score 17.8 +/- 5.8) were included in the efficacy assessments. MMSE and NOSGER scores showed statistically significant improvements in the total patient population and in the subpopulations with severe AD or AD with concomitant Parkinsonian symptoms (ADPS cohort). AEs were reported in a total of 12% of patients and were mostly due to peripheral cholinergic effects. In this observational PMS study, donepezil was shown to be an effective and well-tolerated therapy in the overall patient population, in patients with severe AD, and in the ADPS cohort. Copyright 2003 S. Karger AG, Basel

Video observation in HIT development: lessons learned on benefits and challenges.

PubMed

Høstgaard, Anna Marie; Bertelsen, Pernille

2012-08-22

Experience shows that the precondition for the development of successful health information technologies is a thorough insight into clinical work practice. In contemporary clinical work practice, clinical work and health information technology are integrated, and part of the practice is tacit. When work practice becomes routine, it slips to the background of the conscious awareness and becomes difficult to recognize without the context to support recall. This means that it is difficult to capture with traditional ethnographic research methods or in usability laboratories or clinical set ups. Observation by the use of the video technique within healthcare settings has proven to be capable of providing a thorough insight into the complex clinical work practice and its context - including parts of the tacit practice. The objective of this paper is 1) to argue for the video observation technique to inform and improve health-information-technology development and 2) to share insights and lessons learned on benefits and challenges when using the video observation technique within healthcare settings. A multiple case study including nine case studies conducted by DaCHI researchers 2004-2011 using audio-visual, non-participant video observation for data collection within different healthcare settings. In HIT development, video observation is beneficial for 1) informing and improving system design 2) studying changes in work practice 3) identifying new potentials and 4) documenting current work practices. The video observation technique used within healthcare settings is superior to other ethnographic research methods when it comes to disclosing the complexity in clinical work practice. The insights gained are far more realistic compared to traditional ethnographic studies or usability studies and studies in clinical set ups. Besides, the data generated through video recordings provide a solid basis for dialog between the health care professionals involved. The most important lessons learned are that a well considered methodology and clear formulated objectives are imperative, in order to stay focused during the data rich analysis phase. Additionally, the video observation technique is primarily recommended for studies of specific clinical work practices within delimited clinical settings. Overall, the video observation technique has proven to be capable of improving our understanding of the interwoven relation between clinical work practice and HIT and to inform us about user requirements and needs for HIT, which is a precondition for the development of more successful HIT systems in the future.

Are parent-reported outcomes for self-directed or telephone-assisted behavioral family intervention enhanced if parents are observed?

PubMed

Morawska, Alina; Sanders, Matthew R

2007-05-01

The study examined the effects of conducting observations as part of a broader assessment of families participating in behavior family intervention (BFI). It was designed to investigate whether the observations improve intervention outcomes. Families were randomly assigned to different levels of BFI or a waitlist control condition and subsequently randomly assigned to either observation or no-observation conditions. This study demonstrated significant intervention and observation effects. Mothers in more intensive BFI reported more improvement in their child's behavior and their own parenting. Observed mothers reported lower intensity of child behavior problems and more effective parenting styles. There was also a trend for less anger among mothers who were observed and evidence of an observation-intervention interaction for parental anger, with observed mothers in more intensive intervention reporting less anger compared to those not observed. Implications for clinical and research intervention contexts are discussed.

Limited responsiveness related to the minimal important difference of patient-reported outcomes in rare diseases.

PubMed

Johnston, Bradley C; Miller, Patricia A; Agarwal, Arnav; Mulla, Sohail; Khokhar, Rabia; De Oliveira, Kyle; Hitchcock, Christine L; Sadeghirad, Behnam; Mohiuddin, Mukarram; Sekercioglu, Nigar; Seweryn, Michal; Koperny, Magdalena; Bala, Malgorzata M; Adams-Webber, Thomasin; Granados, Alicia; Hamed, Alaa; Crawford, Mark W; van der Ploeg, Ans T; Guyatt, Gordon H

2016-11-01

To explore the responsiveness of patient-reported outcomes (PROs) in interventional studies involving patients with rare lysosomal storage diseases (LSDs). We searched eight databases for experimental and nonexperimental studies. Pairs of trained reviewers independently screened articles and subsequently extracted data from the eligible studies. Among studies with 10 or more patients using a valid PRO, we assessed the responsiveness of PROs based on a reanalysis of the data using minimal important difference estimates. Our analyses focused on statistically significant within-group differences in PROs for observational studies or the statistically significant between-group differences in PRO scores for controlled studies. Of 2,679 unique records, 62 interventional studies addressing patients with Fabry (55%), Gaucher (19%), Pompe (16%), and mucopolysaccharidoses (11%) proved eligible. The most frequently used PROs were the Short-Form-36 (25 studies), Brief Pain Inventory (20 studies), EuroQoL-5D (9 studies), and the Fatigue Severity Scale (6 studies). Observational studies suggest that PROs sometimes detect significant within-group changes when present. Randomized trials raise questions regarding the responsiveness of PROs to small differences between groups. Most studies have relied on generic PROs to evaluate quality of life and symptoms in patients with rare LSDs. PROs appear more responsive in observational studies than randomized trials. Copyright © 2016 Elsevier Inc. All rights reserved.

Strategies to Make Ramadan Fasting Safer in Type 2 Diabetics

PubMed Central

Lee, Shaun Wen Huey; Lee, Jun Yang; Tan, Christina San San; Wong, Chee Piau

2016-01-01

Abstract Ramadan is the holy month for Muslims whereby they fast from predawn to after sunset and is observed by all healthy Muslim adults as well as a large population of type 2 diabetic Muslims. To determine the comparative effectiveness of various strategies that have been used for type 2 diabetic Muslim who fast during Ramadan. A systematic review and network meta-analysis of randomized controlled studies (RCT) as well as observational studies for patients with type 2 diabetes who fasted during Ramadan was conducted. Eight databases were searched from January 1980 through October 2015 for relevant studies. Two reviewers independently screened and assessed study for eligibility, assessed the risk of bias, and extracted relevant data. A network meta-analysis for each outcome was fitted separately, combining direct and indirect evidence for each comparison. Twenty-nine studies, 16 RCTs and 13 observational studies each met the inclusion criteria. The most common strategy used was drug changes during the Ramadan period, which found that the use of DPP-4 (Dipeptidyl peptidase inhibitor -4) inhibitors were associated with a reduction in incidence of experiencing hypoglycemia during Ramadan in both RCTs (pooled relative risk: 0.56; 95% confidence interval: 0.44–0.72) as well as in observational studies (pooled relative risk: 0.27; 0.09–0.75). Ramadan-focused education was shown to be beneficial in reducing hypoglycemia in observational studies but not RCTs (0.25 versus 1.00). Network meta-analyses suggest that incretin mimetics can reduce the risk of hypoglycemia by nearly 1.5 times. The newer antidiabetic agents appear to lower the risk of hypoglycemia and improved glycemic control when compared with sulfonylureas. Ramadan-focused education shows to be a promising strategy but more rigorous examination from RCTs are required. PMID:26765440

Exposure to fluoride in drinking water and hip fracture risk: a meta-analysis of observational studies.

PubMed

Yin, Xin-Hai; Huang, Guang-Lei; Lin, Du-Ren; Wan, Cheng-Cheng; Wang, Ya-Dong; Song, Ju-Kun; Xu, Ping

2015-01-01

Many observational studies have shown that exposure to fluoride in drinking water is associated with hip fracture risk. However, the findings are varied or even contradictory. In this work, we performed a meta-analysis to assess the relationship between fluoride exposure and hip fracture risk. PubMed and EMBASE databases were searched to identify relevant observational studies from the time of inception until March 2014 without restrictions. Data from the included studies were extracted and analyzed by two authors. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were pooled using random- or fixed-effects models as appropriate. Sensitivity analyses and meta-regression were conducted to explore possible explanations for heterogeneity. Finally, publication bias was assessed. Fourteen observational studies involving thirteen cohort studies and one case-control study were included in the meta-analysis. Exposure to fluoride in drinking water does not significantly increase the incidence of hip fracture (RRs, 1.05; 95% CIs, 0.96-1.15). Sensitivity analyses based on adjustment for covariates, effect measure, country, sex, sample size, quality of Newcastle-Ottawa Scale scores, and follow-up period validated the strength of the results. Meta-regression showed that country, gender, quality of Newcastle-Ottawa Scale scores, adjustment for covariates and sample size were not sources of heterogeneity. Little evidence of publication bias was observed. The present meta-analysis suggests that chronic fluoride exposure from drinking water does not significantly increase the risk of hip fracture. Given the potential confounding factors and exposure misclassification, further large-scale, high-quality studies are needed to evaluate the association between exposure to fluoride in drinking water and hip fracture risk.

Exposure to Fluoride in Drinking Water and Hip Fracture Risk: A Meta-Analysis of Observational Studies

PubMed Central

Yin, Xin-Hai; Huang, Guang-Lei; Lin, Du-Ren; Wan, Cheng-Cheng; Wang, Ya-Dong; Song, Ju-Kun; Xu, Ping

2015-01-01

Background Many observational studies have shown that exposure to fluoride in drinking water is associated with hip fracture risk. However, the findings are varied or even contradictory. In this work, we performed a meta-analysis to assess the relationship between fluoride exposure and hip fracture risk. Methods PubMed and EMBASE databases were searched to identify relevant observational studies from the time of inception until March 2014 without restrictions. Data from the included studies were extracted and analyzed by two authors. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were pooled using random- or fixed-effects models as appropriate. Sensitivity analyses and meta-regression were conducted to explore possible explanations for heterogeneity. Finally, publication bias was assessed. Results Fourteen observational studies involving thirteen cohort studies and one case-control study were included in the meta-analysis. Exposure to fluoride in drinking water does not significantly increase the incidence of hip fracture (RRs, 1.05; 95% CIs, 0.96–1.15). Sensitivity analyses based on adjustment for covariates, effect measure, country, sex, sample size, quality of Newcastle–Ottawa Scale scores, and follow-up period validated the strength of the results. Meta-regression showed that country, gender, quality of Newcastle–Ottawa Scale scores, adjustment for covariates and sample size were not sources of heterogeneity. Little evidence of publication bias was observed. Conclusion The present meta-analysis suggests that chronic fluoride exposure from drinking water does not significantly increase the risk of hip fracture. Given the potential confounding factors and exposure misclassification, further large-scale, high-quality studies are needed to evaluate the association between exposure to fluoride in drinking water and hip fracture risk. PMID:26020536

Epidemiology, quality and reporting characteristics of meta-analyses of observational studies published in Chinese journals.

PubMed

Zhang, Zhe-wen; Cheng, Juan; Liu, Zhuan; Ma, Ji-chun; Li, Jin-long; Wang, Jing; Yang, Ke-hu

2015-12-07

The aim of this study was to examine the epidemiological and reporting characteristics as well as the methodological quality of meta-analyses (MAs) of observational studies published in Chinese journals. 5 Chinese databases were searched for MAs of observational studies published from January 1978 to May 2014. Data were extracted into Excel spreadsheets, and Meta-analysis of Observational Studies in Epidemiology (MOOSE) and Assessment of Multiple Systematic Reviews (AMSTAR) checklists were used to assess reporting characteristics and methodological quality, respectively. A total of 607 MAs were included. Only 52.2% of the MAs assessed the quality of the included primary studies, and the retrieval information was not comprehensive in more than half (85.8%) of the MAs. In addition, 50 (8.2%) MAs did not search any Chinese databases, while 126 (20.8%) studies did not search any English databases. Approximately 41.2% of the MAs did not describe the statistical methods in sufficient details, and most (95.5%) MAs did not report on conflicts of interest. However, compared with the before publication of the MOOSE Checklist, the quality of reporting improved significantly for 20 subitems after publication of the MOOSE Checklist, and 7 items of the included MAs demonstrated significant improvement after publication of the AMSTAR Checklist (p<0.05). Although many MAs of observational studies have been published in Chinese journals, the reporting quality is questionable. Thus, there is an urgent need to increase the use of reporting guidelines and methodological tools in China; we recommend that Chinese journals adopt the MOOSE and AMSTAR criteria. 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/

Infliximab reduces hospitalizations and surgery interventions in patients with inflammatory bowel disease: a systematic review and meta-analysis.

PubMed

Costa, João; Magro, Fernando; Caldeira, Daniel; Alarcão, Joana; Sousa, Rita; Vaz-Carneiro, António

2013-09-01

We systematically reviewed infliximab benefit in reducing hospitalizations and/or major surgery rates in patients with inflammatory bowel disease (IBD). A literature search to May 2012 was performed to identify all studies (experimental and observational) evaluating patients with IBD treated with infliximab and providing data on hospitalizations and/or major surgery rates. Three reviewers independently performed studies' selection, quality assessment, and data extraction. Analyses were carried according to study design (randomized clinical trials [RCTs] and observational studies) and IBD type (Crohn's disease [CD] and ulcerative colitis [UC]). Random-effects meta-analysis was used to derive pooled and 95% confidence intervals (CIs) estimates of odds ratios (OR). Heterogeneity was assessed with I test. Twenty-seven eligible studies were included (9 RCTs and 18 observational studies). Infliximab reduced hospitalization risk, both in pooled RCTs (OR, 0.51; 95% CI 0.40-0.65; I = 0%) and results of observational studies (OR, 0.29, 95% CI, 0.19-0.43; I = 87%), without differences between CD and UC. Infliximab reduced surgery risk in pooled RCTs results, both in CD (OR, 0.31; 95% CI, 0.15-0.64; I = 0%) and UC (OR, 0.57; 95% CI, 0.37-0.88; I = 0%). Pooled estimate from observational studies favored infliximab for patients with CD (OR, 0.32; 95% CI, 0.21-0.49; I = 77%), but not for patients with UC. The best evidence available points toward a reduction of the risk of hospitalization and major surgery requirement in patients with IBD treated with infliximab. This impact is clinically and economically relevant because hospitalization and surgery are considered to be markers of disease severity and significantly contribute to the total direct costs associated with IBD.

Assessing the Relationship Between Observed Teaching Practice and Reading Growth in First Grade English Learners: A Validation Study

ERIC Educational Resources Information Center

Baker, Scott K.; Gersten, Russell; Haager, Diane; Dingle, Mary; Goldenberg, Claude

2005-01-01

Validation of a classroom observation measure for use with English Learners (ELs) in Grade 1 is the focus of this study. Fourteen teachers were observed during reading and language arts instruction with an instrument used to generate overall ratings of instructional quality on a number of dimensions. In these classrooms, the reading performance of…

An Observational Study of Instructional and Curricular Practices Used with Gifted and Talented Students in Regular Classrooms. Research Monograph 93104.

ERIC Educational Resources Information Center

Westberg, Karen L.; And Others

This report describes one part of the Classroom Practices Study, focusing on systematic observations of gifted and talented students in 46 third and fourth grade classrooms. The observations were designed to determine if and how teachers meet the needs of gifted and talented students in regular classroom settings. The Classroom Practices Record…

Beyond a good story: from Hawthorne Effect to reactivity in health professions education research.

PubMed

Paradis, Elise; Sutkin, Gary

2017-01-01

Observational research is increasingly being used in health professions education (HPE) research, yet it is often criticised for being prone to observer effects (also known as the Hawthorne Effect), defined as a research participant's altered behaviour in response to being observed. This article explores this concern. First, this article briefly reviews the initial Hawthorne studies and the original formulation of the Hawthorne Effect, before turning to contemporary studies of the Hawthorne Effect in HPE and beyond. Second, using data from two observational studies (in the operating theatre and in the intensive care unit), this article investigates the Hawthorne Effect in HPE. Evidence of a Hawthorne Effect is scant, and amounts to little more than a good story. This is surprising given the foundational nature of the Hawthorne Studies in the social sciences and the prevalence of our concern with observer effects in HPE research. Moreover, the multiple and inconsistent uses of the Hawthorne Effect have left researchers without a coherent and helpful understanding of research participants' responses to observation. The authors' HPE research illustrates the complexity of observer effects in HPE, suggests that significant alteration of behaviour is unlikely in many research contexts, and shows how sustained contact with participants over time improves the quality of data collection. This article thus concludes with three recommendations: that researchers, editors and reviewers in the HPE community use the phrase 'participant reactivity' when considering the participant, observer and research question triad; that researchers invest in interpersonal relationships at their study site to mitigate the effects of altered behaviour; and that researchers use theory to make sense of participants' altered behaviour and use it as a window into the social world. The term 'participant reactivity' better reflects current scientific understandings of the research process and highlights the cognitive work required of participants to alter their behaviour when observed. Perhaps the most important lesson to be learned from the original Hawthorne experiments is the power of a good story (Levitt & List, 2011). © 2016 John Wiley & Sons Ltd and The Association for the Study of Medical Education.

Tire pressure special study : vehicle observation data

DOT National Transportation Integrated Search

2001-08-01

Twenty seven percent of passenger cars with : regular passenger car tires have at least one : tire that is underinflated by 8 psi or more. : Tire Pressure Special Study: Vehicle : Observation Data is the third in a series of : research notes co...

Time since death and decomposition of the human body: variables and observations in case and experimental field studies.

PubMed

Mann, R W; Bass, W M; Meadows, L

1990-01-01

Much of the difficulty in determining the time since death stems from the lack of systematic observation and research on the decomposition rate of the human body. Continuing studies conducted at the University of Tennessee, Knoxville, provide useful information on the impact of carrion insect activity, ambient temperature, rainfall, clothing, burial and depth, carnivores, bodily trauma, body weight, and the surface with which the body is in contact. This paper reports findings and observations accumulated during eight years of research and case studies that may clarify some of the questions concerning bodily decay.

Dynamics of severe storms through the study of thermospheric-tropospheric coupling

NASA Technical Reports Server (NTRS)

Hung, R. J.; Smith, R. E.

1979-01-01

Atmospheric acoustic-gravity waves associated with severe local thunderstorms, tornadoes, and hurricanes can be studied through the coupling between the thermosphere and the troposphere. Reverse group ray tracing computations of acoustic-gravity waves, observed by an ionospheric Doppler sounder array, show that the wave sources are in the neighborhood of storm systems and the waves are excited prior to the storms. It is suggested that the overshooting and ensuing collapse of convective turrets may be responsible for generating the acoustic-gravity waves observed. The results of this study also show that the study of wave-wave resonant interactions may be a potential tool for investigating the dynamical behavior of severe storm systems using ionospheric observations of atmospheric acoustic-gravity waves associated with severe storms.

A Study of Chemical Composition of δ Scuti-Type Stars Based on the Observations with the BTA and RTT-150

NASA Astrophysics Data System (ADS)

Galeev, A. I.; Berdnikova, V. M.; Ivanova, D. V.; Kudryavtsev, D. O.; Shimanskaya, N. N.; Shimansky, V. V.; Balashova, M. O.

2017-06-01

The results of a study of a sample of δ Scuti-type stars obtained from the observations with the BTA and RTT-150 are presented. Based on photometric data, we measured and analyzed the fundamental parameters of all the studied stars. For eight stars (for two of them for the first time), the fundamental parameters of the atmospheres (Teff, log g, [Fe/H]) and the chemical composition for 29 elements in the LTE-approximation are received using spectroscopic observations. The chemical composition analysis demonstrates both the solar abundances of chemical elements and the anomalies of chemical composition typical of Am stars in the studied sample of δ Scuti-type stars.

Disentangling Greenhouse Warming and Aerosol Cooling to Reveal Earth's Transient Climate Sensitivity

NASA Astrophysics Data System (ADS)

Storelvmo, T.

2015-12-01

Earth's climate sensitivity has been the subject of heated debate for decades, and recently spurred renewed interest after the latest IPCC assessment report suggested a downward adjustment of the most likely range of climate sensitivities. Here, we present an observation-based study based on the time period 1964 to 2010, which is unique in that it does not rely on global climate models (GCMs) in any way. The study uses surface observations of temperature and incoming solar radiation from approximately 1300 surface sites, along with observations of the equivalent CO2 concentration (CO2,eq) in the atmosphere, to produce a new best estimate for the transient climate sensitivity of 1.9K (95% confidence interval 1.2K - 2.7K). This is higher than other recent observation-based estimates, and is better aligned with the estimate of 1.8K and range (1.1K - 2.5K) derived from the latest generation of GCMs. The new estimate is produced by incorporating the observations in an energy balance framework, and by applying statistical methods that are standard in the field of Econometrics, but less common in climate studies. The study further suggests that about a third of the continental warming due to increasing CO2,eq was masked by aerosol cooling during the time period studied.

Geophysical investigation using gravity data in Kinigi geothermal field, northwest Rwanda

NASA Astrophysics Data System (ADS)

Uwiduhaye, Jean d.'Amour; Mizunaga, Hideki; Saibi, Hakim

2018-03-01

A land gravity survey was carried out in the Kinigi geothermal field, Northwest Rwanda using 184 gravity stations during August and September, 2015. The aim of the gravity survey was to understand the subsurface structure and its relation to the observed surface manifestations in the study area. The complete Bouguer Gravity anomaly was produced with a reduction density of 2.4 g/cm3. Bouguer anomalies ranging from -52 to -35 mGals were observed in the study area with relatively high anomalies in the east and northwest zones while low anomalies are observed in the southwest side of the studied area. A decrease of 17 mGals is observed in the southwestern part of the study area and caused by the low-density of the Tertiary rocks. Horizontal gradient, tilt angle and analytical signal methods were applied to the observed gravity data and showed that Mubona, Mpenge and Cyabararika surface springs are structurally controlled while Rubindi spring is not. The integrated results of gravity gradient interpretation methods delineated a dominant geological structure trending in the NW-SE, which is in agreement with the regional geological trend. The results of this gravity study will help aid future geothermal exploration and development in the Kinigi geothermal field.

The role of students' activities in Indonesian realistic mathematics education in primary schools of Aceh

NASA Astrophysics Data System (ADS)

Zubainur, Cut Morina; Veloo, Arsaythamby; Khalid, Rozalina

2015-05-01

This study aims to explore the implementation of the Indonesian Realistic Mathematics Education (PMRI) in Aceh primary schools, Indonesia. This study investigates the students' mathematics activities involved in the implementation of PMRI and for this purpose; students' mathematics activities in the classroom were observed. Students were observed three times within five weeks during mathematics class, based on PMRI. A total of 25 year five students from a public school participated in this study. Observation check list was used in this study based on ten items. The observation conducted was based on two different time periods which were 105 minutes for group A and 70 minutes for group B. The observation was conducted every 5 minutes. The results show that PMRI is being practised in Aceh, but not completely. This study shows that mathematics activities for those who were taught using PMRI are higher than for those using the traditional approach. Overall, the findings showed that the number of student activities undertaken in PMRI achieved 90.56%. The higher percentage of activities suggests that the Aceh Education Office expands the implementation of PMRI in all primary schools so that learning of mathematics is more effective. This indirectly increases the mathematics achievement of students in Aceh to a higher level on par with Indonesia's national achievement.

Upper ocean response to Hurricane Gonzalo (2014): Salinity effects revealed by targeted and sustained underwater glider observations

NASA Astrophysics Data System (ADS)

Domingues, Ricardo; Goni, Gustavo; Bringas, Francis; Lee, Sang-Ki; Kim, Hyun-Sook; Halliwell, George; Dong, Jili; Morell, Julio; Pomales, Luis

2015-09-01

During October 2014, Hurricane Gonzalo traveled within 85 km from the location of an underwater glider situated north of Puerto Rico. Observations collected before, during, and after the passage of this hurricane were analyzed to improve our understanding of the upper ocean response to hurricane winds. The main finding in this study is that salinity potentially played an important role on changes observed in the upper ocean; a near-surface barrier layer likely suppressed the hurricane-induced upper ocean cooling, leading to smaller than expected temperature changes. Poststorm observations also revealed a partial recovery of the ocean to prestorm conditions 11 days after the hurricane. Comparison with a coupled ocean-atmosphere hurricane model indicates that model-observations discrepancies are largely linked to salinity effects described. Results presented in this study emphasize the value of underwater glider observations for improving our knowledge of how the ocean responds to tropical cyclone winds and for tropical cyclone intensification studies and forecasts.

Surgical Versus Nonsurgical Treatment for Midshaft Clavicle Fractures in Patients Aged 16 Years and Older: A Systematic Review, Meta-analysis, and Comparison of Randomized Controlled Trials and Observational Studies.

PubMed

Smeeing, Diederik P J; van der Ven, Denise J C; Hietbrink, Falco; Timmers, Tim K; van Heijl, Mark; Kruyt, Moyo C; Groenwold, Rolf H H; van der Meijden, Olivier A J; Houwert, Roderick M

2017-07-01

There is no consensus on the choice of treatment of midshaft clavicle fractures (MCFs). The aims of this systematic review and meta-analysis were (1) to compare fracture healing disorders and functional outcomes of surgical versus nonsurgical treatment of MCFs and (2) to compare effect estimates obtained from randomized controlled trials (RCTs) and observational studies. Systematic review and meta-analysis. The PubMed/MEDLINE, Embase, CENTRAL, and CINAHL databases were searched for both RCTs and observational studies. Using the MINORS instrument, all included studies were assessed on their methodological quality. The primary outcome was a nonunion. Effects of surgical versus nonsurgical treatment were estimated using random-effects meta-analysis models. A total of 20 studies were included, of which 8 were RCTs and 12 were observational studies including 1760 patients. Results were similar across the different study designs. A meta-analysis of 19 studies revealed that nonunions were significantly less common after surgical treatment than after nonsurgical treatment (odds ratio [OR], 0.18 [95% CI, 0.10-0.33]). The risk of malunions did not differ between surgical and nonsurgical treatment (OR, 0.38 [95% CI, 0.12-1.19]). Both the long-term Disabilities of the Arm, Shoulder and Hand (DASH) and Constant-Murley scores favored surgical treatment (DASH: mean difference [MD], -2.04 [95% CI, -3.56 to -0.52]; Constant-Murley: MD, 3.23 [95% CI, 1.52 to 4.95]). No differences were observed regarding revision surgery (OR, 0.85 [95% CI, 0.42-1.73]). Including only high-quality studies, both the number of malunions and days to return to work show significant differences in favor of surgical treatment (malunions: OR, 0.26 [95% CI, 0.07 to 0.92]; return to work: MD, -8.64 [95% CI, -16.22 to -1.05]). This meta-analysis of high-quality studies showed that surgical treatment of MCFs results in fewer nonunions, fewer malunions, and an accelerated return to work compared with nonsurgical treatment. A meta-analysis of surgical treatments need not be restricted to randomized trials, provided that the included observational studies are of high quality.

FIRE Science Results 1988

NASA Technical Reports Server (NTRS)

Mcdougal, David S. (Editor); Wagner, H. Scott (Editor)

1990-01-01

FIRE (First ISCCP Regional Experiment) is a U.S. cloud-radiation program that seeks to address the issues of a basic understanding and parameterizations of cirrus and marine stratocumulus cloud systems and ISCCP data products. The papers describe research analysis of data collected at the 1986 Cirrus Intensive Field Observations (IFO), the 1987 Marine Stratocumulus IFO, and the Extended Time Observations. The papers are grouped into sessions on satellite studies, lidar/radiative properties/microphysical studies, radiative properties, thermodynamic and dynamic properties, case studies, and large scale environment and modeling studies.

Global satellite triangulation and trilateration for the National Geodetic Satellite Program (solutions WN 12, 14 and 16). [study and analysis of data from artificial satellites

NASA Technical Reports Server (NTRS)

Mueller, I. I.; Kumar, M.; Reilly, J. P.; Saxena, N.; Soler, T.

1973-01-01

A multi-year study and analysis of data from satellites launched specifically for geodetic purposes and from other satellites useful in geodetic studies was conducted. The program of work included theoretical studies and analysis for the geometric determination of station positions derived from photographic observations of both passive and active satellites and from range observations. The current status of data analysis, processing and results are examined.

Observation interventions as a means to manipulate collective efficacy in groups.

PubMed

Bruton, Adam M; Mellalieu, Stephen D; Shearer, David A

2014-02-01

The purpose of this multistudy investigation was to examine observation as an intervention for the manipulation of individual collective efficacy beliefs. Study 1 compared the effects of positive, neutral, and negative video footage of practice trials from an obstacle course task on collective efficacy beliefs in assigned groups. The content of the observation intervention (i.e., positive, neutral, and negative video footage) significantly influenced the direction of change in collective efficacy (p < .05). Study 2 assessed the influence of content familiarity (own team/sport vs. unfamiliar team/sport) on individual collective efficacy perceptions when observing positive footage of competitive basketball performance. Collective efficacy significantly increased for both the familiar and unfamiliar conditions postintervention, with the largest increase for the familiar condition (p < .05). The studies support the use of observation as an intervention to enhance individual perceptions of collective efficacy in group-based activities. The findings suggest that observations of any group displaying positive group characteristics are likely to increase collective efficacy beliefs; however, observation of one's own team leads to the greatest increases.

Land Surface Model Biases and their Impacts on the Assimilation of Snow-related Observations

NASA Astrophysics Data System (ADS)

Arsenault, K. R.; Kumar, S.; Hunter, S. M.; Aman, R.; Houser, P. R.; Toll, D.; Engman, T.; Nigro, J.

2007-12-01

Some recent snow modeling studies have employed a wide range of assimilation methods to incorporate snow cover or other snow-related observations into different hydrological or land surface models. These methods often include taking both model and observation biases into account throughout the model integration. This study focuses more on diagnosing the model biases and presenting their subsequent impacts on assimilating snow observations and modeled snowmelt processes. In this study, the land surface model, the Community Land Model (CLM), is used within the Land Information System (LIS) modeling framework to show how such biases impact the assimilation of MODIS snow cover observations. Alternative in-situ and satellite-based observations are used to help guide the CLM LSM in better predicting snowpack conditions and more realistic timing of snowmelt for a western US mountainous region. Also, MODIS snow cover observation biases will be discussed, and validation results will be provided. The issues faced with inserting or assimilating MODIS snow cover at moderate spatial resolutions (like 1km or less) will be addressed, and the impacts on CLM will be presented.

Characteristics of electron distributions observed during large amplitude whistler wave events in the magnetosphere

NASA Astrophysics Data System (ADS)

Wilson, L. B., III; Cattell, C. A.; Kellogg, P. J.; Goetz, K.; Wygant, J.; Breneman, A. W.; Kersten, K.

2010-12-01

We present a statistical study of the characteristics of electron distributions associated with large amplitude whistler waves inside the terrestrial magnetosphere using waveform capture data as an addition of the study by Kellogg et al., [2010b]. We identified three types of electron distributions observed simultaneously with the whistler waves including beam-like, beam/flattop, and anisotropic distributions. The whistlers exhibited different characteristics dependent upon the observed electron distributions. The majority of the waveforms observed in our study have f/fce ≤ 0.5 and are observed primarily in the radiation belts outside the plasmapause simultaneously with anisotropic electron distributions. We also present an example waveform capture of the largest magnetic field amplitude (≥ 8 nT pk-pk) whistler wave measured in the radiation belts. The majority of the largest amplitude whistlers occur during magnetically active periods (AE > 200 nT).

Characteristics of Electron Distributions Observed During Large Amplitude Whistler Wave Events in the Magnetosphere

NASA Technical Reports Server (NTRS)

Wilson, Lynn B., III

2010-01-01

We present a statistical study of the characteristics of electron distributions associated with large amplitude whistler waves inside the terrestrial magnetosphere using waveform capture data as an addition of the study by Kellogg et al., [2010b]. We identified three types of electron distributions observed simultaneously with the whistler waves including beam-like, beam/flattop, and anisotropic distributions. The whistlers exhibited different characteristics dependent upon the observed electron distributions. The majority of the waveforms observed in our study have f/fce < or = 0.5 and are observed primarily in the radiation belts outside the plasmapause simultaneously with anisotropic electron distributions. We also present an example waveform capture of the largest magnetic field amplitude (> or = 8 nT pk-pk) whistler wave measured in the radiation belts. The majority of the largest amplitude whistlers occur during magnetically active periods (AE > 200 nT).

Hydrologic Conditions Viewed by the Nimbus Meteorological Satellites

NASA Technical Reports Server (NTRS)

Rabchevsky, G. A.

1971-01-01

The unexploited value of the Nimbus meteorological sensor data relates to the satellites' ability for global, temporal, repetitive and uniform tonal and spatial coverage of the earth's surface. Examples are presented illustrating how synoptic views of large areas increase interpretive capability and enable focusing on large targets of interest. The effect of resolution of the Nimbus imaging systems on these observations is discussed, together with the assessment of the areal and temporal magnitude of changes observed by these systems. Two case studies are presented exemplifying the satellites' ability for repetitive observations enabling phenomena to be monitored under special conditions. One study deals with changes observed in the Antarctic ice conditions utilizing the Nimbus 2 and 3 television picture data. The other study deals with terrestrial changes in the Mississippi River Valley and the Niger River Valley (Africa), observed primarily in the 0.7 to 1.3 micron spectral band.

Conceptual study of Earth observation missions with a space-borne laser scanner

NASA Astrophysics Data System (ADS)

Kobayashi, Takashi; Sato, Yohei; Yamakawa, Shiro

2017-11-01

The Japan Aerospace Exploration Agency (JAXA) has started a conceptual study of earth observation missions with a space-borne laser scanner (GLS, as Global Laser Scanner). Laser scanners are systems which transmit intense pulsed laser light to the ground from an airplane or a satellite, receive the scattered light, and measure the distance to the surface from the round-trip delay time of the pulse. With scanning mechanisms, GLS can obtain high-accuracy three-dimensional (3D) information from all over the world. High-accuracy 3D information is quite useful in various areas. Currently, following applications are considered. 1. Observation of tree heights to estimate the biomass quantity. 2. Making the global elevation map with high resolution. 3. Observation of ice-sheets. This paper aims at reporting the present state of our conceptual study of the GLS. A prospective performance of the GLS for earth observation missions mentioned above.

The Earth Observing System. [instrument investigations for flight on EOS-A satellite

NASA Technical Reports Server (NTRS)

Wilson, Stan; Dozier, Jeff

1991-01-01

The Earth Observing System (EOS), the centerpiece of NASA's Mission to Planet Earth, is to study the interactions of the atmosphere, land, oceans, and living organisms, using the perspective of space to observe the earth as a global environmental system. To better understand the role of clouds in global change, EOS will measure incoming and emitted radiation at the top of the atmosphere. Then, to study characteristics of the atmosphere that influence radiation transfer between the top of the atmosphere and the surface, EOS wil observe clouds, water vapor and cloud water, aerosols, temperature and humidity, and directional effects. To elucidate the role of anthropogenic greenhouse gas and terrestrial and marine plants as a source or sink for carbon, EOS will observe the biological productivity of lands and oceans. EOS will also study surface properties that affect biological productivity at high resolution spatially and spectrally.

Within-Day Variability in the Quality of Classroom Interactions during Third and Fifth Grade: Implications for Children's Experiences and Conducting Classroom Observations

ERIC Educational Resources Information Center

Curby, Timothy W.; Stuhlman, Megan; Grimm, Kevin; Mashburn, Andrew; Chomat-Mooney, Lia; Downer, Jason; Hamre, Bridget; Pianta, Robert C.

2011-01-01

The quality of classroom interactions has typically been studied using aggregates of ratings over time. However, within-day ratings may contain important variability. This study investigated within-day variability using the NICHD Study of Early Childcare and Youth Development's observational data during grades 3 and 5. The first question examined…

Socialization to School: A Study of Low-Income and Minority Children in an Early Childhood Setting. Occasional Paper.

ERIC Educational Resources Information Center

Schwartz, Audrey James

This study is a description of the initial socialization of low-income children, aged 3 to 6 years, who were recruited by a middle- and upper-income elementary college-laboratory school. Data for this study were obtained through observations of 11 recruited children and their classmates during a 4-year period. These observations were supplemented…

Inter-observer reliability of animal-based welfare indicators included in the Animal Welfare Indicators welfare assessment protocol for dairy goats.

PubMed

Vieira, A; Battini, M; Can, E; Mattiello, S; Stilwell, G

2018-01-08

This study was conducted within the context of the Animal Welfare Indicators (AWIN) project and the underlying scientific motivation for the development of the study was the scarcity of data regarding inter-observer reliability (IOR) of welfare indicators, particularly given the importance of reliability as a further step for developing on-farm welfare assessment protocols. The objective of this study is therefore to evaluate IOR of animal-based indicators (at group and individual-level) of the AWIN welfare assessment protocol (prototype) for dairy goats. In the design of the study, two pairs of observers, one in Portugal and another in Italy, visited 10 farms each and applied the AWIN prototype protocol. Farms in both countries were visited between January and March 2014, and all the observers received the same training before the farm visits were initiated. Data collected during farm visits, and analysed in this study, include group-level and individual-level observations. The results of our study allow us to conclude that most of the group-level indicators presented the highest IOR level ('substantial', 0.85 to 0.99) in both field studies, pointing to a usable set of animal-based welfare indicators that were therefore included in the first level of the final AWIN welfare assessment protocol for dairy goats. Inter-observer reliability of individual-level indicators was lower, but the majority of them still reached 'fair to good' (0.41 to 0.75) and 'excellent' (0.76 to 1) levels. In the paper we explore reasons for the differences found in IOR between the group and individual-level indicators, including how the number of individual-level indicators to be assessed on each animal and the restraining method may have affected the results. Furthermore, we discuss the differences found in the IOR of individual-level indicators in both countries: the Portuguese pair of observers reached a higher level of IOR, when compared with the Italian observers. We argue how the reasons behind these differences may stem from the restraining method applied, or the different background and experience of the observers. Finally, the discussion of the results emphasizes the importance of considering that reliability is not an absolute attribute of an indicator, but derives from an interaction between the indicators, the observers and the situation in which the assessment is taking place. This highlights the importance of further considering the indicators' reliability while developing welfare assessment protocols.

Using Art to Teach Students Science Outdoors: How Creative Science Instruction Influences Observation, Question Formation, and Involvement

NASA Astrophysics Data System (ADS)

Cone, Christina Schull

Elementary education has become increasingly divided into subjects and focused on the demand for high math and reading scores. Consequently, teachers spend less time devoted to science and art instruction. However, teaching art and science is crucial to developing creative and rational thinking, especially for observation and questioning skills. In this study, third grade students attending an urban school in Portland, Oregon received instruction of an art strategy using observational and quantifying drawing techniques. This study examines, "Will an art strategy observing the local environment help students make observations and ask questions?" and "In what ways are student learning and perspectives of science affected by the art strategy?" The independent variable is the art strategy developed for this study. There are three dependent variables: quality of student observations, quality of questions, and themes on student learning and perspectives of science. I predicted students would develop strong observation and questioning skills and that students would find the strategy useful or have an increased interest in science. The art scores were high for relevance and detail, but not for text. There were significant correlations between art scores and questions. Interviews revealed three themes: observations create questions, drawing is helpful and challenging, and students connected to science. By examining science through art, students were engaged and created strong observations and questions. Teachers need to balance unstructured drawing time with scaffolding for optimal results. This study provides an integrated science and art strategy that teachers can use outdoors or adapt for the classroom.

Consumption of fruit and vegetables reduces risk of pancreatic cancer: evidence from epidemiological studies.

PubMed

Wu, Qi-Jun; Wu, Lang; Zheng, Li-Qiang; Xu, Xin; Ji, Chao; Gong, Ting-Ting

2016-05-01

Observational studies have reported inconsistent results on the association between fruit and vegetable intake and the risk of pancreatic cancer. We carried out a meta-analysis of epidemiological studies to summarize available evidence. We searched PubMed, Scopus, and ISI Web of Science databases for relevant studies published until the end of January 2015. Fixed-effects and random-effects models were used to estimate the summary relative risks (RRs) and 95% confidence intervals (CIs) for the associations between fruit and vegetable intake and the risk of pancreatic cancer. A total of 15 case-control studies, eight prospective studies, and one pooled analysis fulfilled the inclusion criteria. The summary RR for the highest versus the lowest intake was 0.73 (95% CI=0.53-1.00) for fruit and vegetables, 0.73 (95% CI=0.63-0.84) for fruit, and 0.76 (95% CI=0.69-0.83) for vegetables, with significant heterogeneities (I=70.5, 55.7, and 43.0%, respectively). Inverse associations were observed in the stratified analysis by study design, although the results of prospective studies showed borderline significance, with corresponding RR=0.90 (95% CI=0.77-1.05) for fruit and vegetable intake, 0.93 (95% CI=0.83-1.03) for fruit intake, and 0.89 (95% CI=0.80-1.00) for vegetable intake. Besides, significant inverse associations were observed in the majority of other subgroup analyses by study quality, geographic location, exposure assessment method, and adjustment for potential confounders. Findings from the present meta-analysis support that fruit and vegetable intake is associated inversely with the risk of pancreatic cancer. However, study design may play a key role in the observed magnitude of the aforementioned association. Future well-designed prospective studies are warranted to confirm these findings.

Mechanistic study of the azithromycin dosage-form-dependent food effect.

PubMed

Curatolo, William; Foulds, George; Labadie, Robert

2010-07-01

Azithromycin capsules are known to exhibit a negative food effect, manifest as a decrease in azithromycin bioavailability in the fed state. Azithromycin tablets are known to be bioequivalent to capsules in the fasted state, but do not exhibit a food effect. In the present study, the involvement of gastric degradation of azithromycin to des-cladinose azithromycin (DCA) has been investigated as a possible mechanism for the observed capsule food effect. Healthy volunteers were dosed with azithromycin tablets and capsules, fasted and fed, in a four-way randomized crossover study. Serum levels of DCA were measured as a function of time post-dose. Natural log-transformed PK parameters were statistically analyzed using an ANOVA model appropriate for the study design. When capsules were dosed to fed subjects, the systemic AUC for DCA was 243% of the value observed after fasted-state dosing, and the DCA C(max) was 270% of the value observed after fasted-state dosing. When azithromycin tablets were dosed in the fasted and fed states, there was no significant difference in systemic DCA. Gastric degradation of azithromycin to DCA is the likely mechanism for the observed negative food effect observed for azithromycin capsules. This effect is not observed for tablets. These observations suggest that azithromycin capsules exhibit slow and/or delayed disintegration in the fed stomach, resulting in extended gastric residence and degradation of a portion of the gastrically retained azithromycin.

Phenology of lilac (Syringa vulgaris) and elderberry (Sambucus nigra) as the indicator of spring warming

NASA Astrophysics Data System (ADS)

Vincze, E.; Hunkár, M.; Dunkel, Z.

2012-04-01

Phenological observations in Hungary started in 1871. The observation system collapsed and revived time by time. The aim of the observations as well as the locations, the methods and observed plants have been changed many times, therefore data series for a given plant species derived from the same place are rare. If we want to study the responses of biosphere to climate variability we need long time data series from the same places, especially phenological data of native plants. Phenological observations organized by the Hungarian Meteorological Service between 1983- 1999 contain valuable data for lilac (Syringa vulgaris) and elderberry (Sambucus nigra). Those perennial native plants are good indicators of spring warming therefore it is worth to study their phenological development concerning to climate variability. Eight locations in Hungary were selected where the site of the observations remaind the same year by year. Observed phenological phases were: Sprouting of leaves (SL, BBCH:11); Begin of Flowers (BF, BBCH:61); Fall of leaves (FO, BBCH:95). Spatial and temporal trends and variability of phenophases will be presented. The effect of meteorological conditions is studied to build up phenological model controlled by the temperature. Growing degree days above the base temperature was involved together with the duration and severeness of the chilling period. The study is supported by the National Scientific Foundation (OTKA-81979).

Optimization of medical imaging display systems: using the channelized Hotelling observer for detecting lung nodules: experimental study

NASA Astrophysics Data System (ADS)

Platisa, Ljiljana; Vansteenkiste, Ewout; Goossens, Bart; Marchessoux, Cédric; Kimpe, Tom; Philips, Wilfried

2009-02-01

Medical-imaging systems are designed to aid medical specialists in a specific task. Therefore, the physical parameters of a system need to optimize the task performance of a human observer. This requires measurements of human performance in a given task during the system optimization. Typically, psychophysical studies are conducted for this purpose. Numerical observer models have been successfully used to predict human performance in several detection tasks. Especially, the task of signal detection using a channelized Hotelling observer (CHO) in simulated images has been widely explored. However, there are few studies done for clinically acquired images that also contain anatomic noise. In this paper, we investigate the performance of a CHO in the task of detecting lung nodules in real radiographic images of the chest. To evaluate variability introduced by the limited available data, we employ a commonly used study of a multi-reader multi-case (MRMC) scenario. It accounts for both case and reader variability. Finally, we use the "oneshot" methods to estimate the MRMC variance of the area under the ROC curve (AUC). The obtained AUC compares well to those reported for human observer study on a similar data set. Furthermore, the "one-shot" analysis implies a fairly consistent performance of the CHO with the variance of AUC below 0.002. This indicates promising potential for numerical observers in optimization of medical imaging displays and encourages further investigation on the subject.

Predictive Modeling of Human Perception Subjectivity: Feasibility Study of Mammographic Lesion Similarity

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

Xu, Songhua; Tourassi, Georgia

2012-01-01

The majority of clinical content-based image retrieval (CBIR) studies disregard human perception subjectivity, aiming to duplicate the consensus expert assessment of the visual similarity on example cases. The purpose of our study is twofold: (i) discern better the extent of human perception subjectivity when assessing the visual similarity of two images with similar semantic content, and (ii) explore the feasibility of personalized predictive modeling of visual similarity. We conducted a human observer study in which five observers of various expertise were shown ninety-nine triplets of mammographic masses with similar BI-RADS descriptors and were asked to select the two masses withmore » the highest visual relevance. Pairwise agreement ranged between poor and fair among the five observers, as assessed by the kappa statistic. The observers' self-consistency rate was remarkably low, based on repeated questions where either the orientation or the presentation order of a mass was changed. Various machine learning algorithms were explored to determine whether they can predict each observer's personalized selection using textural features. Many algorithms performed with accuracy that exceeded each observer's self-consistency rate, as determined using a cross-validation scheme. This accuracy was statistically significantly higher than would be expected by chance alone (two-tailed p-value ranged between 0.001 and 0.01 for all five personalized models). The study confirmed that human perception subjectivity should be taken into account when developing CBIR-based medical applications.« less

Scientific and Ethical Approaches for Observational Exposure Studies

EPA Science Inventory

Researchers conduct observational human exposure studies to understand how and the extent to which people come into contact with chemicals and environmental stressors in their everyday lives, through the air they breathe, the food and liquids they consume, and the things they tou...

78 FR 57280 - Chlorantraniliprole; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-18

... toxicity studies in rats, minimally increased microvesiculation of adrenal cortex was observed in males... cortex effects observed in rat studies were not considered adverse. Chlorantraniliprole does not exhibit.... 601 et seq.), do not apply. This final rule directly regulates growers, food processors, food handlers...

76 FR 72901 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-28

.... The Shipboard Observation Form for Floating Marine Debris was created based on methods used in studies of floating marine debris by established researchers, previous shipboard observational studies.... This survey will assist in carrying out activities prescribed in the Marine Debris Research, Prevention...

Examination of influential observations in penalized spline regression

NASA Astrophysics Data System (ADS)

Türkan, Semra

2013-10-01

In parametric or nonparametric regression models, the results of regression analysis are affected by some anomalous observations in the data set. Thus, detection of these observations is one of the major steps in regression analysis. These observations are precisely detected by well-known influence measures. Pena's statistic is one of them. In this study, Pena's approach is formulated for penalized spline regression in terms of ordinary residuals and leverages. The real data and artificial data are used to see illustrate the effectiveness of Pena's statistic as to Cook's distance on detecting influential observations. The results of the study clearly reveal that the proposed measure is superior to Cook's Distance to detect these observations in large data set.

Peer observation and feedback of resident teaching.

PubMed

Snydman, Laura; Chandler, Daniel; Rencic, Joseph; Sung, Yung-Chi

2013-02-01

Resident doctors (residents) play a significant role in the education of medical students. Morning work rounds provide an optimal venue to assess resident teaching. The purpose of this study was to assess the feasibility of peer observation of resident work rounds, to evaluate resident perceptions of peer observation and to evaluate resident perceptions of peer feedback.   Twenty-four internal medicine residents were simultaneously observed by an attending physician and a peer while teaching during work rounds (between August2008 and May 2009). At year-end, residents received a survey to characterise their attitudes towards peer observation and feedback. Twenty-one residents (87.5%) completed the survey. Half (52.4%) felt that participating in the peer observation study stimulated their interest in teaching during work rounds. Prior to participation in the study, fewer than half (42.9%) felt comfortable being observed by their peers, compared with 71.4 percent after participation (p=0.02). The proportion of residents who felt comfortable giving feedback to peers increased from 26.3 to 65.0percent (p=0.004), and the proportion of residents who felt comfortable receiving feedback from peers increased from 76.2 to 95.2 percent (p=0.02). Peer observation and feedback of resident teaching during work rounds is feasible and rewarding for the residents involved. Comfort with regards to being observed by peers, with receiving feedback from peers and with giving feedback to peers significantly increased after the study. Most residents reported changes in their teaching behaviour resulting from feedback. Residents felt that observing a peer teach on work rounds was one of the most useful activities to improve their own teaching on work rounds. © Blackwell Publishing Ltd 2013.

Science-Grade Observing Systems as Process Observatories: Mapping and Understanding Nonlinearity and Multiscale Memory with Models and Observations

NASA Astrophysics Data System (ADS)

Barros, A. P.; Wilson, A. M.; Miller, D. K.; Tao, J.; Genereux, D. P.; Prat, O.; Petersen, W. A.; Brunsell, N. A.; Petters, M. D.; Duan, Y.

2015-12-01

Using the planet as a study domain and collecting observations over unprecedented ranges of spatial and temporal scales, NASA's EOS (Earth Observing System) program was an agent of transformational change in Earth Sciences over the last thirty years. The remarkable space-time organization and variability of atmospheric and terrestrial moist processes that emerged from the analysis of comprehensive satellite observations provided much impetus to expand the scope of land-atmosphere interaction studies in Hydrology and Hydrometeorology. Consequently, input and output terms in the mass and energy balance equations evolved from being treated as fluxes that can be used as boundary conditions, or forcing, to being viewed as dynamic processes of a coupled system interacting at multiple scales. Measurements of states or fluxes are most useful if together they map, reveal and/or constrain the underlying physical processes and their interactions. This can only be accomplished through an integrated observing system designed to capture the coupled physics, including nonlinear feedbacks and tipping points. Here, we first review and synthesize lessons learned from hydrometeorology studies in the Southern Appalachians and in the Southern Great Plains using both ground-based and satellite observations, physical models and data-assimilation systems. We will specifically focus on mapping and understanding nonlinearity and multiscale memory of rainfall-runoff processes in mountainous regions. It will be shown that beyond technical rigor, variety, quantity and duration of measurements, the utility of observing systems is determined by their interpretive value in the context of physical models to describe the linkages among different observations. Second, we propose a framework for designing science-grade and science-minded process-oriented integrated observing and modeling platforms for hydrometeorological studies.

[Tendencies of studies addressing the eldest individuals of aged population in the community: a (inter)national systematic review].

PubMed

Rosset, Idiane; Pedrazzi, Elizandra Cristina; Roriz-Cruz, Matheus; de Morais, Eliane Pinheiro; Rodrigues, Rosalina Aparecida Partezani

2011-03-01

The purpose of this study was to identify and analyze the tendencies and types of studies published in Brazil and abroad, involving elders aged>80 years, living in the community. A systematic review of national literature was performed using the LILACS and SciELO databases, and PUBMED and EMBASE for international literature, covering publications of the last two decades. Twelve national and 162 international references were selected. Biological sciences were the prevalent area both at the national (50%) and international (74.1%) levels. All national studies were observational, 91.7% of which were cross-sectional. Of the international studies, 93.3% were observational, 48.1% of which were cross-sectional and 37.6% were cohort studies. The United States were the country responsible for 41.4% of all international publications. Brazil and China were the only developing countries with international publications. Despite the significant number of international scientific publications as of 2005, this fact has not been observed at the national level.

Sleep and Hypertension

PubMed Central

Harding, Susan M.

2010-01-01

Ambulatory BP studies indicate that even small increases in BP, particularly nighttime BP levels, are associated with significant increases in cardiovascular morbidity and mortality. Accordingly, sleep-related diseases that induce increases in BP would be anticipated to substantially affect cardiovascular risk. Both sleep deprivation and insomnia have been linked to increases in incidence and prevalence of hypertension. Likewise, sleep disruption attributable to restless legs syndrome increases the likelihood of having hypertension. Observational studies demonstrate a strong correlation between the severity of obstructive sleep apnea (OSA) and the risk and severity of hypertension, whereas prospective studies of patients with OSA demonstrate a positive relationship between OSA and risk of incident hypertension. Intervention trials with continuous positive airway pressure (CPAP) indicate a modest, but inconsistent effect on BP in patients with severe OSA and a greater likelihood of benefit in patients with most CPAP adherence. Additional prospective studies are needed to reconcile observational studies suggesting that OSA is a strong risk factor for hypertension with the modest antihypertensive effects of CPAP observed in intervention studies. PMID:20682533

Bovine thrombin safety reporting: an example of study design and publication bias.

PubMed

Crean, Sheila; Michels, Shannon L; Moschella, Kevin; Reynolds, Matthew W

2010-01-01

Bovine thrombin, a popular hemostat and sealant since 1945, has recently been subjected to clinical trial testing due to reformulations in 1998. We sought to compare adverse event rates of early observational studies with those of later interventional trials. A MEDLINE-based literature search in publications that report safety in bovine thrombin exposed surgical patients was extracted and reviewed. In 38 studies, about half were case reports and 31.5% were interventional trials. In case reports, 41% of authors reported severe coagulopathic adverse events. In contrast, whereas blood complications were common in large trials, no association of harm was established for bovine thrombin product exposure and/or immunization. In this review, later clinical trials failed to reproduce the common and severe coagulopathy predicted by earlier observational studies in bovine exposed patients. This example illustrates that perceptions of safety can change as a function of study design, even for a widely adopted, well established biologic such as thrombin. Caution must be exercised in interpreting evidence from observational studies alone.

[Randomized, controlled clinical trials with observational follow-up investigations for evaluating efficacy of antihyperglycaemic treatment. I. Main results of the studies].

PubMed

Jermendy, György

2018-04-01

The effect of antihyperglycaemic (antidiabetic) treatment on the late diabetic complications is one of the most important research areas in clinical diabetology. The relationship between glycaemic control and late micro- and macrovascular complications was highlighted by the results of the DCCT (Diabetes Control and Complications Trial) with type 1 and by the UKPDS (United Kingdom Prospective Diabetes Study) with type 2 diabetic patients. In these studies, observational follow-up investigations were also performed after the close-out of the randomized phase of the trial. In addition to these landmark studies, other randomized, controlled efficacy trials were also performed with observational follow-up investigations resulting in the development of the concept of metabolic memory or metabolic legacy. In this article, the main results of the studies are summarized. Orv Hetil. 2018; 159(15): 575-582.

Context Influences Holistic Processing of Non-face Objects in the Composite Task

PubMed Central

Richler, Jennifer J.; Bukach, Cindy M.; Gauthier, Isabel

2013-01-01

We explore whether holistic-like effects can be observed for non-face objects in novices as a result of the task context. We measure contextually-induced congruency effects for novel objects (Greebles) in a sequential matching selective attention task (composite task). When format at study was blocked, congruency effects were observed for study-misaligned, but not study-aligned, conditions (Experiment 1). However, congruency effects were observed in all conditions when study formats were randomized (Experiment 2), revealing that the presence of certain trial types (study-misaligned) in an experiment can induce congruency effects. In a dual task, a congruency effect for Greebles was induced in trials where a face was first encoded, only if it was aligned (Experiment 3). Thus, congruency effects can be induced by context that operates at the scale of the entire experiment or within a single trial. Implications for using the composite task to measure holistic processing are discussed. PMID:19304644

Definition of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage as an outcome event in clinical trials and observational studies: proposal of a multidisciplinary research group.

PubMed

Vergouwen, Mervyn D I; Vermeulen, Marinus; van Gijn, Jan; Rinkel, Gabriel J E; Wijdicks, Eelco F; Muizelaar, J Paul; Mendelow, A David; Juvela, Seppo; Yonas, Howard; Terbrugge, Karel G; Macdonald, R Loch; Diringer, Michael N; Broderick, Joseph P; Dreier, Jens P; Roos, Yvo B W E M

2010-10-01

In clinical trials and observational studies there is considerable inconsistency in the use of definitions to describe delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage. A major cause for this inconsistency is the combining of radiographic evidence of vasospasm with clinical features of cerebral ischemia, although multiple factors may contribute to DCI. The second issue is the variability and overlap of terms used to describe each phenomenon. This makes comparisons among studies difficult. An international ad hoc panel of experts involved in subarachnoid hemorrhage research developed and proposed a definition of DCI to be used as an outcome measure in clinical trials and observational studies. We used a consensus-building approach. It is proposed that in observational studies and clinical trials aiming to investigate strategies to prevent DCI, the 2 main outcome measures should be: (1) cerebral infarction identified on CT or MRI or proven at autopsy, after exclusion of procedure-related infarctions; and (2) functional outcome. Secondary outcome measure should be clinical deterioration caused by DCI, after exclusion of other potential causes of clinical deterioration. Vasospasm on angiography or transcranial Doppler can also be used as an outcome measure to investigate proof of concept but should be interpreted in conjunction with DCI or functional outcome. The proposed measures reflect the most relevant morphological and clinical features of DCI without regard to pathogenesis to be used as an outcome measure in clinical trials and observational studies.

Vitamin C Intake and Pancreatic Cancer Risk: A Meta-Analysis of Published Case-Control and Cohort Studies.

PubMed

Hua, Yong-Fei; Wang, Gao-Qing; Jiang, Wei; Huang, Jing; Chen, Guo-Chong; Lu, Cai-De

2016-01-01

Observational studies inconsistently reported the relationship between vitamin C intake and risk of pancreatic cancer. We conducted a meta-analysis of published case-control and cohort studies to quantify the association. Potentially eligible studies were found on PubMed and EMBASE databases through May 31, 2015. A random-effects model was assigned to compute summary point estimates with corresponding 95% confidence intervals (CIs). Subgroup and meta-regression analyses were also performed to explore sources of heterogeneity. Our final analyses included 20 observational studies comprising nearly 5 thousand cases of pancreatic cancer. When comparing the highest with the lowest categories of vitamin C intake, the summary odds ratio/relative risk for case-control studies (14 studies), cohort studies (6 studies) and all studies combined was 0.58 (95% CI: 0.52-0.66), 0.93 (95% CI: 0.78-1.11) and 0.66 (95% CI: 0.58-0.75), respectively. The difference in the findings between case-control and cohort studies was statistically significant (P < .001). Possible publication bias was shown in the meta-analysis of case-control studies. There is insufficient evidence to conclude any relationship between vitamin C intake and risk of pancreatic cancer. The strong inverse association observed in case-control studies may be affected by biases (eg, recall and selection biases) that particularly affect case-control studies and/or potential publication bias. Future prospective studies of vitamin C intake and pancreatic cancer are needed.

Incident CTS in a large pooled cohort study: associations obtained by a Job Exposure Matrix versus associations obtained from observed exposures.

PubMed

Dale, Ann Marie; Ekenga, Christine C; Buckner-Petty, Skye; Merlino, Linda; Thiese, Matthew S; Bao, Stephen; Meyers, Alysha Rose; Harris-Adamson, Carisa; Kapellusch, Jay; Eisen, Ellen A; Gerr, Fred; Hegmann, Kurt T; Silverstein, Barbara; Garg, Arun; Rempel, David; Zeringue, Angelique; Evanoff, Bradley A

2018-03-29

There is growing use of a job exposure matrix (JEM) to provide exposure estimates in studies of work-related musculoskeletal disorders; few studies have examined the validity of such estimates, nor did compare associations obtained with a JEM with those obtained using other exposures. This study estimated upper extremity exposures using a JEM derived from a publicly available data set (Occupational Network, O*NET), and compared exposure-disease associations for incident carpal tunnel syndrome (CTS) with those obtained using observed physical exposure measures in a large prospective study. 2393 workers from several industries were followed for up to 2.8 years (5.5 person-years). Standard Occupational Classification (SOC) codes were assigned to the job at enrolment. SOC codes linked to physical exposures for forceful hand exertion and repetitive activities were extracted from O*NET. We used multivariable Cox proportional hazards regression models to describe exposure-disease associations for incident CTS for individually observed physical exposures and JEM exposures from O*NET. Both exposure methods found associations between incident CTS and exposures of force and repetition, with evidence of dose-response. Observed associations were similar across the two methods, with somewhat wider CIs for HRs calculated using the JEM method. Exposures estimated using a JEM provided similar exposure-disease associations for CTS when compared with associations obtained using the 'gold standard' method of individual observation. While JEMs have a number of limitations, in some studies they can provide useful exposure estimates in the absence of individual-level observed exposures. © 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.

Interpreting observational studies: why empirical calibration is needed to correct p-values

PubMed Central

Schuemie, Martijn J; Ryan, Patrick B; DuMouchel, William; Suchard, Marc A; Madigan, David

2014-01-01

Often the literature makes assertions of medical product effects on the basis of ‘ p < 0.05’. The underlying premise is that at this threshold, there is only a 5% probability that the observed effect would be seen by chance when in reality there is no effect. In observational studies, much more than in randomized trials, bias and confounding may undermine this premise. To test this premise, we selected three exemplar drug safety studies from literature, representing a case–control, a cohort, and a self-controlled case series design. We attempted to replicate these studies as best we could for the drugs studied in the original articles. Next, we applied the same three designs to sets of negative controls: drugs that are not believed to cause the outcome of interest. We observed how often p < 0.05 when the null hypothesis is true, and we fitted distributions to the effect estimates. Using these distributions, we compute calibrated p-values that reflect the probability of observing the effect estimate under the null hypothesis, taking both random and systematic error into account. An automated analysis of scientific literature was performed to evaluate the potential impact of such a calibration. Our experiment provides evidence that the majority of observational studies would declare statistical significance when no effect is present. Empirical calibration was found to reduce spurious results to the desired 5% level. Applying these adjustments to literature suggests that at least 54% of findings with p < 0.05 are not actually statistically significant and should be reevaluated. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. PMID:23900808

The advances in airglow study and observation by the ground-based airglow observation network over China

NASA Astrophysics Data System (ADS)

Xu, Jiyao; Li, Qinzeng; Yuan, Wei; Liu, Xiao; Liu, Weijun; Sun, Longchang

2017-04-01

Ground-based airglow observation networks over China used to study airglow have been established, which contains 15 stations. Some new results were obtained using the networks. For OH airglow observations, firstly, an unusual outbreak of Concentric Gravity Wave (CGW) events were observed by the first no-gap network nearly every night during the first half of August 2013. Combination of the ground imager network with satellites provides multilevel observations of the CGWs from the troposphere to the mesopause region. Secondly, three-year OH airglow images (2012-2014) from Qujing (25.6°N, 103.7°E) were used to study how orographic features of the Tibetan Plateau (TP) affect the geographical distributions of gravity wave (GW) sources. We find the orographic forcings have a significant impact on the gravity wave propagation features. Thirdly, ground-based observations of the OH (9-4, 8-3, 6-2, 5-1, 3-0) band airglow over Xinglong (40°2N, 117°4E) in northern China from 2012 to 2014 are used to calculate rotational temperatures. By comparing the ground-based OH rotational temperature with SABER's observations, five Einstein coefficient datasets are evaluated. We find rotational temperatures determined using any of the available Einstein coefficient datasets have systematic errors. We have obtained a set of optimal Einstein coefficients ratios for rotational temperature derivation using three years data from ground-based OH spectra and SABER temperatures. For the OI 630.0 nm airglow observations, we used three-year (2011-2013) observations of thermospheric winds (at 250 km) by Fabry-Perot interferometers at Xinglong to study the climatology of atmospheric planetary wave-type oscillations (PWTOs) with periods of 4-19 days. We found these PWTOs occur more frequently in the months from May to October. They are consistent with the summertime preference of middle-latitude ionospheric electron density oscillations noted in other studies. By using an all-sky airglow imager at 630.0 nm over Xinglong, we studied the evolution (generation, amplification, and dissipation) of mesoscale field-aligned irregularity structures (FAIs) ( 150 km) associated with a medium-scale traveling ionospheric disturbance (MSTID) event. We also investigates the statistical features of equatorial plasma bubbles (EPBs) using airglow images from 2012 to 2014 from a ground-based network of four imagers in the equatorial region of China.

Alternative ways of using field-based estimates to calibrate ecosystem models and their implications for ecosystem carbon cycle studies

Treesearch

Y. He; Q. Zhuang; A.D. McGuire; Y. Liu; M. Chen

2013-01-01

Model-data fusion is a process in which field observations are used to constrain model parameters. How observations are used to constrain parameters has a direct impact on the carbon cycle dynamics simulated by ecosystem models. In this study, we present an evaluation of several options for the use of observations inmodeling regional carbon dynamics and explore the...

The Power and Pitfalls of Big Data Research in Obstetrics and Gynecology: A Consumer's Guide

PubMed Central

Goodin, Amie; Delcher, Chris; Valenzuela, Chelsea; Wang, Xi; Zhu, Yanmin; Roussos-Ross, Dikea; Brown, Joshua D.

2017-01-01

Importance Research in obstetrics and gynecology (OB/GYN) increasingly relies on “big data” and observational study designs. There is a gap in practitioner-relevant guides to interpret and critique such research. Objective This guide is an introduction to interpreting research using observational data and provides explanations and context for related terminology. In addition, it serves as a guide for critiquing OB/GYN studies that use observational data by outlining how to assess common pitfalls of experimental and observational study designs. Lastly, the piece provides a compendium of observational data resources commonly used within OB/GYN research. Evidence Acquisition Review of literature was conducted for the collection of definitions and examples of terminology related to observational data research. Data resources were collected via Web search and researcher recommendations. Next, each data resource was reviewed and analyzed for content and accessibility. Contents of data resources were organized into summary tables and matched to relevant literature examples. Results We identified 26 observational data resources frequently used in secondary analysis for OB/GYN research. Cost, accessibility considerations for software/hardware capabilities, and contents of each data resource varied substantially. Conclusions and Relevance Observational data sources can provide researchers with a variety of options in tackling their research questions related to OB/GYN practice, patient health outcomes, trends in utilization of medications/procedures, or prevalence estimates of disease states. Insurance claims data resources are useful for population-level prevalence estimates and utilization trends, whereas electronic health record–derived data and patient survey data may be more useful for exploring patient behaviors and trends in practice. Target Audience Obstetricians and gynecologists, family physicians. Learning Objectives After completing this activity, the learner should be better able to identify and define terminology used in observational data research; compare the features, strengths, and limitations of observational study designs and randomized controlled trials; distinguish between types of observational data (eg, insurance administrative claims, discharges, electronic health record databases, surveys, surveillance data) and weigh the strengths and limitations of research that uses each data type; interpret and critique OB/GYN research that uses observational data and secondary data analysis; and gain exposure and familiarity with a selection of observational data sets used to study topics relevant to obstetrical and gynecological practice and/or health outcomes. PMID:29164265

The clinical course of low back pain: a meta-analysis comparing outcomes in randomised clinical trials (RCTs) and observational studies

PubMed Central

2014-01-01

Background Evidence suggests that the course of low back pain (LBP) symptoms in randomised clinical trials (RCTs) follows a pattern of large improvement regardless of the type of treatment. A similar pattern was independently observed in observational studies. However, there is an assumption that the clinical course of symptoms is particularly influenced in RCTs by mere participation in the trials. To test this assumption, the aim of our study was to compare the course of LBP in RCTs and observational studies. Methods Source of studies CENTRAL database for RCTs and MEDLINE, CINAHL, EMBASE and hand search of systematic reviews for cohort studies. Studies include individuals aged 18 or over, and concern non-specific LBP. Trials had to concern primary care treatments. Data were extracted on pain intensity. Meta-regression analysis was used to compare the pooled within-group change in pain in RCTs with that in cohort studies calculated as the standardised mean change (SMC). Results 70 RCTs and 19 cohort studies were included, out of 1134 and 653 identified respectively. LBP symptoms followed a similar course in RCTs and cohort studies: a rapid improvement in the first 6 weeks followed by a smaller further improvement until 52 weeks. There was no statistically significant difference in pooled SMC between RCTs and cohort studies at any time point:- 6 weeks: RCTs: SMC 1.0 (95% CI 0.9 to 1.0) and cohorts 1.2 (0.7to 1.7); 13 weeks: RCTs 1.2 (1.1 to 1.3) and cohorts 1.0 (0.8 to 1.3); 27 weeks: RCTs 1.1 (1.0 to 1.2) and cohorts 1.2 (0.8 to 1.7); 52 weeks: RCTs 0.9 (0.8 to 1.0) and cohorts 1.1 (0.8 to 1.6). Conclusions The clinical course of LBP symptoms followed a pattern that was similar in RCTs and cohort observational studies. In addition to a shared ‘natural history’, enrolment of LBP patients in clinical studies is likely to provoke responses that reflect the nonspecific effects of seeking and receiving care, independent of the study design. PMID:24607083

Role of observation of live cases done by Japanese experts in the acquisition of ESD skills by a western endoscopist.

PubMed

Draganov, Peter V; Chang, Myron; Coman, Roxana M; Wagh, Mihir S; An, Qi; Gotoda, Takuji

2014-04-28

To evaluate the role of observation of experts performing endoscopic submucosal dissection (ESD) in the acquisition of ESD skills. This prospective study is documenting the learning curve of one Western endoscopist. The study consisted of three periods. In the first period (pre-observation), the trainee performed ESDs in animal models in his home institution in the United States. The second period (observation) consisted of visit to Japan and observation of live ESD cases done by experts. The observation of cases occurred over a 5-wk period. During the third period (post-observation), the trainee performed ESD in animal models in a similar fashion as in the first period. Three animal models were used: live 40-50 kg Yorkshire pig, explanted pig stomach model, and explanted pig rectum model. The outcomes from the ESDs done in the animal models before and after observation of live human cases (main study intervention) were compared. Statistical analysis of the data included: Fisher's exact test to compare distributions of a categorical variable, Wilcoxon rank sum test to compare distributions of a continuous variable between the two groups (pre-observation and post-observation), and Kruskal-Wallis test to evaluate the impact of lesion location and type of model (ex-vivo vs live pig) on lesion removal time. The trainee performed 38 ESDs in animal model (29 pre-observation/9 post-observation). The removal times post-observation were significantly shorter than those pre-observation (32.7 ± 15.0 min vs 63.5 ± 9.8 min, P < 0.001). To minimize the impact of improving physician skill, the 9 lesions post-observation were compared to the last 9 lesions pre-observation and the removal times remained significantly shorter (32.7 ± 15.0 min vs 61.0 ± 7.4 min, P = 0.0011). Regression analysis showed that ESD observation significantly reduced removal time when controlling for the sequence of lesion removal (P = 0.025). Furthermore, it was also noted a trend towards decrease in failure to remove lesions and decrease in complications after the period of observation. This study did not find a significant difference in the time needed to remove lesions in different animal models. This finding could have important implications in designing training programs due to the substantial difference in cost between live animal and explanted organ models. The main limitation of this study is that it reflects the experience of a single endoscopist. Observation of experts performing ESD over short period of time can significantly contribute to the acquisition of ESD skills.

Randomized controlled trials and real-world observational studies in evaluating cardiovascular safety of inhaled bronchodilator therapy in COPD.

PubMed

Kardos, Peter; Worsley, Sally; Singh, Dave; Román-Rodríguez, Miguel; Newby, David E; Müllerová, Hana

2016-01-01

Long-acting muscarinic antagonist (LAMA) or long-acting β2-agonist (LABA) bronchodilators and their combination are recommended for the maintenance treatment of chronic obstructive pulmonary disease (COPD). Although the efficacy of LAMAs and LABAs has been well established through randomized controlled trials (RCTs), questions remain regarding their cardiovascular (CV) safety. Furthermore, while the safety of LAMA and LABA monotherapy has been extensively studied, data are lacking for LAMA/LABA combination therapy, and the majority of the studies that have reported on the CV safety of LAMA/LABA combination therapy were not specifically designed to assess this. Evaluation of CV safety for COPD treatments is important because many patients with COPD have underlying CV comorbidities. However, severe CV and other comorbidities are often exclusion criteria for RCTs, contributing to a lack in external validity and generalizability. Real-world observational studies are another important tool to evaluate the effectiveness and safety of COPD therapies in a broader population of patients and can improve upon the external validity limitations of RCTs. We examine what is already known regarding the CV and cerebrovascular safety of LAMA/LABA combination therapy from RCTs and real-world observational studies, and explore the advantages and limitations of data derived from each study type. We also describe an ongoing prospective, observational, comparative post-authorization safety study of a LAMA/LABA combination therapy (umeclidinium/vilanterol) and LAMA monotherapy (umeclidinium) versus tiotropium, with a focus on the relative merits of the study design.

A Secure Base from which to Cooperate: Security, Child and Parent Willing Stance, and Adaptive and Maladaptive Outcomes in two Longitudinal Studies.

PubMed

Goffin, Kathryn C; Boldt, Lea J; Kochanska, Grazyna

2017-10-17

Early secure attachment plays a key role in socialization by inaugurating a long-term mutual positive, collaborative interpersonal orientation within the parent-child dyad. We report findings from Family Study (community mothers, fathers, and children, from age 2 to 12, N = 102, 51 girls) and Play Study (exclusively low-income mothers and children, from age 3.5 to 7, N = 186, 90 girls). We examined links among observed secure attachment at toddler age, child and parent receptive, willing stance to each other, observed in parent-child contexts at early school age, and developmental outcomes. The developmental outcomes included parent-rated child antisocial behavior problems and observed positive mutuality with regard to conflict issues at age 12 in Family Study, and mother-rated child antisocial behavior problems and observed child regard for rules and moral self at age 7 in Play Study. In mother-child relationships, the child's willing stance mediated indirect effects of child security on positive mutuality in Family Study and on all outcomes in Play Study. In father-child relationships, both the child's and the parent's willing stance mediated indirect effects of child security on both outcomes. Early security initiates an adaptive developmental cascade by enlisting the child and the parent as active, willingly receptive and cooperative agents in the socialization process. Implications for children's parenting interventions are noted.

Overview of clinical research design.

PubMed

Hartung, Daniel M; Touchette, Daniel

2009-02-15

Basic concepts and terminology of clinical research design are presented for new clinical investigators. Clinical research, research involving human subjects, can be described as either observational or experimental. The findings of all clinical research can be threatened by issues of bias and confounding. Biases are systematic errors in how study subjects are selected or measured, which result in false inferences. Confounding is a distortion in findings that is attributable to mixing variable effects. Uncontrolled observation research is generally more prone to bias and confounding than experimental research. Observational research includes designs such as the cohort study, case-control study, and cross-sectional study, while experimental research typically involves a randomized controlled trial (RCT). The cohort study, which includes the RCT, defines subject allocation on the basis of exposure interest (e.g., drug, disease-management program) and follows the patients to assess the outcomes. The case-control study uses the primary outcome of interest (e.g., adverse event) to define subject allocation, and different exposures are assessed in a retrospective manner. Cross-sectional research evaluates both exposure and outcome concurrently. Each of these design methods possesses different strengths and weaknesses in answering research questions, as well as underlying many study subtypes. While experimental research is the strongest method for establishing causality, it can be difficult to accomplish under many scenarios. Observational clinical research offers many design alternatives that may be appropriate if planned and executed carefully.

Working models of attachment to parents and partners: implications for emotional behavior between partners.

PubMed

Mehta, Neera; Cowan, Philip A; Cowan, Carolyn P

2009-12-01

This study examined whether working models of attachment are associated with observed positive emotion, sadness, and anger during marital conflict. Individuals (n = 176) from a longitudinal study of families participated in the current cross-sectional study. Narrative interviews assessed the unique and combined contribution of attachment representations based on parents (adult attachment) and partner (couple attachment). The influence of partner's attachment, depression symptoms, and sex of participant was also examined. Hierarchical linear models demonstrated that one's couple attachment security predicts one's observed positive emotion, whereas the partner's couple attachment security predicts one's observed negative emotion. Partner's depression symptoms moderated the effects of partner's couple attachment. Adult attachment was not related to observed emotional behavior between partners. These findings have important clinical implications for individual, couple, and family therapy.

Rocket and spacecraft studies of ultraviolet emissions from astrophysical targets

NASA Technical Reports Server (NTRS)

Fastie, W. G.; Moos, H. W.; Feldman, P. D.; Henry, R. C.

1975-01-01

Rocket and spacecraft far-UV spectral measurements of several astrophysical targets are reviewed. These include observations of Ly-alpha emissions from Arcturus, Apollo-17 far-UV spectrometry of eta UMa and five other stars, Apollo-17 observations of the lunar atmosphere and the diffuse UV background, and far-UV spectral studies of Venus, Jupiter, and Comet Kohoutek. The Arcturus observations indicated a chromosphere with neutral atomic-hydrogen and atomic-oxygen emissions as well as a very weak atomic-carbon line. The planetary studies revealed O I and C I emissions in the Venusian spectrum as well as large Ly-alpha emissions and possible molecular-hydrogen emissions in that of Jupiter. The lunar observations demonstrated that solar protons do not produce an atomic-hydrogen atmosphere on the moon.

Ionospheric and satellite observations for studying the dynamic behavior of typhoons and the detection of severe storms and tsunamis

NASA Technical Reports Server (NTRS)

Hung, R. J.; Smith, R. E.

1978-01-01

Atmospheric acoustic-gravity waves associated with severe thunderstorms, tornadoes, typhoons (hurricanes) and tsunamis can be studied through the coupling between the ionosphere and the troposphere. Reverse ray tracing computations of acoustic-gravity waves observed by an ionospheric Doppler sounder array show that wave sources are in the nearby storm systems and that the waves are excited prior to the storms. Results show that ionospheric observations, together with satellite observations, can contribute to the understanding of the dynamical behavior of typhoons, severe storms and tsunamis.

Feasibility study for the use of a YF-12 aircraft as a scientific instrument platform for observing the 1970 solar eclipse

NASA Technical Reports Server (NTRS)

Mercer, R. D.

1973-01-01

The scientific and engineering findings are presented of the feasibility study for the use of a YF-12 aircraft as a scientific instrument platform for observing the 1970 solar eclipse. Included in the report is the computer program documentation of the solar eclipse determination; summary data on SR-71A type aircraft capabilities and limitations as an observing platform for solar eclipses; and the recordings of an informal conference on observations of solar eclipses using SR-71A type aircraft.

Statistical models for causation: what inferential leverage do they provide?

PubMed

Freedman, David A

2006-12-01

Experiments offer more reliable evidence on causation than observational studies, which is not to gainsay the contribution to knowledge from observation. Experiments should be analyzed as experiments, not as observational studies. A simple comparison of rates might be just the right tool, with little value added by "sophisticated" models. This article discusses current models for causation, as applied to experimental and observational data. The intention-to-treat principle and the effect of treatment on the treated will also be discussed. Flaws in per-protocol and treatment-received estimates will be demonstrated.

Maternal Antioxidant Levels in Pregnancy and Risk of Preeclampsia and Small for Gestational Age Birth: A Systematic Review and Meta-Analysis.

PubMed

Cohen, Jacqueline M; Beddaoui, Margaret; Kramer, Michael S; Platt, Robert W; Basso, Olga; Kahn, Susan R

2015-01-01

Oxidative stress in preeclampsia and small for gestational age (SGA) birth suggests antioxidant supplementation could prevent these conditions. However, it remains unclear whether maternal antioxidant levels are systematically lower in these pregnancies. To conduct a systematic review of the association between maternal antioxidant levels during pregnancy and preeclampsia or SGA. We searched PubMed, Embase, and several other databases from 1970-2013 for observational studies that measured maternal blood levels of non-enzymatic antioxidants (vitamins A, C, E, and carotenoids) during pregnancy or within 72 hours of delivery. The entire review process was done in duplicate. Study quality was assessed using the Newcastle-Ottawa Scale and additional questions. We pooled the standardized mean difference (SMD) across studies, stratified by outcome and pregnancy trimester, and investigated heterogeneity using meta-regression. We reviewed 1,882 unique citations and 64 studies were included. Most studies were small with important risk of bias. Among studies that addressed preeclampsia (n = 58) and SGA (n = 9), 16% and 66%, respectively, measured levels prior to diagnosis. The SMDs for vitamins A, C, and E were significantly negative for overall preeclampsia, but not for mild or severe preeclampsia subtypes. Significant heterogeneity was observed in all meta-analyses and most could not be explained. Evidence for lower carotenoid antioxidants in preeclampsia and SGA was limited and inconclusive. Publication bias appears likely. Small, low-quality studies limit conclusions that can be drawn from the available literature. Observational studies inconsistently show that vitamins C and E or other antioxidants are lower in women who develop preeclampsia or SGA. Reverse causality remains a possible explanation for associations observed. New clinical trials are not warranted in light of this evidence; however, additional rigorous observational studies measuring antioxidant levels before clinical detection of preeclampsia and SGA may clarify whether levels are altered at a causally-relevant time of pregnancy.

Maternal Antioxidant Levels in Pregnancy and Risk of Preeclampsia and Small for Gestational Age Birth: A Systematic Review and Meta-Analysis

PubMed Central

Cohen, Jacqueline M.; Beddaoui, Margaret; Kramer, Michael S.; Platt, Robert W.; Basso, Olga; Kahn, Susan R.

2015-01-01

Background Oxidative stress in preeclampsia and small for gestational age (SGA) birth suggests antioxidant supplementation could prevent these conditions. However, it remains unclear whether maternal antioxidant levels are systematically lower in these pregnancies. Objective To conduct a systematic review of the association between maternal antioxidant levels during pregnancy and preeclampsia or SGA. Methods We searched PubMed, Embase, and several other databases from 1970–2013 for observational studies that measured maternal blood levels of non-enzymatic antioxidants (vitamins A, C, E, and carotenoids) during pregnancy or within 72 hours of delivery. The entire review process was done in duplicate. Study quality was assessed using the Newcastle-Ottawa Scale and additional questions. We pooled the standardized mean difference (SMD) across studies, stratified by outcome and pregnancy trimester, and investigated heterogeneity using meta-regression. Results We reviewed 1,882 unique citations and 64 studies were included. Most studies were small with important risk of bias. Among studies that addressed preeclampsia (n = 58) and SGA (n = 9), 16% and 66%, respectively, measured levels prior to diagnosis. The SMDs for vitamins A, C, and E were significantly negative for overall preeclampsia, but not for mild or severe preeclampsia subtypes. Significant heterogeneity was observed in all meta-analyses and most could not be explained. Evidence for lower carotenoid antioxidants in preeclampsia and SGA was limited and inconclusive. Publication bias appears likely. Conclusions Small, low-quality studies limit conclusions that can be drawn from the available literature. Observational studies inconsistently show that vitamins C and E or other antioxidants are lower in women who develop preeclampsia or SGA. Reverse causality remains a possible explanation for associations observed. New clinical trials are not warranted in light of this evidence; however, additional rigorous observational studies measuring antioxidant levels before clinical detection of preeclampsia and SGA may clarify whether levels are altered at a causally-relevant time of pregnancy. PMID:26247870

Effects of sharing information on drug administration errors in pediatric wards: a pre–post intervention study

PubMed Central

Chua, Siew-Siang; Choo, Sim-Mei; Sulaiman, Che Zuraini; Omar, Asma; Thong, Meow-Keong

2017-01-01

Background and purpose Drug administration errors are more likely to reach the patient than other medication errors. The main aim of this study was to determine whether the sharing of information on drug administration errors among health care providers would reduce such problems. Patients and methods This study involved direct, undisguised observations of drug administrations in two pediatric wards of a major teaching hospital in Kuala Lumpur, Malaysia. This study consisted of two phases: Phase 1 (pre-intervention) and Phase 2 (post-intervention). Data were collected by two observers over a 40-day period in both Phase 1 and Phase 2 of the study. Both observers were pharmacy graduates: Observer 1 just completed her undergraduate pharmacy degree, whereas Observer 2 was doing her one-year internship as a provisionally registered pharmacist in the hospital under study. A drug administration error was defined as a discrepancy between the drug regimen received by the patient and that intended by the prescriber and also drug administration procedures that did not follow standard hospital policies and procedures. Results from Phase 1 of the study were analyzed, presented and discussed with the ward staff before commencement of data collection in Phase 2. Results A total of 1,284 and 1,401 doses of drugs were administered in Phase 1 and Phase 2, respectively. The rate of drug administration errors reduced significantly from Phase 1 to Phase 2 (44.3% versus 28.6%, respectively; P<0.001). Logistic regression analysis showed that the adjusted odds of drug administration errors in Phase 1 of the study were almost three times that in Phase 2 (P<0.001). The most common types of errors were incorrect administration technique and incorrect drug preparation. Nasogastric and intravenous routes of drug administration contributed significantly to the rate of drug administration errors. Conclusion This study showed that sharing of the types of errors that had occurred was significantly associated with a reduction in drug administration errors. PMID:28356748

Workplace Education Initiative: Case Studies and Observations.

ERIC Educational Resources Information Center

Astrein, Bruce; And Others

Seven workplace education projects funded in the first year of the Massachusetts Workplace Education Initiative are reported. This report includes both general observations and specific information in case studies of the projects. Overall information is provided on students served, the importance of partnerships, the emphasis on…

A mathematical model of case-ascertainment bias: Applied to case-control studies nested within a randomized screening trial.

PubMed

Jansen, Rick J; Alexander, Bruce H; Hayes, Richard B; Miller, Anthony B; Wacholder, Sholom; Church, Timothy R

2018-01-01

When some individuals are screen-detected before the beginning of the study, but otherwise would have been diagnosed symptomatically during the study, this results in different case-ascertainment probabilities among screened and unscreened participants, referred to here as lead-time-biased case-ascertainment (LTBCA). In fact, this issue can arise even in risk-factor studies nested within a randomized screening trial; even though the screening intervention is randomly allocated to trial arms, there is no randomization to potential risk-factors and uptake of screening can differ by risk-factor strata. Under the assumptions that neither screening nor the risk factor affects underlying incidence and no other forms of bias operate, we simulate and compare the underlying cumulative incidence and that observed in the study due to LTBCA. The example used will be constructed from the randomized Prostate, Lung, Colorectal, and Ovarian cancer screening trial. The derived mathematical model is applied to simulating two nested studies to evaluate the potential for screening bias in observational lung cancer studies. Because of differential screening under plausible assumptions about preclinical incidence and duration, the simulations presented here show that LTBCA due to chest x-ray screening can significantly increase the estimated risk of lung cancer due to smoking by 1% and 50%. Traditional adjustment methods cannot account for this bias, as the influence screening has on observational study estimates involves events outside of the study observation window (enrollment and follow-up) that change eligibility for potential participants, thus biasing case ascertainment.

Adverse effects of psychosocial work factors on blood pressure: systematic review of studies on demand-control-support and effort-reward imbalance models.

PubMed

Gilbert-Ouimet, Mahée; Trudel, Xavier; Brisson, Chantal; Milot, Alain; Vézina, Michel

2014-03-01

A growing body of research has investigated the adverse effects of psychosocial work factors on blood pressure (BP) elevation. There is now a clear need for an up-to-date, critical synthesis of reliable findings on this topic. This systematic review aimed to evaluate the adverse effects of psychosocial work factors of both the demand-control-support (DCS) and effort-reward imbalance (ERI) models on BP among men and women, according to the methodological quality of the studies. To be eligible, studies had to: (i) evaluate at least one psychosocial work factor, (ii) evaluate BP or hypertension, (iii) comprise ≥100 workers, (iv) be written in English or French, and (v) be published in a peer-reviewed journal. A total of 74 studies were included. Of these, 64 examined the DCS model, and 12 looked at the ERI model, with 2 studies considering both models. Approximately half the studies observed a significant adverse effect of psychosocial work factors on BP. A more consistent effect was observed, however, among men than women. For job strain, a more consistent effect was also observed in studies of higher methodological quality, ie, studies using a prospective design and ambulatory BP measures. A more consistent adverse effect of psychosocial work factors was observed among men than women and in studies of higher methodological quality. These findings contribute to the current effort of primary prevention of cardiovascular disease by documenting the psychosocial etiology of elevated BP, a major cardiovascular risk factor.

Use of acetaminophen and risk of endometrial cancer: evidence from observational studies.

PubMed

Ding, Yuan-Yuan; Yao, Peng; Verma, Surya; Han, Zhen-Kai; Hong, Tao; Zhu, Yong-Qiang; Li, Hong-Xi

2017-05-23

Previous meta-analyses suggested that aspirin was associated with reduced risk of endometrial cancer. However, there has been no study comprehensively summarize the evidence of acetaminophen use and risk of endometrial cancer from observational studies. We systematically searched electronic databases (PubMed , EMBASE, Web of Science, and Cochrane Library) for relevant cohort or case-control studies up to February 28, 2017. Two independent authors performed the eligibility evaluation and data extraction. All differences were resolved by discussion. A random-effects model was applied to estimate summary relative risks (RRs) with 95% CIs. All statistical tests were two-sided. Seven observational studies including four prospective cohort studies and three case-control studies with 3874 endometrial cancer cases were included for final analysis. Compared with never use acetaminophen, ever use this drug was not associated with risk of endometrial cancer (summarized RR = 1.02; 95% CI: 0.93-1.13, I2 = 0%). Similar null association was also observed when compared the highest category of frequency/duration with never use acetaminophen (summarized RR = 0.88; 95% CI: 0.70-1.11, I2 = 15.2%). Additionally, the finding was robust in the subgroup analyses stratified by study characteristics and adjustment for potential confounders and risk factors. There was no evidence of publication bias by a visual inspection of a funnel plot and formal statistical tests. In summary, the present meta-analysis reveals no association between acetaminophen use and risk of endometrial cancer. More large scale prospective cohort studies are warranted to confirm our findings and carry out the dose-response analysis of aforementioned association.

Clinical review: Statins and trauma - a systematic review

PubMed Central

2013-01-01

Statins, in addition to their lipid-lowering properties, have anti-inflammatory actions. The aim of this review is to evaluate the effect of pre-injury statin use, and statin treatment following injury. MEDLINE, EMBASE, and CENTRAL databases were searched to January 2012 for randomised and observational studies of statins in trauma patients in general, and in patients who have suffered traumatic brain injury, burns, and fractures. Of 985 identified citations, 7 (4 observational studies and 3 randomised controlled trials (RCTs)) met the inclusion criteria. Two studies (both observational) were concerned with trauma patients in general, two with patients who had suffered traumatic brain injury (one observational, one RCT), two with burns patients (one observational, one RCT), and one with fracture healing (RCT). Two of the RCTs relied on surrogate outcome measures. The observational studies were deemed to be at high risk of confounding, and the RCTs at high risk of bias. Three of the observational studies suggested improvements in a number of clinical outcomes in patients taking statins prior to injury (mortality, infection, and septic shock in burns patients; mortality in trauma patients in general; mortality in brain injured patients) whereas one, also of trauma patients in general, showed no difference in mortality or infection, and an increased risk of multi-organ failure. Two of three RCTs on statin treatment in burns patients and brain injured patients showed improvements in E-selectin levels and cognitive function. The third, of patients with radial fractures, showed no acceleration in fracture union. In conclusion, there is some evidence that pre-injury statin use and post-injury statin treatment may have a beneficial effect in patients who have suffered general trauma, traumatic brain injury, and burns. However, these studies are at high risk of confounding and bias, and should be regarded as 'hypothesisgenerating'. A well-designed RCT is required to determine the therapeutic efficacy in improving outcomes in this patient population. PMID:23751018

Topical Review: Families Coping With Child Trauma: A Naturalistic Observation Methodology

PubMed Central

Barrett, Anna; Bowles, Peter; Conroy, Rowena; Mehl, Matthias R.

2016-01-01

Objective To introduce a novel, naturalistic observational methodology (the Electronically Activated Recorder; EAR) as an opportunity to better understand the central role of the family environment in children’s recovery from trauma. Methods Discussion of current research methods and a systematic literature review of EAR studies on health and well-being. Results Surveys, experience sampling, and the EAR method each provide different opportunities and challenges for studying family interactions. We identified 17 articles describing relevant EAR studies. These investigated questions of emotional well-being, communicative behaviors, and interpersonal relationships, predominantly in adults. 5 articles reported innovative research in children, triangulating EAR-observed behavioral data (e.g., on child conflict at home) with neuroendocrine assay, sociodemographic information, and parent report. Finally, we discussed psychometric, practical, and ethical considerations for conducting EAR research with children and families. Conclusions Naturalistic observation methods such as the EAR have potential for pediatric psychology studies regarding trauma and the family environment. PMID:25797943

Cost-efficiency of knowledge creation: randomized controlled trials vs. observational studies.

PubMed

Struck, Rafael; Baumgarten, Georg; Wittmann, Maria

2014-04-01

This article reviews traditional and current perspectives on randomized, controlled trials (RCTs) and observational studies relative to the economic implications for public healthcare stakeholders. It takes an average of 17 years to bring 14% of original research into clinical practice. Results from high-quality observational studies may complement limited RCTs in primary and secondary literature bases, and enhance the incorporation of sound evidence-based guidelines. Observational findings from comprehensive medical databases may offer valuable clues on the effectiveness and relevance of public healthcare interventions. Major expenditures associated with RCTs relate to recruitment, inappropriate site selection, conduct and reporting. Application of business strategies and economic evaluation tools, in addition to the planning and conduct of RCTs, may enhance clinical trial site performances. Considering the strengths and limitations of each study type, clinical researchers should explore the contextual worthiness of either design in promulgating knowledge. They should focus on quality of conduct and reporting that may allow for the liberation of limited public and private clinical research funding.

Myocardial bridges of the coronary arteries in the human fetal heart.

PubMed

Cakmak, Yusuf Ozgür; Cavdar, Safiye; Yalin, Aymelek; Yener, Nuran; Ozdogmus, Omer

2010-09-01

During the last century, many investigators reported on myocardial bridges in the adult human heart. In the present study, 39 human fetal hearts (the mean gestastional age was 30 weeks) were studied for myocardial bridging, and the results were correlated with adult data. Among the 39 (27 male and 12 female) fetal hearts studied, 26 bridges were observed on 18 fetal hearts (46.2%). Ten of the bridges had one myocardial bridge, whereas double myocardial bridges were observed in eight fetal hearts. The most frequent myocardial bridges were observed on the left anterior descending artery (LAD), which had 13 bridges (50%). Eight (30.7%) myocardial bridges were on the diagonal artery, and on the posterior descending artery there were five (19.3%). Myocardial bridges were not observed on the circumflex artery. The data presented in this study may provide potentially useful information for the preoperative evaluation of the newborn and may have a clinical implication for sudden fetal death.

[Adaptability of APSIM model in Southwestern China: A case study of winter wheat in Chongqing City].

PubMed

Dai, Tong; Wang, Jing; He, Di; Zhang, Jian-ping; Wang, Na

2015-04-01

Field experimental data of winter wheat and parallel daily meteorological data at four typical stations in Chongqing City were used to calibrate and validate APSIM-wheat model and determine the genetic parameters for 12 varieties of winter wheat. The results showed that there was a good agreement between the simulated and observed growth periods from sowing to emergence, flowering and maturity of wheat. Root mean squared errors (RMSEs) between simulated and observed emergence, flowering and maturity were 0-3, 1-8, and 0-8 d, respectively. Normalized root mean squared errors (NRMSEs) between simulated and observed above-ground biomass for 12 study varieties were less than 30%. NRMSE between simulated and observed yields for 10 varieties out of 12 study varieties were less than 30%. APSIM-wheat model performed well in simulating phenology, aboveground biomass and yield of winter wheat in Chongqing City, which could provide a foundational support for assessing the impact of climate change on wheat production in the study area based on the model.

Building the Plane Inflight: Observations from Case Studies in Wartime Flight Training for Partner Nations

DTIC Science & Technology

2016-05-26

guidance on how to build an effective SC program. Whether used as pre-decisional guides or ex post facto evaluation tools, they fall short of...Building the Plane Inflight: Observations from Case Studies in Wartime Flight Training for Partner...Nations A Monograph by Major Timothy J. Day United States Air Force School of Advanced Military Studies United States Army Command and General

A Detailed Study and Synthesis of Flow Observables in the IP-Glasma+MUSIC+UrQMD Framework

NASA Astrophysics Data System (ADS)

McDonald, Scott; Shen, Chun; Fillion-Gourdeau, François; Jeon, Sangyong; Gale, Charles

2017-11-01

In this work we use the IP-Glasma+MUSIC+UrQMD framework to systematically study a wide range of hadronic flow observables at 2.76 TeV. In addition to the single particle spectra and anisotropic flow coefficients vn previously studied in [S. McDonald, C. Shen, F. Fillion-Gourdeau, S. Jeon and C. Gale, arxiv:arXiv:1609.02958 [hep-ph

Super-Diffraction Limited Measurements through the Turbulent Atmosphere by Speckle Interferometry

DTIC Science & Technology

1990-02-22

independently confirmed by a submotion in the residuals to spectroscopically obtained radial velocities of the system. / (3) Atmospheric Turbulence Studies ...spectroscopically obtained radial velocities 1. (3) Atmospheric Turbulence Studies - The very extensive data accumu- lated under this project at the two... studies . I B. RESEARCH ACCOMPLISHMENTS 1. Observing Opportunities Observing time on the 1.8-meter telescope was provided by the Lowell Observatory3 on a

Laboratory studies, analysis, and interpretation of the spectra of hydrocarbons present in planetary atmospheres including cyanoacetylene, acetylene, propane, and ethane

NASA Technical Reports Server (NTRS)

Blass, William E.; Daunt, Stephen J.; Peters, Antoni V.; Weber, Mark C.

1990-01-01

Combining broadband Fourier transform spectrometers (FTS) from the McMath facility at NSO and from NRC in Ottawa and narrow band TDL data from the laboratories with computational physics techniques has produced a broad range of results for the study of planetary atmospheres. Motivation for the effort flows from the Voyager/IRIS observations and the needs of Voyager analysis for laboratory results. In addition, anticipation of the Cassini mission adds incentive to pursue studies of observed and potentially observable constituents of planetary atmospheres. Current studies include cyanoacetylene, acetylene, propane, and ethane. Particular attention is devoted to cyanoacetylen (H3CN) which is observed in the atmosphere of Titan. The results of a high resolution infrared laboratory study of the line positions of the 663, 449, and 22.5/cm fundamental bands are presented. Line position, reproducible to better than 5 MHz for the first two bands, are available for infrared astrophysical searches. Intensity and broadening studies are in progress. Acetylene is a nearly ubiquitous atmospheric constituent of the outer planets and Titan due to the nature of methane photochemistry. Results of ambient temperature absolute intensity measurements are presented for the fundamental and two two-quantum hotband in the 730/cm region. Low temperature hotband intensity and linewidth measurements are planned.

Longitudinal changes in gray matter regions after cranial radiation and comparative analysis with whole body radiation: a DTI study.

PubMed

Watve, Apurva; Gupta, Mamta; Khushu, Subash; Rana, Poonam

2018-06-01

Radiation-induced white matter changes are well known and vastly studied. However, radiation-induced gray matter alterations are still a research question. In the present study, these changes were assessed in a longitudinal manner using Diffusion Tensor Imaging (DTI) and further compared for cranial and whole body radiation exposure. Male mice (C57BL/6) were irradiated with cranial or whole body radiation followed by DTI study at 7T animal MRI system during predose, subacute and early delayed phases of radiation sickness. Fractional anisotropy (FA) and mean diffusivity (MD) values were obtained from brain's gray matter regions. Decreased FA with increased MD was observed prominently in animals exposed to cranial radiation showing most changes at 8 months post irradiation. However, whole body radiation induced FA changes were mostly observed at 1 month post irradiation as compared to controls. The differential response after whole body and cranial irradiation observed in the study depicts that radiation exposure of 5 Gy could induce permanent alterations in gray matter regions prominently as observed in Caudoputamen region at all the time points. Thus, our study has bolstered the role of DTI to probe microstructural changes in gray matter regions of brain after radiation exposure.

Squeezing observational data for better causal inference: Methods and examples for prevention research.

PubMed

Garcia-Huidobro, Diego; Michael Oakes, J

2017-04-01

Randomised controlled trials (RCTs) are typically viewed as the gold standard for causal inference. This is because effects of interest can be identified with the fewest assumptions, especially imbalance in background characteristics. Yet because conducting RCTs are expensive, time consuming and sometimes unethical, observational studies are frequently used to study causal associations. In these studies, imbalance, or confounding, is usually controlled with multiple regression, which entails strong assumptions. The purpose of this manuscript is to describe strengths and weaknesses of several methods to control for confounding in observational studies, and to demonstrate their use in cross-sectional dataset that use patient registration data from the Juan Pablo II Primary Care Clinic in La Pintana-Chile. The dataset contains responses from 5855 families who provided complete information on family socio-demographics, family functioning and health problems among their family members. We employ regression adjustment, stratification, restriction, matching, propensity score matching, standardisation and inverse probability weighting to illustrate the approaches to better causal inference in non-experimental data and compare results. By applying study design and data analysis techniques that control for confounding in different ways than regression adjustment, researchers may strengthen the scientific relevance of observational studies. © 2016 International Union of Psychological Science.

Psoriasis increases risk of new-onset atrial fibrillation: a systematic review and meta-analysis of prospective observational studies.

PubMed

Upala, Sikarin; Shahnawaz, Afeefa; Sanguankeo, Anawin

2017-08-01

Psoriasis is a common chronic immune-mediated dermatological disease that increases the risk of cardiovascular disease. We conducted a systematic review and meta-analysis to evaluate the association between psoriasis and atrial fibrillation from prospective observational studies. A comprehensive search of the databases of the MEDLINE and EMBASE was performed from inception through November 2015. The inclusion criterion was the prospective observational study that assessed the risk of new-onset atrial fibrillation in adults with psoriasis. Outcome was the adjusted hazard ratio (HR) of atrial fibrillation comparison between patients with psoriasis and controls. Pooled HR and 95% confidence intervals (CI) were calculated using a random-effects model. The initial search yielded 176 articles. Fifteen articles underwent full-length review and data were extracted from 4 observational studies. Incidence of atrial fibrillation was ascertained by cardiologist-reviewed electrocardiograms. There was a significant increased risk of new-onset atrial fibrillation in patients with psoriasis compared to controls with a pooled HR 1.42 (95%CI 1.22-1.65). Our meta-analysis of prospective studies demonstrated that patients with psoriasis have increased risk of new-onset atrial fibrillation. Future interventional studies addressing the impact of psoriasis treatment and prevention of atrial fibrillation should be performed.

Risk of bias and confounding of observational studies of Zika virus infection: A scoping review of research protocols

PubMed Central

Haby, Michelle M.; Martínez-Vega, Ruth; Pinzón-Flores, Carlos E.; Smith, Emma; Pinart, Mariona; Broutet, Nathalie; Becerra-Posada, Francisco; Aldighieri, Sylvain; Van Kerkhove, Maria D.

2017-01-01

Introduction Given the severity and impact of the current Zika virus (ZIKV) outbreak in the Americas, numerous countries have rushed to develop research studies to assess ZIKV and its potential health consequences. In an effort to ensure that studies are comprehensive, both internally and externally valid, and with reliable results, the World Health Organization, the Pan American Health Organization, Institut Pasteur, the networks of Fiocruz, the Consortia for the Standardization of Influenza Seroepidemiology (CONSISE) and the International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) have generated six standardized clinical and epidemiological research protocols and questionnaires to address key public health questions on ZIKV. Methods We conducted a systematic search of ongoing study protocols related to ZIKV research. We analyzed the content of protocols of 32 cohort studies and 13 case control studies for systematic bias that could produce erroneous results. Additionally we aimed to characterize the risks of bias and confounding in observational studies related to ZIKV and to propose ways to minimize them, including the use of six newly standardized research protocols. Results Observational studies of ZIKV face an array of challenges, including measurement of exposure and outcomes (microcephaly and Guillain-Barré Syndrome). Potential confounders need to be measured where known and controlled for in the analysis. Selection bias due to non-random selection is a significant issue, particularly in the case-control design, and losses to follow-up is equally important for the cohort design. Conclusion Observational research seeking to answer key questions on the ZIKV should consider these restrictions and take precautions to minimize bias in an effort to provide reliable and valid results. Utilization of the standardized research protocols developed by the WHO, PAHO, Institut Pasteur, and CONSISE will harmonize the key methodological aspects of each study design to minimize bias at different stages of the study. Biases need to be considered by researchers implementing the standardized protocols as well as by users of observational epidemiological studies of ZIKV. PMID:28686621

How does light-intensity physical activity associate with adult cardiometabolic health and mortality? Systematic review with meta-analysis of experimental and observational studies.

PubMed

Chastin, Sebastien F M; De Craemer, Marieke; De Cocker, Katrien; Powell, Lauren; Van Cauwenberg, Jelle; Dall, Philippa; Hamer, Mark; Stamatakis, Emmanuel

2018-04-25

To assess the relationship between time spent in light physical activity and cardiometabolic health and mortality in adults. Systematic review and meta-analysis. Searches in Medline, Embase, PsycInfo, CINAHL and three rounds of hand searches. Experimental (including acute mechanistic studies and physical activity intervention programme) and observational studies (excluding case and case-control studies) conducted in adults (aged ≥18 years) published in English before February 2018 and reporting on the relationship between light physical activity (<3 metabolic equivalents) and cardiometabolic health outcomes or all-cause mortality. Study quality appraisal with QUALSYST tool and random effects inverse variance meta-analysis. Seventy-two studies were eligible including 27 experimental studies (and 45 observational studies). Mechanistic experimental studies showed that short but frequent bouts of light-intensity activity throughout the day reduced postprandial glucose (-17.5%; 95% CI -26.2 to -8.7) and insulin (-25.1%; 95% CI -31.8 to -18.3) levels compared with continuous sitting, but there was very limited evidence for it affecting other cardiometabolic markers. Three light physical activity programme intervention studies (n ranging from 12 to 58) reduced adiposity, improved blood pressure and lipidaemia; the programmes consisted of activity of >150 min/week for at least 12 weeks. Six out of eight prospective observational studies that were entered in the meta-analysis reported that more time spent in daily light activity reduced risk of all-cause mortality (pooled HR 0.71; 95% CI 0.62 to 0.83). Light-intensity physical activity could play a role in improving adult cardiometabolic health and reducing mortality risk. Frequent short bouts of light activity improve glycaemic control. Nevertheless, the modest volume of the prospective epidemiological evidence base and the moderate consistency between observational and laboratory evidence inhibits definitive conclusions. © 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.

Reliability of laser Doppler flowmetry curve reading for measurement of toe and ankle pressures: intra- and inter-observer variation.

PubMed

Høyer, C; Paludan, J P D; Pavar, S; Biurrun Manresa, J A; Petersen, L J

2014-03-01

To assess the intra- and inter-observer variation in laser Doppler flowmetry curve reading for measurement of toe and ankle pressures. A prospective single blinded diagnostic accuracy study was conducted on 200 patients with known or suspected peripheral arterial disease (PAD), with a total of 760 curve sets produced. The first curve reading for this study was performed by laboratory technologists blinded to clinical clues and previous readings at least 3 months after the primary data sampling. The pressure curves were later reassessed following another period of at least 3 months. Observer agreement in diagnostic classification according to TASC-II criteria was quantified using Cohen's kappa. Reliability was quantified using intra-class correlation coefficients, coefficients of variance, and Bland-Altman analysis. The overall agreement in diagnostic classification (PAD/not PAD) was 173/200 (87%) for intra-observer (κ = .858) and 175/200 (88%) for inter-observer data (κ = .787). Reliability analysis confirmed excellent correlation for both intra- and inter-observer data (ICC all ≥.931). The coefficients of variance ranged from 2.27% to 6.44% for intra-observer and 2.39% to 8.42% for inter-observer data. Subgroup analysis showed lower observer-variation for reading of toe pressures in patients with diabetes and/or chronic kidney disease than patients not diagnosed with these conditions. Bland-Altman plots showed higher variation in toe pressure readings than ankle pressure readings. This study shows substantial intra- and inter-observer agreement in diagnostic classification and reading of absolute pressures when using laboratory technologists as observers. The study emphasises that observer variation for curve reading is an important factor concerning the overall reproducibility of the method. Our data suggest diabetes and chronic kidney disease have an influence on toe pressure reproducibility. Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Relative efficacy and safety of topical non-steroidal anti-inflammatory drugs for osteoarthritis: a systematic review and network meta-analysis of randomised controlled trials and observational studies.

PubMed

Zeng, Chao; Wei, Jie; Persson, Monica S M; Sarmanova, Aliya; Doherty, Michael; Xie, Dongxing; Wang, YiLun; Li, Xiaoxiao; Li, Jiatian; Long, Huizhong; Lei, Guanghua; Zhang, Weiya

2018-05-01

To compare the efficacy and safety of topical non-steroidal anti-inflammatory drugs (NSAIDs), including salicylate, for the treatment of osteoarthritis (OA). PubMed, Embase, Cochrane Library and Web of Science were searched from 1966 to January 2017. Randomised controlled trials (RCTs) comparing topical NSAIDs with placebo or each other in patients with OA and observational studies comparing topical NSAIDs with no treatment or each other irrespective of disease were included. Two investigators identified studies and independently extracted data. Bayesian network and conventional meta-analyses were conducted. The primary outcomes were pain relief for RCTs and risk of adverse effects (AEs) for observational studies. 43 studies, comprising 36 RCTs (7 900 patients with OA) and seven observational studies (218 074 participants), were included. Overall, topical NSAIDs were superior to placebo for relieving pain (standardised mean difference (SMD)=-0.30, 95% CI -0.40 to -0.20) and improving function (SMD=-0.35, 95% CI -0.45 to -0.24) in OA. Of all topical NSAIDs, diclofenac patches were most effective for OA pain (SMD=-0.81, 95% CI -1.12 to -0.52) and piroxicam was most effective for functional improvement (SMD=-1.04, 95% CI -1.60 to -0.48) compared with placebo. Although salicylate gel was associated with higher withdrawal rates due to AEs, the remaining topical NSAIDs were not associated with any increased local or systemic AEs. Topical NSAIDs were effective and safe for OA. Diclofenac patches may be the most effective topical NSAID for pain relief. No serious gastrointestinal and renal AEs were observed in trials or the general population. However, confirmation of the cardiovascular safety of topical NSAIDs still warrants further observational study. © 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.

Prognostic factors for return to work after depression-related work disability: A systematic review and meta-analysis.

PubMed

Ervasti, Jenni; Joensuu, Matti; Pentti, Jaana; Oksanen, Tuula; Ahola, Kirsi; Vahtera, Jussi; Kivimäki, Mika; Virtanen, Marianna

2017-12-01

Knowledge about factors influencing return to work (RTW) after depression-related absence is highly relevant, but the evidence is scattered. We performed a systematic search of PubMed and Embase databases up to February 1, 2016 to retrieve cohort studies on the association between various predictive factors and return to work among employees with depression for review and meta-analysis. We also analyzed unpublished data from the Finnish Public Sector study. Most-adjusted estimates were pooled using fixed effects meta-analysis. Eleven published studies fulfilled the eligibility criteria, representing 22 358 person-observations from five different countries. With the additional unpublished data from the 14 101 person-observations from the Finnish Public Sector study, the total number of person-observations was 36 459. The pooled estimates were derived from 2 to 5 studies, with the number of observations ranging from 260 to 26 348. Older age (pooled relative risk [RR] 0.95; 95% confidence interval [CI] 0.84-0.87), somatic comorbidity (RR = 0.80, 95% CI 0.77-0.83), psychiatric comorbidity (RR = 0.86, 95% CI 0.83-0.88) and more severe depression (RR = 0.96, 95% CI 0.94-0.98) were associated with a lower rate of return to work, and personality trait conscientiousness with higher (RR = 1.06, 95% CI 1.02-1.10) return to work. While older age and clinical factors predicted slower return, significant heterogeneity was observed between the studies. There is a dearth of observational studies on the predictors of RTW after depression. Future research should pay attention to quality aspects and particularly focus on the role of workplace and labor market factors as well as individual and clinical characteristics on RTW. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relative efficacy and safety of topical non-steroidal anti-inflammatory drugs for osteoarthritis: a systematic review and network meta-analysis of randomised controlled trials and observational studies

PubMed Central

Persson, Monica S M; Sarmanova, Aliya; Doherty, Michael; Xie, Dongxing; Wang, YiLun; Li, Xiaoxiao; Li, Jiatian; Long, Huizhong

2018-01-01

Objectives To compare the efficacy and safety of topical non-steroidal anti-inflammatory drugs (NSAIDs), including salicylate, for the treatment of osteoarthritis (OA). Methods PubMed, Embase, Cochrane Library and Web of Science were searched from 1966 to January 2017. Randomised controlled trials (RCTs) comparing topical NSAIDs with placebo or each other in patients with OA and observational studies comparing topical NSAIDs with no treatment or each other irrespective of disease were included. Two investigators identified studies and independently extracted data. Bayesian network and conventional meta-analyses were conducted. The primary outcomes were pain relief for RCTs and risk of adverse effects (AEs) for observational studies. Results 43 studies, comprising 36 RCTs (7 900 patients with OA) and seven observational studies (218 074 participants), were included. Overall, topical NSAIDs were superior to placebo for relieving pain (standardised mean difference (SMD)=−0.30, 95% CI −0.40 to –0.20) and improving function (SMD=−0.35, 95% CI −0.45 to –0.24) in OA. Of all topical NSAIDs, diclofenac patches were most effective for OA pain (SMD=−0.81, 95% CI −1.12 to –0.52) and piroxicam was most effective for functional improvement (SMD=−1.04, 95% CI −1.60 to –0.48) compared with placebo. Although salicylate gel was associated with higher withdrawal rates due to AEs, the remaining topical NSAIDs were not associated with any increased local or systemic AEs. Conclusions Topical NSAIDs were effective and safe for OA. Diclofenac patches may be the most effective topical NSAID for pain relief. No serious gastrointestinal and renal AEs were observed in trials or the general population. However, confirmation of the cardiovascular safety of topical NSAIDs still warrants further observational study. PMID:29436380

Dipeptidyl peptidase-4 inhibitors and risk of heart failure in type 2 diabetes: systematic review and meta-analysis of randomised and observational studies.

PubMed

Li, Ling; Li, Sheyu; Deng, Ke; Liu, Jiali; Vandvik, Per Olav; Zhao, Pujing; Zhang, Longhao; Shen, Jiantong; Bala, Malgorzata M; Sohani, Zahra N; Wong, Evelyn; Busse, Jason W; Ebrahim, Shanil; Malaga, German; Rios, Lorena P; Wang, Yingqiang; Chen, Qunfei; Guyatt, Gordon H; Sun, Xin

2016-02-17

To examine the association between dipeptidyl peptidase-4 (DPP-4) inhibitors and the risk of heart failure or hospital admission for heart failure in patients with type 2 diabetes. Systematic review and meta-analysis of randomised and observational studies. Medline, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov searched up to 25 June 2015, and communication with experts. Randomised controlled trials, non-randomised controlled trials, cohort studies, and case-control studies that compared DPP-4 inhibitors against placebo, lifestyle modification, or active antidiabetic drugs in adults with type 2 diabetes, and explicitly reported the outcome of heart failure or hospital admission for heart failure. Teams of paired reviewers independently screened for eligible studies, assessed risk of bias, and extracted data using standardised, pilot tested forms. Data from trials and observational studies were pooled separately; quality of evidence was assessed by the GRADE approach. Eligible studies included 43 trials (n=68,775) and 12 observational studies (nine cohort studies, three nested case-control studies; n=1,777,358). Pooling of 38 trials reporting heart failure provided low quality evidence for a possible similar risk of heart failure between DPP-4 inhibitor use versus control (42/15,701 v 33/12,591; odds ratio 0.97 (95% confidence interval 0.61 to 1.56); risk difference 2 fewer (19 fewer to 28 more) events per 1000 patients with type 2 diabetes over five years). The observational studies provided effect estimates generally consistent with trial findings, but with very low quality evidence. Pooling of the five trials reporting admission for heart failure provided moderate quality evidence for an increased risk in patients treated with DPP-4 inhibitors versus control (622/18,554 v 552/18,474; 1.13 (1.00 to 1.26); 8 more (0 more to 16 more)). The pooling of adjusted estimates from observational studies similarly suggested (with very low quality evidence) a possible increased risk of admission for heart failure (adjusted odds ratio 1.41, 95% confidence interval 0.95 to 2.09) in patients treated with DPP-4 inhibitors (exclusively sitagliptin) versus no use. The relative effect of DPP-4 inhibitors on the risk of heart failure in patients with type 2 diabetes is uncertain, given the relatively short follow-up and low quality of evidence. Both randomised controlled trials and observational studies, however, suggest that these drugs may increase the risk of hospital admission for heart failure in those patients with existing cardiovascular diseases or multiple risk factors for vascular diseases, compared with no use. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Visual implant elastomer mark retention through metamorphosis in amphibian larvae

USGS Publications Warehouse

Campbell Grant, Evan H.

2008-01-01

Questions in population ecology require the study of marked animals, and marks are assumed to be permanent and not overlooked by observers. I evaluated retention through metamorphosis of visual implant elastomer marks in larval salamanders and frogs and assessed error in observer identification of these marks. I found 1) individual marks were not retained in larval wood frogs (Rana sylvatica), whereas only small marks were likely to be retained in larval salamanders (Eurycea bislineata), and 2) observers did not always correctly identify marked animals. Evaluating the assumptions of marking protocols is important in the design phase of a study so that correct inference can be made about the population processes of interest. This guidance should be generally useful to the design of mark–recapture studies, with particular application to studies of larval amphibians.

Development and testing of the cancer multidisciplinary team meeting observational tool (MDT-MOT)

PubMed Central

Harris, Jenny; Taylor, Cath; Sevdalis, Nick; Jalil, Rozh; Green, James S.A.

2016-01-01

Abstract Objective To develop a tool for independent observational assessment of cancer multidisciplinary team meetings (MDMs), and test criterion validity, inter-rater reliability/agreement and describe performance. Design Clinicians and experts in teamwork used a mixed-methods approach to develop and refine the tool. Study 1 observers rated pre-determined optimal/sub-optimal MDM film excerpts and Study 2 observers independently rated video-recordings of 10 MDMs. Setting Study 2 included 10 cancer MDMs in England. Participants Testing was undertaken by 13 health service staff and a clinical and non-clinical observer. Intervention None. Main Outcome Measures Tool development, validity, reliability/agreement and variability in MDT performance. Results Study 1: Observers were able to discriminate between optimal and sub-optimal MDM performance (P ≤ 0.05). Study 2: Inter-rater reliability was good for 3/10 domains. Percentage of absolute agreement was high (≥80%) for 4/10 domains and percentage agreement within 1 point was high for 9/10 domains. Four MDTs performed well (scored 3+ in at least 8/10 domains), 5 MDTs performed well in 6–7 domains and 1 MDT performed well in only 4 domains. Leadership and chairing of the meeting, the organization and administration of the meeting, and clinical decision-making processes all varied significantly between MDMs (P ≤ 0.01). Conclusions MDT-MOT demonstrated good criterion validity. Agreement between clinical and non-clinical observers (within one point on the scale) was high but this was inconsistent with reliability coefficients and warrants further investigation. If further validated MDT-MOT might provide a useful mechanism for the routine assessment of MDMs by the local workforce to drive improvements in MDT performance. PMID:27084499

Development and testing of the cancer multidisciplinary team meeting observational tool (MDT-MOT).

PubMed

Harris, Jenny; Taylor, Cath; Sevdalis, Nick; Jalil, Rozh; Green, James S A

2016-06-01

To develop a tool for independent observational assessment of cancer multidisciplinary team meetings (MDMs), and test criterion validity, inter-rater reliability/agreement and describe performance. Clinicians and experts in teamwork used a mixed-methods approach to develop and refine the tool. Study 1 observers rated pre-determined optimal/sub-optimal MDM film excerpts and Study 2 observers independently rated video-recordings of 10 MDMs. Study 2 included 10 cancer MDMs in England. Testing was undertaken by 13 health service staff and a clinical and non-clinical observer. None. Tool development, validity, reliability/agreement and variability in MDT performance. Study 1: Observers were able to discriminate between optimal and sub-optimal MDM performance (P ≤ 0.05). Study 2: Inter-rater reliability was good for 3/10 domains. Percentage of absolute agreement was high (≥80%) for 4/10 domains and percentage agreement within 1 point was high for 9/10 domains. Four MDTs performed well (scored 3+ in at least 8/10 domains), 5 MDTs performed well in 6-7 domains and 1 MDT performed well in only 4 domains. Leadership and chairing of the meeting, the organization and administration of the meeting, and clinical decision-making processes all varied significantly between MDMs (P ≤ 0.01). MDT-MOT demonstrated good criterion validity. Agreement between clinical and non-clinical observers (within one point on the scale) was high but this was inconsistent with reliability coefficients and warrants further investigation. If further validated MDT-MOT might provide a useful mechanism for the routine assessment of MDMs by the local workforce to drive improvements in MDT performance. © The Author 2016. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved.

When and why might a Computer Aided Detection (CAD) system interfere with visual search? An eye-tracking study

PubMed Central

Drew, Trafton; Cunningham, Corbin; Wolfe, Jeremy

2012-01-01

Rational and Objectives Computer Aided Detection (CAD) systems are intended to improve performance. This study investigates how CAD might actually interfere with a visual search task. This is a laboratory study with implications for clinical use of CAD. Methods 47 naïve observers in two studies were asked to search for a target, embedded in 1/f2.4 noise while we monitored their eye-movements. For some observers, a CAD system marked 75% of targets and 10% of distractors while other observers completed the study without CAD. In Experiment 1, the CAD system’s primary function was to tell observers where the target might be. In Experiment 2, CAD provided information about target identity. Results In Experiment 1, there was a significant enhancement of observer sensitivity in the presence of CAD (t(22)=4.74, p<.001), but there was also a substantial cost. Targets that were not marked by the CAD system were missed more frequently than equivalent targets in No CAD blocks of the experiment (t(22)=7.02, p<.001). Experiment 2 showed no behavioral benefit from CAD, but also no significant cost on sensitivity to unmarked targets (t(22)=0.6, p=n.s.). Finally, in both experiments, CAD produced reliable changes in eye-movements: CAD observers examined a lower total percentage of the search area than the No CAD observers (Ex 1: t(48)=3.05, p<.005; Ex 2: t(50)=7.31, p<.001). Conclusions CAD signals do not combine with observers’ unaided performance in a straight-forward manner. CAD can engender a sense of certainty that can lead to incomplete search and elevated chances of missing unmarked stimuli. PMID:22958720

Local Scale Radiobrightness Modeling During the Intensive Observing Period-4 of the Cold Land Processes Experiment-1

NASA Astrophysics Data System (ADS)

Kim, E.; Tedesco, M.; de Roo, R.; England, A. W.; Gu, H.; Pham, H.; Boprie, D.; Graf, T.; Koike, T.; Armstrong, R.; Brodzik, M.; Hardy, J.; Cline, D.

2004-12-01

The NASA Cold Land Processes Field Experiment (CLPX-1) was designed to provide microwave remote sensing observations and ground truth for studies of snow and frozen ground remote sensing, particularly issues related to scaling. CLPX-1 was conducted in 2002 and 2003 in Colorado, USA. One of the goals of the experiment was to test the capabilities of microwave emission models at different scales. Initial forward model validation work has concentrated on the Local-Scale Observation Site (LSOS), a 0.8~ha study site consisting of open meadows separated by trees where the most detailed measurements were made of snow depth and temperature, density, and grain size profiles. Results obtained in the case of the 3rd Intensive Observing Period (IOP3) period (February, 2003, dry snow) suggest that a model based on Dense Medium Radiative Transfer (DMRT) theory is able to model the recorded brightness temperatures using snow parameters derived from field measurements. This paper focuses on the ability of forward DMRT modelling, combined with snowpack measurements, to reproduce the radiobrightness signatures observed by the University of Michigan's Truck-Mounted Radiometer System (TMRS) at 19 and 37~GHz during the 4th IOP (IOP4) in March, 2003. Unlike in IOP3, conditions during IOP4 include both wet and dry periods, providing a valuable test of DMRT model performance. In addition, a comparison will be made for the one day of coincident observations by the University of Tokyo's Ground-Based Microwave Radiometer-7 (GBMR-7) and the TMRS. The plot-scale study in this paper establishes a baseline of DMRT performance for later studies at successively larger scales. And these scaling studies will help guide the choice of future snow retrieval algorithms and the design of future Cold Lands observing systems.

Prevalence of Recommendations Made Within Dental Research Articles Using Uncontrolled Intervention or Observational Study Designs.

PubMed

Wilson, M K; Chestnutt, I G

2016-03-01

Evidence to inform clinical practice is reliant on research carried out using appropriate study design. The objectives of this work were to (i) identify the prevalence of articles reporting on human studies using uncontrolled intervention or observational research designs published in peer-reviewed dental journals and (ii) determine the nature of recommendations made by these articles. Six peer-reviewed dental journals were selected. Issues published in January to June 2013 were examined and the types of articles published categorized. Following pre-defined inclusion/exclusion criteria, human studies classified as using uncontrolled intervention or observational research designs were subject to detailed review by two independent investigators, to examine if they presented clinical, policy or research recommendations and if these recommendations were supported by the data presented. 52.9% (n = 156) of studies published during the time period met the inclusion criteria. Studies with uncontrolled intervention or observational research designs comprised a larger proportion of the primary research studies published in the journals with lower impact factors (73.3%; n = 107) compared to the high impact journals (38.9%; n = 49). Analysis showed that 60.9% (n = 95) of the included studies made recommendations for clinical practice/dental policy. In 28.2% (n = 44) of studies, the clinical/policy recommendations made were judged to not be fully supported by the data presented. Many studies published in the current dental literature, which are not considered to produce strong evidence, make recommendations for clinical practice or policy. There were some cases when the recommendations were not fully supported by the data presented. Copyright © 2016 Elsevier Inc. All rights reserved.

[Toxicity study of cefmatilen hydrochloride hydrate (S-1090) (4)--One- and three-month repeated oral dose toxicity studies in dogs].

PubMed

Yahara, I; Yamagata, H; Ueno, M; Inoue, S; Sato, K; Nishimura, K; Miyauchi, H; Hirata, M; Muraoka, Y; Kimura, Y; Kitamura, T; Kato, I

2001-05-01

One- or three-month repeated oral dose toxicity studies of Cefmatilen hydrochloride hydrate (S-1090) were conducted in beagle dogs. Doses were set at 25, 100 and 400 mg potency/kg/day in both studies. In both studies, no deaths occurred, and reddish-brown feces (due to chelated products of S-1090 and its decomposition products with Fe3+ in the diet) were observed in all treated groups. A transient excretion of reddish urine was observed in the 400 mg potency/kg group and a slight increase in plasma irons was also observed in the 100 and 400 mg potency/kg groups of both studies. However, as no changes suggesting anemia or hepatic injury were noted in these groups, the change of plasma irons was considered to have no toxicological significance. Plasma S-1090 concentrations increased in a manner less than dose-proportional in both studies. In the one-month toxicity study, no toxicologically significant changes, including the above findings, were noted, so the NOAEL was assessed to be 400 mg potency/kg/day. In the three-month toxicity study, urinalysis in the 400 mg potency/kg group revealed a positive reaction to occult blood and erythrocytes in sediments. In the pathological examinations, submucosal edema, hemorrhage, inflammatory cell infiltration and occasionally focal mucosal thickening were observed in the urinary bladder of the 400 mg potency/kg group. The cystisis was considered to result from chronic stimulation with the metabolite(s) of S-1090 in urine, and the reversibility was demonstrable upon one-month drug withdrawal. From these results, the NOAEL of S-1090 in the three-month toxicity study was assessed to be 100 mg potency/kg/day.

Perceptions of participation in an observational epidemiologic study of cancer among African Americans.

PubMed

Gooden, Kyna M; Carter-Edwards, Lori; Hoyo, Cathrine; Akbar, Jabar; Cleveland, Rebecca J; Oates, Veronica; Jackson, Ethel; Furberg, Helena; Gammon, Marilie D

2005-01-01

Recruitment and retention of African Americans in cancer research studies has become increasingly important. However, little is known about factors bearing on recruitment and retention in etiologic observational studies of cancer. We assessed perceptions and attitudes of African Americans towards participation in an observational epidemiologic study of cancer, and attitudes toward the data collection process. Five focus groups, each lasting approximately 2 hours, were conducted. Participants were comprised of men and women between 41-65 years of age. A total of 35 adults from three rural and two urban counties in North Carolina participated. Data were analyzed using NVivo software. Four key themes emerged on the perception of participation and retention in an epidemiologic study of cancer: (1) fear of cancer prognosis; (2) conflicts between mistrust and trust in researchers; (3) comprehension of prospective study purpose, structure, and participation strategies; and (4) the necessity for and obligation to provide feedback. Results indicate that African Americans would be willing to participate in epidemiologic studies to identify etiologic risk factors for cancer. However, culturally appropriate efforts to thoroughly inform them of study process and progress are deemed essential for successful recruitment and retention.

The Effect of Ginger (Zingiber officinale) on Platelet Aggregation: A Systematic Literature Review.

PubMed

Marx, Wolfgang; McKavanagh, Daniel; McCarthy, Alexandra L; Bird, Robert; Ried, Karin; Chan, Alexandre; Isenring, Liz

2015-01-01

The potential effect of ginger on platelet aggregation is a widely-cited concern both within the published literature and to clinicians; however, there has been no systematic appraisal of the evidence to date. Using the PRISMA guidelines, we systematically reviewed the results of clinical and observational trials regarding the effect of ginger on platelet aggregation in adults compared to either placebo or baseline data. Studies included in this review stipulated the independent variable was a ginger preparation or isolated ginger compound, and used measures of platelet aggregation as the primary outcome. Ten studies were included, comprising eight clinical trials and two observational studies. Of the eight clinical trials, four reported that ginger reduced platelet aggregation, while the remaining four reported no effect. The two observational studies also reported mixed findings. Many of the studies appraised for this review had moderate risks of bias. Methodology varied considerably between studies, notably the timeframe studied, dose of ginger used, and the characteristics of subjects recruited (e.g. healthy vs. patients with chronic diseases). The evidence that ginger affects platelet aggregation and coagulation is equivocal and further study is needed to definitively address this question.

The Effect of Ginger (Zingiber officinale) on Platelet Aggregation: A Systematic Literature Review

PubMed Central

Marx, Wolfgang; McKavanagh, Daniel; McCarthy, Alexandra L.; Bird, Robert; Ried, Karin; Chan, Alexandre; Isenring, Liz

2015-01-01

Background The potential effect of ginger on platelet aggregation is a widely-cited concern both within the published literature and to clinicians; however, there has been no systematic appraisal of the evidence to date. Methods Using the PRISMA guidelines, we systematically reviewed the results of clinical and observational trials regarding the effect of ginger on platelet aggregation in adults compared to either placebo or baseline data. Studies included in this review stipulated the independent variable was a ginger preparation or isolated ginger compound, and used measures of platelet aggregation as the primary outcome. Results Ten studies were included, comprising eight clinical trials and two observational studies. Of the eight clinical trials, four reported that ginger reduced platelet aggregation, while the remaining four reported no effect. The two observational studies also reported mixed findings. Discussion Many of the studies appraised for this review had moderate risks of bias. Methodology varied considerably between studies, notably the timeframe studied, dose of ginger used, and the characteristics of subjects recruited (e.g. healthy vs. patients with chronic diseases). Conclusion The evidence that ginger affects platelet aggregation and coagulation is equivocal and further study is needed to definitively address this question. PMID:26488162

XRD and SEM study of alumina silicate porcelain insulator

NASA Astrophysics Data System (ADS)

Duddi, Dharmender; Singh, G. P.; Kalra, Swati; Shekhawat, M. S.; Tak, S. K.

2018-05-01

Higher strength electrical porcelain is a requirement of industry. This will be achieved by a specific composition of raw materials, which is consisted of clays and feldspars. Water absorption, particle size and insulating properties are of special interest now a day. China clay, Ball clay and Quartz are widely used by ceramic industries in Bikaner district of Rajasthan. Sample for present study were prepared by mixing of above clay, feldspar with MnO2, then shrinkage is observed. Bar shaped samples were prepared and heated up to a temperature of about 1185° C to observe shrinkage. For phase study of XRD and SEM are observed.

Determining whether metals nucleate homogeneously on graphite: A case study with copper

DOE PAGES

Appy, David; Lei, Huaping; Han, Yong; ...

2014-11-05

In this study, we observe that Cu clusters grow on surface terraces of graphite as a result of physical vapor deposition in ultrahigh vacuum. We show that the observation is incompatible with a variety of models incorporating homogeneous nucleation and calculations of atomic-scale energetics. An alternative explanation, ion-mediated heterogeneous nucleation, is proposed and validated, both with theory and experiment. This serves as a case study in identifying when and whether the simple, common observation of metal clusters on carbon-rich surfaces can be interpreted in terms of homogeneous nucleation. We describe a general approach for making system-specific and laboratory-specific predictions.

Research designs and making causal inferences from health care studies.

PubMed

Flannelly, Kevin J; Jankowski, Katherine R B

2014-01-01

This article summarizes the major types of research designs used in healthcare research, including experimental, quasi-experimental, and observational studies. Observational studies are divided into survey studies (descriptive and correlational studies), case-studies and analytic studies, the last of which are commonly used in epidemiology: case-control, retrospective cohort, and prospective cohort studies. Similarities and differences among the research designs are described and the relative strength of evidence they provide is discussed. Emphasis is placed on five criteria for drawing causal inferences that are derived from the writings of the philosopher John Stuart Mill, especially his methods or canons. The application of the criteria to experimentation is explained. Particular attention is given to the degree to which different designs meet the five criteria for making causal inferences. Examples of specific studies that have used various designs in chaplaincy research are provided.

Inter-observer variability in the classification of ovarian cancer cell type using microscopy: a pilot study

NASA Astrophysics Data System (ADS)

Gavrielides, Marios A.; Ronnett, Brigitte M.; Vang, Russell; Seidman, Jeffrey D.

2015-03-01

Studies have shown that different cell types of ovarian carcinoma have different molecular profiles, exhibit different behavior, and that patients could benefit from typespecific treatment. Different cell types display different histopathology features, and different criteria are used for each cell type classification. Inter-observer variability for the task of classifying ovarian cancer cell types is an under-examined area of research. This study served as a pilot study to quantify observer variability related to the classification of ovarian cancer cell types and to extract valuable data for designing a validation study of digital pathology (DP) for this task. Three observers with expertise in gynecologic pathology reviewed 114 cases of ovarian cancer with optical microscopy, with specific guidelines for classifications into distinct cell types. For 93 cases all 3 pathologists agreed on the same cell type, for 18 cases 2 out of 3 agreed, and for 3 cases there was no agreement. Across cell types with a minimum sample size of 10 cases, agreement between all three observers was {91.1%, 80.0%, 90.0%, 78.6%, 100.0%, 61.5%} for the high grade serous carcinoma, low grade serous carcinoma, endometrioid, mucinous, clear cell, and carcinosarcoma cell types respectively. These results indicate that unanimous agreement varied over a fairly wide range. However, additional research is needed to determine the importance of these differences in comparison studies. These results will be used to aid in the design and sizing of such a study comparing optical and digital pathology. In addition, the results will help in understanding the potential role computer-aided diagnosis has in helping to improve the agreement of pathologists for this task.

An anatomical study of wormian bones from the eastern part of India: is genetic influence a primary determinant of their morphogenesis?

PubMed

Ghosh, Sanjib Kumar; Biswas, Sudipa; Sharma, Suranjali; Chakraborty, Soumya

2017-06-01

Over the years a number of investigators have analysed the morphology of wormian bones in different population groups across the world. There have been significant variations between findings reported in these studies, and this has prompted researchers to focus on the influence of genetic factors on the morphology of these bones. In the light of the above observation, we considered it justified to conduct anatomical studies on wormian bones in different population groups; hence, we undertook the present study to look into the morphological details of these bones among a population in the eastern part of India. We observed a total of 120 adult dry human skulls of unknown age and sex, and noted the anatomical details of wormian bones when present. It was observed that wormian bones were present in 45 % of skulls, and that 30 % of skulls had more than one wormian bone. We also found that 2.5 % of the skulls had ten or more wormian bones, which is considered as pathognomonic. Maximum incidence (53.33 %) was observed at the lambdoid suture and minimum incidence at the bregma and metopic suture (0.61 % in each case). We noted a high incidence (21.21 %) of Inca bone/lambdoid ossicle, and bilaterally symmetrical wormian bones were present in 12.5 % study skulls. There were statistically significant (P < 0.05) variations between the findings of the present study and values reported in previous studies conducted in other regions of India and different parts of the world. Our observations favour the view that genetic influence primarily determines the morphology of wormian bones.

Antibiotic exposure in neonates and early adverse outcomes: a systematic review and meta-analysis.

PubMed

Esaiassen, Eirin; Fjalstad, Jon Widding; Juvet, Lene Kristine; van den Anker, John N; Klingenberg, Claus

2017-07-01

To systematically review and meta-analyse the relationship between antibiotic exposure in neonates and the following early adverse outcomes: necrotizing enterocolitis (NEC), invasive fungal infections (IFIs) and/or death. Data sources were PubMed, Embase, Medline and the Cochrane Database (to December 2016), supplemented by manual searches of reference lists. Randomized controlled trials (RCTs) and observational studies were included if they provided data on different categories of antibiotic exposures (yes versus no, long versus short duration, and/or broad- versus narrow-spectrum regimens) and the risk of developing NEC, IFI and/or death in the neonatal period. Two reviewers extracted data and evaluated the risk of bias using the Cochrane Handbook, adapted to include observational studies. When appropriate, meta-analyses were conducted using the random-effect model. We identified 9 RCTs and 38 observational studies. The quality of the majority of studies was poor to moderate. There was a significant association between prolonged antibiotic exposure and an increased risk of NEC in five observational studies (5003 participants) and/or risk of death in five observational studies (13 534 participants). Eleven of 15 studies with data on broad- versus narrow-spectrum regimens reported an increased risk of IFI after broad-spectrum antibiotic exposure, in particular with third-generation cephalosporins and carbapenems. Meta-analysis was limited by few and old RCTs, insufficient sample sizes and diversity of antibiotic exposure and outcomes reported. Prolonged antibiotic exposure in uninfected preterm infants is associated with an increased risk of NEC and/or death, and broad-spectrum antibiotic exposure is associated with an increased risk of IFI. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Quantitative weight of evidence assessment of higher tier studies on the toxicity and risks of neonicotinoids in honeybees. 4. Thiamethoxam.

PubMed

Stephenson, Gladys L; Solomon, Keith R

2017-01-01

A quantitative weight of evidence (QWoE) methodology was used to assess several higher-tier studies on the effects of thiamethoxam (TMX) on honeybees. Assessment endpoints were population size and viability of commercially managed honeybee colonies and quantity of hive products. A higher-tier field toxicology study indicated a no-observed-adverse effect concentration (NOAEC) of 29.5 µg TMX/kg syrup, equivalent to an oral no-observed-adverse-effect-dose (NOAED) of 8.6 ng/bee/day for all responses measured. For exposures via deposition of dust, a conservative no-observed-adverse-effect-rate at the level of the colony was 0.1 g TMX/ha. There was minimal risk to honeybees from exposure to TMX via nectar and pollen from its use as a seed-treatment. For exposures via dust and dust/seed applications, there were no concentrations above the risk values for TMX in nectar and pollen. Although some risks were identified for potential exposures via guttation fluid, this route of exposure is incomplete; no apparent adverse effects were observed in field studies. For exposures via dust/seed and dust/foliar applications, few adverse effects were observed. Considering all lines of evidence, the quality of the studies included in this analysis was variable. However, the results of the studies were consistent and point to the same conclusion. The overall weight of evidence based on many studies indicates that TMX has no adverse effects on viability or survival of the colony. Thus, the overall conclusion is that the treatment of seeds with thiamethoxam, as currently used in good agricultural practices, does not present a significant risk to honeybees at the level of the colony.

A prospective, observational, open-label, multicentre study to investigate the daily treatment practice of ranibizumab in patients with neovascular age-related macular degeneration.

PubMed

van Asten, Freekje; Evers-Birkenkamp, Kim U; van Lith-Verhoeven, Janneke J C; de Jong-Hesse, Yvonne; Hoppenreijs, Vincent P T; Hommersom, Richard F; Scholten, Agnes M; Hoyng, Carel B; Klaver, Johannes H J

2015-03-01

The HELIOS (Health Economics with Lucentis in Observational Settings) study was designed on request of the Dutch Health Authority for an observational study to assess the effectiveness and safety of ranibizumab for neovascular age-related macular degeneration (wet AMD) in daily practice. The HELIOS study was a 2-year prospective, observational, open-label, multicentre study involving 14 sites. Patients with wet AMD were enrolled and observed for a period of 24 months. The data were collected at baseline and at the visits closest around the time-points 3, 6, 12, 18 and 24 months after inclusion. Treatment with ranibizumab resulted in prevention of vision loss. The mean ETDRS score increased from 45.1 letters at baseline to 48.5 letters at 24 months. This was achieved with a mean of 7.8 injections over 24 months. Stabilization of visual acuity was also reflected by the scores on the quality of life EQ-5D questionnaire, which did not significantly change over the study period. The more subjective EQ-VAS questionnaire showed an overall improvement. The VFQ-25 questionnaire was also mostly stable over time. After 24 months, 32.2% of the patients gained ≥1 letter and 17.1% gained >15 letters. Patients completing the loading phase were better responders, as demonstrated by increased long-term visual acuity. In addition, ranibizumab was well tolerated and had a safety profile commonly seen in routine clinical practice. This study demonstrates that also in daily practice ranibizumab was effective in preventing vision loss over a period of 24 months. No new safety findings were identified. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

EPA observational studies of children's respiratory health in the Detroit and Dearborn, Michigan

EPA Science Inventory

Previous research has suggested that long-term exposures to mobile-source emissions might be associated with the development of allergies and asthma in children. Between 2004 and 2007, EPA scientists successfully conducted nested observational studies of children aged 7-12 years ...

Engineering studies on joint bar integrity, part I : field surveys and observed failure modes

DOT National Transportation Integrated Search

2014-04-02

This paper is the first of a two-part series describing a : research project, sponsored by the Federal Railroad : Administration (FRA), to study the structural integrity of joint : bars. In Part I of this series, observations from field surveys : con...

[Scanning electron microscope study of chemically disinfected endodontic files].

PubMed

Navarro, G; Mateos, M; Navarro, J L; Canalda, C

1991-01-01

Forty stainless steel endodontic files were observed at scanning electron microscopy after being subjected to ten disinfection cycles of 10 minutes each one, immersed in different chemical disinfectants. Corrosion was not observed on the surface of the files in circumstances that this study was made.

TOLNet - A Tropospheric Ozone Lidar Profiling Network for Satellite Continuity and Process Studies

NASA Technical Reports Server (NTRS)

Newchurch, Michael J.; Kuang, Shi; Wang, Lihua; LeBlanc, Thierry; Alvarez II, Raul J.; Langford, Andrew O.; Senff, Christoph J.; Brown, Steve; Johnson, Bryan; Burris, John F.;

Methods and Processes of Developing the Strengthening the Reporting of Observational Studies in Epidemiology - Veterinary (STROBE-Vet) Statement.

PubMed

Sargeant, J M; O'Connor, A M; Dohoo, I R; Erb, H N; Cevallos, M; Egger, M; Ersbøll, A K; Martin, S W; Nielsen, L R; Pearl, D L; Pfeiffer, D U; Sanchez, J; Torrence, M E; Vigre, H; Waldner, C; Ward, M P

2016-12-01

The reporting of observational studies in veterinary research presents many challenges that often are not adequately addressed in published reporting guidelines. A consensus meeting of experts was organized to develop an extension of the STROBE statement to address observational studies in veterinary medicine with respect to animal health, animal production, animal welfare and food safety outcomes. The consensus meeting was held 11-13 May 2014 in Mississauga, Ontario, Canada. Seventeen experts from North America, Europe and Australia attended the meeting. The experts were epidemiologists and biostatisticians, many of whom hold or have held editorial positions with relevant journals. Prior to the meeting, 19 experts completed a survey about whether they felt any of the 22 items of the STROBE statement should be modified and whether items should be added to address unique issues related to observational studies in animal species with health, production, welfare or food safety outcomes. At the meeting, the participants were provided with the survey responses and relevant literature concerning the reporting of veterinary observational studies. During the meeting, each STROBE item was discussed to determine whether or not re-wording was recommended, and whether additions were warranted. Anonymous voting was used to determine whether there was consensus for each item change or addition. The consensus was that six items needed no modifications or additions. Modifications or additions were made to the STROBE items numbered as follows: 1 (title and abstract), 3 (objectives), 5 (setting), 6 (participants), 7 (variables), 8 (data sources/measurement), 9 (bias), 10 (study size), 12 (statistical methods), 13 (participants), 14 (descriptive data), 15 (outcome data), 16 (main results), 17 (other analyses), 19 (limitations) and 22 (funding). Published literature was not always available to support modification to, or inclusion of, an item. The methods and processes used in the development of this statement were similar to those used for other extensions of the STROBE statement. The use of this extension to the STROBE statement should improve the reporting of observational studies in veterinary research related to animal health, production, welfare or food safety outcomes by recognizing the unique features of observational studies involving food-producing and companion animals, products of animal origin, aquaculture and wildlife. © 2016 The Authors. Zoonoses and Public Health published by Blackwell Verlag GmbH.

A follow-up study of cancer incidence among workers in manufacture of phenoxy herbicides in Denmark.

PubMed Central

Lynge, E.

1985-01-01

The purpose of this cohort study is to shed further light on the potential carcinogenic effect indicated by a Swedish case control study of the 2,4-dichlorophenol and 4-chloro-ortho-cresol based phenoxy herbicides, unlikely to be contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). In the present study it was the intention to include all persons employed in manufacture of phenoxy herbicides in Denmark before 1982. The predominant product was MCPA and only a very limited amount of 2,4,5-T was processed in one of the two factories included in the study. Registration of the cohort was based on company records, supplemented with data from a public pension scheme from 1964 onwards. Ninety-nine percent of registered employees could be followed up. Cancer cases were identified by linkage with the National Cancer Register. Totals of 3,390 males and 1,069 females were included in the study. In the analysis special attention was given to soft tissue sarcomas (STS) and malignant lymphomas (ML) which are the diagnostic groups indicated to be associated with exposure to phenoxy herbicides in the Swedish studies. Five cases of STS were observed among male employees in contrast to 1.84 expected cases. This result supports the Swedish observation of an increased risk of STS following exposure to phenoxy herbicides unlikely to be contaminated with 2,3,7,8-TCDD. However, several potential biases have to be taken into account in interpretation of this observation and these are discussed. Seven cases of ML were observed among male employees in contrast to 5.37 expected which does not support the Swedish observation of an excess risk. The total cancer risk among persons employed in manufacture and packaging of phenoxy herbicides was equivalent to the cancer risk in the Danish population. Among males thus employed 11 lung cancer cases were observed in contrast to 5.33 expected. Attention should be given to exposure to spray dried MCPA-sodium salt in the plants, but other work place exposures and tobacco consumption may have contributed to the increased risk. The tabulation of data by many diagnostic groups may explain the excesses observed for rectum cancer among males and cervical cancer among females. The study has revealed that several potential biases have to be taken into account when the Swedish observations are tested in other settings. PMID:4027168

An observational study of complications in chickenpox with special reference to unusual complications in an apex infectious disease hospital, Kolkata, India.

PubMed

Kole, A K; Roy, R; Kole, D C

2013-01-01

Chickenpox can cause serious complications and even death in persons without any risk factors. To observe the different complications with special reference to unusual complications of chickenpox and their outcomes. The present study was a prospective observational study where 300 patients suffering from chickenpox were evaluated with special reference to unusual complications and outcomes. The usual complications of chickenpox commonly observed were acute hepatitis in 30 (10%) and cerebellar ataxia in 22 patients (7.3%), whereas common unusual complications were acute pancreatitis in 45 (15%), hemorrhagic rash in 10 (3.3%), Guillain-Barrι syndrome in 4 (1.3%), disseminated intravascular coagulation in 4 (1.3%), necrotizing fasciitis in 4 (1.3%), and acute renal failure in 3 patients (1%). It had been observed that most of these unusual complications occurred in patients without any risk factor. A total of 18 patients (6%) died in this study and of them 12 patients (4%) died due to unusual complications. Compulsory childhood varicella vaccination including vaccination of risk groups and susceptible individuals are all essential to reduce the incidence of chickenpox, associated complications, and subsequent death.

Randomized clinical trials and observational studies in the assessment of drug safety.

PubMed

Sawchik, J; Hamdani, J; Vanhaeverbeek, M

2018-05-01

Randomized clinical trials are considered as the preferred design to assess the potential causal relationships between drugs or other medical interventions and intended effects. For this reason, randomized clinical trials are generally the basis of development programs in the life cycle of drugs and the cornerstone of evidence-based medicine. Instead, randomized clinical trials are not the design of choice for the detection and assessment of rare, delayed and/or unexpected effects related to drug safety. Moreover, the highly homogeneous populations resulting from restrictive eligibility criteria make randomized clinical trials inappropriate to describe comprehensively the safety profile of drugs. In that context, observational studies have a key added value when evaluating the benefit-risk balance of the drugs. However, observational studies are more prone to bias than randomized clinical trials and they have to be designed, conducted and reported judiciously. In this article, we discuss the strengths and limitations of randomized clinical trials and of observational studies, more particularly regarding their contribution to the knowledge of medicines' safety profile. In addition, we present general recommendations for the sensible use of observational data. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Observer visitation frequency and success of mourning dove nests: A field experiment

USGS Publications Warehouse

Nichols, J.D.; Percival, H.F.; Coon, R.A.; Conroy, M.J.; Hensler, G.L.; Hines, J.E.

1984-01-01

Field studies of nesting success generally require visits by the investigator to the nests under study. Such visits may themselves influence nesting success, however, and this possibility has been discussed and investigated by a number of workers with a variety of bird species. Livezey (1980) reviewed the relevant literature for duck nests and noted that most studies failed to demonstrate differences in nesting success between visited nests and those not visited. Livezey (1980) found in his own work that nest abandonment may have occurred as a result of disturbance by observers but that nest predation was not related to time spent by observers at nests or number of observers approaching nests. Various components of nesting and breeding success in seabirds are thought to be adversely affected by human disturbance and nest visitation (Gillett et al. 1975, Robert and Ralph 1975, Ollason and Dunnet 1980). Upland, ground-nesting species have also been studied (e.g. Stoddard 1931, Evans and Wolfe 1967, Henry 1969, Roseberry and Klimstra 1970, Klimstra and Roseberry 1975), and, although conclusions have varied, a number of these workers found no effect of observers on nest-predation rates.

New single-aircraft integrated atmospheric observation capabilities

NASA Astrophysics Data System (ADS)

Wang, Z.

2011-12-01

Improving current weather and climate model capabilities requires better understandings of many atmospheric processes. Thus, advancing atmospheric observation capabilities has been regarded as the highest imperatives to advance the atmospheric science in the 21st century. Under the NSF CAREER support, we focus on developing new airborne observation capabilities through the developments of new instrumentations and the single-aircraft integration of multiple remote sensors with in situ probes. Two compact Wyoming cloud lidars were built to work together with a 183 GHz microwave radiometer, a multi-beam Wyoming cloud radar and in situ probes for cloud studies. The synergy of these remote sensor measurements allows us to better resolve the vertical structure of cloud microphysical properties and cloud scale dynamics. Together with detailed in situ data for aerosol, cloud, water vapor and dynamics, we developed the most advanced observational capability to study cloud-scale properties and processes from a single aircraft (Fig. 1). A compact Raman lidar was also built to work together with in situ sampling to characterize boundary layer aerosol and water vapor distributions for many important atmospheric processes studies, such as, air-sea interaction and convective initialization. Case studies will be presented to illustrate these new observation capabilities.

Leading and leadership: reflections on a case study.

PubMed

Joyce, Pauline

2010-05-01

The aim of this case study was to explore if observing leaders in the context of their day-to-day work can provide an insight into how they lead in particular circumstances. The study was carried out in a small organization which was set up 5 years ago. A case study methodology was used. Data were collected by field notes of non-participant and participant observations. Follow-up interviews were transcribed and analysed to contextualize the observations. A reflective diary was used by the researcher to add to the richness of the data. The data demonstrates how the leader responded in key circumstances during scheduled meetings with staff, interactions in the office and during coffee time. These responses are linked to literature on leadership in the areas of power, personal development, coaching and delegation. The findings suggest that observing a leader in the context of their day-to-day work can provide evidence to validate what leaders do in particular circumstances. The implications of the findings for nursing management are the opportunities to use observation as a tool to understand what managers/leaders do, how they manage or lead and why others respond as they do, and with what outcomes.

Unintended effects of statins from observational studies in the general population: systematic review and meta-analysis

PubMed Central

2014-01-01

Background Efficacy of statins has been extensively studied, with much less information reported on their unintended effects. Evidence from randomized controlled trials (RCTs) on unintended effects is often insufficient to support hypotheses generated from observational studies. We aimed to systematically assess unintended effects of statins from observational studies in general populations with comparison of the findings where possible with those derived from randomized trials. Methods Medline (1998 to January 2012, week 3) and Embase (1998 to 2012, week 6) were searched using the standard BMJ Cohort studies filter. The search was supplemented with reference lists of all identified studies and contact with experts in the field. We included prospective studies with a sample size larger than 1,000 participants, case control (of any size) and routine health service linkage studies of over at least one year duration. Studies in subgroups of patients or follow-up of patient case series were excluded, as well as hospital-based cohort studies. Results Ninety studies were identified, reporting on 48 different unintended effects. Statins were associated with lower risks of dementia and cognitive impairment, venous thrombo-embolism, fractures and pneumonia, but these findings were attenuated in analyses restricted to higher quality studies (respectively: OR 0.74 (95% CI 0.62 to 0.87); OR 0.92 (95% CI 0.81 to 1.03); OR 0.97 (95% CI 0.88 to 1.05); OR 0.92 (95% CI 0.83 to 1.02)); and marked heterogeneity of effects across studies remained. Statin use was not related to any increased risk of depression, common eye diseases, renal disorders or arthritis. There was evidence of an increased risk of myopathy, raised liver enzymes and diabetes (respectively: OR 2.63 (95% CI 1.50 to 4.61); OR 1.54 (95% CI 1.47 to 1.62); OR 1.31 (95% CI 0.99 to 1.73)). Conclusions Our systematic review and meta-analyses indicate that high quality observational data can provide relevant evidence on unintended effects of statins to add to the evidence from RCTs. The absolute excess risk of the observed harmful unintended effects of statins is very small compared to the beneficial effects of statins on major cardiovascular events. PMID:24655568

Reporting and Methodology of Multivariable Analyses in Prognostic Observational Studies Published in 4 Anesthesiology Journals: A Methodological Descriptive Review.

PubMed

Guglielminotti, Jean; Dechartres, Agnès; Mentré, France; Montravers, Philippe; Longrois, Dan; Laouénan, Cedric

2015-10-01

Prognostic research studies in anesthesiology aim to identify risk factors for an outcome (explanatory studies) or calculate the risk of this outcome on the basis of patients' risk factors (predictive studies). Multivariable models express the relationship between predictors and an outcome and are used in both explanatory and predictive studies. Model development demands a strict methodology and a clear reporting to assess its reliability. In this methodological descriptive review, we critically assessed the reporting and methodology of multivariable analysis used in observational prognostic studies published in anesthesiology journals. A systematic search was conducted on Medline through Web of Knowledge, PubMed, and journal websites to identify observational prognostic studies with multivariable analysis published in Anesthesiology, Anesthesia & Analgesia, British Journal of Anaesthesia, and Anaesthesia in 2010 and 2011. Data were extracted by 2 independent readers. First, studies were analyzed with respect to reporting of outcomes, design, size, methods of analysis, model performance (discrimination and calibration), model validation, clinical usefulness, and STROBE (i.e., Strengthening the Reporting of Observational Studies in Epidemiology) checklist. A reporting rate was calculated on the basis of 21 items of the aforementioned points. Second, they were analyzed with respect to some predefined methodological points. Eighty-six studies were included: 87.2% were explanatory and 80.2% investigated a postoperative event. The reporting was fairly good, with a median reporting rate of 79% (75% in explanatory studies and 100% in predictive studies). Six items had a reporting rate <36% (i.e., the 25th percentile), with some of them not identified in the STROBE checklist: blinded evaluation of the outcome (11.9%), reason for sample size (15.1%), handling of missing data (36.0%), assessment of colinearity (17.4%), assessment of interactions (13.9%), and calibration (34.9%). When reported, a few methodological shortcomings were observed, both in explanatory and predictive studies, such as an insufficient number of events of the outcome (44.6%), exclusion of cases with missing data (93.6%), or categorization of continuous variables (65.1%.). The reporting of multivariable analysis was fairly good and could be further improved by checking reporting guidelines and EQUATOR Network website. Limiting the number of candidate variables, including cases with missing data, and not arbitrarily categorizing continuous variables should be encouraged.

Knowledge translation interventions for critically ill patients: a systematic review*.

PubMed

Sinuff, Tasnim; Muscedere, John; Adhikari, Neill K J; Stelfox, Henry T; Dodek, Peter; Heyland, Daren K; Rubenfeld, Gordon D; Cook, Deborah J; Pinto, Ruxandra; Manoharan, Venika; Currie, Jan; Cahill, Naomi; Friedrich, Jan O; Amaral, Andre; Piquette, Dominique; Scales, Damon C; Dhanani, Sonny; Garland, Allan

2013-11-01

We systematically reviewed ICU-based knowledge translation studies to assess the impact of knowledge translation interventions on processes and outcomes of care. We searched electronic databases (to July, 2010) without language restrictions and hand-searched reference lists of relevant studies and reviews. Two reviewers independently identified randomized controlled trials and observational studies comparing any ICU-based knowledge translation intervention (e.g., protocols, guidelines, and audit and feedback) to management without a knowledge translation intervention. We focused on clinical topics that were addressed in greater than or equal to five studies. Pairs of reviewers abstracted data on the clinical topic, knowledge translation intervention(s), process of care measures, and patient outcomes. For each individual or combination of knowledge translation intervention(s) addressed in greater than or equal to three studies, we summarized each study using median risk ratio for dichotomous and standardized mean difference for continuous process measures. We used random-effects models. Anticipating a small number of randomized controlled trials, our primary meta-analyses included randomized controlled trials and observational studies. In separate sensitivity analyses, we excluded randomized controlled trials and collapsed protocols, guidelines, and bundles into one category of intervention. We conducted meta-analyses for clinical outcomes (ICU and hospital mortality, ventilator-associated pneumonia, duration of mechanical ventilation, and ICU length of stay) related to interventions that were associated with improvements in processes of care. From 11,742 publications, we included 119 investigations (seven randomized controlled trials, 112 observational studies) on nine clinical topics. Interventions that included protocols with or without education improved continuous process measures (seven observational studies and one randomized controlled trial; standardized mean difference [95% CI]: 0.26 [0.1, 0.42]; p = 0.001 and four observational studies and one randomized controlled trial; 0.83 [0.37, 1.29]; p = 0.0004, respectively). Heterogeneity among studies within topics ranged from low to extreme. The exclusion of randomized controlled trials did not change our results. Single-intervention and lower-quality studies had higher standardized mean differences compared to multiple-intervention and higher-quality studies (p = 0.013 and 0.016, respectively). There were no associated improvements in clinical outcomes. Knowledge translation interventions in the ICU that include protocols with or without education are associated with the greatest improvements in processes of critical care.

Concordance of Results from Randomized and Observational Analyses within the Same Study: A Re-Analysis of the Women's Health Initiative Limited-Access Dataset.

PubMed

Bolland, Mark J; Grey, Andrew; Gamble, Greg D; Reid, Ian R

2015-01-01

Observational studies (OS) and randomized controlled trials (RCTs) often report discordant results. In the Women's Health Initiative Calcium and Vitamin D (WHI CaD) RCT, women were randomly assigned to CaD or placebo, but were permitted to use personal calcium and vitamin D supplements, creating a unique opportunity to compare results from randomized and observational analyses within the same study. WHI CaD was a 7-year RCT of 1g calcium/400IU vitamin D daily in 36,282 post-menopausal women. We assessed the effects of CaD on cardiovascular events, death, cancer and fracture in a randomized design- comparing CaD with placebo in 43% of women not using personal calcium or vitamin D supplements- and in a observational design- comparing women in the placebo group (44%) using personal calcium and vitamin D supplements with non-users. Incidence was assessed using Cox proportional hazards models, and results from the two study designs deemed concordant if the absolute difference in hazard ratios was ≤0.15. We also compared results from WHI CaD to those from the WHI Observational Study(WHI OS), which used similar methodology for analyses and recruited from the same population. In WHI CaD, for myocardial infarction and stroke, results of unadjusted and 6/8 covariate-controlled observational analyses (age-adjusted, multivariate-adjusted, propensity-adjusted, propensity-matched) were not concordant with the randomized design results. For death, hip and total fracture, colorectal and total cancer, unadjusted and covariate-controlled observational results were concordant with randomized results. For breast cancer, unadjusted and age-adjusted observational results were concordant with randomized results, but only 1/3 other covariate-controlled observational results were concordant with randomized results. Multivariate-adjusted results from WHI OS were concordant with randomized WHI CaD results for only 4/8 endpoints. Results of randomized analyses in WHI CaD were concordant with observational analyses for 5/8 endpoints in WHI CaD and 4/8 endpoints in WHI OS.

Concordance of Results from Randomized and Observational Analyses within the Same Study: A Re-Analysis of the Women’s Health Initiative Limited-Access Dataset

PubMed Central

Bolland, Mark J.; Grey, Andrew; Gamble, Greg D.; Reid, Ian R.

2015-01-01

Background Observational studies (OS) and randomized controlled trials (RCTs) often report discordant results. In the Women’s Health Initiative Calcium and Vitamin D (WHI CaD) RCT, women were randomly assigned to CaD or placebo, but were permitted to use personal calcium and vitamin D supplements, creating a unique opportunity to compare results from randomized and observational analyses within the same study. Methods WHI CaD was a 7-year RCT of 1g calcium/400IU vitamin D daily in 36,282 post-menopausal women. We assessed the effects of CaD on cardiovascular events, death, cancer and fracture in a randomized design- comparing CaD with placebo in 43% of women not using personal calcium or vitamin D supplements- and in a observational design- comparing women in the placebo group (44%) using personal calcium and vitamin D supplements with non-users. Incidence was assessed using Cox proportional hazards models, and results from the two study designs deemed concordant if the absolute difference in hazard ratios was ≤0.15. We also compared results from WHI CaD to those from the WHI Observational Study(WHI OS), which used similar methodology for analyses and recruited from the same population. Results In WHI CaD, for myocardial infarction and stroke, results of unadjusted and 6/8 covariate-controlled observational analyses (age-adjusted, multivariate-adjusted, propensity-adjusted, propensity-matched) were not concordant with the randomized design results. For death, hip and total fracture, colorectal and total cancer, unadjusted and covariate-controlled observational results were concordant with randomized results. For breast cancer, unadjusted and age-adjusted observational results were concordant with randomized results, but only 1/3 other covariate-controlled observational results were concordant with randomized results. Multivariate-adjusted results from WHI OS were concordant with randomized WHI CaD results for only 4/8 endpoints. Conclusions Results of randomized analyses in WHI CaD were concordant with observational analyses for 5/8 endpoints in WHI CaD and 4/8 endpoints in WHI OS. PMID:26440516

A new technique for measuring aerosols with moonlight observations and a sky background model

NASA Astrophysics Data System (ADS)

Jones, Amy; Noll, Stefan; Kausch, Wolfgang; Kimeswenger, Stefan; Szyszka, Ceszary; Unterguggenberger, Stefanie

2014-05-01

There have been an ample number of studies on aerosols in urban, daylight conditions, but few for remote, nocturnal aerosols. We have developed a new technique for investigating such aerosols using our sky background model and astronomical observations. With a dedicated observing proposal we have successfully tested this technique for nocturnal, remote aerosol studies. This technique relies on three requirements: (a) sky background model, (b) observations taken with scattered moonlight, and (c) spectrophotometric standard star observations for flux calibrations. The sky background model was developed for the European Southern Observatory and is optimized for the Very Large Telescope at Cerro Paranal in the Atacama desert in Chile. This is a remote location with almost no urban aerosols. It is well suited for studying remote background aerosols that are normally difficult to detect. Our sky background model has an uncertainty of around 20 percent and the scattered moonlight portion is even more accurate. The last two requirements are having astronomical observations with moonlight and of standard stars at different airmasses, all during the same night. We had a dedicated observing proposal at Cerro Paranal with the instrument X-Shooter to use as a case study for this method. X-Shooter is a medium resolution, echelle spectrograph which covers the wavelengths from 0.3 to 2.5 micrometers. We observed plain sky at six different distances (7, 13, 20, 45, 90, and 110 degrees) to the Moon for three different Moon phases (between full and half). Also direct observations of spectrophotometric standard stars were taken at two different airmasses for each night to measure the extinction curve via the Langley method. This is an ideal data set for testing this technique. The underlying assumption is that all components, other than the atmospheric conditions (specifically aerosols and airglow), can be calculated with the model for the given observing parameters. The scattered moonlight model is designed for the average atmospheric conditions at Cerro Paranal. The Mie scattering is calculated for the average distribution of aerosol particles, but this input can be modified. We can avoid the airglow emission lines, and near full Moon the airglow continuum can be ignored. In the case study, by comparing the scattered moonlight for the various angles and wavelengths along with the extinction curve from the standard stars, we can iteratively find the optimal aerosol size distribution for the time of observation. We will present this new technique, the results from this case study, and how it can be implemented for investigating aerosols using the X-Shooter archive and other astronomical archives.

Constraining cloud responses to CO2 and warming in climate models: physical and statistical approaches

NASA Astrophysics Data System (ADS)

Sherwood, S. C.; Fuchs, D.; Bony, S.; Jean-Louis, D.

2014-12-01

Earth's climate sensitivity has been the subject of heated debate for decades, and recently spurred renewed interest after the latest IPCC assessment report suggested a downward adjustment of the most likely range of climate sensitivities. Here, we present an observation-based study based on the time period 1964 to 2010, which is unique in that it does not rely on global climate models (GCMs) in any way. The study uses surface observations of temperature and incoming solar radiation from approximately 1300 surface sites, along with observations of the equivalent CO2 concentration (CO2,eq) in the atmosphere, to produce a new best estimate for the transient climate sensitivity of 1.9K (95% confidence interval 1.2K - 2.7K). This is higher than other recent observation-based estimates, and is better aligned with the estimate of 1.8K and range (1.1K - 2.5K) derived from the latest generation of GCMs. The new estimate is produced by incorporating the observations in an energy balance framework, and by applying statistical methods that are standard in the field of Econometrics, but less common in climate studies. The study further suggests that about a third of the continental warming due to increasing CO2,eq was masked by aerosol cooling during the time period studied.

Mars atmosphere studies with the OMEGA/Mars Express experiment: I. Overview and detection of lfuorescent emission by CO2

NASA Astrophysics Data System (ADS)

Drossart, P.; Combes, M.; Encrenaz, T.; Melchiorri, R.; Fouchet, T.; Forget, F.; Moroz, V.; Ignatiev, N.; Bibring, J.-P.; Langevin, Y.; OMEGA Team

Observations of Mars by the OMEGA/Mars Express experiment provide extended maps of the martian disk at all latitudes, and with various conditions of illumination, between 0.4 to 5 micron. The atmospheric investigations so far conducted by our team are focussed on the infrared part of the spectrum (1-5 micron), and include: the development of a correction algorithm for atmospheric gaseous absorption, to give access to fine mineralogic studies, largely decorrelated from atmospheric effects the study of dust opacity effects in the near infrared, with the aim to correct also the rough spectra from dust opacity perturbation the study of minor constituents like CO, to search for regional or global variations the study of CO2 emission at 4.3 micron related to fluorescent emission This last effect is prominently detected in limb observations obtained in 3-axis stabilized mode of Mars Express, with high altitude emission in the CO2 fundamental at 4.3 micron, usually seen in absorption in nadir observations. These emissions are related to non-LTE atmospheric layers, well above the solid surface in the mesosphere. Such emissions are also present in Earth and Venus limb observations. They are present also in nadir observations, but are reinforced in limb viewing geometry due to the tangential view. A numerical model of these emission will be presented.

[Traumatic childhood in a private male population of liberty events: prevalence study].

PubMed

Vallejo, Miguel; Bertone, Matias Salvador

2016-01-01

We have observed, in several studies, high rates of psychiatric disorders and traumatic childhood experiences in people who are deprived of their freedom in prison institutions. The aim of the study was to assess the prevalence of different types of adverse childhood experiences and the prevalence of psychiatric disorders in patient-internal male in a prison psychiatric institution. An epidemiological study was conducted between March and July 2011 in which 59 inmates-patients were evaluated in the observation room and Psychiatric Evaluation (SOEP) of the unit 20 in the Central Psychiatric Service Men, which was located on the campus of J.T. Borda Hospital of the City of Buenos Aires, in the province of Buenos Aires, Argentina. SCID I and II, and ACE (Adverse Experience Childhood) scales were used. 91% of participants had suffered any adverse experience in childhood. Physical (59%), emotional (54%), sexual (18%) and negligence (66%): a high rate of abuse in its various forms was found At the same time it was observed that all patients had a mental disorder. The most common diagnosis is personality disorder (69.4%). It was observed that most of the abuses were perpetrated by people in your household. high prevalence rates of adverse childhood experiences and psychiatric disorders private individuals of their liberty were observed to coincide with that shown in other studies in similar populations.

An Expressive Bodily Movement Repertoire for Marimba Performance, Revealed through Observers' Laban Effort-Shape Analyses, and Allied Musical Features: Two Case Studies

PubMed Central

Broughton, Mary C.; Davidson, Jane W.

2016-01-01

Musicians' expressive bodily movements can influence observers' perception of performance. Furthermore, individual differences in observers' music and motor expertise can shape how they perceive and respond to music performance. However, few studies have investigated the bodily movements that different observers of music performance perceive as expressive, in order to understand how they might relate to the music being produced, and the particular instrument type. In this paper, we focus on marimba performance through two case studies—one solo and one collaborative context. This study aims to investigate the existence of a core repertoire of marimba performance expressive bodily movements, identify key music-related features associated with the core repertoire, and explore how observers' perception of expressive bodily movements might vary according to individual differences in their music and motor expertise. Of the six professional musicians who observed and analyzed the marimba performances, three were percussionists and experienced marimba players. Following training, observers implemented the Laban effort-shape movement analysis system to analyze marimba players' bodily movements that they perceived as expressive in audio-visual recordings of performance. Observations that were agreed by all participants as being the same type of action at the same location in the performance recording were examined in each case study, then across the two studies. A small repertoire of bodily movements emerged that the observers perceived as being expressive. Movements were primarily allied to elements of the music structure, technique, and expressive interpretation, however, these elements appeared to be interactive. A type of body sway movement and more localized sound generating actions were perceived as expressive. These movements co-occurred and also appeared separately. Individual participant data revealed slightly more variety in the types and locations of actions observed, with judges revealing preferences for observing particular types of expressive bodily movements. The particular expressive bodily movements that are produced and perceived in marimba performance appear to be shaped by music-related and sound generating features, musical context, and observer music and motor expertise. With an understanding of bodily movements that are generated and perceived as expressive, embodied music performance training programs might be developed to enhance expressive performer-audience communication. PMID:27630585

Empirical studies of design software: Implications for software engineering environments

NASA Technical Reports Server (NTRS)

Krasner, Herb

1988-01-01

The empirical studies team of MCC's Design Process Group conducted three studies in 1986-87 in order to gather data on professionals designing software systems in a range of situations. The first study (the Lift Experiment) used thinking aloud protocols in a controlled laboratory setting to study the cognitive processes of individual designers. The second study (the Object Server Project) involved the observation, videotaping, and data collection of a design team of a medium-sized development project over several months in order to study team dynamics. The third study (the Field Study) involved interviews with the personnel from 19 large development projects in the MCC shareholders in order to study how the process of design is affected by organizationl and project behavior. The focus of this report will be on key observations of design process (at several levels) and their implications for the design of environments.

The prevalence of distraction among passenger vehicle drivers: a roadside observational approach.

PubMed

Huisingh, Carrie; Griffin, Russell; McGwin, Gerald

2015-01-01

Distracted driving contributes to a large proportion of motor vehicle crashes, yet little is known about the prevalence of distracted driving and the specific types of distracting behaviors. The objective of this study was to estimate the prevalence of driver distraction using a roadside observational study design. A cross-sectional survey involving direct roadside observation was conducted at 11 selected intersections. Trained investigators observed a sample of passenger vehicles and recorded distraction-related behaviors, driver characteristics, and contextual factors such as vehicle speed and traffic flow. Of the 3,265 drivers observed, the prevalence of distracted driving was 32.7%. Among those involved in a distracting activity, the most frequently observed distractions included interacting with another passenger (53.2%, where passengers were present), talking on the phone (31.4%), external-vehicle distractions (20.4%), and texting/dialing a phone (16.6%). The prevalence of talking on the phone was higher among females than males (38.6% vs. 24.3%), whereas external vehicle distractions were higher among males than females (25.8% vs. 24.3%). Drivers <30 years were observed being engaged in any distracting activity, interacting with other passengers, and texting/dialing more frequently than drivers aged 30-50 and >50 years. Drivers were engaged in distracting behaviors more frequently when the car was stopped. When using similar methodology, roadside observational studies generate comparable prevalence estimates of driver distraction as naturalistic driving studies. Driver distraction is a common problem among passenger vehicle drivers. Despite the increased awareness on the dangers of texting and cell phone use while driving, these specific activities were 2 of the most frequently observed distractions. There is a continued need for road safety education about the dangers of distracted driving, especially for younger drivers.

Pulse Shape Evolution, HER X-1

NASA Technical Reports Server (NTRS)

VanParadijs, Johannes A.

1998-01-01

This study focuses on the pulse shape evolution and spectral properties of the X-ray binary Her X-1 with regard to the well known 35-day cycle of Her X-1. A follow-up set of RXTE observations has been conducted in RXTE AO-2 phase and the two observation sets are being analyzed together. We presented results of early analysis of pulse shape evolution in "Proceedings of the Fourth Compton Symposium." More advanced analysis was presented at the HEAD meeting in November, 1997 in Estes Park, Colorado. A related study of the 35-day cycle using RXTE/ASM data, which laid out the overall picture within which the more detailed PCA observations could be placed has also been conducted. The results of this study have been published in The Astrophysical Journal, vol. 510, 974. A pair of papers on the detailed pulse evolution and the spectral/color evolution are currently being prepared for publication. Some of the significant results of this study have been a confirmation of the detailed pulse profile changes at the end of the Main High state in Her X-1 first observed by GINGA, observations of the pulse evolution in several Short High states which agree with the pulse evolution pattern predicted using a disk occultation model in the PhD Thesis of Scott 1993, observation of a systematic lengthening of the eclipse egress during the Main High state of the 35-day phase and observation of a new type of extended eclipse ingress during which pulsations cease to observed during the Short High state.

Examination of Teacher Observation Dynamics: Role of Observer Effort on Teacher Growth

ERIC Educational Resources Information Center

Bury, Michael Shaun

2017-01-01

This study examined the teacher observation cycle to understand the effect of observer knowledge, observer effort, observer power, and school culture on teachers' perceptions of whether the observation process helped them grow, implement strategies, or increase student learning. The concepts of power and expertise were defined by blending the…

Moon-based Earth Observation for Large Scale Geoscience Phenomena

NASA Astrophysics Data System (ADS)

Guo, Huadong; Liu, Guang; Ding, Yixing

2016-07-01

The capability of Earth observation for large-global-scale natural phenomena needs to be improved and new observing platform are expected. We have studied the concept of Moon as an Earth observation in these years. Comparing with manmade satellite platform, Moon-based Earth observation can obtain multi-spherical, full-band, active and passive information,which is of following advantages: large observation range, variable view angle, long-term continuous observation, extra-long life cycle, with the characteristics of longevity ,consistency, integrity, stability and uniqueness. Moon-based Earth observation is suitable for monitoring the large scale geoscience phenomena including large scale atmosphere change, large scale ocean change,large scale land surface dynamic change,solid earth dynamic change,etc. For the purpose of establishing a Moon-based Earth observation platform, we already have a plan to study the five aspects as follows: mechanism and models of moon-based observing earth sciences macroscopic phenomena; sensors' parameters optimization and methods of moon-based Earth observation; site selection and environment of moon-based Earth observation; Moon-based Earth observation platform; and Moon-based Earth observation fundamental scientific framework.

Dermoscopic patterns of melanocytic nevi in children and adolescents: a cross-sectional study*

PubMed Central

Piazza, Christiane Donato; Yamada, Sergio; Marcassi, Aline P; Maciel, Marina G; Seize, Maria P; Cestari, Silmara C P

2017-01-01

Background Childhood is a dynamic period regarding nevogenesis. Dermoscopy is a noninvasive technique, recommended for the evaluation of pigmented cutaneous lesions. Objectives The purpose of this study was to describe the structures and dermoscopic patterns of melanocytic nevi observed in children and adolescents. Methods Dermoscopy with photographic documentation was used for nevi located on the face, trunk, and extremities of 38 patients aged from one to 16 years examined at the Pediatric Dermatology Outpatient Clinic of the Federal University of São Paulo. Results The study included 201 skin lesions that were diagnosed as nevi during clinic examination. Upon evaluation of the global dermoscopic pattern of the lesions, the most frequently observed nevi were reticular (39.0%), followed by homogeneous (23.9%) and globular nevi (16.4%). During evaluation of the dermoscopic structures, according to the body site, the pigment network was the most observed in the extremities. Study limitations A limitation to be considered is that the inclusion of small or new lesions may hinder the differentiation between dots and globules. Conclusions In our study, the most observed pattern was reticular. There was a difference in the predominance of structures dependent on the anatomical location. PMID:29186245

Expanding the Evidence Base: Comparing Randomized Controlled Trials and Observational Studies of Statins.

PubMed

Atar, Dan; Ong, Seleen; Lansberg, Peter J

2015-01-01

It is widely accepted that randomized controlled trials (RCTs) are the gold standard for demonstrating the efficacy of a given therapy (results under ideal conditions). Observational studies, on the other hand, can complement this by demonstrating effectiveness (results under real-world conditions). To examine the role that observational studies can play in complementing data from RCTs, we reviewed published studies for statins, a class of drugs that have been widely used to reduce the risk of cardiovascular (CV) events by lowering low-density lipoprotein cholesterol levels. RCTs have consistently demonstrated the benefits of statin treatment in terms of CV risk reduction and have demonstrated that more intensive statin therapy has incremental benefits over less intensive treatment. Observational studies of statin use in 'real-world' populations have served to augment the evidence base generated from statin RCTs in preselected populations of patients who are often at high CV risk and have led to similar safety and efficacy findings. They have also raised questions about factors affecting medication adherence, under-treatment, switching between statins, and failure to reach low-density lipoprotein cholesterol target levels, questions for which the answers could lead to improved patient care.

ED services: the impact of caring behaviors on patient loyalty.

PubMed

Liu, Sandra S; Franz, David; Allen, Monette; Chang, En-Chung; Janowiak, Dana; Mayne, Patricia; White, Ruth

2010-09-01

This article describes an observational study of caring behaviors in the emergency departments of 4 Ascension Health hospitals and the impact of these behaviors on patient loyalty to the associated hospital. These hospitals were diverse in size and geography, representing 3 large urban community hospitals in metropolitan areas and 1 in a midsized city. Research assistants from Purdue University (West Lafayette, IN) conducted observations at the first study site and validated survey instruments. The Purdue research assistants trained contracted observers at the subsequent study sites. The research assistants conducted observational studies of caregivers in the emergency departments at 4 study sites using convenience sampling of patients. Caring behaviors were rated from 0 (did not occur) to 5 (high intensity). The observation included additional information, for example, caregiver roles, timing, and type of visit. Observed and unobserved patients completed exit surveys that recorded patient responses to the likelihood-to-recommend (loyalty) questions, patient perceptions of care, and demographic information. Common themes across all study sites emerged, including (1) the area that patients considered most important to an ED experience (prompt attention to their needs upon arrival to the emergency department); (2) the area that patients rated as least positive in their actual ED experience (prompt attention to their needs upon arrival to the emergency department); (3) caring behaviors that significantly affected patient loyalty (eg, making sure that the patient is aware of care-related details, working with a caring touch, and making the treatment procedure clearly understood by the patient); and (4) the impact of wait time to see a caregiver on patient loyalty. A number of correlations between caring behaviors and patient loyalty were statistically significant (P < .05) at all sites. The study results raised considerations for ED caregivers, particularly with regard to those caring behaviors that are most closely linked to patient loyalty but that occurred least frequently. The study showed through factor analysis that some caring behaviors tended to occur together, suggesting an underlying, unifying dimension to that factor. Copyright © 2010 Emergency Nurses Association. Published by Mosby, Inc. All rights reserved.

Network meta-analysis combining individual patient and aggregate data from a mixture of study designs with an application to pulmonary arterial hypertension.

PubMed

Thom, Howard H Z; Capkun, Gorana; Cerulli, Annamaria; Nixon, Richard M; Howard, Luke S

2015-04-12

Network meta-analysis (NMA) is a methodology for indirectly comparing, and strengthening direct comparisons of two or more treatments for the management of disease by combining evidence from multiple studies. It is sometimes not possible to perform treatment comparisons as evidence networks restricted to randomized controlled trials (RCTs) may be disconnected. We propose a Bayesian NMA model that allows to include single-arm, before-and-after, observational studies to complete these disconnected networks. We illustrate the method with an indirect comparison of treatments for pulmonary arterial hypertension (PAH). Our method uses a random effects model for placebo improvements to include single-arm observational studies into a general NMA. Building on recent research for binary outcomes, we develop a covariate-adjusted continuous-outcome NMA model that combines individual patient data (IPD) and aggregate data from two-arm RCTs with the single-arm observational studies. We apply this model to a complex comparison of therapies for PAH combining IPD from a phase-III RCT of imatinib as add-on therapy for PAH and aggregate data from RCTs and single-arm observational studies, both identified by a systematic review. Through the inclusion of observational studies, our method allowed the comparison of imatinib as add-on therapy for PAH with other treatments. This comparison had not been previously possible due to the limited RCT evidence available. However, the credible intervals of our posterior estimates were wide so the overall results were inconclusive. The comparison should be treated as exploratory and should not be used to guide clinical practice. Our method for the inclusion of single-arm observational studies allows the performance of indirect comparisons that had previously not been possible due to incomplete networks composed solely of available RCTs. We also built on many recent innovations to enable researchers to use both aggregate data and IPD. This method could be used in similar situations where treatment comparisons have not been possible due to restrictions to RCT evidence and where a mixture of aggregate data and IPD are available.

A method to integrate descriptive and experimental field studies at the level of data and empirical concepts1

PubMed Central

Bijou, Sidney W.; Peterson, Robert F.; Ault, Marion H.

1968-01-01

It is the thesis of this paper that data from descriptive and experimental field studies can be interrelated at the level of data and empirical concepts if both sets are derived from frequency-of-occurrence measures. The methodology proposed for a descriptive field study is predicated on three assumptions: (1) The primary data of psychology are the observable interactions of a biological organism and environmental events, past and present. (2) Theoretical concepts and laws are derived from empirical concepts and laws, which in turn are derived from the raw data. (3) Descriptive field studies describe interactions between behavioral and environmental events; experimental field studies provide information on their functional relationships. The ingredients of a descriptive field investigation using frequency measures consist of: (1) specifying in objective terms the situation in which the study is conducted, (2) defining and recording behavioral and environmental events in observable terms, and (3) measuring observer reliability. Field descriptive studies following the procedures suggested here would reveal interesting new relationships in the usual ecological settings and would also provide provocative cues for experimental studies. On the other hand, field-experimental studies using frequency measures would probably yield findings that would suggest the need for describing new interactions in specific natural situations. PMID:16795175

Hand assessment in older adults with musculoskeletal hand problems: a reliability study.

PubMed

Myers, Helen L; Thomas, Elaine; Hay, Elaine M; Dziedzic, Krysia S

2011-01-07

Musculoskeletal hand pain is common in the general population. This study aims to investigate the inter- and intra-observer reliability of two trained observers conducting a simple clinical interview and physical examination for hand problems in older adults. The reliability of applying the American College of Rheumatology (ACR) criteria for hand osteoarthritis to community-dwelling older adults will also be investigated. Fifty-five participants aged 50 years and over with a current self-reported hand problem and registered with one general practice were recruited from a previous health questionnaire study. Participants underwent a standardised, structured clinical interview and physical examination by two independent trained observers and again by one of these observers a month later. Agreement beyond chance was summarised using Kappa statistics and intra-class correlation coefficients. Median values for inter- and intra-observer reliability for clinical interview questions were found to be "substantial" and "moderate" respectively [median agreement beyond chance (Kappa) was 0.75 (range: -0.03, 0.93) for inter-observer ratings and 0.57 (range: -0.02, 1.00) for intra-observer ratings]. Inter- and intra-observer reliability for physical examination items was variable, with good reliability observed for some items, such as grip and pinch strength, and poor reliability observed for others, notably assessment of altered sensation, pain on resisted movement and judgements based on observation and palpation of individual features at single joints, such as bony enlargement, nodes and swelling. Moderate agreement was observed both between and within observers when applying the ACR criteria for hand osteoarthritis. Standardised, structured clinical interview is reliable for taking a history in community-dwelling older adults with self reported hand problems. Agreement between and within observers for physical examination items is variable. Low Kappa values may have resulted, in part, from a low prevalence of clinical signs and symptoms in the study participants. The decision to use clinical interview and hand assessment variables in clinical practice or further research in primary care should include consideration of clinical applicability and training alongside reliability. Further investigation is required to determine the relationship between these clinical questions and assessments and the clinical course of hand pain and hand problems in community-dwelling older adults.

Observational study of atmospheric surface layer and coastal weather in northern Qatar

NASA Astrophysics Data System (ADS)

Samanta, Dhrubajyoti; Sadr, Reza

2016-04-01

Atmospheric surface layer is the interaction medium between atmosphere and Earth's surface. Better understanding of its turbulence nature is essential in characterizing the local weather, climate variability and modeling of turbulent exchange processes. The importance of Middle East region, with its unique geographical, economical and weather condition is well recognized. However, high quality micrometeorological observational studies are rare in this region. Here we show experimental results from micrometeorological observations from an experimental site in the coastal region of Qatar during August-December 2015. Measurements of winds are obtained from three sonic anemometers installed on a 9 m tower placed at Al Ghariyah beach in northern Qatar (26.08 °N, 51.36 °E). Different surface layer characteristics is analyzed and compared with earlier studies in equivalent weather conditions. Monthly statistics of wind speed, wind direction, temperature, humidity and heat index are made from concurrent observations from sonic anemometer and weather station to explore variations with surface layer characteristics. The results also highlights potential impact of sea breeze circulation on local weather and atmospheric turbulence. The observed daily maximum temperature and heat index during morning period may be related to sea breeze circulations. Along with the operational micrometeorological observation system, a camera system and ultrasonic wave measurement system are installed recently in the site to study coastline development and nearshore wave dynamics. Overall, the complete observational set up is going to provide new insights about nearshore wind dynamics and wind-wave interaction in Qatar.

Levels-of-growing-stock cooperative study in Douglas-fir: report no. 09—Some comparisons of DFSIM estimates with growth in the levels-of-growing-stock study.

Treesearch

Robert O. Curtis

1987-01-01

Initial stand statistics for the levels-of-growing-stock study installations were projected by the Douglas-fir stand simulation program (DFSIM) over the available periods of observation. Estimates were compared with observed volume and basal area growth, diameter change, and mortality. Overall agreement was reasonably good, although results indicate some biases and a...

The Comet Halley archive: Summary volume

NASA Technical Reports Server (NTRS)

Sekanina, Zdenek (Editor); Fry, Lori (Editor)

1991-01-01

The contents are as follows: The Organizational History of the International Halley Watch; Operations of the International Halley Watch from a Lead Center Perspective; The Steering Group; Astrometry Network; Infrared Studies Network; Large-Scale Phenomena Network; Meteor Studies Network; Near-Nucleus Studies Network; Photometry and Polarimetry Network; Radio Science Network; Spectroscopy and Spectrophotometry Network; Amateur Observation Network; Use of the CD-ROM Archive; The 1986 Passage of Comet Halley; and Recent Observations of Comet Halley.

Representing Geospatial Environment Observation Capability Information: A Case Study of Managing Flood Monitoring Sensors in the Jinsha River Basin

PubMed Central

Hu, Chuli; Guan, Qingfeng; Li, Jie; Wang, Ke; Chen, Nengcheng

2016-01-01

Sensor inquirers cannot understand comprehensive or accurate observation capability information because current observation capability modeling does not consider the union of multiple sensors nor the effect of geospatial environmental features on the observation capability of sensors. These limitations result in a failure to discover credible sensors or plan for their collaboration for environmental monitoring. The Geospatial Environmental Observation Capability (GEOC) is proposed in this study and can be used as an information basis for the reliable discovery and collaborative planning of multiple environmental sensors. A field-based GEOC (GEOCF) information representation model is built. Quintuple GEOCF feature components and two GEOCF operations are formulated based on the geospatial field conceptual framework. The proposed GEOCF markup language is used to formalize the proposed GEOCF. A prototype system called GEOCapabilityManager is developed, and a case study is conducted for flood observation in the lower reaches of the Jinsha River Basin. The applicability of the GEOCF is verified through the reliable discovery of flood monitoring sensors and planning for the collaboration of these sensors. PMID:27999247

The Type IIP SN 2005ay: An Extensive Study From UltraViolet To Near-IR

NASA Astrophysics Data System (ADS)

Bufano, F. M.; Turatto, M.; Zampieri, L.; Gal-Yam, A.

2006-08-01

Several supernova types are thought to explode via the gravitational collapse of the core of massive stars at the end of their lifetimes. The great observational diversity has not been fully understood even if it clearly involves the progenitor masses and configurations at the time of explosion. These Supernovae, called Core Collapse Supernovae (CC SNe), are expected to dominate the counts of SNe observed at high redshifts and to be the only observable probe of the first generation stars (Pop III). Recently indicated as reliable distance indicators (Hamuy 02, Pastorello `03), CC SNe are objects of great interest but significantly less studied in comparison with the Termonuclear ones. With the aim to understand better the reasons of the heterogeneous behaviour , we have started an extensive study of the properties of SN II with different observational features (luminosity, velocity, etc..). Here we present the last results on our first observed target, SN2005ay, a Type IIP supernova observed in an extended way from the Ultraviolet wavelengths, provided by the GALEX , to the Optical and near-IR , obtained with IISP (Italian Intensive Supernova Program).

The earth's radiation budget and its relation to atmospheric hydrology. I - Observations of the clear sky greenhouse effect. II - Observations of cloud effects

NASA Technical Reports Server (NTRS)

Stephens, Graeme L.; Greenwald, Thomas J.

1991-01-01

The clear-sky components of the earth's radiation budget (ERB), the relationship of these components to the sea surface temperature (SST), and microwave-derived water-vapor amount are analyzed in an observational study along with the relationship between the cloudy-sky components of ERB and space/time coincident observations of SST, microwave-derived cloud liquid water, and cloud cover. The purpose of the study is to use these observations for establishing an understanding of the couplings between radiation and the atmosphere that are important to understanding climate feedback. A strategy for studying the greenhouse effect of earth by analyzing the emitted clear-sky longwave flux over the ocean is proposed. It is concluded that the largest observed influence of clouds on ERB is more consistent with macrophysical properties of clouds as opposed to microphysical properties. The analysis for clouds and the greenhouse effect of clouds is compared quantitatively with the clear sky results. Land-ocean differences and tropical-midlatitude differences are shown and explained in terms of the cloud macrostructure.

Representing Geospatial Environment Observation Capability Information: A Case Study of Managing Flood Monitoring Sensors in the Jinsha River Basin.

PubMed

Hu, Chuli; Guan, Qingfeng; Li, Jie; Wang, Ke; Chen, Nengcheng

2016-12-16

Sensor inquirers cannot understand comprehensive or accurate observation capability information because current observation capability modeling does not consider the union of multiple sensors nor the effect of geospatial environmental features on the observation capability of sensors. These limitations result in a failure to discover credible sensors or plan for their collaboration for environmental monitoring. The Geospatial Environmental Observation Capability (GEOC) is proposed in this study and can be used as an information basis for the reliable discovery and collaborative planning of multiple environmental sensors. A field-based GEOC (GEOCF) information representation model is built. Quintuple GEOCF feature components and two GEOCF operations are formulated based on the geospatial field conceptual framework. The proposed GEOCF markup language is used to formalize the proposed GEOCF. A prototype system called GEOCapabilityManager is developed, and a case study is conducted for flood observation in the lower reaches of the Jinsha River Basin. The applicability of the GEOCF is verified through the reliable discovery of flood monitoring sensors and planning for the collaboration of these sensors.

The Development and Deployment of a Maintenance Operations Safety Survey.

PubMed

Langer, Marie; Braithwaite, Graham R

2016-11-01

Based on the line operations safety audit (LOSA), two studies were conducted to develop and deploy an equivalent tool for aircraft maintenance: the maintenance operations safety survey (MOSS). Safety in aircraft maintenance is currently measured reactively, based on the number of audit findings, reportable events, incidents, or accidents. Proactive safety tools designed for monitoring routine operations, such as flight data monitoring and LOSA, have been developed predominantly for flight operations. In Study 1, development of MOSS, 12 test peer-to-peer observations were collected to investigate the practicalities of this approach. In Study 2, deployment of MOSS, seven expert observers collected 56 peer-to-peer observations of line maintenance checks at four stations. Narrative data were coded and analyzed according to the threat and error management (TEM) framework. In Study 1, a line check was identified as a suitable unit of observation. Communication and third-party data management were the key factors in gaining maintainer trust. Study 2 identified that on average, maintainers experienced 7.8 threats (operational complexities) and committed 2.5 errors per observation. The majority of threats and errors were inconsequential. Links between specific threats and errors leading to 36 undesired states were established. This research demonstrates that observations of routine maintenance operations are feasible. TEM-based results highlight successful management strategies that maintainers employ on a day-to-day basis. MOSS is a novel approach for safety data collection and analysis. It helps practitioners understand the nature of maintenance errors, promote an informed culture, and support safety management systems in the maintenance domain. © 2016, Human Factors and Ergonomics Society.

The intra- and inter-observer reliability of the physical examination methods used to assess patients with patellofemoral joint instability.

PubMed

Smith, Toby O; Clark, Allan; Neda, Sophia; Arendt, Elizabeth A; Post, William R; Grelsamer, Ronald P; Dejour, David; Almqvist, Karl Fredrik; Donell, Simon T

2012-08-01

An accurate physical examination of patients with patellar instability is an important aspect of the diagnosis and treatment. While previous studies have assessed the diagnostic accuracy of such physical examination tests, little has been undertaken to assess the inter- and intra-tester reliability of such techniques. The purpose of this study was to determine the inter- and intra-tester reliability of the physical examination tests used for patients with patellar instability. Five patients (10 knees) with bilateral recurrent patellar instability were assessed by five members of the International Patellofemoral Study Group. Each surgeon assessed each patient twice using 18 reported physical examination tests. The inter- and intra-observer reliability was assessed using weighted Kappa statistics with 95% confidence intervals. The findings of the study suggested that there were very poor inter-observer reliability for the majority of the physical tests, with only the assessments of patellofemoral crepitus, foot arch position and the J-sign presenting with fair to moderate agreement respectively. The intra-observer reliability indicated largely moderate to substantial agreement between the first and second tests performed by each assessor, with the greatest agreement seen for the assessment of tibial torsion, popliteal angle and the Bassett's sign. For the common physical examination tests used in the management of patients with patellar instability inter-observer reliability is poor, while intra-observer reliability is moderate. Standardization of physical exam assessments and further study of these results among different clinicians and more divergent patient groups is indicated. Copyright © 2011 Elsevier B.V. All rights reserved.

The Development and Deployment of a Maintenance Operations Safety Survey

PubMed Central

Langer, Marie; Braithwaite, Graham R.

2016-01-01

Objective: Based on the line operations safety audit (LOSA), two studies were conducted to develop and deploy an equivalent tool for aircraft maintenance: the maintenance operations safety survey (MOSS). Background: Safety in aircraft maintenance is currently measured reactively, based on the number of audit findings, reportable events, incidents, or accidents. Proactive safety tools designed for monitoring routine operations, such as flight data monitoring and LOSA, have been developed predominantly for flight operations. Method: In Study 1, development of MOSS, 12 test peer-to-peer observations were collected to investigate the practicalities of this approach. In Study 2, deployment of MOSS, seven expert observers collected 56 peer-to-peer observations of line maintenance checks at four stations. Narrative data were coded and analyzed according to the threat and error management (TEM) framework. Results: In Study 1, a line check was identified as a suitable unit of observation. Communication and third-party data management were the key factors in gaining maintainer trust. Study 2 identified that on average, maintainers experienced 7.8 threats (operational complexities) and committed 2.5 errors per observation. The majority of threats and errors were inconsequential. Links between specific threats and errors leading to 36 undesired states were established. Conclusion: This research demonstrates that observations of routine maintenance operations are feasible. TEM-based results highlight successful management strategies that maintainers employ on a day-to-day basis. Application: MOSS is a novel approach for safety data collection and analysis. It helps practitioners understand the nature of maintenance errors, promote an informed culture, and support safety management systems in the maintenance domain. PMID:27411354

Derivation of Aerosol Profiles for MC3E Convection Studies and Use in Simulations of the 20 May Squall Line Case

NASA Technical Reports Server (NTRS)

Fridlind, Ann M.; Li, Xiaowen; Wu, Di; van Lier-Walqui, Marcus; Ackerman, Andrew S.; Tao, Wei-Kuo; McFarquhar, Greg M.; Wu, Wei; Dong, Xiquan; Wang, Jingyu;

The effect of video-guidance on passive movement in patients with cerebral palsy: fMRI study.

PubMed

Dinomais, Mickael; Chinier, Eva; Lignon, Gregoire; Richard, Isabelle; Ter Minassian, Aram; Tich, Sylvie Nguyen The

2013-10-01

In patients with cerebral palsy (CP), neuroimaging studies have demonstrated that passive movement and action-observation tasks have in common to share neuronal activation in all or part of areas involved in motor system. Action observation with simultaneous congruent passive movements may have additional effects in the recruitment of brain motor areas. The aim of this functional magnetic resonance imaging (fMRI) study was to examine brain activation in patients with unilateral CP during passive movement with and without simultaneous observation of simple hand movement. Eighteen patients with unilateral CP (fourteen male, mean age 14 years and 2 months) participated in the study. Using fMRI block design, brain activation following passive simple opening-closing hand movement of either the paretic or nonparetic hand with and without simultaneous observation of a similar movement performed by either the left or right hand of an actor was compared. Passive movement of the paretic hand performed simultaneously to the observation of congruent movement activated more "higher motor areas" including contralesional pre-supplementary motor area, superior frontal gyrus (extending to premotor cortex), and superior and inferior parietal regions than nonvideo-guided passive movement of the paretic hand. Passive movement of the paretic hand recruited more ipsilesional sensorimotor areas compared to passive movement of the nonparetic hand. Our study showed that the combination of observation of congruent hand movement simultaneously to passive movement of the paretic hand recruits more motor areas, giving neuronal substrate to propose video-guided passive movement of paretic hand in CP rehabilitation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Observing Aggression of Teachers in School Teams

ERIC Educational Resources Information Center

Ben Sasson, Dvora; Somech, Anit

2015-01-01

To fill the gap in theoretical and empirical knowledge on workplace aggression by teachers working in teams, this study explored its components, its targets, and its contextual determinants. Data were collected through three observations at different schools and at different times on 29 math, homeroom, language, and science studies teams.…

Observations of bi-directional leader development in a triggered lightning flash

NASA Technical Reports Server (NTRS)

Laroche, P.; Idone, V.; Eybert-Berard, A.; Barret, L.

1991-01-01

Observations of a modified form of rocket triggered lightning are described. A flash triggered during the summer of 1989 is studied as part of an effort to model bidirectional discharge. It is suggested that the altitude triggering technique provides a realistic means of studying the attachment process.

ENVIRONMENTAL EXPOSURES TO CHLOROPHENOXY HERBICIDES AND ASSOCIATION WITH ADVERSE HUMAN HEALTH EFFECTS: EXAMPLE OF THE NEED FOR BETTER METHODS

EPA Science Inventory

Previous studies have made the following observations: newly emerging global patterns of disease have been observed, and environmental exposures have been implicated. Ecologic studies are fundamental for the identification of public health problems. Some level of exposure in a...

78 FR 32406 - Submission for OMB Review; 30-Day Comment Request: Women's Health Initiative Observational Study

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-30

...; 30-Day Comment Request: Women's Health Initiative Observational Study SUMMARY: Under the provisions... proposed project contact: Shari Eason Ludlam, Project Officer, Women's Health Initiative Program Office... additional plans and instruments must be requested in writing. Proposed Collection: Women's Health Initiative...

Formative Assessment Design for PDA Integrated Ecology Observation

ERIC Educational Resources Information Center

Hung, Pi-Hsia; Lin, Yu-Fen; Hwang, Gwo-Jen

2010-01-01

Ubiquitous computing and mobile technologies provide a new perspective for designing innovative outdoor learning experiences. The purpose of this study is to propose a formative assessment design for integrating PDAs into ecology observations. Three learning activities were conducted in this study. An action research approach was applied to…

Shared Decision-Making and the Limits of Democratization: A Case Study of Site-Based Reform.

ERIC Educational Resources Information Center

Radnofsky, Mary L.; Spielmann, Guy

This paper presents findings of an ethnographic study of a school district's Staff Development, Supervision, and Evaluation Program (SDSEP). Data were gathered through interviews, observations, participant observation, analysis of kinesics and proxemics, semiotic analysis of discourse, unobtrusive measures, and analysis of official documents. The…

Evaluation of Immediate Actions Taken to Deal with Cracking Problems Observed in Wheels of Rail Commuter Cars

DOT National Transportation Integrated Search

1993-07-01

The report is the first in a series of engineering studies on railroad vehicle wheel performance. Preliminary studies are summarized, involving evaluation of actions taken to respond to high rates of crack occurrence observed in the wheels of certain...

Transformative Learning through Education Abroad: A Case Study of a Community College Program

ERIC Educational Resources Information Center

Brenner, Ashley A.

2014-01-01

This case study examined how participating in a short-term education abroad program fostered transformative learning for a small group of community college students. As a participant-observer, I utilized ethnographic methods, including interviews, observations, and document analysis, to understand students' perceptions of their experiences…

Exploring Patient Activation in the Clinic: Measurement from Three Perspectives

ERIC Educational Resources Information Center

Ledford, Christy J. W.; Ledford, Christopher C.; Childress, Marc A.

2013-01-01

Objective. To further conceptualize and operationalize patient activation (PA), using measures from patient, physician, and researcher perspectives. Data Source/Study Setting. Multimethod observation in 2010 within a family medicine clinic. Study Design. Part of an intervention with 130 patients with type 2 diabetes, this observational study…

VISUALLY OBSERVED MOLD AND MOLDY ODOR VERSUS QUANTITATIVELY MEASURED MICROBIAL EXPOSURE IN HOMES

EPA Science Inventory

The main study objective was to compare different methods for assessing mold exposure in conjunction with an epidemiologic study on the development of children's asthma. Homes of 184 children were assessed for mold by visual observations and dust sampling at child's age 1 (Year ...

Multiple Integrated Examinations: An Observational Study of Different Academic Curricula Based on a Business Administration Assessment

ERIC Educational Resources Information Center

Ardolino, Piermatteo; Noventa, Stefano; Formicuzzi, Maddalena; Cubico, Serena; Favretto, Giuseppe

2016-01-01

An observational study has been carried out to analyse differences in performance between students of different undergraduate curricula in the same written business administration examination, focusing particularly on possible effects of "integrated" or "multi-modular" examinations, a recently widespread format in Italian…

The Indiana Science Initiative: Lessons from a Classroom Observation Study

ERIC Educational Resources Information Center

Cook, Nicole D.; Walker, William S.; Weaver, Gabriela C.; Sorge, Brandon H.

2015-01-01

The Indiana Science Initiative (ISI) is a systemic effort to reform K-8 science education. The program provides teachers with professional development, reform-oriented science modules, and materials support. To examine the impact of the initiative's professional development, a participant observation study was conducted in the program's pilot…

Factors Associated with South Korean Early Childhood Educators' Observed Behavior Support Strategies

ERIC Educational Resources Information Center

Kim, Yeon Ha; Stormont, Melissa

2012-01-01

This study was an exploratory study of 34 South Korean early childhood educators' strategies for addressing behavior problems in natural settings. Factors related to teachers' strategy implementation were also explored. Four specific teacher behaviors were observed: precorrection, behavioral-specific praise, redirection, and reprimand/punishment.…

Site-Based Leadership: Extrapolating from Small Business to Charter Schools

ERIC Educational Resources Information Center

Arbisi Little, Joan

2012-01-01

Using a participant-observer perspective, this comparative case study sought to identify similarities between business and education to contribute to charter school training, leadership development, and school reform. This inquiry is a qualitative comparative case study using a participant observer perspective presented in a scholarly personal…

Different Regions, Diverse Classrooms? a Study of Primary Classrooms in China

ERIC Educational Resources Information Center

McNaught, Carmel; Lok, Beatrice; Yin, Hongbiao; Lee, John Chi-Kin; Song, Huan

2014-01-01

Classroom experience is shaped by a number of factors. In this paper, we report a classroom observation study in China, illustrating regional variation in students' classroom learning experiences. Through comparing and contrasting observed classroom practices in three different regions in China (Chongqing, Hong Kong and Shanghai), the paper…

Repeated helicopter-based surveys of fugitive hydrocarbon emissions from tight oil operations: Persistence and driving factors

NASA Astrophysics Data System (ADS)

Englander, J. G.; Brandt, A. R.; Jackson, R. B.; Alvarez, R.; Lyon, D. R.

2016-12-01

A recent study used helicopters and optical gas imaging (infrared-based) to study hydrocarbon leaks [1] across numerous oil and gas producing basins. The appearance of leaks appeared to have small statistical correlations with factors such as age of wells, production rate, or water production. However, there have not been few if any attempts to observe the presence of leaks over time. In this work, we used the same helicopter-based optical gas imaging techniques to revisit wells in the Bakken formation that had previously been measured in 2014 [1] In this study, we visited 353 of the total 683 well pads in Bakken from the original study, and we also visited 50 randomly selected well pads that were newly developed between studies. We first examine the presence of leaks as a function of different factors, including: operator, number of wells, tanks, and treaters on a well pad; and numerous other possible emissions drivers. In addition, using the previous years observations as our prior, we conducted a Bayesian analysis to determine the likelihood of finding a leaking or non-leaking well pad and compared the observations to a Monte Carlo simulation of randomly distributed leaks. We find that the overall prevalence of observed emissions was similar for each year (11% for 2014 observations and 10% for 2015 observations). We also find whether a pad was found to be leaking in the first observation year had a statistically significant influence (4.9σ) on the presence of a leak in the following observation year. Similar levels of persistence are also apparent for non-leaking well pads. [1] D. R. Lyon, R. A. Alvarez, D. Zavala-Araiza, A. R. Brandt, R. B. Jackson, and S. P. Hamburg, "Aerial surveys of elevated hydrocarbon emissions from oil and gas production sites," Environ. Sci. Technol., p. acs.est.6b00705, Apr. 2016.

Comparisons of Cloud Properties over the Southern Ocean between In situ Observations and WRF Simulations

NASA Astrophysics Data System (ADS)

D'Alessandro, J.; Diao, M.; Wu, C.; Liu, X.

2017-12-01

Numerical weather models often struggle at representing clouds since small scale cloud processes must be parameterized. For example, models often utilize simple parameterizations for transitioning from liquid to ice, usually set as a function of temperature. However, supercooled liquid water (SLW) often persists at temperatures much lower than threshold values used in microphysics parameterizations. Previous observational studies of clouds over the Southern Ocean have found high frequencies of SLW (e.g., Morrison et al., 2011). Many of these studies have relied on satellite retrievals, which provide relatively low resolution observations and are often associated with large uncertainties due to assumptions of microphysical properties (e.g., particle size distributions). Recently, the NSF/NCAR O2/N2 Ratio and CO2 Airborne Southern Ocean Study (ORCAS) campaign took observations via the NSF/NCAR HIAPER research aircraft during January and February of 2016, providing in situ observations over the Southern Ocean (50°W to 92°W). We compare simulated results from the Weather Research and Forecasting (WRF) model with in situ observations from ORCAS. Differences between observations and simulations are evaluated via statistical analyses. Initial results from ORCAS reveal a high frequency of SLW at temperatures as low as -15°C, and the existence of SLW around -30°C. Recent studies have found that boundary layer clouds are underestimated by WRF in regions unaffected by cyclonic activity (Huang et al., 2014), suggesting a lack of low-level moisture due to local processes. To explore this, relative humidity distributions are examined and controlled by cloud microphysical characteristics (e.g., total water content) and relevant ambient properties (e.g., vertical velocity). A relatively low frequency of simulated SLW may in part explain the discrepancies in WRF, as cloud-top SLW results in stronger radiative cooling and turbulent motions conducive for long-lived cloud regimes. Results presented in this study will help improve our understanding of Southern Ocean clouds and the observed discrepancies seen in WRF simulations.

Observational studies using propensity score analysis underestimated the effect sizes in critical care medicine.

PubMed

Zhang, Zhongheng; Ni, Hongying; Xu, Xiao

2014-08-01

Propensity score (PS) analysis has been increasingly used in critical care medicine; however, its validation has not been systematically investigated. The present study aimed to compare effect sizes in PS-based observational studies vs. randomized controlled trials (RCTs) (or meta-analysis of RCTs). Critical care observational studies using PS were systematically searched in PubMed from inception to April 2013. Identified PS-based studies were matched to one or more RCTs in terms of population, intervention, comparison, and outcome. The effect sizes of experimental treatments were compared for PS-based studies vs. RCTs (or meta-analysis of RCTs) with sign test. Furthermore, ratio of odds ratio (ROR) was calculated from the interaction term of treatment × study type in a logistic regression model. A ROR < 1 indicates greater benefit for experimental treatment in RCTs compared with PS-based studies. RORs of each comparison were pooled by using meta-analytic approach with random-effects model. A total of 20 PS-based studies were identified and matched to RCTs. Twelve of the 20 comparisons showed greater beneficial effect for experimental treatment in RCTs than that in PS-based studies (sign test P = 0.503). The difference was statistically significant in four comparisons. ROR can be calculated from 13 comparisons, of which four showed significantly greater beneficial effect for experimental treatment in RCTs. The pooled ROR was 0.71 (95% CI: 0.63, 0.79; P = 0.002), suggesting that RCTs (or meta-analysis of RCTs) were more likely to report beneficial effect for the experimental treatment than PS-based studies. The result remained unchanged in sensitivity analysis and meta-regression. In critical care literature, PS-based observational study is likely to report less beneficial effect of experimental treatment compared with RCTs (or meta-analysis of RCTs). Copyright © 2014 Elsevier Inc. All rights reserved.

Calculations of the conditions for bunch leakage in the Los Alamos proton storage ring

NASA Astrophysics Data System (ADS)

Neuffer, D.; Ohmori, C.

1994-04-01

Observations are consistent with the possibility of an "ep" instability in the Los Alamos Proton Storage Ring (PSR) with both bunched and unbunched beam. The instability requires electrons to be trapped within the beam, and calculations have shown that such trapping requires leakage of beam into the interbunch gap. Observationally, leakage of beam into the gap appears necessary for the onset of the instability. In this paper we present results of studies of the longitudinal beam dynamics at PSR parameters. The studies indicate that the combined effects of the rf buncher, longitudinal space charge, and injection mismatch are sufficient to cause the observed bunch leakage. Simulation results are presented and compared with PSR observations. Variations of PSR performance parameters are considered, and methods of improving bunch confinement are suggested and studied.

Studies on post weld heat treatment of dissimilar aluminum alloys by laser beam welding technique

NASA Astrophysics Data System (ADS)

Srinivas, B.; Krishna, N. Murali; Cheepu, Muralimohan; Sivaprasad, K.; Muthupandi, V.

2018-03-01

The present study mainly focuses on post weld heat treatment (PWHT) of AA5083 and AA6061 alloys by joining these using laser beam welding at three different laser power and two different beam spot sizes and three different welding speeds. Effects of these parameters on microstructural and mechanical properties like hardness, tensile strength were studied at PWHT condition and significant changes had been observed. The PWHT used was artificial aging technique. The microstructural observations revealed that there was a appreciable changes were taken place in the grain size. The microhardness observations proven that the change in the hardness profile in AA6061 was appreciable than in the AA5083. The tensile strength of 246 MPa was recorded as highest. The fractured surfaces observed are predominantly ductile in nature.

Comparing integral and incidental emotions: Testing insights from emotions as social information theory and attribution theory.

PubMed

Hillebrandt, Annika; Barclay, Laurie J

2017-05-01

Studies have indicated that observers can infer information about others' behavioral intentions from others' emotions and use this information in making their own decisions. Integrating emotions as social information (EASI) theory and attribution theory, we argue that the interpersonal effects of emotions are not only influenced by the type of discrete emotion (e.g., anger vs. happiness) but also by the target of the emotion (i.e., how the emotion relates to the situation). We compare the interpersonal effects of emotions that are integral (i.e., related to the situation) versus incidental (i.e., lacking a clear target in the situation) in a negotiation context. Results from 4 studies support our general argument that the target of an opponent's emotion influences the degree to which observers attribute the emotion to their own behavior. These attributions influence observers' inferences regarding the perceived threat of an impasse or cooperativeness of an opponent, which can motivate observers to strategically adjust their behavior. Specifically, emotion target influenced concessions for both anger and happiness (Study 1, N = 254), with perceived threat and cooperativeness mediating the effects of anger and happiness, respectively (Study 2, N = 280). Study 3 (N = 314) demonstrated the mediating role of attributions and moderating role of need for closure. Study 4 (N = 193) outlined how observers' need for cognitive closure influences how they attribute incidental anger. We discuss theoretical implications related to the social influence of emotions as well as practical implications related to the impact of personality on negotiators' biases and behaviors. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

"A Bayesian sensitivity analysis to evaluate the impact of unmeasured confounding with external data: a real world comparative effectiveness study in osteoporosis".

PubMed

Zhang, Xiang; Faries, Douglas E; Boytsov, Natalie; Stamey, James D; Seaman, John W

2016-09-01

Observational studies are frequently used to assess the effectiveness of medical interventions in routine clinical practice. However, the use of observational data for comparative effectiveness is challenged by selection bias and the potential of unmeasured confounding. This is especially problematic for analyses using a health care administrative database, in which key clinical measures are often not available. This paper provides an approach to conducting a sensitivity analyses to investigate the impact of unmeasured confounding in observational studies. In a real world osteoporosis comparative effectiveness study, the bone mineral density (BMD) score, an important predictor of fracture risk and a factor in the selection of osteoporosis treatments, is unavailable in the data base and lack of baseline BMD could potentially lead to significant selection bias. We implemented Bayesian twin-regression models, which simultaneously model both the observed outcome and the unobserved unmeasured confounder, using information from external sources. A sensitivity analysis was also conducted to assess the robustness of our conclusions to changes in such external data. The use of Bayesian modeling in this study suggests that the lack of baseline BMD did have a strong impact on the analysis, reversing the direction of the estimated effect (odds ratio of fracture incidence at 24 months: 0.40 vs. 1.36, with/without adjusting for unmeasured baseline BMD). The Bayesian twin-regression models provide a flexible sensitivity analysis tool to quantitatively assess the impact of unmeasured confounding in observational studies. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Hip fracture risk in relation to vitamin D supplementation and serum 25-hydroxyvitamin D levels: a systematic review and meta-analysis of randomised controlled trials and observational studies

PubMed Central

2010-01-01

Background Vitamin D supplementation for fracture prevention is widespread despite conflicting interpretation of relevant randomised controlled trial (RCT) evidence. This study summarises quantitatively the current evidence from RCTs and observational studies regarding vitamin D, parathyroid hormone (PTH) and hip fracture risk. Methods We undertook separate meta-analyses of RCTs examining vitamin D supplementation and hip fracture, and observational studies of serum vitamin D status (25-hydroxyvitamin D (25(OH)D) level), PTH and hip fracture. Results from RCTs were combined using the reported hazard ratios/relative risks (RR). Results from case-control studies were combined using the ratio of 25(OH)D and PTH measurements of hip fracture cases compared with controls. Original published studies of vitamin D, PTH and hip fracture were identified through PubMed and Web of Science databases, searches of reference lists and forward citations of key papers. Results The seven eligible RCTs identified showed no significant difference in hip fracture risk in those randomised to cholecalciferol or ergocalciferol supplementation versus placebo/control (RR = 1.13[95%CI 0.98-1.29]; 801 cases), with no significant difference between trials of <800 IU/day and ≥800 IU/day. The 17 identified case-control studies found 33% lower serum 25(OH)D levels in cases compared to controls, based on 1903 cases. This difference was significantly greater in studies with population-based compared to hospital-based controls (χ21 (heterogeneity) = 51.02, p < 0.001) and significant heterogeneity was present overall (χ216 (heterogeneity) = 137.9, p < 0.001). Serum PTH levels in hip fracture cases did not differ significantly from controls, based on ten case-control studies with 905 cases (χ29 (heterogeneity) = 149.68, p < 0.001). Conclusions Neither higher nor lower dose vitamin D supplementation prevented hip fracture. Randomised and observational data on vitamin D and hip fracture appear to differ. The reason for this is unclear; one possible explanation is uncontrolled confounding in observational studies. Post-fracture PTH levels are unrelated to hip fracture risk. PMID:20540727

A cross-national study to objectively evaluate the quality of diverse simulation approaches for undergraduate nursing students.

PubMed

Kable, Ashley K; Levett-Jones, Tracy L; Arthur, Carol; Reid-Searl, Kerry; Humphreys, Melanie; Morris, Sara; Walsh, Pauline; Witton, Nicola J

2018-01-01

The aim of this paper is to report the results of a cross-national study that evaluated a range of simulation sessions using an observation schedule developed from evidence-based quality indicators. Observational data were collected from 17 simulation sessions conducted for undergraduate nursing students at three universities in Australia and the United Kingdom. The observation schedule contained 27 questions that rated simulation quality. Data were collected by direct observation and from video recordings of the simulation sessions. Results indicated that the highest quality scores were for provision of learning objectives prior to the simulation session (90%) and debriefing (72%). Student preparatiosn and orientation (67%) and perceived realism and fidelity (67%) were scored lower than other components of the simulation sessions. This observational study proved to be an effective strategy to identify areas of strength and those needing further development to improve simulation sessions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Use of a mobile phone diary for observing weight management and related behaviours.

PubMed

Mattila, Elina; Lappalainen, Raimo; Pärkkä, Juha; Salminen, Jukka; Korhonen, Ilkka

2010-01-01

We studied self-observations related to weight management recorded with a Wellness Diary application on a mobile phone. The data were recorded by 27 participants in a 12-week study, which included a short weight management lecture followed by independent usage of the Wellness Diary. We studied the validity of self-observed weight, and behavioural changes and weight patterns related to weight management success. Self-observed weight data tended to underestimate pre- and poststudy measurements, but there were high correlations between the measures (r >or= 0.80). The amount of physical activity correlated significantly with weight loss (r = 0.44) as did different measures representing healthy changes in dietary behaviours (r >or= 0.45). Weight changes and the weekly rhythms of weight indicated a strong tendency to compensate for high-risk periods among successful weight-losers compared to unsuccessful ones. These preliminary results suggest that the mobile phone diary is a valid tool for observing weight management and related behaviours.