Local drinking water filters reduce diarrheal disease in Cambodia: a randomized, controlled trial of the ceramic water purifier.

PubMed

Brown, Joe; Sobsey, Mark D; Loomis, Dana

2008-09-01

A randomized, controlled intervention trial of two household-scale drinking water filters was conducted in a rural village in Cambodia. After collecting four weeks of baseline data on household water quality, diarrheal disease, and other data related to water use and handling practices, households were randomly assigned to one of three groups of 60 households: those receiving a ceramic water purifier (CWP), those receiving a second filter employing an iron-rich ceramic (CWP-Fe), and a control group receiving no intervention. Households were followed for 18 weeks post-baseline with biweekly follow-up. Households using either filter reported significantly less diarrheal disease during the study compared with a control group of households without filters as indicated by longitudinal prevalence ratios CWP: 0.51 (95% confidence interval [CI]: 0.41-0.63); CWP-Fe: 0.58 (95% CI: 0.47-0.71), an effect that was observed in all age groups and both sexes after controlling for clustering within households and within individuals over time.

Marginal and Random Intercepts Models for Longitudinal Binary Data with Examples from Criminology

ERIC Educational Resources Information Center

Long, Jeffrey D.; Loeber, Rolf; Farrington, David P.

2009-01-01

Two models for the analysis of longitudinal binary data are discussed: the marginal model and the random intercepts model. In contrast to the linear mixed model (LMM), the two models for binary data are not subsumed under a single hierarchical model. The marginal model provides group-level information whereas the random intercepts model provides…

Ready-to-use supplementary food increases fat mass and BMI in Haitian school-aged children.

PubMed

Iannotti, Lora L; Henretty, Nicole M; Delnatus, Jacques Raymond; Previl, Windy; Stehl, Tom; Vorkoper, Susan; Bodden, Jaime; Maust, Amanda; Smidt, Rachel; Nash, Marilyn L; Tamimie, Courtney A; Owen, Bridget C; Wolff, Patricia B

2015-04-01

In Haiti and other countries, large-scale investments in school feeding programs have been made with marginal evidence of nutrition outcomes. We aimed to examine the effectiveness of a fortified ready-to-use supplementary food (RUSF), Mamba, on reduced anemia and improved body composition in school-aged children compared to an unfortified cereal bar, Tablet Yo, and control groups. A cluster, randomized trial with children ages 3-13 y (n = 1167) was conducted in the north of Haiti. Six schools were matched and randomized to the control group, Tablet Yo group (42 g, 165 kcal), or Mamba group (50 g, 260 kcal, and >75% of the RDA for critical micronutrients). Children in the supplementation groups received the snack daily for 100 d, and all were followed longitudinally for hemoglobin concentrations, anthropometry, and bioelectrical impedance measures: baseline (December 2012), midline (March 2013), and endline (June 2013). Parent surveys were conducted at baseline and endline to examine secondary outcomes of morbidities and dietary intakes. Longitudinal regression modeling using generalized least squares and logit with random effects tested the main effects. At baseline,14.0% of children were stunted, 14.5% underweight, 9.1% thin, and 73% anemic. Fat mass percentage (mean ± SD) was 8.1% ± 4.3% for boys and 12.5% ± 4.4% for girls. In longitudinal modeling, Mamba supplementation increased body mass index z score (regression coefficient ± SEE) 0.25 ± 0.06, fat mass 0.45 ± 0.14 kg, and percentage fat mass 1.28% ± 0.27% compared with control at each time point (P < 0.001). Among boys, Mamba increased fat mass (regression coefficient ± SEE) 0.73 ± 0.19 kg and fat-free mass 0.62 ± 0.34 kg compared with control (P < 0.001). Mamba reduced the odds of developing anemia by 28% compared to control (adjusted OR: 0.72; 95% CI: 0.57, 0.91; P < 0.001). No treatment effect was found for hemoglobin concentration. To our knowledge, this is the first study to give evidence of body composition effects from an RUSF in school-aged children. © 2015 American Society for Nutrition.

Development of Children at Risk for Adverse Outcomes Participating in Early Intervention in Developing Countries: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Wallander, Jan L.; Bann, Carla M.; Biasini, Fred J.; Goudar, Shivaprasad S.; Pasha, Omrana; Chomba, Elwyn; McClure, Elizabeth; Carlo, Waldemar A.

2014-01-01

Background: Previous research has indicated positive effects of early developmental intervention (EDI) on the development of children in developing countries. Few studies, however, have examined longitudinally when differential treatment effects may be observed and whether differential outcomes are associated with exposure to different risk…

Parent-Infant Vocalisations at 12 Months Predict Psychopathology at 7 Years

ERIC Educational Resources Information Center

Allely, C. S.; Purves, D.; McConnachie, A.; Marwick, H.; Johnson, P.; Doolin, O.; Puckering, C.; Golding, J.; Gillberg, C.; Wilson, P.

2013-01-01

This study investigated the utility of adult and infant vocalisation in the prediction of child psychopathology. Families were sampled from the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. Vocalisation patterns were obtained from 180 videos (60 cases and 120 randomly selected sex-matched controls) of parent-infant…

Writing Week-Journals to Improve the Writing Quality of Fourth-Graders' Compositions

ERIC Educational Resources Information Center

Rosário, Pedro; Högemann, Julia; Núñez, José Carlos; Vallejo, Guillermo; Cunha, Jennifer; Oliveira, Vera; Fuentes, Sonia; Rodrigues, Celestino

2017-01-01

Students' writing problems are a global educational concern and is in need of particular attention. This study aims to examine the impact of providing extra writing opportunities (i.e., writing journals) on the quality of writing compositions. A longitudinal cluster-randomized controlled design using a multilevel modeling analysis with 182 fourth…

Power Analysis for Models of Change in Cluster Randomized Designs

ERIC Educational Resources Information Center

Li, Wei; Konstantopoulos, Spyros

2017-01-01

Field experiments in education frequently assign entire groups such as schools to treatment or control conditions. These experiments incorporate sometimes a longitudinal component where for example students are followed over time to assess differences in the average rate of linear change, or rate of acceleration. In this study, we provide methods…

Mechanisms in Psychosocial Interventions for Adults Living with Cancer: Opportunity for Integration of Theory, Research, and Practice

ERIC Educational Resources Information Center

Stanton, Annette L.; Luecken, Linda J.; MacKinnon, David P.; Thompson, Elizabeth H.

2013-01-01

Objective: The diagnosis and treatment of cancer are highly stressful experiences that can profoundly affect emotional and physical well-being. Hundreds of longitudinal investigations that identify risk and protective factors for psychological and physical adjustment in adults living with cancer and numerous randomized controlled psychosocial…

A Randomized Controlled Trial of a Multi-Dose Bystander Intervention Program Using Peer Education Theater

ERIC Educational Resources Information Center

McMahon, Sarah; Winter, Samantha C.; Palmer, Jane E.; Postmus, Judy L.; Peterson, N. Andrew; Zucker, Sharon; Koenick, RuthAnne

2015-01-01

This article reports findings from a longitudinal, experimental evaluation of a peer education theater program, Students Challenging Realities and Educating Against Myths (SCREAM) Theater. This study examines the impact of SCREAM Theater on a range of bystander-related outcomes (i.e. bystander intentions, bystander efficacy, perception of friend…

Longitudinal impact of the project PATHS on adolescent risk behavior: what happened after five years?

PubMed

Shek, Daniel T L; Yu, Lu

2012-01-01

The present study investigated the longitudinal impact of the Project PATHS, a large-scale curriculum-based positive youth development program in Hong Kong, on the development of adolescents' risk behavior over a period of five years. Using a longitudinal randomized controlled design, eight waves of data were collected from 19 experimental schools in which students participated in the Project PATHS (N = 2,850 at Wave 8) and 24 control schools without joining the Project PATHS (N = 3,640 at Wave 8). At each wave, students responded to measures assessing their current risk behaviors, including delinquency, use of different types of drug, and their intentions of participating in risk behaviors in the future. Results demonstrated that adolescents receiving the program exhibited significantly slower increases in delinquent behaviors and substance use as compared to the control participants. During two years after the completion of the program, differences in youth risk behaviors in the two groups still existed. These results suggest that the Project PATHS has long-term effect in preventing adolescent problem behavior through promoting positive youth development.

KiVa Anti-Bullying Program in Italy: Evidence of Effectiveness in a Randomized Control Trial.

PubMed

Nocentini, Annalaura; Menesini, Ersilia

2016-11-01

The present study aims to evaluate the effectiveness of the KiVa anti-bullying program in Italy through a randomized control trial of students in grades 4 and 6. The sample involved 2042 students (51 % female; grade 4, mean age = 8.85; ds = 0.43; grade 6, mean age = 10.93; ds = 0.50); 13 comprehensive schools were randomly assigned into intervention (KiVa) or control (usual school provision) conditions. Different outcomes (bullying, victimization, pro-bullying attitudes, pro-victim attitudes, empathy toward victims), analyses (longitudinal mixed model with multiple-item scales; longitudinal prevalence of bullies and victims using Olweus' single question), and estimates of effectiveness (Cohen's d; odds ratios) were considered in order to compare the Italian results with those from other countries. Multilevel models showed that KiVa reduced bullying and victimization and increased pro-victim attitudes and empathy toward the victim in grade 4, with effect sizes from 0.24 to 0.40. In grade 6, KiVa reduced bullying, victimization, and pro-bullying attitudes; the effects were smaller as compared to grade 4, yet significant (d ≥ 0.20). Finally, using Olweus dichotomous definition of bullies and victims, results showed that the odds of being a victim were 1.93 times higher for a control student than for a KiVa student in grade 4. Overall, the findings provide evidence of the effectiveness of the program in Italy; the discussion will focus on factors that influenced successfully the transportability of the KiVa program in Italy.

A Randomized Educational Intervention Trial to Determine the Effect of Online Education on the Quality of Resident-Delivered Care.

PubMed

Dolan, Brigid M; Yialamas, Maria A; McMahon, Graham T

2015-09-01

There is limited research on whether online formative self-assessment and learning can change the behavior of medical professionals. We sought to determine if an adaptive longitudinal online curriculum in bone health would improve resident physicians' knowledge, and change their behavior regarding prevention of fragility fractures in women. We used a randomized control trial design in which 50 internal medicine resident physicians at a large academic practice were randomized to either receive a standard curriculum in bone health care alone, or to receive it augmented with an adaptive, longitudinal, online formative self-assessment curriculum delivered via multiple-choice questions. Outcomes were assessed 10 months after the start of the intervention. Knowledge outcomes were measured by a multiple-choice question examination. Clinical outcomes were measured by chart review, including bone density screening rate, calculation of the fracture risk assessment tool (FRAX) score, and rate of appropriate bisphosphonate prescription. Compared to the control group, residents participating in the intervention had higher scores on the knowledge test at the end of the study. Bone density screening rates and appropriate use of bisphosphonates were significantly higher in the intervention group compared with the control group. FRAX score reporting did not differ between the groups. Residents participating in a novel adaptive online curriculum outperformed peers in knowledge of fragility fracture prevention and care practices to prevent fracture. Online adaptive education can change behavior to improve patient care.

A Randomized Educational Intervention Trial to Determine the Effect of Online Education on the Quality of Resident-Delivered Care

PubMed Central

Dolan, Brigid M.; Yialamas, Maria A.; McMahon, Graham T.

2015-01-01

Background There is limited research on whether online formative self-assessment and learning can change the behavior of medical professionals. Objective We sought to determine if an adaptive longitudinal online curriculum in bone health would improve resident physicians' knowledge, and change their behavior regarding prevention of fragility fractures in women. Methods We used a randomized control trial design in which 50 internal medicine resident physicians at a large academic practice were randomized to either receive a standard curriculum in bone health care alone, or to receive it augmented with an adaptive, longitudinal, online formative self-assessment curriculum delivered via multiple-choice questions. Outcomes were assessed 10 months after the start of the intervention. Knowledge outcomes were measured by a multiple-choice question examination. Clinical outcomes were measured by chart review, including bone density screening rate, calculation of the fracture risk assessment tool (FRAX) score, and rate of appropriate bisphosphonate prescription. Results Compared to the control group, residents participating in the intervention had higher scores on the knowledge test at the end of the study. Bone density screening rates and appropriate use of bisphosphonates were significantly higher in the intervention group compared with the control group. FRAX score reporting did not differ between the groups. Conclusions Residents participating in a novel adaptive online curriculum outperformed peers in knowledge of fragility fracture prevention and care practices to prevent fracture. Online adaptive education can change behavior to improve patient care. PMID:26457142

Mindfulness in the Maintenance of Cognitive Capacities in Alzheimer's Disease: A Randomized Clinical Trial.

PubMed

Quintana-Hernández, Domingo J; Miró-Barrachina, María T; Ibáñez-Fernández, Ignacio J; Pino, Angelo Santana-Del; Quintana-Montesdeoca, María P; Rodríguez-de Vera, Bienvenida; Morales-Casanova, David; Pérez-Vieitez, María Del Carmen; Rodríguez-García, Javier; Bravo-Caraduje, Noelia

2016-01-01

The Canary Islands longitudinal study on non-pharmacological treatments showed the overall effectiveness of mindfulness in Alzheimer's disease (AD). However, no specific data on the maintenance of cognitive capacities were presented. To determine whether the practice of mindfulness modifies the course of cognitive impairment in AD. Longitudinal, non-inferiority and equivalence, randomized clinical trial, repeated-measures design, with three experimental groups and one control group. Patients with AD who voluntarily attended the Lidia García Foundation (n = 502). Only those who were treated with donepezil and MMSE ≥18 were included (n = 120). Over a two-year period, each group carried out three weekly sessions of stimulation based on mindfulness, cognitive stimulation therapy, and progressive muscle relaxation. Cognitive assessment CAMDEX-R (MMSE and CAMCOG). Repeated-measures ANOVA (p <  0.05) and the effect size Cohen's d were performed. The mindfulness group showed significant scores compared with the control and muscle relaxation groups (p <  0.05), while mindfulness and cognitive stimulation therapy were equivalent (p≥0.05). Group cognitive stimulation evolved better than the control (p <  0.05) group but not better than the muscle relaxation group (p≥0.05). The effect size compared over two years was large for the mindfulness group (p≥0.80), moderate for the relaxation group (p≥0.50), and low for the cognitive stimulation group (p≥0.20). The practice of mindfulness maintained cognitive function over a period of two years. This longitudinal study suggests that mindfulness can be used as a non-pharmacological treatment to slow cognitive impairment in AD.

Neuroprotection after a first episode of mania: a randomized controlled maintenance trial comparing the effects of lithium and quetiapine on grey and white matter volume

PubMed Central

Berk, M; Dandash, O; Daglas, R; Cotton, S M; Allott, K; Fornito, A; Suo, C; Klauser, P; Liberg, B; Henry, L; Macneil, C; Hasty, M; McGorry, P; Pantelis, Cs; Yücel, M

2017-01-01

Lithium and quetiapine are effective treatments for bipolar disorder, but their potential neuroprotective effects in humans remain unclear. A single blinded equivalence randomized controlled maintenance trial was conducted in a prospective cohort of first-episode mania (FEM) patients (n=26) to longitudinally compare the putative protective effects of lithium and quetapine on grey and white matter volume. A healthy control sample was also collected (n=20). Using structural MRI scans, voxel-wise grey and white matter volumes at baseline and changes over time in response to treatment were investigated. Patients were assessed at three time points (baseline, 3 and 12-month follow-up), whereas healthy controls were assessed at two time points (baseline and 12-month follow-up). Patients were randomized to lithium (serum level 0.6 mmol l−1, n=20) or quetiapine (flexibly dosed up to 800 mg per day, n=19) monotherapy. At baseline, compared with healthy control subjects, patients with FEM showed reduced grey matter in the orbitofrontal cortex, anterior cingulate, inferior frontal gyrus and cerebellum. In addition, patients had reduced internal capsule white matter volume bilaterally (t1,66>3.20, P<0.01). Longitudinally, there was a significant treatment × time effect only in the white matter of the left internal capsule (F2,112=8.54, P<0.01). Post hoc testing showed that, compared with baseline, lithium was more effective than quetiapine in slowing the progression of white matter volume reduction after 12 months (t1,24=3.76, P<0.01). Our data support the role of lithium but not quetiapine therapy in limiting white matter reduction early in the illness course after FEM. PMID:28117843

Estimating correlation between multivariate longitudinal data in the presence of heterogeneity.

PubMed

Gao, Feng; Philip Miller, J; Xiong, Chengjie; Luo, Jingqin; Beiser, Julia A; Chen, Ling; Gordon, Mae O

2017-08-17

Estimating correlation coefficients among outcomes is one of the most important analytical tasks in epidemiological and clinical research. Availability of multivariate longitudinal data presents a unique opportunity to assess joint evolution of outcomes over time. Bivariate linear mixed model (BLMM) provides a versatile tool with regard to assessing correlation. However, BLMMs often assume that all individuals are drawn from a single homogenous population where the individual trajectories are distributed smoothly around population average. Using longitudinal mean deviation (MD) and visual acuity (VA) from the Ocular Hypertension Treatment Study (OHTS), we demonstrated strategies to better understand the correlation between multivariate longitudinal data in the presence of potential heterogeneity. Conditional correlation (i.e., marginal correlation given random effects) was calculated to describe how the association between longitudinal outcomes evolved over time within specific subpopulation. The impact of heterogeneity on correlation was also assessed by simulated data. There was a significant positive correlation in both random intercepts (ρ = 0.278, 95% CI: 0.121-0.420) and random slopes (ρ = 0.579, 95% CI: 0.349-0.810) between longitudinal MD and VA, and the strength of correlation constantly increased over time. However, conditional correlation and simulation studies revealed that the correlation was induced primarily by participants with rapid deteriorating MD who only accounted for a small fraction of total samples. Conditional correlation given random effects provides a robust estimate to describe the correlation between multivariate longitudinal data in the presence of unobserved heterogeneity (NCT00000125).

Longitudinal associations of intimate partner violence attitudes and perpetration: Dyadic couples data from a randomized controlled trial in rural India

PubMed Central

Shakya, Holly B.; Fleming, Paul; Saggurti, Niranjan; Donta, Balaiah; Silverman, Jay; Raj, Anita

2018-01-01

We conducted longitudinal analyses examining the associations between intimate partner violence (IPV) attitudes and women’s reported IPV in couples (N = 762) using 3 waves of data from a randomized controlled trial in Maharashtra, India. We found that, between Waves 1 and 2, men’s and women’s acceptance of IPV in the overall population decreased significantly while reports of IPV increased. These changes, we hypothesize, are evidence of an exogenous shock, possibly a high profile rape in Delhi in December 2012, that may have impacted the entire population. Cross-sectional associations between men’s attitudes towards IPV and reported IPV were not significant in Wave 1, while positively and significantly associated in Waves 2 and 3. Longitudinal analysis showed that reduction in men’s acceptance of IPV between Waves 1 and 2 was associated with a lower likelihood of reported IPV in Wave 3. Women’s Wave 1 acceptance of IPV was positively associated with reported IPV in the Wave 1 cross-sectional analysis, while Wave 2 and Wave 3 measures of IPV acceptance were negatively associated with reported IPV in Waves 2 and 3 respectively. Longitudinal analyses of the change in women’s attitudes towards IPV from Wave 1 to 2 and reported IPV in Wave 3 were insignificant. However, When women first reported IPV in Waves 2 or 3 they were less likely to report acceptance of IPV in that same wave. Findings suggest that changes in husbands’ IPV acceptance is predictive of subsequent IPV, while newly experienced IPV predicts decreased IPV acceptance for women. Wave 2 and Wave 3 results were significant for the control group only, evidence that the intervention affected those associations, potentially changing attitudes more quickly than behavior. We recommend interventions that expose community opposition to IPV as a new social norm, and analysis of how the 2012 Delhi rape case may have affected these norms. PMID:28260640

Outcome of a Tobacco Use Cessation Randomized Trial with High-School Students

PubMed Central

BURTON, Dee; CHAKRAVORTY, B.; WEEKS, K.; FLAY, B. R.; DENT, C.; STACY, A.; SUSSMAN, S.

2009-01-01

This study analyzed quantitative data on tobacco use and dependency for 3,589 high-school students, qualitative data for 448 students, and outcome data for a randomized trial comparing the efficacy of two cessation interventions and a control condition for 337 students. Data were collected from 1988 through 1992 in California and Illinois as part of a larger longitudinal study. Smokeless tobacco users, but not smokers, were more likely than controls to maintain cessation for 4 months: biochemically validated cessation at 4 months was 6.5% versus 3.2% for smokers and 14.3% versus 0.0% for smokeless tobacco users. Implications and limitations are discussed. PMID:19938938

An Experimental Study Comparing English-Only and Transitional Bilingual Education on Spanish-Speaking Preschoolers' Early Literacy Development

ERIC Educational Resources Information Center

Duran, Lillian K.; Roseth, Cary J.; Hoffman, Patricia

2010-01-01

A longitudinal, experimental-control design was used to test the hypothesis that native language instruction enhances English language learner's (ELL's) native language and literacy development without significant cost to English development. In this study, 31 Spanish-speaking preschoolers (aged 38-48 months) were randomly assigned to two Head…

The Impact of TCARE[R] on Service Recommendation, Use, and Caregiver Well-Being

ERIC Educational Resources Information Center

Kwak, Jung; Montgomery, Rhonda J. V.; Kosloski, Karl; Lang, Josh

2011-01-01

Purpose of the Study: Findings are reported from a study that examined the effects of the Tailored Caregiver Assessment and Referral (TCARE[R]) protocol, a care management process designed to help family caregivers, on care planning and caregiver outcomes. Design and Methods: A longitudinal, randomized controlled trial was conducted with 97…

Longitudinal Effects of Induction on Teaching Skills and Attrition Rates of Beginning Teachers

ERIC Educational Resources Information Center

Helms-Lorenz, Michelle; van de Grift, Wim; Maulana, Ridwan

2016-01-01

The teaching profession faces a shortage as well as a decline of teaching skills. A possible way to mitigate this is to implement evidence-based induction arrangements. Seventy-one schools with 338 beginning secondary education teachers were randomly allocated to an experimental or a control group. The experimental schools used induction…

Prevention of Cyberbullying and Cyber Victimization: Evaluation of the ViSC Social Competence Program

ERIC Educational Resources Information Center

Gradinger, Petra; Yanagida, Takuya; Strohmeier, Dagmar; Spiel, Christiane

2015-01-01

It is well-documented that cyberbullying and victimization co-occur with traditional forms indicating that they share similar mechanisms. Therefore, it was hypothesized that the general antibullying program ViSC might also be effective in tackling these new forms of bullying. A longitudinal randomized control group design has been applied to…

Longitudinal Findings from the Early College High School Initiative Impact Study

ERIC Educational Resources Information Center

Haxton, Clarisse; Song, Mengli; Zeiser, Kristina; Berger, Andrea; Turk-Bicakci, Lori; Garet, Michael S.; Knudson, Joel; Hoshen, Gur

2016-01-01

This study is a randomized controlled trial that assessed the impact of Early College High Schools on students' high school graduation, college enrollment, and college degree attainment, as well as students' high school experiences using extant data and survey data. The study included 10 Early Colleges that enrolled students in Grades 9 to 12 in…

National Implementation of an Evidence-Based HIV Prevention and Reproductive Health Program for Bahamian Youth

ERIC Educational Resources Information Center

Knowles, Valerie; Kaljee, Linda; Deveaux, Lynette; Lunn, Sonja; Rolle, Glenda; Stanton, Bonita

2012-01-01

A wide range of behavioral prevention interventions have been demonstrated through longitudinal, randomized controlled trials to reduce sexual risk behaviors. Many of these interventions have been made available at little cost for implementation on a public health scale. However, efforts to utilize such programs typically have been met with a…

Children's Executive Function and High-Calorie, Low-Nutrient Food Intake: Mediating Effects of Child-Perceived Adult Fast Food Intake

ERIC Educational Resources Information Center

Tate, Eleanor B.; Unger, Jennifer B.; Chou, Chih-Ping; Spruijt-Metz, Donna; Pentz, Mary Ann; Riggs, Nathaniel R.

2015-01-01

Objective: This study tested the relationships among child executive function (EF), child-perceived parent fast food intake, and child self-reported subsequent consumption of high-calorie, low-nutrient (HCLN) food. Design: One year and 6-month longitudinal observation from a larger randomized controlled trial. Setting. Southern California…

Stress management and mind-body medicine: a randomized controlled longitudinal evaluation of students' health and effects of a behavioral group intervention at a middle-size German university (SM-MESH).

PubMed

Esch, Tobias; Sonntag, Ulrike; Esch, Sonja Maren; Thees, Stefanie

2013-01-01

Student life can be stressful. Hence, we started a regular mind-body medical stress management program in 2006. By today, more than 500 students took part and evaluations showed significant results, especially with regard to a reduction of stress warning signals. For further analysis, we now decided to run a randomized controlled longitudinal trial. Participating students at Coburg University were randomized into an intervention (n = 24) or a waitlist control group (n = 19). The intervention group completed 3 sets (pre/post/follow-up) and the control group 2 sets (pre/post) of self-administered questionnaires. The questionnaires included: SF-12 Health Survey, Perceived Stress Scale (PSS), Sense of Coherence (SOC-L9), Visual Analogue Scale (VAS) concerning stress, and the Stress Warning Signs (SWS) scale. Randomly selected participants of the intervention group were also queried in qualitative interviews. The intervention consisted of an 8 week stress management group program (mind-body medical stress reduction - MBMSR). Follow-up measures were taken after 6 months. Virtually, no drop-out occurred. Our study showed significant effects in the intervention group concerning SF-12 Mental Component Scale (p = 0.05), SF-12 Physical Component Scale (p = 0.001), VAS (in general, p = 0.001) and SWS (emotional reactions, p <0.001), underlined by qualitative results, which showed a higher quality of life. The effectiveness of an MBMSR program in a group of supposedly healthy students could be demonstrated. Findings suggest that stress management might be given importance at universities that care for the performance, the quality of life, and stress-health status of their students, acknowledging and accounting for the challenging circumstances of university life, as well as the specific needs of the modern student population. Copyright © 2013 S. Karger AG, Basel.

Perceived control moderates the relationship between social capital and binge drinking: longitudinal findings from the Montreal Neighborhood Networks and Health Aging (MoNNET-HA) panel.

PubMed

Child, Stephanie; Stewart, Steven; Moore, Spencer

2017-02-01

Cross-sectional research suggests social capital has negative consequences for problem drinking behaviors. Previous studies have suggested psychosocial resources, including perceived control, may buffer this association. Little research has examined whether such relationships persist longitudinally. Random effects models examined between-person relationships among problem drinking, social capital, and perceived control, and whether perceived control moderated the relationship between social capital and drinking. Fixed effects models assessed whether social capital and perceived control were related to changes in problem drinking. Greater network capital and generalized trust predicted higher odds of binge drinking (RR = 1.08; 95% CI = 1.03-1.12 and RR = 1.23; 95% CI = 1.03-1.48, respectively). Perceived control moderated the positive association of network capital with binge drinking (RR = 0.91; 95% CI = 0.87-0.96). The present findings support previous notions about the complex role of social capital on health, and offer new insights on the role of perceived control on problem drinking. Copyright © 2016 Elsevier Inc. All rights reserved.

Beneficial effects of growth hormone treatment on cognition in children with Prader-Willi syndrome: a randomized controlled trial and longitudinal study.

PubMed

Siemensma, Elbrich P C; Tummers-de Lind van Wijngaarden, Roderick F A; Festen, Dederieke A M; Troeman, Zyrhea C E; van Alfen-van der Velden, A A E M Janielle; Otten, Barto J; Rotteveel, Joost; Odink, Roelof J H; Bindels-de Heus, G C B Karen; van Leeuwen, Mariette; Haring, Danny A J P; Oostdijk, Wilma; Bocca, Gianni; Mieke Houdijk, E C A; van Trotsenburg, A S Paul; Hoorweg-Nijman, J J Gera; van Wieringen, Hester; Vreuls, René C F M; Jira, Petr E; Schroor, Eelco J; van Pinxteren-Nagler, Evelyn; Willem Pilon, Jan; Lunshof, L Bert; Hokken-Koelega, Anita C S

2012-07-01

Knowledge about the effects of GH treatment on cognitive functioning in children with Prader-Willi syndrome (PWS) is limited. Fifty prepubertal children aged 3.5 to 14 yr were studied in a randomized controlled GH trial during 2 yr, followed by a longitudinal study during 4 yr of GH treatment. Cognitive functioning was measured biennially by short forms of the WPPSI-R or WISC-R, depending on age. Total IQ (TIQ) score was estimated based on two subtest scores. During the randomized controlled trial, mean sd scores of all subtests and mean TIQ score remained similar compared to baseline in GH-treated children with PWS, whereas in untreated controls mean subtest sd scores and mean TIQ score decreased and became lower compared to baseline. This decline was significant for the Similarities (P = 0.04) and Vocabulary (P = 0.03) subtests. After 4 yr of GH treatment, mean sd scores on the Similarities and Block design subtests were significantly higher than at baseline (P = 0.01 and P = 0.03, respectively), and scores on Vocabulary and TIQ remained similar compared to baseline. At baseline, children with a maternal uniparental disomy had a significantly lower score on the Block design subtest (P = 0.01) but a larger increment on this subtest during 4 yr of GH treatment than children with a deletion. Lower baseline scores correlated significantly with higher increases in Similarities (P = 0.04) and Block design (P < 0.0001) sd scores. Our study shows that GH treatment prevents deterioration of certain cognitive skills in children with PWS on the short term and significantly improves abstract reasoning and visuospatial skills during 4 yr of GH treatment. Furthermore, children with a greater deficit had more benefit from GH treatment.

Prevention of adolescent problem behavior: longitudinal impact of the Project P.A.T.H.S. in Hong Kong.

PubMed

Shek, Daniel T L; Yu, Lu

2011-03-07

The present study attempts to examine the longitudinal impact of a curriculum-based positive youth development program, entitled the Project P.A.T.H.S. (Positive Adolescent Training through Holistic Social Programmes), on adolescent problem behavior in Hong Kong. Using a longitudinal randomized group design, six waves of data were collected from 19 experimental schools (n = 3,797 at Wave 1) in which students participated in the Project P.A.T.H.S. and 24 control schools (n = 4,049 at Wave 1). At each wave, students responded to questions asking about their current problem behaviors, including delinquency and use of different types of drugs, and their intentions of engaging in such behaviors in the future. Results based on individual growth curve modeling generally showed that the participants displayed lower levels of substance abuse and delinquent behavior than did the control students. Participants who regarded the program to be helpful also showed lower levels of problem behavior than did the control students. The present findings suggest that the Project P.A.T.H.S. is effective in preventing adolescent problem behavior in the junior secondary school years.

The Efficacy of a Home-School Intervention for Preschoolers with Challenging Behaviors: A Randomized Controlled Trial of Preschool First Step to Success

ERIC Educational Resources Information Center

Feil, Edward G.; Frey, Andy; Walker, Hill M.; Small, Jason W.; Seeley, John R.; Golly, Annemieke; Forness, Steven R.

2014-01-01

The field of early intervention is currently faced with the challenge of reducing the prevalence of antisocial behavior in children. Longitudinal outcomes research indicates that increased antisocial behavior and impairments in social competence skills during the preschool years often serve as harbingers of future adjustment problems in a number…

The Impact of Community-Based Outreach on Psychological Distress and Victim Safety in Women Exposed to Intimate Partner Abuse

ERIC Educational Resources Information Center

DePrince, Anne P.; Labus, Jennifer; Belknap, Joanne; Buckingham, Susan; Gover, Angela

2012-01-01

Objective: Using a longitudinal, randomized controlled trial, this study assessed the impact of a community-based outreach versus a more traditional criminal justice system-based referral program on women's distress and safety following police-reported intimate partner abuse (IPA). Method: Women (N = 236 women) with police-reported IPA were…

The Effect of Integrated Basic Education Programs on Women's Social and Economic Well-Being in Bolivia.

ERIC Educational Resources Information Center

Hua, Haiyan; Burchfield, Shirley

A large-scale longitudinal study in Bolivia examined the relationship between adult women's basic education and their social and economic well-being and development. A random sample of 1,600 participants and 600 nonparticipants, aged 15-45, was tracked for 3 years (the final sample included 717 participants and 224 controls). The four adult…

Theory of Planned Behavior: Sensitivity and Specificity in Predicting Graduation and Drop-Out among College and University Students?

ERIC Educational Resources Information Center

Fichten, Catherine S.; Amsel, Rhonda; Jorgensen, Mary; Nguyen, Mai Nhu; Budd, Jillian; King, Laura; Jorgensen, Shirley; Asuncion, Jennison

2016-01-01

We examined sensitivity and specificity when using the three theory of planned behavior (TPB) scales (Perceived Behavioral Control, Subjective Norms, Attitude) to predict graduation and drop-out in a longitudinal study of 252 college and university students with disabilities and in a separate cross-sectional study of a random sample of 1380…

Effects of Simulated Interventions to Improve School Entry Academic Skills on Socioeconomic Inequalities in Educational Achievement

ERIC Educational Resources Information Center

Chittleborough, Catherine R.; Mittinty, Murthy N.; Lawlor, Debbie A.; Lynch, John W.

2014-01-01

Randomized controlled trial evidence shows that interventions before age 5 can improve skills necessary for educational success; the effect of these interventions on socioeconomic inequalities is unknown. Using trial effect estimates, and marginal structural models with data from the Avon Longitudinal Study of Parents and Children (n = 11,764,…

Comparison of torsional and microburst longitudinal phacoemulsification: a prospective, randomized, masked clinical trial.

PubMed

Vasavada, Abhay R; Raj, Shetal M; Patel, Udayan; Vasavada, Vaishali; Vasavada, Viraj

2010-01-01

To compare intraoperative performance and postoperative outcome of three phacoemulsification technologies in patients undergoing microcoaxial phacoemulsification through 2.2-mm corneal incisions. The prospective, randomized, single-masked study included 360 eyes randomly assigned to torsional (Infiniti Vision System; Alcon Laboratories, Fort Worth, TX), microburst with longitudinal (Infiniti), or microburst with longitudinal (Legacy Everest, Alcon Laboratories) ultrasound. Assessments included surgical clock time, fluid volume, and intraoperative complications, central corneal thickness on day 1 and months 1 and 3 postoperatively, and endothelial cell density at 3 months postoperatively. Comparisons among groups were conducted. Torsional ultrasound required significantly less surgical clock time and fluid volume than the other groups. There were no intraoperative complications. Change in central corneal thickness and endothelial cell loss was significantly lower in the torsional ultrasound group at all postoperative visits (P < .001, Kruskal-Wallis test) compared to microburst longitudinal ultrasound modalities. Torsional ultrasound demonstrated quantitatively superior intraoperative performance and showed less increase in corneal thickness and less endothelial cell loss compared to microburst longitudinal ultrasound. Copyright 2010, SLACK Incorporated.

Effects of the TCARE® intervention on caregiver burden and depressive symptoms: preliminary findings from a randomized controlled study.

PubMed

Montgomery, Rhonda J V; Kwak, Jung; Kosloski, Karl; O'Connell Valuch, Katharine

2011-09-01

We examined the effects of a manualized care management protocol specifically designed for care managers working with caregivers, the Tailored Caregiver Assessment and Referral® (TCARE®) protocol, on caregiver identity discrepancy, burden, and depressive symptoms. Preliminary data from a longitudinal, randomized, controlled intervention study with 266 family caregivers served by 52 care managers in 4 states were analyzed using repeated measures random effects regression procedures. Caregivers in the intervention and control groups were repeatedly assessed for up to 9 months on caregiver identity discrepancy, 3 areas of caregiving burden-objective, relationship, and stress burdens; depression; and intention for nursing home placement. We found significant group by time interaction effects for caregiver identity discrepancy, relationship burden, stress burden, depression, and intention for nursing home placement. Caregivers in the intervention group experienced significant improvement on these measures, whereas caregivers in the control group worsened on these measures over time. The preliminary findings provide strong support for effectiveness of the TCARE® protocol on improving caregiver well-being and mental health outcomes.

Effects of the TCARE® Intervention on Caregiver Burden and Depressive Symptoms: Preliminary Findings From a Randomized Controlled Study

PubMed Central

Kwak, Jung; Kosloski, Karl; O’Connell Valuch, Katharine

2011-01-01

Objectives. We examined the effects of a manualized care management protocol specifically designed for care managers working with caregivers, the Tailored Caregiver Assessment and Referral® (TCARE®) protocol, on caregiver identity discrepancy, burden, and depressive symptoms. Methods. Preliminary data from a longitudinal, randomized, controlled intervention study with 266 family caregivers served by 52 care managers in 4 states were analyzed using repeated measures random effects regression procedures. Caregivers in the intervention and control groups were repeatedly assessed for up to 9 months on caregiver identity discrepancy, 3 areas of caregiving burden—objective, relationship, and stress burdens; depression; and intention for nursing home placement. Results. We found significant group by time interaction effects for caregiver identity discrepancy, relationship burden, stress burden, depression, and intention for nursing home placement. Caregivers in the intervention group experienced significant improvement on these measures, whereas caregivers in the control group worsened on these measures over time. Discussion. The preliminary findings provide strong support for effectiveness of the TCARE® protocol on improving caregiver well-being and mental health outcomes. PMID:21840840

Using a shared parameter mixture model to estimate change during treatment when termination is related to recovery speed.

PubMed

Gottfredson, Nisha C; Bauer, Daniel J; Baldwin, Scott A; Okiishi, John C

2014-10-01

This study demonstrates how to use a shared parameter mixture model (SPMM) in longitudinal psychotherapy studies to accommodate missingness that is due to a correlation between rate of improvement and termination of therapy. Traditional growth models assume that such a relationship does not exist (i.e., assume that data are missing at random) and produce biased results if this assumption is incorrect. We used longitudinal data from 4,676 patients enrolled in a naturalistic study of psychotherapy to compare results from a latent growth model and an SPMM. In this data set, estimates of the rate of improvement during therapy differed by 6.50%-6.66% across the two models, indicating that participants with steeper trajectories left psychotherapy earliest, thereby potentially biasing inference for the slope in the latent growth model. We conclude that reported estimates of change during therapy may be underestimated in naturalistic studies of therapy in which participants and their therapists determine the end of treatment. Because non-randomly missing data can also occur in randomized controlled trials or in observational studies of development, the utility of the SPMM extends beyond naturalistic psychotherapy data. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Revisiting typhoid fever surveillance in low and middle income countries: lessons from systematic literature review of population-based longitudinal studies.

PubMed

Mogasale, Vittal; Mogasale, Vijayalaxmi V; Ramani, Enusa; Lee, Jung Seok; Park, Ju Yeon; Lee, Kang Sung; Wierzba, Thomas F

2016-01-29

The control of typhoid fever being an important public health concern in low and middle income countries, improving typhoid surveillance will help in planning and implementing typhoid control activities such as deployment of new generation Vi conjugate typhoid vaccines. We conducted a systematic literature review of longitudinal population-based blood culture-confirmed typhoid fever studies from low and middle income countries published from 1(st) January 1990 to 31(st) December 2013. We quantitatively summarized typhoid fever incidence rates and qualitatively reviewed study methodology that could have influenced rate estimates. We used meta-analysis approach based on random effects model in summarizing the hospitalization rates. Twenty-two papers presented longitudinal population-based and blood culture-confirmed typhoid fever incidence estimates from 20 distinct sites in low and middle income countries. The reported incidence and hospitalizations rates were heterogeneous as well as the study methodology across the sites. We elucidated how the incidence rates were underestimated in published studies. We summarized six categories of under-estimation biases observed in these studies and presented potential solutions. Published longitudinal typhoid fever studies in low and middle income countries are geographically clustered and the methodology employed has a potential for underestimation. Future studies should account for these limitations.

A Randomized Trial of Longitudinal Effects of Low-Intensity Responsivity Education/Prelinguistic Milieu Teaching

ERIC Educational Resources Information Center

Warren, Steven F.; Fey, Marc E.; Finestack, Lizbeth, H.; Brady, Nancy C.; Bredin-Oja, Shelley L.; Fleming, Kandace K.

2008-01-01

Purpose: To evaluate the longitudinal effects of a 6-month course of responsivity education (RE)/prelinguistic milieu teaching (PMT) for young children with developmental delay. Method: Fifty-one children, age 24-33 months, with fewer than 10 expressive words were randomly assigned to early-treatment/no-treatment groups. All treatment was added as…

Applying New Methods to the Measurement of Fidelity of Implementation: Examining the Critical Ingredients of the Responsive Classroom Approach in Relation to Mathematics Achievement

ERIC Educational Resources Information Center

Abry, Tashia D. S.; Rimm-Kaufman, Sara E.; Larsen, Ross A.; Brewer, Alix J.

2011-01-01

The present study examines data collected during the second year of a three-year longitudinal cluster randomized controlled trial, the Responsive Classroom Efficacy Study (RCES). In the context of and RCT, the research questions address naturally occurring variability in the independent variables of interest (i.e., teachers' (fidelity of…

"Learn Young, Learn Fair", a Stress Management Program for Fifth and Sixth Graders: Longitudinal Results from an Experimental Study

ERIC Educational Resources Information Center

Kraag, Gerda; Van Breukelen, Gerard J. P.; Kok, Gerjo; Hosman, Clemens

2009-01-01

Background: This study examined the effects of a universal stress management program (Learn Young, Learn Fair) on stress, coping, anxiety and depression in fifth and sixth grade children. Methods: Fifty-two schools (1467 children) participated in a clustered randomized controlled trial. Data was collected in the fall of 2002, the spring of 2003,…

A Family Focused Randomized Controlled Trial to Prevent Adolescent Alcohol and Tobacco Use: The Moderating Roles of Positive Parenting and Adolescent Gender

ERIC Educational Resources Information Center

Jones, Deborah J.; Olson, Ardis L.; Forehand, Rex; Gaffney, Cecelia A.; Zens, Michael S.; Bau, J. J.

2005-01-01

Four years of longitudinal data from 2,153 families with a 5th- or 6th-grade preadolescent participating in a family-focused pediatric primary-care-based prevention program were used to examine whether prevention effects were moderated by positive parenting and/or adolescent gender. Alcohol and tobacco use, internalizing problems, and…

Using Social-Emotional and Character Development to Improve Academic Outcomes: A Matched-Pair, Cluster-Randomized Controlled Trial in Low-Income, Urban Schools

ERIC Educational Resources Information Center

Bavarian, Niloofar; Lewis, Kendra M.; DuBois, David L.; Acock, Alan; Vuchinich, Samuel; Silverthorn, Naida; Snyder, Frank J.; Day, Joseph; Ji, Peter; Flay, Brian R.

2013-01-01

Background: School-based social-emotional and character development (SECD) programs can influence not only SECD but also academic-related outcomes. This study evaluated the impact of one SECD program, Positive Action (PA), on educational outcomes among low-income, urban youth. Methods: The longitudinal study used a matched-pair, cluster-randomized…

WWC Review of the Report "Efficacy of the Responsive Classroom Approach: Results from a 3-Year, Longitudinal Randomized Controlled Trial." What Works Clearinghouse Single Study Review

ERIC Educational Resources Information Center

What Works Clearinghouse, 2015

2015-01-01

The study authors examined the impact of "Responsive Classroom," a professional development program for teachers, on student achievement. This study took place in a large, ethnically and socioeconomically diverse district in a mid-Atlantic state. The intervention was implemented during 3 school years from 2008 to 2011. Study authors…

Efficacy and Safety of Atomoxetine in the Treatment of Children and Adolescents with Attention Deficit Hyperactivity Disorder

PubMed Central

Kohn, Michael R.; Tsang, Tracey W.; Clarke, Simon D.

2012-01-01

Several non-stimulant medications have been used in the treatment of attention deficit hyperactivity disorder (ADHD). Atomoxetine, was introduced in 2002. The safety and efficacy of atomoxetine in the treatment of ADHD for children, adolescents, and adults has been evaluated in over 4000 patients in randomized controlled studies and double blinded studies as well as in recent large longitudinal studies. This paper provides an updated summary of the literature on atomoxetine, particularly in relation to findings on the short- and long-term safety of atomoxetine in children and adolescents arising from recent large longitudinal cohort studies. Information is presented about the efficacy, safety, and tolerability of this medication. PMID:23641171

The influence of a learning object with virtual simulation for dentistry: A randomized controlled trial.

PubMed

Tubelo, Rodrigo Alves; Branco, Vicente Leitune Castelo; Dahmer, Alessandra; Samuel, Susana Maria Werner; Collares, Fabrício Mezzomo

2016-01-01

The study aimed to evaluate the influence of virtual learning object (VLO) in the theoretical knowledge and skill practice of undergraduate dentistry students as it relates to zinc phosphate cement (ZPC). Only students enrolled in the dentistry course the course were included in the trial. Forty-six students received a live class regarding ZPC and were randomized by electronic sorting into the following 4 groups: VLO Immediate (GIVLOn=9), VLO longitudinal (GLVLOn=15) and two control groups without VLO (GICn=9 and GLCn=13). The immediate groups had access to VLO or a book for 20 min before the ability assessment, whereas the longitudinal groups had access to VLO or a book for 15 days. A pre- and posttest on theoretical knowledge and two laboratory skill tests, evaluated by blinded examiners, were performed regarding zinc phosphate cement manipulation in all groups. The students who used the VLO obtained better results in all the tests performed than the control students. The theoretical posttest showed a significant difference between the longitudinal groups, GLC (6.0 ± 1.15) and GLVLO (7.33 ± 1.43). The lower film thickness presented with a significant difference in the VLO groups: (GIC 25 ± 9.3) and GIVLO (16.24 ± 5.17); GLC (50 ± 27.08) and GLVLO (22.5±9.65). The higher setting time occurred in the VLO groups, and the immediate group showed a significant difference (GIC 896 ± 218.90) and GIVLO (1138.5 ± 177.95). The ZPC manipulated by the students who used the VLO had better mechanical properties in the laboratory tests. Therefore, the groups that used the VLO had clinical handling skills superior to its controls and greater retention of knowledge after 15 days. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Longitudinal Pediatric Palliative Care: Quality of Life & Spiritual Struggle (FACE): design and methods.

PubMed

Dallas, Ronald H; Wilkins, Megan L; Wang, Jichuan; Garcia, Ana; Lyon, Maureen E

2012-09-01

As life expectancy increases for adolescents ever diagnosed with AIDS due to treatment advances, the optimum timing of advance care planning is unclear. Left unprepared for end-of-life (EOL) decisions, families may encounter miscommunication and disagreements, resulting in families being charged with neglect, court battles and even legislative intervention. Advanced care planning (ACP) is a valuable tool rarely used with adolescents. The Longitudinal Pediatric Palliative Care: Quality of Life & Spiritual Struggle study is a two-arm, randomized controlled trial assessing the effectiveness of a disease specific FAmily CEntered (FACE) advanced care planning intervention model among adolescents diagnosed with AIDS, aimed at relieving psychological, spiritual, and physical suffering, while maximizing quality of life through facilitated conversations about ACP. Participants will include 130 eligible dyads (adolescent and family decision-maker) from four urban cities in the United States, randomized to either the FACE intervention or a Healthy Living Control. Three 60-minute sessions will be conducted at weekly intervals. The dyads will be assessed at baseline as well as 3-, 6-, 12-, and 18-month post-intervention. The primary outcome measures will be in congruence with EOL treatment preferences, decisional conflict, and quality of communication. The mediating and moderating effects of threat appraisal, HAART adherence, and spiritual struggle on the relationships among FACE and quality of life and hospitalization/dialysis use will also be assessed. This study will be the first longitudinal study of an AIDS-specific model of ACP with adolescents. If successful, this intervention could quickly translate into clinical practice. Copyright © 2012 Elsevier Inc. All rights reserved.

The Multigroup Multilevel Categorical Latent Growth Curve Models

ERIC Educational Resources Information Center

Hung, Lai-Fa

2010-01-01

Longitudinal data describe developmental patterns and enable predictions of individual changes beyond sampled time points. Major methodological issues in longitudinal data include modeling random effects, subject effects, growth curve parameters, and autoregressive residuals. This study embedded the longitudinal model within a multigroup…

Clinical, cognitive, and behavioural correlates of white matter damage in progressive supranuclear palsy.

PubMed

Agosta, Federica; Galantucci, Sebastiano; Svetel, Marina; Lukić, Milica Ječmenica; Copetti, Massimiliano; Davidovic, Kristina; Tomić, Aleksandra; Spinelli, Edoardo G; Kostić, Vladimir S; Filippi, Massimo

2014-05-01

White matter (WM) tract alterations were assessed in patients with progressive supranuclear palsy (PSP) relative to healthy controls and patients with idiopathic Parkinson's disease (PD) to explore the relationship of WM tract damage with clinical disease severity, performance on cognitive tests, and apathy. 37 PSP patients, 41 PD patients, and 34 healthy controls underwent an MRI scan and clinical testing to evaluate physical disability, cognitive impairment, and apathy. In PSP, the contribution of WM tract damage to global disease severity and cognitive and behavioural disturbances was assessed using Random Forest analysis. Relative to controls, PSP patients showed diffusion tensor (DT) MRI abnormalities of the corpus callosum, superior cerebellar peduncle (SCP), cingulum and uncinate fasciculus bilaterally, and right inferior longitudinal fasciculus. Corpus callosum and SCP DT MRI measures distinguished PSP from PD patients with high accuracy (area under the curve ranging from 0.89 to 0.72). In PSP, DT MRI metrics of the corpus callosum and superior cerebellar peduncles were the best predictors of global disease severity scale scores. DT MRI metrics of the corpus callosum, right superior longitudinal and inferior longitudinal fasciculus, and left uncinate were the best predictors of executive dysfunction. In PSP, apathy severity was related to the damage to the corpus callosum, right superior longitudinal, and uncinate fasciculi. In conclusion, WM tract damage contributes to the motor, cognitive, and behavioural deficits in PSP. DT MRI offers markers for PSP diagnosis, assessment, and monitoring.

Impact of the Project P.A.T.H.S. in the junior secondary school years: objective outcome evaluation based on eight waves of longitudinal data.

PubMed

Shek, Daniel T L; Ma, Cecilia M S

2012-01-01

To assess the effectiveness of the Tier 1 Program of the Project P.A.T.H.S., a randomized group trial with eight waves of data collected was carried out. At the fifth year of data collection, 19 experimental schools (n = 2, 662 students) and 24 control schools (n = 3, 272 students) participated in the study. Analyses based on individual growth curve modeling showed that participants in the experimental schools displayed better positive youth development than did participants in the control schools in terms of different indicators derived from the Chinese Positive Youth Development Scale, including moral competence and behavioral competence and cognitive behavioral competencies. Significant results were also found when examining the trajectories of psychological development among control and experimental participants who perceived the program to be beneficial. Findings based on longitudinal objective outcome evaluation strongly suggest that the Project P.A.T.H.S. is effective in promoting positive development in Hong Kong secondary school students.

Bayesian analysis of longitudinal dyadic data with informative missing data using a dyadic shared-parameter model.

PubMed

Ahn, Jaeil; Morita, Satoshi; Wang, Wenyi; Yuan, Ying

2017-01-01

Analyzing longitudinal dyadic data is a challenging task due to the complicated correlations from repeated measurements and within-dyad interdependence, as well as potentially informative (or non-ignorable) missing data. We propose a dyadic shared-parameter model to analyze longitudinal dyadic data with ordinal outcomes and informative intermittent missing data and dropouts. We model the longitudinal measurement process using a proportional odds model, which accommodates the within-dyad interdependence using the concept of the actor-partner interdependence effects, as well as dyad-specific random effects. We model informative dropouts and intermittent missing data using a transition model, which shares the same set of random effects as the longitudinal measurement model. We evaluate the performance of the proposed method through extensive simulation studies. As our approach relies on some untestable assumptions on the missing data mechanism, we perform sensitivity analyses to evaluate how the analysis results change when the missing data mechanism is misspecified. We demonstrate our method using a longitudinal dyadic study of metastatic breast cancer.

The effect of indapamide versus hydrochlorothiazide on ventricular and arterial function in patients with hypertension and diabetes: results of a randomized trial.

PubMed

Vinereanu, Dragos; Dulgheru, Raluca; Magda, Stefania; Dragoi Galrinho, Ruxandra; Florescu, Maria; Cinteza, Mircea; Granger, Christopher; Ciobanu, Andrea O

2014-10-01

The objective of this study is to compare the effects of 2 types of diuretics, indapamide and hydrochlorothiazide, added to an angiotensin-converting enzyme inhibitor, on ventricular and arterial functions in patients with hypertension and diabetes. This is a prospective, randomized, active-controlled, PROBE design study in 56 patients (57 ± 9 years, 52% men) with mild-to-moderate hypertension and type 2 diabetes, with normal ejection fraction, randomized to either indapamide (1.5 mg Slow Release (SR)/day) or hydrochlorothiazide (25 mg/d), added to quinapril (10-40 mg/d). All patients had conventional, tissue Doppler and speckle tracking echocardiography and assessment of endothelial and arterial functions and biomarkers, at baseline and after 6 months. Baseline characteristics were similar between groups; systolic and diastolic blood pressures decreased similarly, by 15% and 9% on indapamide and by 17% and 10% on hydrochlorothiazide (P < .05). Mean longitudinal systolic velocity and longitudinal strain increased by 7% and 14% on indapamide (from 5.6 ± 1.8 to 6.0 ± 1.1 cm/s and from 16.2% ± 1.8% to 18.5% ± 1.1%, both P < .05), but did not change on hydrochlorothiazide (P < .05 for intergroup differences), whereas ejection fraction and radial systolic function did not change. Similarly, mean longitudinal early diastolic velocity increased by 31% on indapamide (P < .05), but did not change on hydrochlorothiazide (P < .05 for intergroup differences). These changes were associated with improved endothelial and arterial functions on indapamide, but not on hydrochlorothiazide. Indapamide was found to improve measures of endothelial and arterial functions and to increase longitudinal left ventricular function compared with hydrochlorothiazide in patients with hypertension and diabetes, after 6 months of treatment. This study suggests that indapamide, a thiazide-like diuretic, has important vascular effects that can improve ventriculoarterial coupling. Copyright © 2014 Mosby, Inc. All rights reserved.

De qeurvian tenosynovitis: clinical outcomes of surgical treatment with longitudinal and transverse incision.

PubMed

Abrisham, Syyed Jalil; Karbasi, Mohammad Hosein Akhavan; Zare, Jalil; Behnamfar, Zahra; Tafti, Arefah Dehghani; Shishesaz, Behzad

2011-03-01

De Quervain disease is a mechanical tenosynovitis due to inadequacy volume between abductor pollicis longus, extensor pollicis brevis and their tunnel. Treatment methods include immobilization, steroid injections, and operation. For the first time Fritz De Quervain described surgical treatment of this disease. Since then, various ways of treatment have been reported. The purpose of this study is to compare the clinical outcomes of a longitudinal incision with a transverse incision in De Quervain disease. This was a randomized controlled clinical trial conducted in three hospitals in Iran, Yazd from March 2003 to September 2008. One hundred-twenty patients with De Quervain disease who did not respond to conservative treatment were operated with two different incisions. The patients were followed for three months to compare the surgical outcomes. During a three month follow-up, a significant difference was shown between the two methods (p=0.03). Results of surgical treatment with longitudinal incision were excellent (only 5 hypertrophic scars), but there were 13 postoperative complaints with transverse incision. According to our findings, longitudinal incision in surgical treatment of De Quervain disease is better than transverse incision.

Reading Skill Transfer across Languages: Outcomes from Longitudinal Bilingual Randomized Control Trials in Kenya and Haiti

ERIC Educational Resources Information Center

Piper, Benjamin; Bulat, Jennae; Johnston, Andrew

2015-01-01

If children do not learn how to read in the first few years of primary school, they will struggle to complete the cycle, and are at greater risk of dropping out. It is therefore crucial to identify and test interventions that have the potential of making a large impact, can be implemented quickly, and are affordable to be taken to scale. This is…

Neurorehabilitation in Parkinson's Disease: A Critical Review of Cognitive Rehabilitation Effects on Cognition and Brain.

PubMed

Díez-Cirarda, María; Ibarretxe-Bilbao, Naroa; Peña, Javier; Ojeda, Natalia

2018-01-01

Parkinson's disease (PD) patients experience cognitive impairment which has been related to reduced quality of life and functional disability. These symptoms usually progress until dementia occurs. Some studies have been published assessing the efficacy of cognitive treatments on improving cognition, functional outcome, and producing changes in brain activity. A critical review was performed to present up-to-date neurorehabilitation effects of cognitive rehabilitation in PD, with special emphasis on the efficacy on cognition, quality of life aspects, brain changes, and the longitudinal maintenance of these changes. After exclusions, 13 studies were reviewed, including 6 randomized controlled trials for the efficacy on cognition, 2 randomized controlled trials regarding the brain changes after cognitive training, and 5 studies which evaluated the long-term effects of cognitive treatments. Cognitive rehabilitation programs have demonstrated to be effective on improving cognitive functions, but more research is needed focusing on the efficacy on improving behavioral aspects and producing brain changes in patients with PD. Moreover, there is a need of randomized controlled trials with long-term follow-up periods.

Explicating the Conditions Under Which Multilevel Multiple Imputation Mitigates Bias Resulting from Random Coefficient-Dependent Missing Longitudinal Data.

PubMed

Gottfredson, Nisha C; Sterba, Sonya K; Jackson, Kristina M

2017-01-01

Random coefficient-dependent (RCD) missingness is a non-ignorable mechanism through which missing data can arise in longitudinal designs. RCD, for which we cannot test, is a problematic form of missingness that occurs if subject-specific random effects correlate with propensity for missingness or dropout. Particularly when covariate missingness is a problem, investigators typically handle missing longitudinal data by using single-level multiple imputation procedures implemented with long-format data, which ignores within-person dependency entirely, or implemented with wide-format (i.e., multivariate) data, which ignores some aspects of within-person dependency. When either of these standard approaches to handling missing longitudinal data is used, RCD missingness leads to parameter bias and incorrect inference. We explain why multilevel multiple imputation (MMI) should alleviate bias induced by a RCD missing data mechanism under conditions that contribute to stronger determinacy of random coefficients. We evaluate our hypothesis with a simulation study. Three design factors are considered: intraclass correlation (ICC; ranging from .25 to .75), number of waves (ranging from 4 to 8), and percent of missing data (ranging from 20 to 50%). We find that MMI greatly outperforms the single-level wide-format (multivariate) method for imputation under a RCD mechanism. For the MMI analyses, bias was most alleviated when the ICC is high, there were more waves of data, and when there was less missing data. Practical recommendations for handling longitudinal missing data are suggested.

Effects of Transcranial Direct Current Stimulation With Sensory Modulation on Stroke Motor Rehabilitation: A Randomized Controlled Trial.

PubMed

Koh, Chia-Lin; Lin, Jau-Hong; Jeng, Jiann-Shing; Huang, Sheau-Ling; Hsieh, Ching-Lin

2017-12-01

To test whether a multistrategy intervention enhanced recovery immediately and longitudinally in patients with severe to moderate upper extremity (UE) paresis. Double-blind, randomized controlled trial with placebo control. Outpatient department of a local medical center. People (N=25) with chronic stroke were randomly assigned to 1 of 2 groups: a transcranial direct current stimulation with sensory modulation (tDCS-SM) group (n=14; mean age ± SD, 55.3±11.4y) or a control group (n=11; mean age ± SD, 56.9±13.5y). Eight-week intervention. The tDCS-SM group received bilateral tDCS, bilateral cutaneous anesthesia, and high repetitions of passive movements on the paretic hand. The control group received the same passive movements but with sham tDCS and sham anesthesia. During the experiment, all participants continued their regular rehabilitation. Voluntary UE movement, spasticity, UE function, and basic activities of daily living. Outcomes were assessed at baseline, at postintervention, and at 3- and 6-month follow-ups. No significant differences were found between groups. However, there was a trend that the voluntary UE movement improved more in the tDCS-SM group than in the control group, with a moderate immediate effect (partial η 2 [η p 2 ]=.14, P=.07) and moderate long-term effects (3-mo follow-up: η p 2 =.17, P=.05; 6-mo follow-up: η p 2 =.12, P=.10). Compared with the control group, the tDCS-SM group had a trend of a small immediate effect (η p 2 =.02-.04) on reducing spasticity, but no long-term effect. A trend of small immediate and long-term effects in favor of tDCS-SM was found on UE function and daily function recovery (η p 2 =.02-.09). Accompanied with traditional rehabilitation, tDCS-SM had a nonsignificant trend of having immediate and longitudinal effects on voluntary UE movement recovery in patients with severe to moderate UE paresis after stroke, but its effects on spasticity reduction and functional recovery may be limited. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Using a Shared Parameter Mixture Model to Estimate Change during Treatment when Termination is Related to Recovery Speed

PubMed Central

Gottfredson, Nisha C.; Bauer, Daniel J.; Baldwin, Scott A.; Okiishi, John C.

2014-01-01

Objective This study demonstrates how to use a shared parameter mixture model (SPMM) in longitudinal psychotherapy studies to accommodate missing that are due to a correlation between rate of improvement and termination of therapy. Traditional growth models assume that such a relationship does not exist (i.e., assume that data are missing at random) and will produce biased results if this assumption is incorrect. Method We use longitudinal data from 4,676 patients enrolled in a naturalistic study of psychotherapy to compare results from a latent growth model and a shared parameter mixture model (SPMM). Results In this dataset, estimates of the rate of improvement during therapy differ by 6.50 – 6.66% across the two models, indicating that participants with steeper trajectories left psychotherapy earliest, thereby potentially biasing inference for the slope in the latent growth model. Conclusion We conclude that reported estimates of change during therapy may be underestimated in naturalistic studies of therapy in which participants and their therapists determine the end of treatment. Because non-randomly missing data can also occur in randomized controlled trials or in observational studies of development, the utility of the SPMM extends beyond naturalistic psychotherapy data. PMID:24274626

Right Ventricular Longitudinal Strain Is Depressed in a Bovine Model of Pulmonary Hypertension.

PubMed

Bartels, Karsten; Brown, R Dale; Fox, Daniel L; Bull, Todd M; Neary, Joseph M; Dorosz, Jennifer L; Fonseca, Brian M; Stenmark, Kurt R

2016-05-01

Pulmonary hypertension and resulting right ventricular (RV) dysfunction are associated with significant perioperative morbidity and mortality. Although echocardiography permits real-time, noninvasive assessment of RV function, objective and comparative measures are underdeveloped, and appropriate animal models to study their utility are lacking. Longitudinal strain analysis is a novel echocardiographic method to quantify RV performance. Herein, we hypothesized that peak RV longitudinal strain would worsen in a bovine model of pulmonary hypertension compared with control animals. Newborn Holstein calves were randomly chosen for induction of pulmonary hypertension versus control conditions. Pulmonary hypertension was induced by exposing animals to 14 days of hypoxia (equivalent to 4570 m above sea level or 430 mm Hg barometric pressure). Control animals were kept at ambient pressure/normoxia. At the end of the intervention, transthoracic echocardiography was performed in awake calves. Longitudinal wall strain was analyzed from modified apical 4-chamber views focused on the RV. Comparisons between measurements in hypoxic versus nonhypoxic conditions were performed using Student t test for independent samples and unequal variances. After 14 days at normoxic versus hypoxic conditions, 15 calves were examined with echocardiography. Pulmonary hypertension was confirmed by right heart catheterization and associated with reduced RV systolic function. Mean systolic strain measurements were compared in normoxia-exposed animals (n = 8) and hypoxia-exposed animals (n = 7). Peak global systolic longitudinal RV strain after hypoxia worsened compared to normoxia (-10.5% vs -16.1%, P = 0.0031). Peak RV free wall strain also worsened after hypoxia compared to normoxia (-9.6% vs -17.3%, P = 0.0031). Findings from strain analysis were confirmed by measurement of tricuspid annular peak systolic excursion. Peak longitudinal RV strain detected worsened RV function in animals with hypoxia-induced pulmonary hypertension compared with control animals. This relationship was demonstrated in the transthoracic echocardiographic 4-chamber view independently for the RV free wall and for the combination of the free and septal walls. This innovative model of bovine pulmonary hypertension may prove useful to compare different monitoring technologies for the assessment of early events of RV dysfunction. Further studies linking novel RV imaging applications with mechanistic and therapeutic approaches are needed.

Feeling Thanks and Saying Thanks: A Randomized Controlled Trial Examining If and How Socially Oriented Gratitude Journals Work.

PubMed

O'Connell, Brenda H; O'Shea, Deirdre; Gallagher, Stephen

2017-10-01

This study examined the effect of a reflective interpersonal gratitude journal, a reflective-behavioral interpersonal gratitude journal and an active control journal, on primary qualities of well-being and depression. Participants (n = 192; 67.2% female) completed this 3-month longitudinal randomized controlled design. Participants in the reflective-behavioral condition experienced the greatest improvements in affect balance and reductions in depression at immediate posttest. Both gratitude interventions improved affect balance at 1 month, compared to the control. Changes in affect balance for those in the reflective-behavioral condition were mediated by the rate at which people expressed gratitude in their existing relationships. This effect was moderated by participant's baseline depressive status. Expressing felt gratitude to others appears to be a crucial step in deriving benefits, and these benefits may not be limited to the emotionally healthy. Given the applied popularity of gratitude interventions, understanding not only if but also how they work is essential. © 2017 Wiley Periodicals, Inc.

Human comfort response to dominant random motions in longitudinal modes of aircraft motion

NASA Technical Reports Server (NTRS)

Stone, R. W., Jr.

1980-01-01

The effects of random vertical and longitudinal accelerations and pitching velocity passenger ride comfort responses were examined on the NASA Langley Visual Motion Simulator. Effects of power spectral density shape were studied for motions where the peak was between 0 and 2 Hz. The subjective rating data and the physical motion data obtained are presented without interpretation or detailed analysis. There existed motions in all other degrees of freedom as well as the particular pair of longitudinal airplane motions studied. These unwanted motions, caused by the characteristics of the simulator may have introduced some interactive effects on passenger responses.

A panel multinomial logit analysis of elderly living arrangements: evidence from Aging In Manitoba longitudinal data, Canada.

PubMed

Sarma, Sisira; Simpson, Wayne

2007-12-01

Utilizing a unique longitudinal survey linked with home care use data, this paper analyzes the determinants of elderly living arrangements in Manitoba, Canada using a random effects multinomial logit model that accounts for unobserved individual heterogeneity. Because current home ownership is potentially endogenous in a living arrangements choice model, we use prior home ownership as an instrument. We also use prior home care use as an instrument for home care and use a random coefficient framework to account for unobserved health status. After controlling for relevant socio-demographic factors and accounting for unobserved individual heterogeneity, we find that home care and home ownership reduce the probability of living in a nursing home. Consistent with previous studies, we find that age is a strong predictor of nursing home entry. We also find that married people, those who have lived longer in the same community, and those who are healthy are more likely to live independently and less likely to be institutionalized or to cohabit with individuals other than their spouse.

On the repeated measures designs and sample sizes for randomized controlled trials.

PubMed

Tango, Toshiro

2016-04-01

For the analysis of longitudinal or repeated measures data, generalized linear mixed-effects models provide a flexible and powerful tool to deal with heterogeneity among subject response profiles. However, the typical statistical design adopted in usual randomized controlled trials is an analysis of covariance type analysis using a pre-defined pair of "pre-post" data, in which pre-(baseline) data are used as a covariate for adjustment together with other covariates. Then, the major design issue is to calculate the sample size or the number of subjects allocated to each treatment group. In this paper, we propose a new repeated measures design and sample size calculations combined with generalized linear mixed-effects models that depend not only on the number of subjects but on the number of repeated measures before and after randomization per subject used for the analysis. The main advantages of the proposed design combined with the generalized linear mixed-effects models are (1) it can easily handle missing data by applying the likelihood-based ignorable analyses under the missing at random assumption and (2) it may lead to a reduction in sample size, compared with the simple pre-post design. The proposed designs and the sample size calculations are illustrated with real data arising from randomized controlled trials. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Mixed models approaches for joint modeling of different types of responses.

PubMed

Ivanova, Anna; Molenberghs, Geert; Verbeke, Geert

2016-01-01

In many biomedical studies, one jointly collects longitudinal continuous, binary, and survival outcomes, possibly with some observations missing. Random-effects models, sometimes called shared-parameter models or frailty models, received a lot of attention. In such models, the corresponding variance components can be employed to capture the association between the various sequences. In some cases, random effects are considered common to various sequences, perhaps up to a scaling factor; in others, there are different but correlated random effects. Even though a variety of data types has been considered in the literature, less attention has been devoted to ordinal data. For univariate longitudinal or hierarchical data, the proportional odds mixed model (POMM) is an instance of the generalized linear mixed model (GLMM; Breslow and Clayton, 1993). Ordinal data are conveniently replaced by a parsimonious set of dummies, which in the longitudinal setting leads to a repeated set of dummies. When ordinal longitudinal data are part of a joint model, the complexity increases further. This is the setting considered in this paper. We formulate a random-effects based model that, in addition, allows for overdispersion. Using two case studies, it is shown that the combination of random effects to capture association with further correction for overdispersion can improve the model's fit considerably and that the resulting models allow to answer research questions that could not be addressed otherwise. Parameters can be estimated in a fairly straightforward way, using the SAS procedure NLMIXED.

Comparative Effectiveness of PCI Education's "PCI Reading Program": Phase 2--A Report of a Comparison Group Study in Brevard Public Schools and Miami-Dade County Public Schools. Research Summary

ERIC Educational Resources Information Center

Empirical Education Inc., 2010

2010-01-01

PCI Education sought scientifically based evidence on the comparative effectiveness of the "PCI Reading Program" through a five-year longitudinal study. Phase 1 of the study consisted of a randomized control trial studying the efficacy of the "PCI Reading Program-Level One" that was conducted in the 2007-2008 in Miami-Dade…

Marginal and Random Intercepts Models for Longitudinal Binary Data With Examples From Criminology.

PubMed

Long, Jeffrey D; Loeber, Rolf; Farrington, David P

2009-01-01

Two models for the analysis of longitudinal binary data are discussed: the marginal model and the random intercepts model. In contrast to the linear mixed model (LMM), the two models for binary data are not subsumed under a single hierarchical model. The marginal model provides group-level information whereas the random intercepts model provides individual-level information including information about heterogeneity of growth. It is shown how a type of numerical averaging can be used with the random intercepts model to obtain group-level information, thus approximating individual and marginal aspects of the LMM. The types of inferences associated with each model are illustrated with longitudinal criminal offending data based on N = 506 males followed over a 22-year period. Violent offending indexed by official records and self-report were analyzed, with the marginal model estimated using generalized estimating equations and the random intercepts model estimated using maximum likelihood. The results show that the numerical averaging based on the random intercepts can produce prediction curves almost identical to those obtained directly from the marginal model parameter estimates. The results provide a basis for contrasting the models and the estimation procedures and key features are discussed to aid in selecting a method for empirical analysis.

Patient-reported outcomes in a phase iii study of everolimus versus placebo in patients with metastatic carcinoma of the kidney that has progressed on vascular endothelial growth factor receptor tyrosine kinase inhibitor therapy.

PubMed

Beaumont, Jennifer L; Butt, Zeeshan; Baladi, Jeanfrancois; Motzer, Robert J; Haas, Tomas; Hollaender, Norbert; Kay, Andrea; Cella, David

2011-01-01

A phase III, randomized, double-blind, placebo-controlled trial was conducted in patients with metastatic renal cell carcinoma. The focus of this paper is to evaluate the patient-reported outcomes. Patients were randomly assigned (2:1) to receive oral everolimus 10 mg once daily or placebo. The Functional Assessment of Cancer Therapy Kidney Symptom Index-Disease-Related Symptoms (FKSI-DRS) and European Organization for the Research and Treatment of Cancer (EORTC) QLQ-C30 were administered before randomization and on day 1 of each cycle. The FKSI-DRS and the EORTC QLQ-C30 Physical Functioning and Global Quality of Life scores were the primary endpoints examined. Longitudinal models were used to compare treatment arms. Sensitivity analyses were conducted to explore the impact of missing data assumptions. Longitudinal trends for FKSI-DRS scores did not differ by treatment arm. Taking nonignorable missing data into account, there were significant differences between treatment arms in the trend over time for physical functioning and global quality of life, with the everolimus arm exhibiting greater decreases. All three of these measures of health-related quality of life were significantly related to progression-free survival. There was no evidence of a difference between everolimus and placebo in longitudinal patterns of disease-related symptoms, and little difference between the arms in physical functioning or global quality of life trends. This supports the conclusion that delay in tumor progression demonstrated by everolimus is associated with minimal impact on symptoms, physical functioning, or quality of life, as reported by patients.

Patient-Reported Outcomes in a Phase III Study of Everolimus Versus Placebo in Patients with Metastatic Carcinoma of the Kidney That Has Progressed on Vascular Endothelial Growth Factor Receptor Tyrosine Kinase Inhibitor Therapy

PubMed Central

Butt, Zeeshan; Baladi, Jeanfrancois; Motzer, Robert J.; Haas, Tomas; Hollaender, Norbert; Kay, Andrea; Cella, David

2011-01-01

Purpose. A phase III, randomized, double-blind, placebo-controlled trial was conducted in patients with metastatic renal cell carcinoma. The focus of this paper is to evaluate the patient-reported outcomes. Methods. Patients were randomly assigned (2:1) to receive oral everolimus 10 mg once daily or placebo. The Functional Assessment of Cancer Therapy Kidney Symptom Index—Disease-Related Symptoms (FKSI-DRS) and European Organization for the Research and Treatment of Cancer (EORTC) QLQ-C30 were administered before randomization and on day 1 of each cycle. The FKSI-DRS and the EORTC QLQ-C30 Physical Functioning and Global Quality of Life scores were the primary endpoints examined. Longitudinal models were used to compare treatment arms. Sensitivity analyses were conducted to explore the impact of missing data assumptions. Results. Longitudinal trends for FKSI-DRS scores did not differ by treatment arm. Taking nonignorable missing data into account, there were significant differences between treatment arms in the trend over time for physical functioning and global quality of life, with the everolimus arm exhibiting greater decreases. All three of these measures of health-related quality of life were significantly related to progression-free survival. Conclusions. There was no evidence of a difference between everolimus and placebo in longitudinal patterns of disease-related symptoms, and little difference between the arms in physical functioning or global quality of life trends. This supports the conclusion that delay in tumor progression demonstrated by everolimus is associated with minimal impact on symptoms, physical functioning, or quality of life, as reported by patients. PMID:21459902

The estimation of branching curves in the presence of subject-specific random effects.

PubMed

Elmi, Angelo; Ratcliffe, Sarah J; Guo, Wensheng

2014-12-20

Branching curves are a technique for modeling curves that change trajectory at a change (branching) point. Currently, the estimation framework is limited to independent data, and smoothing splines are used for estimation. This article aims to extend the branching curve framework to the longitudinal data setting where the branching point varies by subject. If the branching point is modeled as a random effect, then the longitudinal branching curve framework is a semiparametric nonlinear mixed effects model. Given existing issues with using random effects within a smoothing spline, we express the model as a B-spline based semiparametric nonlinear mixed effects model. Simple, clever smoothness constraints are enforced on the B-splines at the change point. The method is applied to Women's Health data where we model the shape of the labor curve (cervical dilation measured longitudinally) before and after treatment with oxytocin (a labor stimulant). Copyright © 2014 John Wiley & Sons, Ltd.

Longitudinal Impact of a Randomized Clinical Trial to Improve Family Function, Reduce Maternal Stress and Improve Child Outcomes in Families of Children with ADHD.

PubMed

Churchill, Shervin S; Leo, Michael C; Brennan, Eileen M; Sellmaier, Claudia; Kendall, Judy; Houck, Gail M

2018-02-23

Objective Evaluate the efficacy of a 12 month nursing case-management intervention over a period of 18 months, 6 months after the end of intervention, for families of children attention deficit hyperactivity disorder (ADHD). Methods Mother and child dyads were enrolled to participate in a randomized controlled clinical trial. Children were 4-18 years old. Data were collected at baseline, 6, 12, and 18 months or 6 months after the termination of direct intervention. Longitudinal analyses, using generalized estimating equations, were conducted to assess change in study outcomes relating to family function, maternal stress, and child behavior over the 18 month period. Results Compared to control families, some family function outcomes were moderately improved in the intervention group. In particular, intervention families demonstrated substantial improvement in implementing family behavior controls (p value = 0.038) and improvement in family satisfaction (not statistically significant p = 0.062). Although there was improvement in the overall family function measure there was not a statistically significant difference between groups. Maternal stress and child behavior outcomes were not significantly different between control and intervention groups by the end of the intervention. Conclusions for Practice Addressing ADHD is complex and requires the assessment of comorbidities that might exacerbate negative behavior. Our findings support the latest American Academy of Pediatrics guidelines to use behavioral therapy as the first line of treatment in young children. Nursing case-management interventions that provide direct family education and improve family function, especially with respect to providing structure and behavior control, may complement and facilitate behavioral therapy for treatment of ADHD and improving child behavior.

Comparison Between Transverse Mini-Incision and Longitudinal Mini-Incision for the Resection of Locally Advanced Colonic Cancer

PubMed Central

Ishida, Hideyuki; Sobajima, Jun; Yokoyama, Masaru; Nakada, Hiroshi; Okada, Norimichi; Kumamoto, Kensuke; Ishibashi, Keiichiro

2014-01-01

We performed a retrospective review of non-overweight (body mass index ≤ 25 kg/m2) patients scheduled to undergo a curative resection of locally advanced colon cancer via a transverse mini-incision (n = 62) or a longitudinal mini-incision (skin incision ≤7 cm, n = 62), with the latter group of patients randomly selected as historical controls matched with the former group according to tumor location. Extension of the transverse mini-incision wound was necessary in 3 patients (5%). Both groups were largely equivalent in terms of demographic, clinicopathological, and surgical factors and frequency of postoperative complications. Postoperative analgesic was significantly less (P = 0.04) and postoperative length of the hospital stay was significantly shorter (P < 0.01) in the transverse mini-incision group. Concerning a mini-incision approach for locally advanced colonic cancer, a transverse incision seems to be advantageous with regard to minimal invasiveness and early recovery compared with a longitudinal incision. PMID:24833142

Effects of prenatal yoga on women's stress and immune function across pregnancy: A randomized controlled trial.

PubMed

Chen, Pao-Ju; Yang, Luke; Chou, Cheng-Chen; Li, Chia-Chi; Chang, Yu-Cune; Liaw, Jen-Jiuan

2017-04-01

The effects of prenatal yoga on biological indicators have not been widely studied. Thus, we compared changes in stress and immunity salivary biomarkers from 16 to 36 weeks' gestation between women receiving prenatal yoga and those receiving routine prenatal care. For this longitudinal, prospective, randomized controlled trial, we recruited 94 healthy pregnant women at 16 weeks' gestation through convenience sampling from a prenatal clinic in Taipei. Participants were randomly assigned to intervention (n=48) or control (n=46) groups using Clinstat block randomization. The 20-week intervention comprised two weekly 70-min yoga sessions led by a midwife certified as a yoga instructor; the control group received only routine prenatal care. In both groups, participants' salivary cortisol and immunoglobulin A levels were collected before and after yoga every 4 weeks from 16 to 36 weeks' gestation. The intervention group had lower salivary cortisol (p<0.001) and higher immunoglobulin A (p<0.001) levels immediately after yoga than the control group. Specifically, the intervention group had significantly higher long-term salivary immunoglobulin A levels than the control group (p=0.018), and infants born to women in the intervention group weighed more than those born to the control group (p<0.001). Prenatal yoga significantly reduced pregnant women's stress and enhanced their immune function. Clinicians should learn the mechanisms of yoga and its effects on pregnant women. Our findings can guide clinicians to help pregnant women alleviate their stress and enhance their immune function. Copyright © 2017. Published by Elsevier Ltd.

[Variables related to the emergence of differential patterns in work motivation].

PubMed

Arrieta, Carlos; Navarro, José; Vicente, Susana

2008-11-01

Several longitudinal studies have shown that motivation at work acts chaotically. In very few cases, it may be linear or random. However, the factors that might explain why these different patterns emerge have not been analysed to date. In this exploratory study, we interviewed 73 employees whose motivational patterns were previously known. The results revealed that chaotic patterns were associated with high levels of motivation, self-efficacy beliefs, and perceptions of instrumentality, and also with intrinsic personal goal orientation and a perception of high work control. Linear patterns were associated with extrinsic goals and a perception of work as difficult, and random patterns were linked to high flexibility at work.

Impact of Project P.A.T.H.S. on adolescent developmental outcomes in Hong Kong: findings based on seven waves of data.

PubMed

Shek, Daniel T L; Ma, Cecilia M S

2012-01-18

The present study examined the longitudinal impact of Project P.A.T.H.S. (Positive Adolescent Training through Holistic Social Programmes) on adolescent developmental outcomes in Hong Kong. Using a longitudinal randomized group design, seven waves of data were collected from 24 experimental schools (n=4049 at wave 1) in which students participated in the Tier 1 Program of Project P.A.T.H.S. and 24 control schools (n=3797 at wave 1). Results based on individual growth curve modeling generally showed that, relative to the control participants, participants in the experimental group had: (a) a higher level of positive development; (b) a lower level of substance abuse; and (c) a lower level of delinquent behavior. Participants who regarded the program to be beneficial also showed higher levels of positive development and lower levels of problem behavior than did the control school students. The present findings suggest that Project P.A.T.H.S. is effective in promoting positive development and preventing adolescent problem behavior in Chinese adolescents in Hong Kong.

De Qeurvian Tenosynovitis: Clinical Outcomes of Surgical Treatment with Longitudinal and Transverse Incision

PubMed Central

Abrisham, Syyed Jalil; Karbasi, Mohammad Hosein Akhavan; Zare, Jalil; Behnamfar, Zahra; Tafti, Arefah Dehghani; Shishesaz, Behzad

2011-01-01

Objectives De Quervain disease is a mechanical tenosynovitis due to inadequacy volume between abductor pollicis longus, extensor pollicis brevis and their tunnel. Treatment methods include immobilization, steroid injections, and operation. For the first time Fritz De Quervain described surgical treatment of this disease. Since then, various ways of treatment have been reported. The purpose of this study is to compare the clinical outcomes of a longitudinal incision with a transverse incision in De Quervain disease. Methods This was a randomized controlled clinical trial conducted in three hospitals in Iran, Yazd from March 2003 to September 2008. One hundred-twenty patients with De Quervain disease who did not respond to conservative treatment were operated with two different incisions. The patients were followed for three months to compare the surgical outcomes. Results During a three month follow-up, a significant difference was shown between the two methods (p=0.03). Results of surgical treatment with longitudinal incision were excellent (only 5 hypertrophic scars), but there were 13 postoperative complaints with transverse incision. Conclusion According to our findings, longitudinal incision in surgical treatment of De Quervain disease is better than transverse incision. PMID:22043391

Reciprocal longitudinal relations between weight/shape concern and comorbid pathology among women at very high risk for eating disorder onset.

PubMed

Fitzsimmons-Craft, Ellen E; Eichen, Dawn M; Kass, Andrea E; Trockel, Mickey; Crosby, Ross D; Taylor, C Barr; Wilfley, Denise E

2017-12-28

Understanding how known eating disorder (ED) risk factors change in relating to one another over time may inform efficient intervention targets. We examined short-term (i.e., 1 month) reciprocal longitudinal relations between weight/shape concern and comorbid symptoms (i.e., depressed mood, anxiety) and behaviors (i.e., binge drinking) over the course of 24 months using cross-lagged panel models. Participants were 185 women aged 18-25 years at very high risk for ED onset, randomized to an online ED preventive intervention or waitlist control. We also tested whether relations differed based on intervention receipt. Weight/shape concern in 1 month significantly predicted depressed mood the following month; depressed mood in 1 month also predicted weight/shape concern the following month, but the effect size was smaller. Likewise, weight/shape concern in 1 month significantly predicted anxiety the following month, but the reverse was not true. Results showed no temporal relations between weight/shape concern and binge drinking in either direction. Relations between weight/shape concern, and comorbid symptoms and behaviors did not differ based on intervention receipt. Results support focusing intervention on reducing weight/shape concern over reducing comorbid constructs for efficient short-term change. Level I, evidence obtained from a properly designed randomized controlled trial.

Reducing diarrhoea in Guatemalan children: randomized controlled trial of flocculant-disinfectant for drinking-water.

PubMed

Chiller, Tom M; Mendoza, Carlos E; Lopez, M Beatriz; Alvarez, Maricruz; Hoekstra, Robert M; Keswick, Bruce H; Luby, Stephen P

2006-01-01

To examine the effect of a new point-of-use treatment for drinking-water, a commercially developed flocculant-disinfectant, on the prevalence of diarrhoea in children. We conducted a randomized controlled trial among 514 rural Guatemalan households, divided into 42 neighbourhood clusters, for 13 weeks, from 4 November 2002 through 31 January 2003. Clusters assigned to water treatment with the flocculant-disinfectant were compared with those using their usual water-handling practices. The longitudinal prevalence of diarrhoea was calculated as the proportion of total days with diarrhoea divided by the total number of days of observation. The prevalence of diarrhoea was compared using the Wilcoxon rank-sum test. The 1702 people in households receiving the disinfectant had a prevalence of diarrhoea that was 40% lower than that among the 1699 people using standard water-handling practices (0.9% versus 1.5%; P = 0.001). In households using the flocculant-disinfectant, children < 1 year of age had a 39% lower prevalence of diarrhoea than those in households using their standard practices (3.7% versus 6.0%; P = 0.005). In settings where families rarely treat drinking-water, we introduced a novel flocculant-disinfectant that reduced the longitudinal prevalence of diarrhoea, especially among children aged < 1 year, among whom diarrhoea has been strongly associated with mortality. Successful introduction and use of this product could contribute to preventing diarrhoeal disease globally.

Improved power for characterizing longitudinal amyloid-β PET changes and evaluating amyloid-modifying treatments with a cerebral white matter reference region.

PubMed

Chen, Kewei; Roontiva, Auttawut; Thiyyagura, Pradeep; Lee, Wendy; Liu, Xiaofen; Ayutyanont, Napatkamon; Protas, Hillary; Luo, Ji Luo; Bauer, Robert; Reschke, Cole; Bandy, Daniel; Koeppe, Robert A; Fleisher, Adam S; Caselli, Richard J; Landau, Susan; Jagust, William J; Weiner, Michael W; Reiman, Eric M

2015-04-01

In this article, we describe an image analysis strategy with improved power for tracking longitudinal amyloid-β (Aβ) PET changes and evaluating Aβ-modifying treatments. Our aims were to compare the power of template-based cerebellar, pontine, and cerebral white matter reference regions to track 24-mo florbetapir standardized uptake value (SUV) ratio (SUVR) changes; to relate those changes to 24-mo clinical declines; and to evaluate Aβ-modifying treatments in Aβ-positive (Aβ+) and Aβ-negative (Aβ-) patients with probable Alzheimer dementia (pAD), in patients with mild cognitive impairment (MCI), in cognitively normal controls (NCs), and in cognitively normal apolipoprotein E4 (APOE4) carriers and noncarriers. We used baseline and follow-up (∼24 mo) florbetapir PET scans from 332 Aβ+ and Aβ- subjects participating in the multicenter Alzheimer's Disease Neuroimaging Initiative. Each of the proposed analyses included 31 pAD patients, 187 MCI patients, and 114 NCs. Cerebral-to-white matter, cerebellar, and pontine SUVRs were characterized in terms of their longitudinal variability; their power to track longitudinal fibrillar Aβ increases in Aβ+ and Aβ- subgroups and cognitively normal APOE4 carriers and noncarriers; the sample sizes needed to detect attenuated accumulation of or clearance of fibrillar Aβ accumulation in randomized clinical trials; and their ability to relate 24-mo fibrillar Aβ increases to clinical declines. As predicted, cerebral-to-white matter SUVR changes were significantly less variable and had significantly greater power to detect 24-mo fibrillar Aβ increases and evaluate Aβ-modifying treatment effects in Aβ+ pAD, MCI, and NC subjects and cognitively normal APOE4 carriers. They were also distinguished by the ability to detect significant associations between 24-mo Aβ increases and clinical declines. A cerebral white matter reference region may improve the power to track longitudinal fibrillar Aβ increases, to characterize their relationship to longitudinal clinical declines, and to evaluate Aβ-modifying treatments in randomized clinical trials. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Analysis of baseline, average, and longitudinally measured blood pressure data using linear mixed models.

PubMed

Hossain, Ahmed; Beyene, Joseph

2014-01-01

This article compares baseline, average, and longitudinal data analysis methods for identifying genetic variants in genome-wide association study using the Genetic Analysis Workshop 18 data. We apply methods that include (a) linear mixed models with baseline measures, (b) random intercept linear mixed models with mean measures outcome, and (c) random intercept linear mixed models with longitudinal measurements. In the linear mixed models, covariates are included as fixed effects, whereas relatedness among individuals is incorporated as the variance-covariance structure of the random effect for the individuals. The overall strategy of applying linear mixed models decorrelate the data is based on Aulchenko et al.'s GRAMMAR. By analyzing systolic and diastolic blood pressure, which are used separately as outcomes, we compare the 3 methods in identifying a known genetic variant that is associated with blood pressure from chromosome 3 and simulated phenotype data. We also analyze the real phenotype data to illustrate the methods. We conclude that the linear mixed model with longitudinal measurements of diastolic blood pressure is the most accurate at identifying the known single-nucleotide polymorphism among the methods, but linear mixed models with baseline measures perform best with systolic blood pressure as the outcome.

Nonlinear dual-axis biodynamic response of the semi-supine human body during longitudinal horizontal whole-body vibration

NASA Astrophysics Data System (ADS)

Huang, Ya; Griffin, Michael J.

2008-04-01

The resonance frequencies in frequency response functions of the human body (e.g. apparent mass and transmissibility) decrease with increasing vibration magnitude. This nonlinear biodynamic response is found with various sitting and standing postures requiring postural control. The present study measured the apparent mass of the body in a relaxed semi-supine posture with two types of longitudinal horizontal vibration (in the z-axis of the semi-supine body): (i) continuous random excitation (0.25-20 Hz) at five magnitudes (0.125, 0.25, 0.5, 0.75 and 1.0 ms -2 rms); (ii) intermittent random excitation (0.25-20 Hz) alternately at 0.25 and 1.0 ms -2 rms. With continuous random vibration, the dominant primary resonance frequency in the median normalised apparent mass decreased from 3.7 to 2.4 Hz as the vibration magnitude increased from 0.125 to 1.0 ms -2 rms. A nonlinear response was apparent in both the horizontal ( z-axis) apparent mass and the vertical ( x-axis) cross-axis apparent mass. With intermittent random vibration, as the vibration magnitude increased from 0.25 to 1.0 ms -2 rms, the median resonance frequency of the apparent mass decreased from 3.2 to 2.5 Hz whereas, with continuous random vibration over the same range of magnitudes, the resonance frequency decreased from 3.4 to 2.4 Hz. The median change in the resonance frequency (between 0.25 and 1.0 ms -2 rms) was 0.6 Hz with the intermittent random vibration and 0.9 Hz with the continuous random vibration. With intermittent vibration, the resonance frequency was higher at the high magnitude and lower at the low magnitude than with continuous vibration at the same magnitudes. The responses were consistent with passive thixotropy being a primary cause of nonlinear biodynamic responses to whole-body vibration, although reflex activity of the muscles may also have an influence.

Benefits from antidepressants: synthesis of 6-week patient-level outcomes from double-blind placebo-controlled randomized trials of fluoxetine and venlafaxine.

PubMed

Gibbons, Robert D; Hur, Kwan; Brown, C Hendricks; Davis, John M; Mann, J John

2012-06-01

Some meta-analyses suggest that efficacy of antidepressants for major depression is overstated and limited to severe depression. To determine the short-term efficacy of antidepressants for treating major depressive disorder in youth, adult, and geriatric populations. Reanalysis of all intent-to-treat person-level longitudinal data during the first 6 weeks of treatment of major depressive disorder from 12 adult, 4 geriatric, and 4 youth randomized controlled trials of fluoxetine hydrochloride and 21 adult trials of venlafaxine hydrochloride. All sponsor-conducted randomized controlled trials of fluoxetine and venlafaxine. Children's Depression Rating Scale-Revised scores (youth population), Hamilton Depression Rating Scale scores (adult and geriatric populations), and estimated response and remission rates at 6 weeks were analyzed for 2635 adults, 960 geriatric patients, and 708 youths receiving fluoxetine and for 2421 adults receiving immediate-release venlafaxine and 2461 adults receiving extended-release venlafaxine. Patients in all age and drug groups had significantly greater improvement relative to control patients receiving placebo. The differential rate of improvement was largest for adults receiving fluoxetine (34.6% greater than those receiving placebo). Youths had the largest treated vs control difference in response rates (24.1%) and remission rates (30.1%), with adult differences generally in the 15.6% (remission) to 21.4% (response) range. Geriatric patients had the smallest drug-placebo differences, an 18.5% greater rate of improvement, 9.9% for response and 6.5% for remission. Immediate-release venlafaxine produced larger effects than extended-release venlafaxine. Baseline severity could not be shown to affect symptom reduction. To our knowledge, this is the first research synthesis in this area to use complete longitudinal person-level data from a large set of published and unpublished studies. The results do not support previous findings that antidepressants show little benefit except for severe depression. The antidepressants fluoxetine and venlafaxine are efficacious for major depressive disorder in all age groups, although more so in youths and adults compared with geriatric patients. Baseline severity was not significantly related to degree of treatment advantage over placebo.

Does Mass Azithromycin Distribution Impact Child Growth and Nutrition in Niger? A Cluster-Randomized Trial

PubMed Central

Amza, Abdou; Yu, Sun N.; Kadri, Boubacar; Nassirou, Baido; Stoller, Nicole E.; Zhou, Zhaoxia; West, Sheila K.; Bailey, Robin L.; Gaynor, Bruce D.; Keenan, Jeremy D.; Porco, Travis C.; Lietman, Thomas M.

2014-01-01

Background Antibiotic use on animals demonstrates improved growth regardless of whether or not there is clinical evidence of infectious disease. Antibiotics used for trachoma control may play an unintended benefit of improving child growth. Methodology In this sub-study of a larger randomized controlled trial, we assess anthropometry of pre-school children in a community-randomized trial of mass oral azithromycin distributions for trachoma in Niger. We measured height, weight, and mid-upper arm circumference (MUAC) in 12 communities randomized to receive annual mass azithromycin treatment of everyone versus 12 communities randomized to receive biannual mass azithromycin treatments for children, 3 years after the initial mass treatment. We collected measurements in 1,034 children aged 6–60 months of age. Principal Findings We found no difference in the prevalence of wasting among children in the 12 annually treated communities that received three mass azithromycin distributions compared to the 12 biannually treated communities that received six mass azithromycin distributions (odds ratio = 0.88, 95% confidence interval = 0.53 to 1.49). Conclusions/Significance We were unable to demonstrate a statistically significant difference in stunting, underweight, and low MUAC of pre-school children in communities randomized to annual mass azithromycin treatment or biannual mass azithromycin treatment. The role of antibiotics on child growth and nutrition remains unclear, but larger studies and longitudinal trials may help determine any association. PMID:25210836

Engagement and Retention of Suicide Attempters in Clinical Research

PubMed Central

Gibbons, Carly J.; Stirman, Shannon Wiltsey; Brown, Gregory K.; Beck, Aaron T.

2010-01-01

Background High attrition rates in longitudinal research can limit study generalizability, threaten internal validity, and decrease statistical power. Research has demonstrated that there can be significant differences between participants who complete a research study and those who drop out prematurely, and that treatment outcomes may be dependent on retention in a treatment protocol. Aims The current paper describes the challenges encountered when implementing a randomized controlled trial of cognitive therapy for the prevention of suicide attempts and the solutions developed to overcome these problems. Methods Problems unique to suicide attempters are discussed, and strategies successfully implemented to boost retention rates are provided. Results The methods implemented appeared to increase retention rates in the randomized controlled trial. Conclusions Many steps can be taken to work with this difficult population, and researchers are encouraged to be as involved and flexible with participants as possible. PMID:20418211

Scale of reference bias and the evolution of health.

PubMed

Groot, Wim

2003-09-01

The analysis of subjective measures of well-being-such as self-reports by individuals about their health status is frequently hampered by the problem of scale of reference bias. A particular form of scale of reference bias is age norming. In this study we corrected for scale of reference bias by allowing for individual specific effects in an equation on subjective health. A random effects ordered response model was used to analyze scale of reference bias in self-reported health measures. The results indicate that if we do not control for unobservable individual specific effects, the response to a subjective health state measure suffers from age norming. Age norming can be controlled for by a random effects estimation technique using longitudinal data. Further, estimates are presented on the rate of depreciation of health. Finally, simulations of life expectancy indicate that the estimated model provides a reasonably good fit of the true life expectancy.

Application of pattern mixture models to address missing data in longitudinal data analysis using SPSS.

PubMed

Son, Heesook; Friedmann, Erika; Thomas, Sue A

2012-01-01

Longitudinal studies are used in nursing research to examine changes over time in health indicators. Traditional approaches to longitudinal analysis of means, such as analysis of variance with repeated measures, are limited to analyzing complete cases. This limitation can lead to biased results due to withdrawal or data omission bias or to imputation of missing data, which can lead to bias toward the null if data are not missing completely at random. Pattern mixture models are useful to evaluate the informativeness of missing data and to adjust linear mixed model (LMM) analyses if missing data are informative. The aim of this study was to provide an example of statistical procedures for applying a pattern mixture model to evaluate the informativeness of missing data and conduct analyses of data with informative missingness in longitudinal studies using SPSS. The data set from the Patients' and Families' Psychological Response to Home Automated External Defibrillator Trial was used as an example to examine informativeness of missing data with pattern mixture models and to use a missing data pattern in analysis of longitudinal data. Prevention of withdrawal bias, omitted data bias, and bias toward the null in longitudinal LMMs requires the assessment of the informativeness of the occurrence of missing data. Missing data patterns can be incorporated as fixed effects into LMMs to evaluate the contribution of the presence of informative missingness to and control for the effects of missingness on outcomes. Pattern mixture models are a useful method to address the presence and effect of informative missingness in longitudinal studies.

Longitudinal Care Improves Cessation in Smokers Who Do Not Initially Respond to Treatment by Increasing Cessation Self-Efficacy, Satisfaction, and Readiness to Quit: A Mediated Moderation Analysis

PubMed Central

Burns, Rachel J.; Rothman, Alexander J.; Fu, Steven S.; Lindgren, Bruce; Vock, David M.; Joseph, Anne M.

2015-01-01

Background The Tobacco Longitudinal Care study was a randomized controlled trial for smoking cessation. It demonstrated that longitudinal care for smoking cessation, in which telephone-based counseling and nicotine replacement therapy was offered for 12 months, was more effective than standard 8-week treatment. Purpose To identify for whom and how longitudinal care increased the likelihood of abstinence. Methods Mediated moderation analyses across three time points. Results There was a trend towards smokers who did not respond to treatment (i.e., were still smoking) by 21 days being more likely to be abstinent at 6 months if they received longitudinal care rather than usual care. Similarly, those who did not respond to treatment by 3 months were more likely to be abstinent at 12 months if they received longitudinal care. At both time points, the likelihood of abstinence did not differ across treatment conditions among participants who responded to treatment (i.e., quit smoking). The effect on 6-month outcomes was mediated by satisfaction and readiness to quit. Cessation self-efficacy, satisfaction, and readiness to quit mediated the effect on 12-month outcomes. The effect of treatment condition on the likelihood of abstinence at 18 months was not moderated by response to treatment at 6 months. Conclusions Smokers who did not respond to initial treatment benefited from longitudinal care. Differential effects of treatment condition were not observed among those who responded to early treatment. Conditional assignment to longitudinal care may be useful. Determining for whom and how interventions work over time will advance theory and practice. PMID:26373657

Longitudinal Care Improves Cessation in Smokers Who Do Not Initially Respond to Treatment by Increasing Cessation Self-Efficacy, Satisfaction, and Readiness to Quit: A Mediated Moderation Analysis.

PubMed

Burns, Rachel J; Rothman, Alexander J; Fu, Steven S; Lindgren, Bruce; Vock, David M; Joseph, Anne M

2016-02-01

The Tobacco Longitudinal Care study was a randomized controlled trial for smoking cessation. It demonstrated that longitudinal care for smoking cessation, in which telephone-based counseling and nicotine replacement therapy were offered for 12 months, was more effective than the standard 8-week treatment. This study aims to identify for whom and how longitudinal care increased the likelihood of abstinence. Mediated moderation analyses were utilized across three time points. There was a trend towards smokers who did not respond to treatment (i.e., were still smoking) by 21 days being more likely to be abstinent at 6 months if they received longitudinal care rather than usual care. Similarly, those who did not respond to treatment by 3 months were more likely to be abstinent at 12 months if they received longitudinal care. At both time points, the likelihood of abstinence did not differ across treatment conditions among participants who responded to treatment (i.e., quit smoking). The effect on 6-month outcomes was mediated by satisfaction and readiness to quit. Cessation self-efficacy, satisfaction, and readiness to quit mediated the effect on 12-month outcomes. The effect of treatment condition on the likelihood of abstinence at 18 months was not moderated by response to treatment at 6 months. Smokers who did not respond to initial treatment benefited from longitudinal care. Differential effects of treatment condition were not observed among those who responded to early treatment. Conditional assignment to longitudinal care may be useful. Determining for whom and how interventions work over time will advance theory and practice.

A randomized controlled trial of an online, modular, active learning training program for behavioral activation for depression.

PubMed

Puspitasari, Ajeng J; Kanter, Jonathan W; Busch, Andrew M; Leonard, Rachel; Dunsiger, Shira; Cahill, Shawn; Martell, Christopher; Koerner, Kelly

2017-08-01

This randomized-controlled trial assessed the efficacy of a trainer-led, active-learning, modular, online behavioral activation (BA) training program compared with a self-paced online BA training with the same modular content. Seventy-seven graduate students (M = 30.3 years, SD = 6.09; 76.6% female) in mental health training programs were randomly assigned to receive either the trainer-led or self-paced BA training. Both trainings consisted of 4 weekly sessions covering 4 core BA strategies. Primary outcomes were changes in BA skills as measured by an objective role-play assessment and self-reported use of BA strategies. Assessments were conducted at pre-, post-, and 6-weeks after training. A series of longitudinal mixed effect models assessed changes in BA skills and a longitudinal model implemented with generalized estimating equations assessed BA use over time. Significantly greater increases in total BA skills were found in the trainer-led training condition. The trainer-led training condition also showed greater increases in all core BA skills either at posttraining, follow-up, or both. Reported use of BA strategies with actual clients increased significantly from pre- to posttraining and maintained at follow-up in both training conditions. This trial adds to the literature on the efficacy of online training as a method to disseminate BA. Online training with an active learning, modular approach may be a promising and accessible implementation strategy. Additional strategies may need to be paired with the online BA training to assure the long-term implementation and sustainability of BA in clinical practice. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Conditional Monte Carlo randomization tests for regression models.

PubMed

Parhat, Parwen; Rosenberger, William F; Diao, Guoqing

2014-08-15

We discuss the computation of randomization tests for clinical trials of two treatments when the primary outcome is based on a regression model. We begin by revisiting the seminal paper of Gail, Tan, and Piantadosi (1988), and then describe a method based on Monte Carlo generation of randomization sequences. The tests based on this Monte Carlo procedure are design based, in that they incorporate the particular randomization procedure used. We discuss permuted block designs, complete randomization, and biased coin designs. We also use a new technique by Plamadeala and Rosenberger (2012) for simple computation of conditional randomization tests. Like Gail, Tan, and Piantadosi, we focus on residuals from generalized linear models and martingale residuals from survival models. Such techniques do not apply to longitudinal data analysis, and we introduce a method for computation of randomization tests based on the predicted rate of change from a generalized linear mixed model when outcomes are longitudinal. We show, by simulation, that these randomization tests preserve the size and power well under model misspecification. Copyright © 2014 John Wiley & Sons, Ltd.

B-737 Linear Autoland Simulink Model

NASA Technical Reports Server (NTRS)

Belcastro, Celeste (Technical Monitor); Hogge, Edward F.

2004-01-01

The Linear Autoland Simulink model was created to be a modular test environment for testing of control system components in commercial aircraft. The input variables, physical laws, and referenced frames used are summarized. The state space theory underlying the model is surveyed and the location of the control actuators described. The equations used to realize the Dryden gust model to simulate winds and gusts are derived. A description of the pseudo-random number generation method used in the wind gust model is included. The longitudinal autopilot, lateral autopilot, automatic throttle autopilot, engine model and automatic trim devices are considered as subsystems. The experience in converting the Airlabs FORTRAN aircraft control system simulation to a graphical simulation tool (Matlab/Simulink) is described.

Are Evidence-based Practices Associated With Effective Prevention of Hospital-acquired Pressure Ulcers in US Academic Medical Centers?

PubMed

Padula, William V; Gibbons, Robert D; Valuck, Robert J; Makic, Mary B F; Mishra, Manish K; Pronovost, Peter J; Meltzer, David O

2016-05-01

In 2008, the Centers for Medicare and Medicaid Services (CMS) established nonpayment policies resulting from costliness of hospital-acquired pressure ulcers (HAPUs) to hospitals. This prompted hospitals to adopt quality improvement (QI) interventions that increase use of evidence-based practices (EBPs) for HAPU prevention. To evaluate the longitudinal impact of CMS policy and QI adoption on HAPU rates. We characterized longitudinal adoption of 25 QI interventions that support EBPs through hospital leadership, staff, information technology, and performance and improvement. Quarterly counts of HAPU incidence and inpatient characteristics were collected from 55 University HealthSystem Consortium hospitals between 2007 and 2012. Mixed-effects regression models tested the longitudinal association of CMS policy, HAPU coding, and QI on HAPU rates. The models assumed level-2 random intercepts and random effects for CMS policy and EBP implementation to account for between-hospital variability in HAPU incidence. Controlling for all 25 QI interventions, specific updates to EBPs for HAPU prevention had a significant, though modest reduction on HAPU rates (-1.86 cases/quarter; P=0.002) and the effect of CMS nonpayment policy on HAPU prevention was much greater (-11.32 cases/quarter; P<0.001). HAPU rates were significantly lower after changes in CMS reimbursement. Reductions are associated with hospital-wide implementation of EBPs for HAPU prevention. Given that administrative data were used, it remains unknown whether these improvements were due to changes in coding or improved quality of care.

Are Evidence-based Practices Associated with Effective Prevention of Hospital-acquired Pressure Ulcers in U.S. Academic Medical Centers?

PubMed Central

Padula, William V.; Gibbons, Robert D.; Valuck, Robert J.; Makic, Mary Beth F.; Mishra, Manish K.; Pronovost, Peter J.; Meltzer, David O.

2016-01-01

Background In 2008, the Centers for Medicare and Medicaid Services (CMS) established nonpayment policies resulting from costliness of hospital-acquired pressure ulcers (HAPUs) to hospitals. This prompted hospitals to adopt quality improvement (QI) interventions that increase use of evidence-based practices (EBPs) for HAPU prevention. Objective To evaluate the longitudinal impact of CMS policy and QI adoption on HAPU rates. Methods We characterized longitudinal adoption of 25 QI interventions that support EBPs through hospital leadership, staff, information technology, and performance and improvement. Quarterly counts of HAPU incidence and inpatient characteristics were collected from 55 UHC hospitals between 2007–2012. Mixed-effects regression models tested the longitudinal association of CMS policy, HAPU coding and QI on HAPU rates. The models assumed level-2 random-intercepts and random effects for CMS policy and EBP implementation to account for between-hospital variability in HAPU incidence. Results Controlling for all 25 QI interventions, specific updates to EBPs for HAPU prevention had a significant, though modest reduction on HAPU rates (−1.86 cases/quarter; p=0.002) and the effect of CMS nonpayment policy on HAPU prevention was much greater (−11.32 cases/quarter; p<0.001). Conclusions HAPU rates were significantly lower following changes in CMS reimbursement. Reductions are associated with hospital-wide implementation of EBPs for HAPU prevention. Given that administrative data were used, it remains unknown whether these improvements were due to changes in coding or improved quality of care. PMID:27078824

Transversely polarized source cladding for an optical fiber

NASA Technical Reports Server (NTRS)

Egalon, Claudio Oliveira (Inventor); Rogowski, Robert S. (Inventor)

1994-01-01

An optical fiber comprising a fiber core having a longitudinal symmetry axis is provided. An active cladding surrounds a portion of the fiber core and comprises light-producing sources which emit light in response to chemical or light excitation. The cladding sources are oriented transversely with respect to the longitudinal axis of the fiber core. This polarization results in a superior power efficiency compared to active cladding sources that are randomly polarized or longitudinally polarized parallel with the longitudinal symmetry axis.

Stimulus control and affect in dietary behaviours. An intensive longitudinal study.

PubMed

Schüz, Benjamin; Bower, Jodie; Ferguson, Stuart G

2015-04-01

Dietary behaviours are substantially influenced by environmental and internal stimuli, such as mood, social situation, and food availability. However, little is known about the role of stimulus control for eating in non-clinical populations, and no studies so far have looked at eating and drinking behaviour simultaneously. 53 individuals from the general population took part in an intensive longitudinal study with repeated, real-time assessments of eating and drinking using Ecological Momentary Assessment. Eating was assessed as main meals and snacks, drinks assessments were separated along alcoholic and non-alcoholic drinks. Situational and internal stimuli were assessed during both eating and drinking events, and during randomly selected non-eating occasions. Hierarchical multinomial logistic random effects models were used to analyse data, comparing dietary events to non-eating occasions. Several situational and affective antecedents of dietary behaviours could be identified. Meals were significantly associated with having food available and observing others eat. Snacking was associated with negative affect, having food available, and observing others eat. Engaging in activities and being with others decreased the likelihood of eating behaviours. Non-alcoholic drinks were associated with observing others eat, and less activities and company. Alcoholic drinks were associated with less negative affect and arousal, and with observing others eat. RESULTS support the role of stimulus control in dietary behaviours, with support for both internal and external, in particular availability and social stimuli. The findings for negative affect support the idea of comfort eating, and results point to the formation of eating habits via cue-behaviour associations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of a theory-based (AIDS Risk Reduction Model) cognitive behavioral intervention versus enhanced counseling for abused ethnic minority adolescent women on infection with sexually transmitted infection: results of a randomized controlled trial.

PubMed

Champion, Jane Dimmitt; Collins, Jennifer L

2012-02-01

Ethnic minority adolescent women with a history of sexual or physical abuse and sexually transmitted infections represent a vulnerable population at risk for HIV. Community-based interventions for behavior modification and subsequent risk reduction have not been effective among these women. To evaluate the effects of a theory-based (AIDS Risk Reduction Model) cognitive behavioral intervention model versus enhanced counseling for abused ethnic minority adolescent women on infection with sexually transmitted infection at 6 and 12 months follow-up. Controlled randomized trial with longitudinal follow-up. Southwestern United States, Metropolitan community-based clinic. Mexican-and-African American adolescent women aged 14-18 years with a history of abuse or sexually transmitted infection seeking sexual health care. Extensive preliminary study for intervention development was conducted including individual interviews, focus groups, secondary data analysis, pre-testing and feasibility testing for modification of an evidence-based intervention prior to testing in the randomized controlled trial. Following informed consents for participation in the trial, detailed interviews concerning demographics, abuse history, sexual risk behavior, sexual health and physical exams were obtained. Randomization into either control or intervention groups was conducted. Intervention participants received workshop, support group and individual counseling sessions. Control participants received abuse and enhanced clinical counseling. Follow-up including detailed interview and physical exam was conducted at 6 and 12 months following study entry to assess for infection. Intention to treat analysis was conducted to assess intervention effects using chi-square and multiple regression models. 409 Mexican-(n=342) and African-(n=67) American adolescent women with abuse and sexually transmitted infection histories were enrolled; 90% intervention group attendance; longitudinal follow-up at 6 (93%) and 12 (94%) months. Intervention (n=199) versus control (n=210) group participants experienced fewer infections at 0-6 (0% versus 6.6%, p=.001), 6-12 (3.6% versus 7.8%, p=.005, CI 95% lower-upper .001-.386) and 0-12 (4.8% versus 13.2%, p=.002, CI 95% lower-upper, .002-.531) month intervals. A cognitive behavioral intervention specifically designed for ethnic minority adolescent women with a history of abuse and sexually transmitted infection was effective for prevention of infection. These results provide evidence for development of evidence-based interventions for sexually transmitted infection/HIV. Implications include translation to community-clinic-based settings for prevention of adverse outcomes regarding sexual health of adolescent women. Copyright © 2011 Elsevier Ltd. All rights reserved.

Growth hormone combined with child-specific motor training improves motor development in infants with Prader-Willi syndrome: a randomized controlled trial.

PubMed

Reus, Linda; Pelzer, Ben J; Otten, Barto J; Siemensma, Elbrich P C; van Alfen-van der Velden, Janielle A A E M; Festen, Dederieke A M; Hokken-Koelega, Anita C S; Nijhuis-van der Sanden, Maria W G

2013-10-01

Although severe motor problems in infants with Prader-Willi syndrome (PWS) are striking, motor development has never been studied longitudinally and the results of growth hormone (GH) treatment on motor development are contradictory. The authors studied whether GH treatment can enhance the effect of physical training on motor development in infants with PWS. Twenty-two infants were followed for two years during a randomized controlled trial. The treatment and control groups began GH after baseline or following a control period, respectively. Both groups followed a child-specific physical training program. Motor performance was measured every three months. Multi-level regression analysis revealed that motor development differed significantly between infants (p<.001), and this could be partially explained by baseline motor developmental level (p<.01). GH treatment enhanced the effects of child-specific physical training on both motor developmental rate and motor developmental potential. Moreover, this effect was more pronounced when GH treatment was initiated at a younger age. Copyright © 2013 Elsevier Ltd. All rights reserved.

Maintaining Engagement in Long-term Interventions with Relational Agents

PubMed Central

Bickmore, Timothy; Schulman, Daniel; Yin, Langxuan

2011-01-01

We discuss issues in designing virtual humans for applications which require long-term voluntary use, and the problem of maintaining engagement with users over time. Concepts and theories related to engagement from a variety of disciplines are reviewed. We describe a platform for conducting studies into long-term interactions between humans and virtual agents, and present the results of two longitudinal randomized controlled experiments in which the effect of manipulations of agent behavior on user engagement was assessed. PMID:21318052

Cancer-related fatigue--mechanisms, risk factors, and treatments.

PubMed

Bower, Julienne E

2014-10-01

Fatigue is one of the most common adverse effects of cancer that might persist for years after treatment completion in otherwise healthy survivors. Cancer-related fatigue causes disruption in all aspects of quality of life and might be a risk factor of reduced survival. The prevalence and course of fatigue in patients with cancer have been well characterized and there is growing understanding of the underlying biological mechanisms. Inflammation seems to have a key role in fatigue before, during, and after cancer-treatment. However, there is a considerable variability in the presentation of cancer-related fatigue, much of which is not explained by disease-related or treatment-related characteristics, suggesting that host factors might be important in the development and persistence of this symptom. Indeed, longitudinal studies have identified genetic, biological, psychosocial, and behavioural risk factors associated with cancer-related fatigue. Although no current gold-standard treatment for fatigue is available, a variety of intervention approaches have shown beneficial effects in randomized controlled trials, including physical activity, psychosocial, mind-body, and pharmacological treatments. This Review describes the mechanisms, risk factors, and possible interventions for cancer-related fatigue, focusing on recent longitudinal studies and randomized trials that have targeted fatigued patients.

A randomized clinical trial aimed at preventing poor psychosocial and glycemic outcomes in teens with type 1 diabetes (T1D)

PubMed Central

Weissberg-Benchell, Jill; Rausch, Joseph; Iturralde, Esti; Jedraszko, Aneta; Hood, Korey

2016-01-01

Adolescents with type 1 diabetes have an increased risk for a variety of emotional and behavioral challenges as well as negative diabetes outcomes. This study was designed to compare the effectiveness of a depression-prevention, resilience promotion program with an advanced diabetes education program. Each program consisted of 9 group-based sessions. There were 264 adolescents enrolled in this multi-site randomized clinical trial. The primary outcomes were depressive symptoms and glycemic control; secondary outcomes included resilience skills, diabetes management and adherence, and diabetes-specific distress. The goal of the present paper is to describe the study design, the intervention, and the baseline characteristics of the sample. Preliminary data suggests that enrollment, randomization and retention were successful. Longitudinal follow-up and examination of mechanisms of action as they relate to psychosocial and glycemic outcomes will be explored in the future. PMID:27267154

Longitudinal Control for Mengshi Autonomous Vehicle via Cloud Model

NASA Astrophysics Data System (ADS)

Gao, H. B.; Zhang, X. Y.; Li, D. Y.; Liu, Y. C.

2018-03-01

Dynamic robustness and stability control is a requirement for self-driving of autonomous vehicle. Longitudinal control method of autonomous is a key technique which has drawn the attention of industry and academe. In this paper, we present a longitudinal control algorithm based on cloud model for Mengshi autonomous vehicle to ensure the dynamic stability and tracking performance of Mengshi autonomous vehicle. An experiments is applied to test the implementation of the longitudinal control algorithm. Empirical results show that if the longitudinal control algorithm based Gauss cloud model are applied to calculate the acceleration, and the vehicles drive at different speeds, a stable longitudinal control effect is achieved.

Analysis of longitudinal "time series" data in toxicology.

PubMed

Cox, C; Cory-Slechta, D A

1987-02-01

Studies focusing on chronic toxicity or on the time course of toxicant effect often involve repeated measurements or longitudinal observations of endpoints of interest. Experimental design considerations frequently necessitate between-group comparisons of the resulting trends. Typically, procedures such as the repeated-measures analysis of variance have been used for statistical analysis, even though the required assumptions may not be satisfied in some circumstances. This paper describes an alternative analytical approach which summarizes curvilinear trends by fitting cubic orthogonal polynomials to individual profiles of effect. The resulting regression coefficients serve as quantitative descriptors which can be subjected to group significance testing. Randomization tests based on medians are proposed to provide a comparison of treatment and control groups. Examples from the behavioral toxicology literature are considered, and the results are compared to more traditional approaches, such as repeated-measures analysis of variance.

Research Assistants Caught in Limbo: Considering Their Role in Quantitative, Longitudinal Research with Vulnerable Populations.

PubMed

Zerger, Suzanne; Pridham, Katherine Francombe; Plenert, Erin; Newberry, Caitlin; Whisler, Adam; Fernando, Indira; Ahmed, Naveed

2015-11-01

Research assistants (RAs) play a variety of roles that are critical in making research happen and in determining its quality and effectiveness. Yet their locus of power in the production of knowledge stands in sharp contrast to their relative powerlessness in the hierarchical research organization. This article explores the experiences of RAs engaged in a randomized controlled longitudinal field trial of a Housing First intervention for individuals experiencing homelessness and mental illness in Toronto. They encountered several unexpected effects of navigating the power ascribed to them by both study participants and community service providers. This study underscores the importance of acknowledging that RAs are the face of the research study in the field, and of better understanding implications associated with that fact, especially when marginalized populations and their providers are involved.

Examining solutions to missing data in longitudinal nursing research.

PubMed

Roberts, Mary B; Sullivan, Mary C; Winchester, Suzy B

2017-04-01

Longitudinal studies are highly valuable in pediatrics because they provide useful data about developmental patterns of child health and behavior over time. When data are missing, the value of the research is impacted. The study's purpose was to (1) introduce a three-step approach to assess and address missing data and (2) illustrate this approach using categorical and continuous-level variables from a longitudinal study of premature infants. A three-step approach with simulations was followed to assess the amount and pattern of missing data and to determine the most appropriate imputation method for the missing data. Patterns of missingness were Missing Completely at Random, Missing at Random, and Not Missing at Random. Missing continuous-level data were imputed using mean replacement, stochastic regression, multiple imputation, and fully conditional specification (FCS). Missing categorical-level data were imputed using last value carried forward, hot-decking, stochastic regression, and FCS. Simulations were used to evaluate these imputation methods under different patterns of missingness at different levels of missing data. The rate of missingness was 16-23% for continuous variables and 1-28% for categorical variables. FCS imputation provided the least difference in mean and standard deviation estimates for continuous measures. FCS imputation was acceptable for categorical measures. Results obtained through simulation reinforced and confirmed these findings. Significant investments are made in the collection of longitudinal data. The prudent handling of missing data can protect these investments and potentially improve the scientific information contained in pediatric longitudinal studies. © 2017 Wiley Periodicals, Inc.

Accelerated longitudinal designs: An overview of modelling, power, costs and handling missing data.

PubMed

Galbraith, Sally; Bowden, Jack; Mander, Adrian

2017-02-01

Longitudinal studies are often used to investigate age-related developmental change. Whereas a single cohort design takes a group of individuals at the same initial age and follows them over time, an accelerated longitudinal design takes multiple single cohorts, each one starting at a different age. The main advantage of an accelerated longitudinal design is its ability to span the age range of interest in a shorter period of time than would be possible with a single cohort longitudinal design. This paper considers design issues for accelerated longitudinal studies. A linear mixed effect model is considered to describe the responses over age with random effects for intercept and slope parameters. Random and fixed cohort effects are used to cope with the potential bias accelerated longitudinal designs have due to multiple cohorts. The impact of other factors such as costs and the impact of dropouts on the power of testing or the precision of estimating parameters are examined. As duration-related costs increase relative to recruitment costs the best designs shift towards shorter duration and eventually cross-sectional design being best. For designs with the same duration but differing interval between measurements, we found there was a cutoff point for measurement costs relative to recruitment costs relating to frequency of measurements. Under our model of 30% dropout there was a maximum power loss of 7%.

Zero-inflated count models for longitudinal measurements with heterogeneous random effects.

PubMed

Zhu, Huirong; Luo, Sheng; DeSantis, Stacia M

2017-08-01

Longitudinal zero-inflated count data arise frequently in substance use research when assessing the effects of behavioral and pharmacological interventions. Zero-inflated count models (e.g. zero-inflated Poisson or zero-inflated negative binomial) with random effects have been developed to analyze this type of data. In random effects zero-inflated count models, the random effects covariance matrix is typically assumed to be homogeneous (constant across subjects). However, in many situations this matrix may be heterogeneous (differ by measured covariates). In this paper, we extend zero-inflated count models to account for random effects heterogeneity by modeling their variance as a function of covariates. We show via simulation that ignoring intervention and covariate-specific heterogeneity can produce biased estimates of covariate and random effect estimates. Moreover, those biased estimates can be rectified by correctly modeling the random effects covariance structure. The methodological development is motivated by and applied to the Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence (COMBINE) study, the largest clinical trial of alcohol dependence performed in United States with 1383 individuals.

On framing the research question and choosing the appropriate research design.

PubMed

Parfrey, Patrick S; Ravani, Pietro

2015-01-01

Clinical epidemiology is the science of human disease investigation with a focus on diagnosis, prognosis, and treatment. The generation of a reasonable question requires definition of patients, interventions, controls, and outcomes. The goal of research design is to minimize error, to ensure adequate samples, to measure input and output variables appropriately, to consider external and internal validities, to limit bias, and to address clinical as well as statistical relevance. The hierarchy of evidence for clinical decision-making places randomized controlled trials (RCT) or systematic review of good quality RCTs at the top of the evidence pyramid. Prognostic and etiologic questions are best addressed with longitudinal cohort studies.

On framing the research question and choosing the appropriate research design.

PubMed

Parfrey, Patrick; Ravani, Pietro

2009-01-01

Clinical epidemiology is the science of human disease investigation with a focus on diagnosis, prognosis, and treatment. The generation of a reasonable question requires the definition of patients, interventions, controls, and outcomes. The goal of research design is to minimize error, ensure adequate samples, measure input and output variables appropriately, consider external and internal validities, limit bias, and address clinical as well as statistical relevance. The hierarchy of evidence for clinical decision making places randomized controlled trials (RCT) or systematic review of good quality RCTs at the top of the evidence pyramid. Prognostic and etiologic questions are best addressed with longitudinal cohort studies.

Predictors for Physical Activity in Adolescent Girls Using Statistical Shrinkage Techniques for Hierarchical Longitudinal Mixed Effects Models

PubMed Central

Grant, Edward M.; Young, Deborah Rohm; Wu, Tong Tong

2015-01-01

We examined associations among longitudinal, multilevel variables and girls’ physical activity to determine the important predictors for physical activity change at different adolescent ages. The Trial of Activity for Adolescent Girls 2 study (Maryland) contributed participants from 8th (2009) to 11th grade (2011) (n=561). Questionnaires were used to obtain demographic, and psychosocial information (individual- and social-level variables); height, weight, and triceps skinfold to assess body composition; interviews and surveys for school-level data; and self-report for neighborhood-level variables. Moderate to vigorous physical activity minutes were assessed from accelerometers. A doubly regularized linear mixed effects model was used for the longitudinal multilevel data to identify the most important covariates for physical activity. Three fixed effects at the individual level and one random effect at the school level were chosen from an initial total of 66 variables, consisting of 47 fixed effects and 19 random effects variables, in additional to the time effect. Self-management strategies, perceived barriers, and social support from friends were the three selected fixed effects, and whether intramural or interscholastic programs were offered in middle school was the selected random effect. Psychosocial factors and friend support, plus a school’s physical activity environment, affect adolescent girl’s moderate to vigorous physical activity longitudinally. PMID:25928064

Ten-year longitudinal trajectories of older adults' basic and everyday cognitive abilities.

PubMed

Yam, Anna; Gross, Alden L; Prindle, John J; Marsiske, Michael

2014-11-01

To examine the longitudinal trajectories of everyday cognition and longitudinal associations with basic (i.e., laboratory and experimentally measured) cognitive abilities, including verbal memory, inductive reasoning, visual processing speed, and vocabulary. Participants were healthy older adults drawn from the no-treatment control group (N = 698) of the Advanced Cognitive Training for the Independent and Vital Elderly (Willis et al., 2006) randomized trial and were assessed at baseline and 1, 2, 3, 5, and 10 years later. Analyses were conducted using latent growth models. Modeling revealed an overall inverted-U shape (quadratic) trajectory across cognitive domains. Among basic cognitive predictors, level and slope in reasoning demonstrated the closest association to level and slope of everyday cognition, and accounted for most of the individual differences in linear gain in everyday cognition. Everyday cognition is not buffered against decline, and is most closely related to inductive reasoning in healthy older adults. To establish the clinical utility of everyday cognitive measures, future research should examine these associations in samples with more cognitive impairment. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Modeling Achievement Trajectories when Attrition Is Informative

ERIC Educational Resources Information Center

Feldman, Betsy J.; Rabe-Hesketh, Sophia

2012-01-01

In longitudinal education studies, assuming that dropout and missing data occur completely at random is often unrealistic. When the probability of dropout depends on covariates and observed responses (called "missing at random" [MAR]), or on values of responses that are missing (called "informative" or "not missing at random" [NMAR]),…

Computerized counseling reduces HIV-1 viral load and sexual transmission risk: findings from a randomized controlled trial.

PubMed

Kurth, Ann E; Spielberg, Freya; Cleland, Charles M; Lambdin, Barrot; Bangsberg, David R; Frick, Pamela A; Severynen, Anneleen O; Clausen, Marc; Norman, Robert G; Lockhart, David; Simoni, Jane M; Holmes, King K

2014-04-15

Evaluate a computerized intervention supporting antiretroviral therapy (ART) adherence and HIV transmission prevention. Longitudinal randomized controlled trial. An academic HIV clinic and a community-based organization in Seattle. In a total of 240 HIV-positive adults on ART, 209 completed 9-month follow-up (87% retention). Randomization to computerized counseling or assessment only, 4 sessions over 9 months. HIV-1 viral suppression, and self-reported ART adherence and transmission risks, compared using generalized estimating equations. Overall, intervention participants had reduced viral load: mean 0.17 log10 decline, versus 0.13 increase in controls, P = 0.053, and significant difference in ART adherence baseline to 9 months (P = 0.046). Their sexual transmission risk behaviors decreased (odds ratio = 0.55, P = 0.020), a reduction not seen among controls (odds ratio = 1.1, P = 0.664), and a significant difference in change (P = 0.040). Intervention effect was driven by those most in need; among those with detectable virus at baseline (>30 copies/mL, n = 89), intervention effect was mean 0.60 log10 viral load decline versus 0.15 increase in controls, P = 0.034. ART adherence at the final follow-up was 13 points higher among intervention participants versus controls, P = 0.038. Computerized counseling is promising for integrated ART adherence and safer sex, especially for individuals with problems in these areas. This is the first intervention to report improved ART adherence, viral suppression, and reduced secondary sexual transmission risk behavior.

Estimating mono- and bi-phasic regression parameters using a mixture piecewise linear Bayesian hierarchical model

PubMed Central

Zhao, Rui; Catalano, Paul; DeGruttola, Victor G.; Michor, Franziska

2017-01-01

The dynamics of tumor burden, secreted proteins or other biomarkers over time, is often used to evaluate the effectiveness of therapy and to predict outcomes for patients. Many methods have been proposed to investigate longitudinal trends to better characterize patients and to understand disease progression. However, most approaches assume a homogeneous patient population and a uniform response trajectory over time and across patients. Here, we present a mixture piecewise linear Bayesian hierarchical model, which takes into account both population heterogeneity and nonlinear relationships between biomarkers and time. Simulation results show that our method was able to classify subjects according to their patterns of treatment response with greater than 80% accuracy in the three scenarios tested. We then applied our model to a large randomized controlled phase III clinical trial of multiple myeloma patients. Analysis results suggest that the longitudinal tumor burden trajectories in multiple myeloma patients are heterogeneous and nonlinear, even among patients assigned to the same treatment cohort. In addition, between cohorts, there are distinct differences in terms of the regression parameters and the distributions among categories in the mixture. Those results imply that longitudinal data from clinical trials may harbor unobserved subgroups and nonlinear relationships; accounting for both may be important for analyzing longitudinal data. PMID:28723910

Onion epidermis as a new model to study the control of growth anisotropy in higher plants.

PubMed

Suslov, Dmitry; Verbelen, Jean-Pierre; Vissenberg, Kris

2009-01-01

To elucidate the role of cellulose microfibrils in the control of growth anisotropy, a link between their net orientation, in vitro cell wall extensibility, and anisotropic cell expansion was studied during development of the adaxial epidermis of onion (Allium cepa) bulb scales using polarization confocal microscopy, creep tests, and light microscopy. During growth the net cellulose alignment across the whole thickness of the outer epidermal wall changed from transverse through random to longitudinal and back to transverse relative to the bulb axis. Cell wall extension in vitro was always higher transverse than parallel to the net cellulose alignment. The direction of growth anisotropy was perpendicular to the net microfibril orientation and changed during development from longitudinal to transverse to the bulb axis. The correlation between the degree of growth anisotropy and the net cellulose alignment was poor. Thus the net cellulose microfibril orientation across the whole thickness of the outer periclinal epidermis wall defines the direction but not the degree of growth anisotropy. Strips isolated from the epidermis in the directions perpendicular and transverse to a net cellulose orientation can be used as an extensiometric model to prove a protein involvement in the control of growth anisotropy.

Longitudinal impact of the Cyber Friendly Schools program on adolescents' cyberbullying behavior.

PubMed

Cross, Donna; Shaw, Thérèse; Hadwen, Kate; Cardoso, Patricia; Slee, Phillip; Roberts, Clare; Thomas, Laura; Barnes, Amy

2016-01-01

Cyberbullying is a major public health problem associated with serious mental, social, and academic consequences for young people. To date, few programs addressing cyberbullying have been developed and empirically tested. The Cyber Friendly Schools (CFS) group-randomized controlled trial measured the longitudinal impact of a whole-school online cyberbullying prevention and intervention program, developed in partnership with young people. Non-government secondary schools in Perth, Western Australia, (N = 35; 3,000+ students) were randomized to an intervention (n = 19) or usual practice control group (n = 16 schools). Students completed online questionnaires in 2010, 2011, and at 1-year follow-up in 2012, measuring their cyberbullying experiences during the previous school term. The intervention group received the program in Grades 8 and 9 (aged 13-14 years). Program effects were tested using two-part growth models. The program was associated with significantly greater declines in the odds of involvement in cyber-victimization and perpetration from pre- to the first post-test, but no other differences were evident between the study conditions. However, teachers implemented only one third of the program content. More work is needed to build teacher capacity and self-efficacy to effectively implement cyberbullying programs. Whole-school cyberbullying interventions implemented in conjunction with other bullying prevention programs may reduce cyber-victimization more than traditional school-based bullying prevention programs alone. Aggr. Behav. 42:166-180, 2016. © 2015 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Health-related quality-of-life outcomes: a reflexology trial with patients with advanced-stage breast cancer.

PubMed

Wyatt, Gwen; Sikorskii, Alla; Rahbar, Mohammad Hossein; Victorson, David; You, Mei

2012-11-01

To evaluate the safety and efficacy of reflexology, a complementary therapy that applies pressure to specific areas of the feet. Longitudinal, randomized clinical trial. Thirteen community-based medical oncology clinics across the midwestern United States. A convenience sample of 385 predominantly Caucasian women with advanced-stage breast cancer receiving chemotherapy and/or hormonal therapy. Following the baseline interview, women were randomized into three primary groups: reflexology (n = 95), lay foot manipulation (LFM) (n = 95), or conventional care (n = 96). Two preliminary reflexology (n = 51) and LFM (n = 48) test groups were used to establish the protocols. Participants were interviewed again postintervention at study weeks 5 and 11. Breast cancer-specific health-related quality of life (HRQOL), physical functioning, and symptoms. No adverse events were reported. A longitudinal comparison revealed significant improvements in physical functioning for the reflexology group compared to the control group (p = 0.04). Severity of dyspnea was reduced in the reflexology group compared to the control group (p < 0.01) and the LFM group (p = 0.02). No differences were found on breast cancer-specific HRQOL, depressive symptomatology, state anxiety, pain, and nausea. Reflexology may be added to existing evidence-based supportive care to improve HRQOL for patients with advanced-stage breast cancer during chemotherapy and/or hormonal therapy. Reflexology can be recommended for safety and usefulness in relieving dyspnea and enhancing functional status among women with advanced-stage breast cancer.

[Effectiveness of educational interventions conducted in latin america for the prevention of overweight and obesity in scholar children from 6-17 years old; a systematic review].

PubMed

Mancipe Navarrete, Jenny Alejandra; Garcia Villamil, Shanen Samanta; Correa Bautista, Jorge Enrique; Meneses-Echávez, José Francisco; González-Jiménez, Emilio; Schmidt Rio-Valle, Jacqueline

2014-10-03

Overweight and obesity are serious public health problem, which is specially among children populations. To determine the effectiveness of educational interventions conducted in Latino America for the prevention of overweight and obesity in scholar children from 6 to 17 years old. Metodology: MEDLINE, LILACS and EMBASE were searched between february and may 2014 to retrieve randomized controlled trials and longitudinal studies that evaluated the effects of educational interventions intended to retrieve randomized controlled trials and longitudinal studies aiming to prevent overweight and obesity among Latinoamerican children. Risk of bias was evaluated using the PEDro scale and the CASPe tool. Twenty one studies were included (n=12,092). Different types of educational interventions were identified, such as nutritional campaigns, physical activity practice and environmental changes. Mixed approaches combining nutritional campaigns, physical activity promotion and enviromental changes were the most effective interventions, since their results produced the largest improvements in the overweight and obesity of children. None evidence of reporting bias was observed. Educational interventions performed in the educational environment that combined an adequate nutrition and the promotion of physical activity practice, are more effective for preventing overweight and obesity in Latino American children, although familiar interventions are also encouraged approach, associated with better responses on the behavioral change in scholar children. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Reducing diarrhoea in Guatemalan children: randomized controlled trial of flocculant-disinfectant for drinking-water.

PubMed Central

Chiller, Tom M.; Mendoza, Carlos E.; Lopez, M. Beatriz; Alvarez, Maricruz; Hoekstra, Robert M.; Keswick, Bruce H.; Luby, Stephen P.

2006-01-01

OBJECTIVE: To examine the effect of a new point-of-use treatment for drinking-water, a commercially developed flocculant-disinfectant, on the prevalence of diarrhoea in children. METHODS: We conducted a randomized controlled trial among 514 rural Guatemalan households, divided into 42 neighbourhood clusters, for 13 weeks, from 4 November 2002 through 31 January 2003. Clusters assigned to water treatment with the flocculant-disinfectant were compared with those using their usual water-handling practices. The longitudinal prevalence of diarrhoea was calculated as the proportion of total days with diarrhoea divided by the total number of days of observation. The prevalence of diarrhoea was compared using the Wilcoxon rank-sum test. FINDINGS: The 1702 people in households receiving the disinfectant had a prevalence of diarrhoea that was 40% lower than that among the 1699 people using standard water-handling practices (0.9% versus 1.5%; P = 0.001). In households using the flocculant-disinfectant, children < 1 year of age had a 39% lower prevalence of diarrhoea than those in households using their standard practices (3.7% versus 6.0%; P = 0.005). CONCLUSION: In settings where families rarely treat drinking-water, we introduced a novel flocculant-disinfectant that reduced the longitudinal prevalence of diarrhoea, especially among children aged < 1 year, among whom diarrhoea has been strongly associated with mortality. Successful introduction and use of this product could contribute to preventing diarrhoeal disease globally. PMID:16501712

Longitudinal Relationship Among Physical Fitness, Walking-Related Physical Activity, and Fatigue in Children With Cerebral Palsy.

PubMed

Balemans, Astrid C J; van Wely, Leontien; Becher, Jules G; Dallmeijer, Annet J

2015-07-01

A vicious circle of decreased physical fitness, early fatigue, and low physical activity levels (PAL) is thought to affect children with cerebral palsy (CP). However, the relationship of changes in physical fitness to changes in PAL and fatigue is unclear. The objective of this study was to investigate the associations among changes in physical fitness, walking-related PAL, and fatigue in children with CP. This study was a secondary analysis of a randomized controlled trial with measurements at baseline, 6 months (after the intervention period), and 12 months. Twenty-four children with bilateral spastic CP and 22 with unilateral spastic CP, aged 7 to 13 years, all walking, participated in this study. Physical fitness was measured by aerobic capacity, anaerobic threshold, anaerobic capacity, and isometric and functional muscle strength. Walking-related PAL was measured using an ankle-worn activity monitor for 1 week. Fatigue was determined with the Pediatric Quality of Life (PedsQL) Multidimensional Fatigue Scale. Longitudinal associations were analyzed by random coefficient regression analysis. In children with bilateral CP, all fitness parameters showed a positive, significant association with walking-related PAL, whereas no associations between physical fitness and walking-related PAL were seen in children with unilateral CP. No clinically relevant association between physical fitness and fatigue was found. Although random coefficient regression analysis can be used to investigate longitudinal associations between parameters, a causal relationship cannot be determined. The actual direction of the association between physical fitness and walking-related PAL, therefore, remains inconclusive. Children with bilateral spastic CP might benefit from improved physical fitness to increase their PAL or vice versa, although this is not the case in children with unilateral CP. There appears to be no relationship between physical fitness and self-reported fatigue in children with CP. Interventions aimed at improving PAL may be differently targeted in children with either bilateral or unilateral CP. © 2015 American Physical Therapy Association.

Causal mediation analysis for longitudinal data with exogenous exposure

PubMed Central

Bind, M.-A. C.; Vanderweele, T. J.; Coull, B. A.; Schwartz, J. D.

2016-01-01

Mediation analysis is a valuable approach to examine pathways in epidemiological research. Prospective cohort studies are often conducted to study biological mechanisms and often collect longitudinal measurements on each participant. Mediation formulae for longitudinal data have been developed. Here, we formalize the natural direct and indirect effects using a causal framework with potential outcomes that allows for an interaction between the exposure and the mediator. To allow different types of longitudinal measures of the mediator and outcome, we assume two generalized mixed-effects models for both the mediator and the outcome. The model for the mediator has subject-specific random intercepts and random exposure slopes for each cluster, and the outcome model has random intercepts and random slopes for the exposure, the mediator, and their interaction. We also expand our approach to settings with multiple mediators and derive the mediated effects, jointly through all mediators. Our method requires the absence of time-varying confounding with respect to the exposure and the mediator. This assumption is achieved in settings with exogenous exposure and mediator, especially when exposure and mediator are not affected by variables measured at earlier time points. We apply the methodology to data from the Normative Aging Study and estimate the direct and indirect effects, via DNA methylation, of air pollution, and temperature on intercellular adhesion molecule 1 (ICAM-1) protein levels. Our results suggest that air pollution and temperature have a direct effect on ICAM-1 protein levels (i.e. not through a change in ICAM-1 DNA methylation) and that temperature has an indirect effect via a change in ICAM-1 DNA methylation. PMID:26272993

Longitudinal trends in gasoline price and physical activity: The CARDIA study

PubMed Central

Hou, Ningqi; Popkin, Barry M; Jacobs, David R; Song, Yan; Guilkey, David K; He, Ka; Lewis, Cora E.; Gordon-Larsen, Penny

2011-01-01

Objective To investigate longitudinal associations between community-level gasoline price and physical activity (PA). Method In the Coronary Artery Risk Development in Young Adults study, 5,115 black and white participants aged 18–30 at baseline 1985–86 were recruited from four U.S. cities (Birmingham, Chicago, Minneapolis and Oakland) and followed over time. We used data from 3 follow-up exams: 1992–93, 1995–96, and 2000–01, when the participants were located across 48 states. From questionnaire data, a total PA score was summarized in exercise units (EU) based on intensity and frequency of 13 PA categories. Using Geographic Information Systems, participants’ residential locations were linked to county-level inflation-adjusted gasoline price data collected by the Council for Community & Economic Research. We used a random-effect longitudinal regression model to examine associations between time-varying gasoline price and time-varying PA, controlling for age, race, gender, baseline study center, and time-varying education, marital status, household income, county cost of living, county bus fare, census block-group poverty, and urbanicity. Results Holding all control variables constant, a 25-cent increase in inflation-adjusted gasoline price was significantly associated with an increase of 9.9 EU in total PA (95%CI: 0.8–19.1). Conclusion Rising prices of gasoline may be associated with an unintended increase in leisure PA. PMID:21338621

Use of remote sensing to identify spatial risk factors for malaria in a region of declining transmission: a cross-sectional and longitudinal community survey.

PubMed

Moss, William J; Hamapumbu, Harry; Kobayashi, Tamaki; Shields, Timothy; Kamanga, Aniset; Clennon, Julie; Mharakurwa, Sungano; Thuma, Philip E; Glass, Gregory

2011-06-10

The burden of malaria has decreased dramatically within the past several years in parts of sub-Saharan Africa. Further malaria control will require targeted control strategies based on evidence of risk. The objective of this study was to identify environmental risk factors for malaria transmission using remote sensing technologies to guide malaria control interventions in a region of declining burden of malaria. Satellite images were used to construct a sampling frame for the random selection of households enrolled in prospective longitudinal and cross-sectional surveys of malaria parasitaemia in Southern Province, Zambia. A digital elevation model (DEM) was derived from the Shuttle Radar Topography Mission version 3 DEM and used for landscape characterization, including landforms, elevation, aspect, slope, topographic wetness, topographic position index and hydrological models of stream networks. A total of 768 individuals from 128 randomly selected households were enrolled over 21 months, from the end of the rainy season in April 2007 through December 2008. Of the 768 individuals tested, 117 (15.2%) were positive by malaria rapid diagnostic test (RDT). Individuals residing within 3.75 km of a third order stream were at increased risk of malaria. Households at elevations above the baseline elevation for the region were at decreasing risk of having RDT-positive residents. Households where new infections occurred were overlaid on a risk map of RDT positive households and incident infections were more likely to be located in high-risk areas derived from prevalence data. Based on the spatial risk map, targeting households in the top 80th percentile of malaria risk would require malaria control interventions directed to only 24% of the households. Remote sensing technologies can be used to target malaria control interventions in a region of declining malaria transmission in southern Zambia, enabling a more efficient use of resources for malaria elimination.

A pattern-mixture model approach for handling missing continuous outcome data in longitudinal cluster randomized trials.

PubMed

Fiero, Mallorie H; Hsu, Chiu-Hsieh; Bell, Melanie L

2017-11-20

We extend the pattern-mixture approach to handle missing continuous outcome data in longitudinal cluster randomized trials, which randomize groups of individuals to treatment arms, rather than the individuals themselves. Individuals who drop out at the same time point are grouped into the same dropout pattern. We approach extrapolation of the pattern-mixture model by applying multilevel multiple imputation, which imputes missing values while appropriately accounting for the hierarchical data structure found in cluster randomized trials. To assess parameters of interest under various missing data assumptions, imputed values are multiplied by a sensitivity parameter, k, which increases or decreases imputed values. Using simulated data, we show that estimates of parameters of interest can vary widely under differing missing data assumptions. We conduct a sensitivity analysis using real data from a cluster randomized trial by increasing k until the treatment effect inference changes. By performing a sensitivity analysis for missing data, researchers can assess whether certain missing data assumptions are reasonable for their cluster randomized trial. Copyright © 2017 John Wiley & Sons, Ltd.

Longitudinal data analysis with non-ignorable missing data.

PubMed

Tseng, Chi-hong; Elashoff, Robert; Li, Ning; Li, Gang

2016-02-01

A common problem in the longitudinal data analysis is the missing data problem. Two types of missing patterns are generally considered in statistical literature: monotone and non-monotone missing data. Nonmonotone missing data occur when study participants intermittently miss scheduled visits, while monotone missing data can be from discontinued participation, loss to follow-up, and mortality. Although many novel statistical approaches have been developed to handle missing data in recent years, few methods are available to provide inferences to handle both types of missing data simultaneously. In this article, a latent random effects model is proposed to analyze longitudinal outcomes with both monotone and non-monotone missingness in the context of missing not at random. Another significant contribution of this article is to propose a new computational algorithm for latent random effects models. To reduce the computational burden of high-dimensional integration problem in latent random effects models, we develop a new computational algorithm that uses a new adaptive quadrature approach in conjunction with the Taylor series approximation for the likelihood function to simplify the E-step computation in the expectation-maximization algorithm. Simulation study is performed and the data from the scleroderma lung study are used to demonstrate the effectiveness of this method. © The Author(s) 2012.

Examining Solutions to Missing Data in Longitudinal Nursing Research

PubMed Central

Roberts, Mary B.; Sullivan, Mary C.; Winchester, Suzy B.

2017-01-01

Purpose Longitudinal studies are highly valuable in pediatrics because they provide useful data about developmental patterns of child health and behavior over time. When data are missing, the value of the research is impacted. The study’s purpose was to: (1) introduce a 3-step approach to assess and address missing data; (2) illustrate this approach using categorical and continuous level variables from a longitudinal study of premature infants. Methods A three-step approach with simulations was followed to assess the amount and pattern of missing data and to determine the most appropriate imputation method for the missing data. Patterns of missingness were Missing Completely at Random, Missing at Random, and Not Missing at Random. Missing continuous-level data were imputed using mean replacement, stochastic regression, multiple imputation, and fully conditional specification. Missing categorical-level data were imputed using last value carried forward, hot-decking, stochastic regression, and fully conditional specification. Simulations were used to evaluate these imputation methods under different patterns of missingness at different levels of missing data. Results The rate of missingness was 16–23% for continuous variables and 1–28% for categorical variables. Fully conditional specification imputation provided the least difference in mean and standard deviation estimates for continuous measures. Fully conditional specification imputation was acceptable for categorical measures. Results obtained through simulation reinforced and confirmed these findings. Practice Implications Significant investments are made in the collection of longitudinal data. The prudent handling of missing data can protect these investments and potentially improve the scientific information contained in pediatric longitudinal studies. PMID:28425202

Advanced Issues in Propensity Scores: Longitudinal and Missing Data

ERIC Educational Resources Information Center

Kupzyk, Kevin A.; Beal, Sarah J.

2017-01-01

In order to investigate causality in situations where random assignment is not possible, propensity scores can be used in regression adjustment, stratification, inverse-probability treatment weighting, or matching. The basic concepts behind propensity scores have been extensively described. When data are longitudinal or missing, the estimation and…

A Composite Likelihood Inference in Latent Variable Models for Ordinal Longitudinal Responses

ERIC Educational Resources Information Center

Vasdekis, Vassilis G. S.; Cagnone, Silvia; Moustaki, Irini

2012-01-01

The paper proposes a composite likelihood estimation approach that uses bivariate instead of multivariate marginal probabilities for ordinal longitudinal responses using a latent variable model. The model considers time-dependent latent variables and item-specific random effects to be accountable for the interdependencies of the multivariate…

Dysbiosis, inflammation, and response to treatment: a longitudinal study of pediatric subjects with newly diagnosed inflammatory bowel disease.

PubMed

Shaw, Kelly A; Bertha, Madeline; Hofmekler, Tatyana; Chopra, Pankaj; Vatanen, Tommi; Srivatsa, Abhiram; Prince, Jarod; Kumar, Archana; Sauer, Cary; Zwick, Michael E; Satten, Glen A; Kostic, Aleksandar D; Mulle, Jennifer G; Xavier, Ramnik J; Kugathasan, Subra

2016-07-13

Gut microbiome dysbiosis has been demonstrated in subjects with newly diagnosed and chronic inflammatory bowel disease (IBD). In this study we sought to explore longitudinal changes in dysbiosis and ascertain associations between dysbiosis and markers of disease activity and treatment outcome. We performed a prospective cohort study of 19 treatment-naïve pediatric IBD subjects and 10 healthy controls, measuring fecal calprotectin and assessing the gut microbiome via repeated stool samples. Associations between clinical characteristics and the microbiome were tested using generalized estimating equations. Random forest classification was used to predict ultimate treatment response (presence of mucosal healing at follow-up colonoscopy) or non-response using patients' pretreatment samples. Patients with Crohn's disease had increased markers of inflammation and dysbiosis compared to controls. Patients with ulcerative colitis had even higher inflammation and dysbiosis compared to those with Crohn's disease. For all cases, the gut microbial dysbiosis index associated significantly with clinical and biological measures of disease severity, but did not associate with treatment response. We found differences in specific gut microbiome genera between cases/controls and responders/non-responders including Akkermansia, Coprococcus, Fusobacterium, Veillonella, Faecalibacterium, and Adlercreutzia. Using pretreatment microbiome data in a weighted random forest classifier, we were able to obtain 76.5 % accuracy for prediction of responder status. Patient dysbiosis improved over time but persisted even among those who responded to treatment and achieved mucosal healing. Although dysbiosis index was not significantly different between responders and non-responders, we found specific genus-level differences. We found that pretreatment microbiome signatures are a promising avenue for prediction of remission and response to treatment.

Persistent osteopenia in ballet dancers with amenorrhea and delayed menarche despite hormone therapy: a longitudinal study.

PubMed

Warren, Michelle P; Brooks-Gunn, Jeanne; Fox, Richard P; Holderness, Claire C; Hyle, Emily P; Hamilton, William G; Hamilton, Linda

2003-08-01

To investigate the role of estrogen deprivation and replacement in amenorrheic and nonamenorrheic dancers on hormone therapy and calcium. Clinical, placebo-controlled, randomized trial study.Healthy volunteers in an academic research environment. Fifty-five dancers (mean age: 22.0 +/- 4.6, age at menarche: 14.7 +/- 2.3 years), including 24 amenorrheics. Amenorrheics were randomized in a controlled trial to receive placebo or Premarin, 0.625 mg for 25 days monthly, with Provera, 10 mg, for 10 of these 25 days (hormone therapy) for 2 years. These women were compared to normally menstruating controls. The study participants also received 1250 mg of calcium per day. Bone mineral density (BMD) measured at the foot, wrist, and lumbar spine. Our overall results showed no difference in BMD between the treated or placebo groups, indicating that hormone therapy did not change or normalize BMD when compared to normals. Five patients (all on placebo) who resumed menses during the study showed an increase in BMD without normalization. These findings suggest that mechanisms other than hypoestrogenism may be involved with the osteopenia associated with exercise-induced amenorrhea.

Gene expression models for prediction of longitudinal dispersion coefficient in streams

NASA Astrophysics Data System (ADS)

Sattar, Ahmed M. A.; Gharabaghi, Bahram

2015-05-01

Longitudinal dispersion is the key hydrologic process that governs transport of pollutants in natural streams. It is critical for spill action centers to be able to predict the pollutant travel time and break-through curves accurately following accidental spills in urban streams. This study presents a novel gene expression model for longitudinal dispersion developed using 150 published data sets of geometric and hydraulic parameters in natural streams in the United States, Canada, Europe, and New Zealand. The training and testing of the model were accomplished using randomly-selected 67% (100 data sets) and 33% (50 data sets) of the data sets, respectively. Gene expression programming (GEP) is used to develop empirical relations between the longitudinal dispersion coefficient and various control variables, including the Froude number which reflects the effect of reach slope, aspect ratio, and the bed material roughness on the dispersion coefficient. Two GEP models have been developed, and the prediction uncertainties of the developed GEP models are quantified and compared with those of existing models, showing improved prediction accuracy in favor of GEP models. Finally, a parametric analysis is performed for further verification of the developed GEP models. The main reason for the higher accuracy of the GEP models compared to the existing regression models is that exponents of the key variables (aspect ratio and bed material roughness) are not constants but a function of the Froude number. The proposed relations are both simple and accurate and can be effectively used to predict the longitudinal dispersion coefficients in natural streams.

Nocturnal enuresis in a longitudinal perspective. A primary problem of maturity and/or a secondary environmental reaction?

PubMed

Klackenberg, G

1981-07-01

The study is part of a prospective longitudinal investigation, involving annual somatic, psychological and social check-ups in a random sample of 212 children. Data are presented on the gradual achievement of bladder control, with relapses into wetting. Information is provided on relationships with training, with behavioural variables, with emotional maturity (Rorschach) and with sleep. It seems probable that primary enuresis usually ceases by the age of 8 at the latest and that enuresis in older children is a secondary emotional disorder which may, however, have started at an earlier age. The 6-year-old enuretic shows signs of delayed emotional maturity. The relation with somnambulism is ambiguous. Enuresis is not significantly related to training. None of the data obtained in this study conflict with the theory that primary enuresis is chiefly a maturity problem, the nature of which can be emotional. The neurophysiological aspect has not been investigated.

Associations among comorbid anxiety, psychiatric symptomatology, and diabetic control in a population with serious mental illness and diabetes: Findings from an interventional randomized controlled trial.

PubMed

Aftab, Awais; Bhat, Chetan; Gunzler, Douglas; Cassidy, Kristin; Thomas, Charles; McCormick, Richard; Dawson, Neal V; Sajatovic, Martha

2018-05-01

Objective Serious mental illness and type II diabetes mellitus have a high comorbidity, and both have a higher prevalence of anxiety disorders compared to the general population. Targeted Training in Illness Management is a group-based self-management training approach which targets serious mental illness and type II diabetes mellitus concurrently. This analysis examines data from a randomized controlled trial of Targeted Training in Illness Management intervention to examine the impact of comorbid anxiety on baseline psychiatric symptomatology and diabetic control, and on longitudinal treatment outcomes. Methods We conducted secondary analyses on data from a prospective, 60-week, randomized controlled trial testing Targeted Training in Illness Management versus treatment as usual in 200 individuals with serious mental illness and diabetes. Primary outcomes included measures related to serious mental illness symptoms, functional status, general health status, and diabetes control. Measures were compared between those participants with anxiety disorders versus those without anxiety at baseline as well as over time using linear mixed effects analyses. Results Forty seven percent of the participants had one or more anxiety disorders. At baseline, those with an anxiety diagnosis had higher illness severity, depressive, and other psychiatric symptomatology and disability. Diabetic control (HbA1c) was not significantly different at baseline. In the longitudinal analyses, no significant mean slope differences over time (group-by-time interaction effect) between those with anxiety diagnoses and those without in treatment as usual group were found for primary outcomes. Within the Targeted Training in Illness Management arm, those with anxiety disorders had significantly greater improvement in mental health functioning. Those with anxiety comorbidity in the Targeted Training in Illness Management group demonstrated significantly lower HbA1c levels compared to no anxiety comorbidity and also demonstrated a greater improvement in HbA1c over the first 30 weeks compared to those without anxiety comorbidity. Conclusion Comorbid anxiety in serious mental illness and type II diabetes mellitus population is associated with increased psychiatric symptomatology and greater disability. Individuals from this population appear to experience greater improvement in functioning from baseline with the Targeted Training in Illness Management intervention. Anxiety comorbidity in the serious mental illness and type II diabetes mellitus population does not appear to have a negative impact on diabetic control. These complex relationships need further study. Clinical Trials Registration ClinicalTrials.gov: Improving outcomes for individuals with serious mental illness and diabetes (NCT01410357).

Bayesian randomized clinical trials: From fixed to adaptive design.

PubMed

Yin, Guosheng; Lam, Chi Kin; Shi, Haolun

2017-08-01

Randomized controlled studies are the gold standard for phase III clinical trials. Using α-spending functions to control the overall type I error rate, group sequential methods are well established and have been dominating phase III studies. Bayesian randomized design, on the other hand, can be viewed as a complement instead of competitive approach to the frequentist methods. For the fixed Bayesian design, the hypothesis testing can be cast in the posterior probability or Bayes factor framework, which has a direct link to the frequentist type I error rate. Bayesian group sequential design relies upon Bayesian decision-theoretic approaches based on backward induction, which is often computationally intensive. Compared with the frequentist approaches, Bayesian methods have several advantages. The posterior predictive probability serves as a useful and convenient tool for trial monitoring, and can be updated at any time as the data accrue during the trial. The Bayesian decision-theoretic framework possesses a direct link to the decision making in the practical setting, and can be modeled more realistically to reflect the actual cost-benefit analysis during the drug development process. Other merits include the possibility of hierarchical modeling and the use of informative priors, which would lead to a more comprehensive utilization of information from both historical and longitudinal data. From fixed to adaptive design, we focus on Bayesian randomized controlled clinical trials and make extensive comparisons with frequentist counterparts through numerical studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Dyadic planning of health-behavior change after prostatectomy: a randomized-controlled planning intervention.

PubMed

Burkert, Silke; Scholz, Urte; Gralla, Oliver; Roigas, Jan; Knoll, Nina

2011-09-01

In this study, we investigated the role of dyadic planning for health-behavior change. Dyadic planning refers to planning health-behavior change together with a partner. We assumed that dyadic planning would affect the implementation of regular pelvic-floor exercise (PFE), with other indicators of social exchange and self-regulation strategies serving as mediators. In a randomized-controlled trial at a German University Medical Center, 112 prostatectomy-patients with partners were randomly assigned to a dyadic PFE-planning condition or one of three active control conditions. Questionnaire data were assessed at multiple time points within six months post-surgery, measuring self-reported dyadic PFE-planning and pelvic-floor exercise as primary outcomes and social exchange (support, control) and a self-regulation strategy (action control) as mediating mechanisms. There were no specific intervention effects with regard to dyadic PFE-planning or pelvic-floor exercise, as two active control groups also showed increases in either of these variables. However, results suggested that patients instructed to plan dyadically still benefited from self-reported dyadic PFE-planning regarding pelvic-floor exercise. Cross-sectionally, received negative control from partners was negatively related with PFE only in control groups and individual action control mediated between self-reported dyadic PFE-planning and PFE for participants instructed to plan PFE dyadically. Longitudinally, action control mediated between self-reported dyadic PFE-planning and pelvic-floor exercise for all groups. Findings provide support for further investigation of dyadic planning in health-behavior change with short-term mediating effects of behavior-specific social exchange and long-term mediating effects of better self-regulation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Involving fathers in teaching youth about farm tractor seatbelt safety--a randomized control study.

PubMed

Jinnah, Hamida Amirali; Stoneman, Zolinda; Rains, Glen

2014-03-01

Farm youth continue to experience high rates of injury and deaths as a result of agricultural activities. Farm machinery, especially tractors, is the most common cause of casualties to youth. A Roll-Over Protection Structure (ROPS) along with a fastened seatbelt can prevent almost all injuries and fatalities from tractor overturns. Despite this knowledge, the use of seatbelts by farmers on ROPS tractors remains low. This study treats farm safety as a family issue and builds on the central role of parents as teachers and role models of farm safety for youth. This research study used a longitudinal, repeated-measures, randomized-control design in which youth 10-19 years of age were randomly assigned to either of two intervention groups (parent-led group and staff-led group) or the control group. Fathers in the parent-led group were less likely to operate ROPS tractors without a seatbelt compared with other groups. They were more likely to have communicated with youth about the importance of wearing seatbelts on ROPS tractors. Consequently, youth in the parent-led group were less likely to operate a ROPS tractor without a seatbelt than the control group at post-test. This randomized control trial supports the effectiveness of a home-based, father-led farm safety intervention as a promising strategy for reducing youth as well as father-unsafe behaviors (related to tractor seatbelts) on the farm. This intervention appealed to fathers' strong motivation to practice tractor safety for the sake of their youth. Involving fathers helped change both father as well as youth unsafe tractor-seatbelt behaviors. Copyright © 2014 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Orbitofrontal gray matter deficits as marker of Internet gaming disorder: converging evidence from a cross-sectional and prospective longitudinal design.

PubMed

Zhou, Feng; Montag, Christian; Sariyska, Rayna; Lachmann, Bernd; Reuter, Martin; Weber, Bernd; Trautner, Peter; Kendrick, Keith M; Markett, Sebastian; Becker, Benjamin

2017-10-23

Internet gaming disorder represents a growing health issue. Core symptoms include unsuccessful attempts to control the addictive patterns of behavior and continued use despite negative consequences indicating a loss of regulatory control. Previous studies revealed brain structural deficits in prefrontal regions subserving regulatory control in individuals with excessive Internet use. However, because of the cross-sectional nature of these studies, it remains unknown whether the observed brain structural deficits preceded the onset of excessive Internet use. Against this background, the present study combined a cross-sectional and longitudinal design to determine the consequences of excessive online video gaming. Forty-one subjects with a history of excessive Internet gaming and 78 gaming-naive subjects were enrolled in the present study. To determine effects of Internet gaming on brain structure, gaming-naive subjects were randomly assigned to 6 weeks of daily Internet gaming (training group) or a non-gaming condition (training control group). At study inclusion, excessive Internet gamers demonstrated lower right orbitofrontal gray matter volume compared with Internet gaming-naive subjects. Within the Internet gamers, a lower gray matter volume in this region was associated with higher online video gaming addiction severity. Longitudinal analysis revealed initial evidence that left orbitofrontal gray matter volume decreased during the training period in the training group as well as in the group of excessive gamers. Together, the present findings suggest an important role of the orbitofrontal cortex in the development of Internet addiction with a direct association between excessive engagement in online gaming and structural deficits in this brain region. © 2017 Society for the Study of Addiction.

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

Gupta, Shashaank; Belianinov, Alex; Okatan, Mahmut B

(001)pc textured K0.5Na0.5NbO3 (KNN) ceramic was found to exhibit a 65% improvement in the longitudinal piezoelectric response as compared to its random counterpart. Piezoresponse force microscopy study revealed the existence of larger 180 and non-180 domains for textured ceramic as compared to that of the random ceramic. Improvement in piezoresponse by the development of (001)pc texture is discussed in terms of the crystallographic nature of KNN and domain morphology. A comparative analysis performed with a rhombohedral composition suggested that the improvement in longitudinal piezoresponse of polycrystalline ceramics by the development of (001)pc texture is limited by the crystal structure.

Exploratory Analysis of Exercise Adherence Patterns with Sedentary Pregnant Women

PubMed Central

Yeo, SeonAe; Cisewski, Jessi; Lock, Eric F.; Marron, J. S.

2010-01-01

Background It is not well understood how sedentary women who wish to engage in regular exercise adhere to interventions during pregnancy and what factors may influence adherence over time. Objective To examine longitudinal patterns of pregnant women’s adherence to exercise. Methods Exploratory secondary data analyses were carried out with 124 previously sedentary pregnant women (ages 31 ± 5 years; 85% non-Hispanic White) from a randomized controlled trial. Daily exercise logs (n = 92) from 18 through 35 weeks of gestation were explored using linear regression, functional data, and principal component analyses. Results Adherence decreased as gestation week increased (p < .001); the top adherers maintained levels of adherence, and the bottom adherers decreased levels of adherence; and adherence pattern was influenced by types of exercise throughout the study period. Discussion Exercise behavior patterns were explored in a randomized controlled trial study, using chronometric data on exercise attendance. A new analytic approach revealed that sedentary pregnant women may adopt exercise habits differently from other populations. PMID:20585224

Mindfulness-based resilience training to reduce health risk, stress reactivity, and aggression among law enforcement officers: A feasibility and preliminary efficacy trial.

PubMed

Christopher, Michael S; Hunsinger, Matthew; Goerling, Lt Richard J; Bowen, Sarah; Rogers, Brant S; Gross, Cynthia R; Dapolonia, Eli; Pruessner, Jens C

2018-06-01

The primary objective of this study was to assess feasibility and gather preliminary outcome data on Mindfulness-Based Resilience Training (MBRT) for law enforcement officers. Participants (n = 61) were randomized to either an 8-week MBRT course or a no intervention control group. Self-report and physiological data were collected at baseline, post-training, and three months following intervention completion. Attendance, adherence, post-training participant feedback, and interventionist fidelity to protocol all demonstrated feasibility of MBRT for law enforcement officers. Compared to no intervention controls, MBRT participants experienced greater reductions in salivary cortisol, self-reported aggression, organizational stress, burnout, sleep disturbance, and reported increases in psychological flexibility and non-reactivity at post-training; however, group differences were not maintained at three-month follow-up. This initial randomized trial suggests MBRT is a feasible intervention. Outcome data suggest MBRT targets key physiological, psychological, and health risk factors in law enforcement officers, consistent with the potential to improve officer health and public safety. However, follow-up training or "booster" sessions may be needed to maintain training gains. A fully powered longitudinal randomized trial is warranted. Copyright © 2018 Elsevier B.V. All rights reserved.

The Influence of Parental Control and Parent-Child Relational Qualities on Adolescent Internet Addiction: A 3-Year Longitudinal Study in Hong Kong

PubMed Central

Shek, Daniel T. L.; Zhu, Xiaoqin; Ma, Cecilia M. S.

2018-01-01

This study investigated how parental behavioral control, parental psychological control, and parent-child relational qualities predicted the initial level and rate of change in adolescent internet addiction (IA) across the junior high school years. The study also investigated the concurrent and longitudinal effects of different parenting factors on adolescent IA. Starting from the 2009/2010 academic year, 3,328 Grade 7 students (Mage = 12.59 ± 0.74 years) from 28 randomly selected secondary schools in Hong Kong responded on a yearly basis to a questionnaire measuring multiple constructs including socio-demographic characteristics, perceived parenting characteristics, and IA. Individual growth curve (IGC) analyses showed that adolescent IA slightly decreased during junior high school years. While behavioral control of both parents was negatively related to the initial level of adolescent IA, only paternal behavioral control showed a significant positive relationship with the rate of linear change in IA, suggesting that higher paternal behavioral control predicted a slower decrease in IA. In addition, fathers' and mothers' psychological control was positively associated with the initial level of adolescent IA, but increase in maternal psychological control predicted a faster drop in IA. Finally, parent-child relational qualities negatively and positively predicted the initial level and the rate of change in IA, respectively. When all parenting factors were considered simultaneously, multiple regression analyses revealed that paternal behavioral control and psychological control as well as maternal psychological control and mother-child relational quality were significant concurrent predictors of adolescent IA at Wave 2 and Wave 3. Regarding the longitudinal predicting effects, paternal psychological control and mother-child relational quality at Wave 1 were the two most robust predictors of later adolescent IA at Wave 2 and Wave 3. The above findings underscore the importance of the parent-child subsystem qualities in influencing adolescent IA in the junior high school years. In particular, these findings shed light on the different impacts of fathering and mothering which are neglected in the scientific literature. While the findings based on the levels of IA are consistent with the existing theoretical models, findings on the rate of change are novel. PMID:29765349

The Influence of Parental Control and Parent-Child Relational Qualities on Adolescent Internet Addiction: A 3-Year Longitudinal Study in Hong Kong.

PubMed

Shek, Daniel T L; Zhu, Xiaoqin; Ma, Cecilia M S

2018-01-01

This study investigated how parental behavioral control, parental psychological control, and parent-child relational qualities predicted the initial level and rate of change in adolescent internet addiction (IA) across the junior high school years. The study also investigated the concurrent and longitudinal effects of different parenting factors on adolescent IA. Starting from the 2009/2010 academic year, 3,328 Grade 7 students ( M age = 12.59 ± 0.74 years) from 28 randomly selected secondary schools in Hong Kong responded on a yearly basis to a questionnaire measuring multiple constructs including socio-demographic characteristics, perceived parenting characteristics, and IA. Individual growth curve (IGC) analyses showed that adolescent IA slightly decreased during junior high school years. While behavioral control of both parents was negatively related to the initial level of adolescent IA, only paternal behavioral control showed a significant positive relationship with the rate of linear change in IA, suggesting that higher paternal behavioral control predicted a slower decrease in IA. In addition, fathers' and mothers' psychological control was positively associated with the initial level of adolescent IA, but increase in maternal psychological control predicted a faster drop in IA. Finally, parent-child relational qualities negatively and positively predicted the initial level and the rate of change in IA, respectively. When all parenting factors were considered simultaneously, multiple regression analyses revealed that paternal behavioral control and psychological control as well as maternal psychological control and mother-child relational quality were significant concurrent predictors of adolescent IA at Wave 2 and Wave 3. Regarding the longitudinal predicting effects, paternal psychological control and mother-child relational quality at Wave 1 were the two most robust predictors of later adolescent IA at Wave 2 and Wave 3. The above findings underscore the importance of the parent-child subsystem qualities in influencing adolescent IA in the junior high school years. In particular, these findings shed light on the different impacts of fathering and mothering which are neglected in the scientific literature. While the findings based on the levels of IA are consistent with the existing theoretical models, findings on the rate of change are novel.

A serum protein-based algorithm for the detection of Alzheimer disease.

PubMed

O'Bryant, Sid E; Xiao, Guanghua; Barber, Robert; Reisch, Joan; Doody, Rachelle; Fairchild, Thomas; Adams, Perrie; Waring, Steven; Diaz-Arrastia, Ramon

2010-09-01

To develop an algorithm that separates patients with Alzheimer disease (AD) from controls. Longitudinal case-control study. The Texas Alzheimer's Research Consortium project. Patients  We analyzed serum protein-based multiplex biomarker data from 197 patients diagnosed with AD and 203 controls. Main Outcome Measure  The total sample was randomized equally into training and test sets and random forest methods were applied to the training set to create a biomarker risk score. The biomarker risk score had a sensitivity and specificity of 0.80 and 0.91, respectively, and an area under the curve of 0.91 in detecting AD. When age, sex, education, and APOE status were added to the algorithm, the sensitivity, specificity, and area under the curve were 0.94, 0.84, and 0.95, respectively. These initial data suggest that serum protein-based biomarkers can be combined with clinical information to accurately classify AD. A disproportionate number of inflammatory and vascular markers were weighted most heavily in the analyses. Additionally, these markers consistently distinguished cases from controls in significant analysis of microarray, logistic regression, and Wilcoxon analyses, suggesting the existence of an inflammatory-related endophenotype of AD that may provide targeted therapeutic opportunities for this subset of patients.

Cardio-autonomic control and wellbeing due to oscillating color light exposure.

PubMed

Grote, Vincent; Kelz, Christina; Goswami, Nandu; Stossier, Harald; Tafeit, Erwin; Moser, Maximilian

2013-04-10

We investigated the cardio-autonomic and psychological effects of colored light cycling with the wavelength of ultradian rhythms. In two consecutive experiments, an explorative, longitudinal test followed by a randomized crossover design, 20 healthy subjects each were exposed to oscillating red, green and blue light. Heart rate, heart rate variability (HRV) and subjective wellbeing were measured. Significant effects of the oscillating color light exposure were observed for heart rate and cardio-autonomic control rhythms, derived from HRV (p≤.001). These effects on HRV were replicated in the second experiment in comparison to a similar white light exposure protocol (p≤.05). Vigilance showed improvement over the two weeks (p≤.001) in the longitudinal study. External color light cycling at the wavelength of blood pressure oscillations appears to amplify the endogenous autonomic oscillations. This leads to an optimization of cardio-autonomic control; an effect that was reflected shortly after the onset of the light exposure sessions by the increase of heart rate variability. From the results, we conclude that it takes repeated light exposure session to foster the positive effects on the psychological aspects, as we observed an increase of subjectively perceived mood only in the longitudinal study, not for the crossover design study. The results of our study imply some possible health effects of a color light exposure that is adjusted to 10 s and 1 min oscillations of humans' ultradian rhythms. These novel results show possible applications of oscillating visual inputs to the activation of processes connected to physiological regulation. Copyright © 2013 Elsevier Inc. All rights reserved.

Determinants of Anemia and Hemoglobin Concentration in Haitian School-Aged Children

PubMed Central

Iannotti, Lora L.; Delnatus, Jacques R.; Odom, Audrey R.; Eaton, Jacob C.; Griggs, Jennifer J.; Brown, Sarah; Wolff, Patricia B.

2015-01-01

Anemia diminishes oxygen transport in the body, resulting in potentially irreversible growth and developmental consequences for children. Limited evidence for determinants of anemia exists for school-aged children. We conducted a cluster randomized controlled trial in Haiti from 2012 to 2013 to test the efficacy of a fortified school snack. Children (N = 1,047) aged 3–13 years were followed longitudinally at three time points for hemoglobin (Hb) concentrations, anthropometry, and bioelectrical impedance measures. Dietary intakes, infectious disease morbidities, and socioeconomic and demographic factors were collected at baseline and endline. Longitudinal regression modeling with generalized least squares and logit models with random effects identified anemia risk factors beyond the intervention effect. At baseline, 70.6% of children were anemic and 2.6% were severely anemic. Stunting increased the odds of developing anemia (adjusted odds ratio [OR]: 1.48, 95% confidence interval [CI]: 1.05–2.08) and severe anemia (adjusted OR: 2.47, 95% CI: 1.30–4.71). Parent-reported vitamin A supplementation and deworming were positively associated with Hb concentrations, whereas fever and poultry ownership showed a negative relationship with Hb concentration and increased odds of severe anemia, respectively. Further research should explore the full spectrum of anemia etiologies in school children, including genetic causes. PMID:26350448

Parenthood and the Quality of Experience in Daily Life: A Longitudinal Study

ERIC Educational Resources Information Center

Fave, Antonella Delle; Massimini, Fausto

2004-01-01

This longitudinal study analyzes the time budget and the quality of experience reported by new parents. Five primiparous couples were repeatedly administered Experience Sampling Method. They carried pagers sending random signals 6-8 times a day; at the signal reception, they filled out forms sampling current thoughts, activities, and the quality…

Human comfort response to random motions with a dominant longitudinal motion

NASA Technical Reports Server (NTRS)

Stone, R. W., Jr.

1975-01-01

Subjective ride comfort response ratings were measured on the Langley Visual Motion Simulator with longitudinal acceleration inputs with various power spectra shapes and magnitudes. The results show only little influence of spectra shape on comfort response. The effects of magnitude on comfort response indicate the applicability of psychophysical precepts for comfort modeling.

Using Fit Indexes to Select a Covariance Model for Longitudinal Data

ERIC Educational Resources Information Center

Liu, Siwei; Rovine, Michael J.; Molenaar, Peter C. M.

2012-01-01

This study investigated the performance of fit indexes in selecting a covariance structure for longitudinal data. Data were simulated to follow a compound symmetry, first-order autoregressive, first-order moving average, or random-coefficients covariance structure. We examined the ability of the likelihood ratio test (LRT), root mean square error…

An INAR(1) Negative Multinomial Regression Model for Longitudinal Count Data.

ERIC Educational Resources Information Center

Bockenholt, Ulf

1999-01-01

Discusses a regression model for the analysis of longitudinal count data in a panel study by adapting an integer-valued first-order autoregressive (INAR(1)) Poisson process to represent time-dependent correlation between counts. Derives a new negative multinomial distribution by combining INAR(1) representation with a random effects approach.…

Predicting Posttraumatic Stress Symptoms Longitudinally in a Representative Sample of Hospitalized Injured Adolescents

ERIC Educational Resources Information Center

Zatzick, Douglas F.; Grossman, David C.; Russo, Joan; Pynoos, Robert; Berliner, Lucy; Jurkovich, Gregory; Sabin, Janice A.; Katon, Wayne; Ghesquiere, Angela; McCauley, Elizabeth; Rivara, Frederick P.

2006-01-01

Objective: Adolescents constitute a high-risk population for traumatic physical injury, yet few longitudinal investigations have assessed the development of posttraumatic stress disorder (PTSD) symptoms over time in representative samples. Method: Between July 2002 and August 2003,108 randomly selected injured adolescent patients ages 12 to 18 and…

Longitudinal Changes of Angle Configuration in Primary Angle-Closure Suspects

PubMed Central

Jiang, Yuzhen; Chang, Dolly S.; Zhu, Haogang; Khawaja, Anthony P.; Aung, Tin; Huang, Shengsong; Chen, Qianyun; Munoz, Beatriz; Grossi, Carlota M.

2015-01-01

Objective To determine longitudinal changes in angle configuration in the eyes of primary angle-closure suspects (PACS) treated by laser peripheral iridotomy (LPI) and in untreated fellow eyes. Design Longitudinal cohort study. Participants Primary angle-closure suspects aged 50 to 70 years were enrolled in a randomized, controlled clinical trial. Methods Each participant was treated by LPI in 1 randomly selected eye, with the fellow eye serving as a control. Angle width was assessed in a masked fashion using gonioscopy and anterior segment optical coherence tomography (AS-OCT) before and at 2 weeks, 6 months, and 18 months after LPI. Main Outcome Measures Angle width in degrees was calculated from Shaffer grades assessed under static gonioscopy. Angle configuration was also evaluated using angle opening distance (AOD250, AOD500, AOD750), trabecular-iris space area (TISA500, TISA750), and angle recess area (ARA) measured in AS-OCT images. Results No significant difference was found in baseline measures of angle configuration between treated and untreated eyes. At 2 weeks after LPI, the drainage angle on gonioscopy widened from a mean of 13.5° at baseline to a mean of 25.7° in treated eyes, which was also confirmed by significant increases in all AS-OCT angle width measures (P<0.001 for all variables). Between 2 weeks and 18 months after LPI, a significant decrease in angle width was observed over time in treated eyes (P<0.001 for all variables), although the change over the first 5.5 months was not statistically significant for angle width measured under gonioscopy (P = 0.18), AOD250 (P = 0.167) and ARA (P = 0.83). In untreated eyes, angle width consistently decreased across all follow-up visits after LPI, with a more rapid longitudinal decrease compared with treated eyes (P values for all variables ≤0.003). The annual rate of change in angle width was equivalent to 1.2°/year (95% confidence interval [CI], 0.8–1.6) in treated eyes and 1.6°/year (95% CI, 1.3–2.0) in untreated eyes (P<0.001). Conclusions Angle width of treated eyes increased markedly after LPI, remained stable for 6 months, and then decreased significantly by 18 months after LPI. Untreated eyes experienced a more consistent and rapid decrease in angle width over the same time period. PMID:24835757

Causal mediation analysis for longitudinal data with exogenous exposure.

PubMed

Bind, M-A C; Vanderweele, T J; Coull, B A; Schwartz, J D

2016-01-01

Mediation analysis is a valuable approach to examine pathways in epidemiological research. Prospective cohort studies are often conducted to study biological mechanisms and often collect longitudinal measurements on each participant. Mediation formulae for longitudinal data have been developed. Here, we formalize the natural direct and indirect effects using a causal framework with potential outcomes that allows for an interaction between the exposure and the mediator. To allow different types of longitudinal measures of the mediator and outcome, we assume two generalized mixed-effects models for both the mediator and the outcome. The model for the mediator has subject-specific random intercepts and random exposure slopes for each cluster, and the outcome model has random intercepts and random slopes for the exposure, the mediator, and their interaction. We also expand our approach to settings with multiple mediators and derive the mediated effects, jointly through all mediators. Our method requires the absence of time-varying confounding with respect to the exposure and the mediator. This assumption is achieved in settings with exogenous exposure and mediator, especially when exposure and mediator are not affected by variables measured at earlier time points. We apply the methodology to data from the Normative Aging Study and estimate the direct and indirect effects, via DNA methylation, of air pollution, and temperature on intercellular adhesion molecule 1 (ICAM-1) protein levels. Our results suggest that air pollution and temperature have a direct effect on ICAM-1 protein levels (i.e. not through a change in ICAM-1 DNA methylation) and that temperature has an indirect effect via a change in ICAM-1 DNA methylation. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Randomized Controlled Trial of BASICS for Heavy Drinking Mandated and Volunteer Undergraduates: 12-Month Outcomes

PubMed Central

Terlecki, Meredith A.; Buckner, Julia D.; Larimer, Mary E.; Copeland, Amy L.

2014-01-01

This is the first randomized trial testing whether heavy drinking undergraduates mandated to the Brief Alcohol Screening and Intervention for College Students (BASICS) program following a campus alcohol violation would benefit as much as heavy drinking volunteers up to one year post-intervention using control groups with high-risk drinkers to model disciplinary-related and naturalistic changes in drinking. Participants (61% male; 51% mandated; 84% Caucasian; Mage = 20.14 years) were screened for heavy drinking and randomized to BASICS (n = 115) or assessment-only control (n = 110). Outcome measures (drinking, alcohol problems) were collected at baseline, 4 weeks, 3, 6, and 12 months post-intervention. At 4 weeks post-intervention, intent-to-treat multilevel longitudinal models showed that regardless of referral group (mandated or volunteer) BASICS significantly decreased weekly drinking, typical drinks, and peak drinks relative to controls (ds = .41-.92). BASICS had a large effect on decreases in alcohol problems (d = .87). At 12 months post-intervention, BASICS participants (regardless of referral group) reported significantly fewer alcohol problems (d = .56) compared to controls. Significant long-term intervention gains for peak and typical drinks were sustained in both referral groups relative to controls (ds = .42; .11). Referral group had no significant main effect and did not interact with intervention condition to predict outcomes. Given that BASICS was associated with less drinking and fewer alcohol problems (even among heavier drinking mandated students up to one year post-intervention), provision of BASICS-style programs within disciplinary settings may help reduce heavy and problematic drinking among at-risk students. PMID:25844834

Resilience Mediates the Longitudinal Relationships Between Social Support and Mental Health Outcomes in Multiple Sclerosis.

PubMed

Koelmel, Emily; Hughes, Abbey J; Alschuler, Kevin N; Ehde, Dawn M

2017-06-01

To investigate the longitudinal relationships between social support and subsequent mental health outcomes in individuals with multiple sclerosis (MS), and to examine resilience as a mediator between social support and subsequent mental health outcomes in this population. Observational, longitudinal cohort study. Participants were assessed at 4 time points over 12 months in the context of a previously reported randomized controlled trial. Telephone-based measures administered to community-based participants. Individuals (N=163) with MS and 1 or more of the following symptoms: depression, fatigue, and pain. Not applicable. Mental health outcomes included (1) depressive symptomatology, assessed using the Patient Health Questionnaire-9; (2) anxious symptomatology, assessed using the short form of the Emotional Distress-Anxiety Scale from the Patient-Reported Outcomes Measurement Information System; and (3) general mental health status, assessed using the Mental Component Summary score from the Short Form-8 Health Survey. Resilience was assessed using the Connor-Davidson Resilience Scale. At any given time, social support from significant others, family members, and friends was significantly associated with subsequent mental health outcomes for all 3 measures assessed (all P values <.05). Resilience measured concomitantly with social support significantly mediated the relationships between social support and subsequent mental health outcomes. After controlling for resilience, most of the direct relationships between social support and mental health outcomes were no longer significant. There are significant longitudinal relationships between social support, resilience, and mental health outcomes for people with MS. Given the mediating role of resilience in supporting better mental health outcomes, future clinical research and practice may benefit from an emphasis on resilience-focused psychological interventions. Copyright © 2016 American Congress of Rehabilitation Medicine. All rights reserved.

A mixed-effects regression model for longitudinal multivariate ordinal data.

PubMed

Liu, Li C; Hedeker, Donald

2006-03-01

A mixed-effects item response theory model that allows for three-level multivariate ordinal outcomes and accommodates multiple random subject effects is proposed for analysis of multivariate ordinal outcomes in longitudinal studies. This model allows for the estimation of different item factor loadings (item discrimination parameters) for the multiple outcomes. The covariates in the model do not have to follow the proportional odds assumption and can be at any level. Assuming either a probit or logistic response function, maximum marginal likelihood estimation is proposed utilizing multidimensional Gauss-Hermite quadrature for integration of the random effects. An iterative Fisher scoring solution, which provides standard errors for all model parameters, is used. An analysis of a longitudinal substance use data set, where four items of substance use behavior (cigarette use, alcohol use, marijuana use, and getting drunk or high) are repeatedly measured over time, is used to illustrate application of the proposed model.

UNSTEADY DISPERSION IN RANDOM INTERMITTENT FLOW

EPA Science Inventory

The longitudinal dispersion coefficient of a conservative tracer was calculated from flow tests in a dead-end pipe loop system. Flow conditions for these tests ranged from laminar to transitional flow, and from steady to intermittent and random. Two static mixers linked in series...

Comparison of endothelial changes and power settings between torsional and longitudinal phacoemulsification.

PubMed

Reuschel, Anna; Bogatsch, Holger; Barth, Thomas; Wiedemann, Renate

2010-11-01

To compare the intraoperative and postoperative outcomes of conventional longitudinal phacoemulsification and torsional phacoemulsification. Department of Ophthalmology, University of Leipzig, Germany. Randomized single-center clinical trial. Eyes with senile cataract were randomized to have phacoemulsification using the Infiniti Vision System and the torsional mode (OZil) or conventional longitudinal mode. Primary outcomes were corrected distance visual acuity (CDVA) and central endothelial cell density (ECD), calculated according to the Conference on Harmonisation-E9 Guidelines in which missing values were substituted by the median in each group (primary analysis) and the loss was then calculated using actual data (secondary analysis). Secondary outcomes were ultrasound (US) time, cumulative dissipated energy (CDE), and percentage total equivalent power in position 3. Postoperative follow-up was at 3 months. The mean preoperative CDVA was 0.41 logMAR in the torsional group and 0.38 logMAR in the longitudinal group, improving to 0.07 logMAR postoperatively in both groups. The mean ECD loss was 7.2% ± 4.6% in the torsional group (72 patients) and 7.1% ± 4.4% in the longitudinal group (76 patients), with no statistically significant differences in the primary analysis (P = .342) or secondary analysis (P = .906). The mean US time, CDE, and percentage total equivalent power in position 3 were statistically significantly lower in the torsional group (98 patients) than in the longitudinal group (94 patients) (P<.001). The torsional mode was as safe as the longitudinal mode in phacoemulsification for age-related cataract. Copyright © 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Health-Related Quality-of-Life Outcomes: A Reflexology Trial With Patients With Advanced-Stage Breast Cancer

PubMed Central

Wyatt, Gwen; Sikorskii, Alla; Rahbar, Mohammad Hossein; Victorson, David; You, Mei

2013-01-01

Purpose/Objectives To evaluate the safety and efficacy of reflexology, a complementary therapy that applies pressure to specific areas of the feet. Design Longitudinal, randomized clinical trial. Setting Thirteen community-based medical oncology clinics across the midwestern United States. Sample A convenience sample of 385 predominantly Caucasian women with advanced-stage breast cancer receiving chemotherapy and/or hormonal therapy. Methods Following the baseline interview, women were randomized into three primary groups: reflexology (n = 95), lay foot manipulation (LFM) (n = 95), or conventional care (n = 96). Two preliminary reflexology (n = 51) and LFM (n = 48) test groups were used to establish the protocols. Participants were interviewed again postintervention at study weeks 5 and 11. Main Research Variables Breast cancer–specific health-related quality of life (HRQOL), physical functioning, and symptoms. Findings No adverse events were reported. A longitudinal comparison revealed significant improvements in physical functioning for the reflexology group compared to the control group (p = 0.04). Severity of dyspnea was reduced in the reflexology group compared to the control group (p < 0.01) and the LFM group (p = 0.02). No differences were found on breast cancer–specific HRQOL, depressive symptomatology, state anxiety, pain, and nausea. Conclusions Reflexology may be added to existing evidence-based supportive care to improve HRQOL for patients with advanced-stage breast cancer during chemotherapy and/or hormonal therapy. Implications for Nursing Reflexology can be recommended for safety and usefulness in relieving dyspnea and enhancing functional status among women with advanced-stage breast cancer. PMID:23107851

Individualizing drug dosage with longitudinal data.

PubMed

Zhu, Xiaolu; Qu, Annie

2016-10-30

We propose a two-step procedure to personalize drug dosage over time under the framework of a log-linear mixed-effect model. We model patients' heterogeneity using subject-specific random effects, which are treated as the realizations of an unspecified stochastic process. We extend the conditional quadratic inference function to estimate both fixed-effect coefficients and individual random effects on a longitudinal training data sample in the first step and propose an adaptive procedure to estimate new patients' random effects and provide dosage recommendations for new patients in the second step. An advantage of our approach is that we do not impose any distribution assumption on estimating random effects. Moreover, the new approach can accommodate more general time-varying covariates corresponding to random effects. We show in theory and numerical studies that the proposed method is more efficient compared with existing approaches, especially when covariates are time varying. In addition, a real data example of a clozapine study confirms that our two-step procedure leads to more accurate drug dosage recommendations. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Methods to Limit Attrition in Longitudinal Comparative Effectiveness Trials: Lessons from the Lithium Use for Bipolar Disorder (LiTMUS) Study

PubMed Central

Sylvia, Louisa G.; Reilly-Harrington, Noreen A.; Leon, Andrew C.; Kansky, Christine I.; Ketter, Terence A.; Calabrese, Joseph R.; Thase, Michael E.; Bowden, Charles L.; Friedman, Edward S.; Ostacher, Michael J.; Iosifescu, Dan V.; Severe, Joanne; Nierenberg, Andrew A.

2013-01-01

Background High attrition rates which occur frequently in longitudinal clinical trials of interventions for bipolar disorder limit the interpretation of results. Purpose The aim of this article is to present design approaches that limited attrition in the Lithium Use for Bipolar Disorder (LiTMUS) Study. Methods LiTMUS was a 6-month randomized, longitudinal multi-site comparative effectiveness trial that examined bipolar participants who were at least mildly ill. Participants were randomized to either low to moderate doses of lithium or no lithium, in addition to other treatments needed for mood stabilization administered in a guideline-informed, empirically supported, and personalized fashion (N=283). Results Components of the study design that may have contributed to the low attrition rate of the study included use of: (1) an intent-to-treat design; (2) a randomized adjunctive single-blind design; (3) participant reimbursement; (4) intent-to-attend the next study visit (includes a discussion of attendance obstacles when intention is low); (5) quality care with limited participant burden; and (6) target windows for study visits. Limitations Site differences and the effectiveness and tolerability data have not been analyzed yet. Conclusions These components of the LiTMUS study design may have reduced the probability of attrition which would inform the design of future randomized clinical effectiveness trials. PMID:22076437

But I Trust My Teen: Parents' Attitudes and Response to a Parental Monitoring Intervention

PubMed Central

Metzger, Aaron; Ice, Christa; Cottrell, Lesley

2012-01-01

Parental knowledge gained from monitoring activities protects against adolescent risk involvement. Parental monitoring approaches are varied and may be modified with successful interventions but not all parents or adolescents respond to monitoring programs the same way. 339 parent-adolescent dyads randomized to receive a parental monitoring intervention and 169 parent-adolescent dyads in the control group were followed for one year over four measurement periods. Parent attitudes about the usefulness of monitoring, the importance of trust and respecting their teens' privacy, and the appropriateness of adolescent risk-taking behavior and experimentation were examined as predictors of longitudinal change in parental monitoring and open communication. Similar effects were found in both the intervention and control group models regarding open communication. Parental attitudes impacted longitudinal patterns of teen-reported parent monitoring, and these patterns differed across experimental groups. In the intervention group, parents' beliefs about the importance of trust and privacy were associated with a steeper decline in monitoring across time. Finally, parents' attitudes about the normative nature of teen experimentation were associated with a quadratic parental monitoring time trend in the intervention but not the control group. These findings suggest that parental attitudes may impact how families respond to an adolescent risk intervention. PMID:22720144

Impact on quality of life in teachers after educational actions for prevention of voice disorders: a longitudinal study.

PubMed

Pizolato, Raquel Aparecida; Rehder, Maria Inês Beltrati Cornacchioni; Meneghim, Marcelo de Castro; Ambrosano, Glaucia Maria Bovi; Mialhe, Fábio Luiz; Pereira, Antonio Carlos

2013-02-27

Voice problems are more common in teachers due to intensive voice use during routine at work. There is evidence that occupational disphonia prevention programs are important in improving the quality voice and consequently the quality of subjects' lives. To investigate the impact of educational voice interventions for teachers on quality of life and voice. A longitudinal interventional study involving 70 teachers randomly selected from 11 public schools, 30 to receive educational intervention with vocal training exercises and vocal hygiene habits (experimental group) and 40 to receive guidance on vocal hygiene habits (control group control). Before the process of educational activities, the Voice-Related Quality of Life instrument (V-RQOL) was applied, and 3 months after conclusion of the activities, the subjects were interviewed again, using the same instrument. For data analysis, Prox MIXED were applied, with a level of significance α < 0.05. Teachers showed significantly higher domain and overall V-RQOL scores after preventive intervention, in both control and experimental groups. Nevertheless, there was no statistical difference in scores between the groups. Educational actions for vocal health had a positive impact on the quality of life of the participants, and the incorporation of permanent educational actions at institutional level is suggested.

Impact on quality of life in teachers after educational actions for prevention of voice disorders: a longitudinal study

PubMed Central

2013-01-01

Background Voice problems are more common in teachers due to intensive voice use during routine at work. There is evidence that occupational disphonia prevention programs are important in improving the quality voice and consequently the quality of subjects’ lives. Aim To investigate the impact of educational voice interventions for teachers on quality of life and voice. Methods A longitudinal interventional study involving 70 teachers randomly selected from 11 public schools, 30 to receive educational intervention with vocal training exercises and vocal hygiene habits (experimental group) and 40 to receive guidance on vocal hygiene habits (control group control). Before the process of educational activities, the Voice-Related Quality of Life instrument (V-RQOL) was applied, and 3 months after conclusion of the activities, the subjects were interviewed again, using the same instrument. For data analysis, Prox MIXED were applied, with a level of significance α < 0.05. Results: Teachers showed significantly higher domain and overall V-RQOL scores after preventive intervention, in both control and experimental groups. Nevertheless, there was no statistical difference in scores between the groups. Conclusion Educational actions for vocal health had a positive impact on the quality of life of the participants, and the incorporation of permanent educational actions at institutional level is suggested. PMID:23445566

Dispersivity of Bidisperse Packings of Spheres and Evidence for Distinct Random Structures

NASA Astrophysics Data System (ADS)

Scheven, U. M.

2018-05-01

The intrinsic longitudinal and transverse dispersivity of bidisperse random packings of spheres with size ratio 5 ∶1 was determined by pulsed field gradient nuclear magnetic resonance, in the dilute regime where small spheres occupy between 0% and 5% of the packings' volume. Small spheres plugging pores systematically raise the mechanical transverse and longitudinal dispersivity above that of reference packings of monodisperse spheres. NMR-derived porosities, widths of velocity distributions, and dispersivities reveal distinct states of structural disorder above and below a relative sphere concentration n /N =1 , where n and N are the number densities of small and large spheres.

Permeability of model porous medium formed by random discs

NASA Astrophysics Data System (ADS)

Gubaidullin, A. A.; Gubkin, A. S.; Igoshin, D. E.; Ignatev, P. A.

2018-03-01

Two-dimension model of the porous medium with skeleton of randomly located overlapping discs is proposed. The geometry and computational grid are built in open package Salome. Flow of Newtonian liquid in longitudinal and transverse directions is calculated and its flow rate is defined. The numerical solution of the Navier-Stokes equations for a given pressure drop at the boundaries of the area is realized in the open package OpenFOAM. Calculated value of flow rate is used for defining of permeability coefficient on the base of Darcy law. For evaluating of representativeness of computational domain the permeability coefficients in longitudinal and transverse directions are compered.

How has the economic downturn affected communities and implementation of science-based prevention in the randomized trial of communities that care?

PubMed

Kuklinski, Margaret R; Hawkins, J David; Plotnick, Robert D; Abbott, Robert D; Reid, Carolina K

2013-06-01

This study examined implications of the economic downturn that began in December 2007 for the Community Youth Development Study (CYDS), a longitudinal randomized controlled trial of the Communities That Care (CTC) prevention system. The downturn had the potential to affect the internal validity of the CYDS research design and implementation of science-based prevention in study communities. We used archival economic indicators and community key leader reports of economic conditions to assess the extent of the economic downturn in CYDS communities and potential internal validity threats. We also examined whether stronger economic downturn effects were associated with a decline in science-based prevention implementation. Economic indicators suggested the downturn affected CYDS communities to different degrees. We found no evidence of systematic differences in downturn effects in CTC compared to control communities that would threaten internal validity of the randomized trial. The Community Economic Problems scale was a reliable measure of community economic conditions, and it showed criterion validity in relation to several objective economic indicators. CTC coalitions continued to implement science-based prevention to a significantly greater degree than control coalitions 2 years after the downturn began. However, CTC implementation levels declined to some extent as unemployment, the percentage of students qualifying for free lunch, and community economic problems worsened. Control coalition implementation levels were not related to economic conditions before or after the downturn, but mean implementation levels of science-based prevention were also relatively low in both periods.

The clinical and cost-effectiveness of the BRinging Information and Guided Help Together (BRIGHT) intervention for the self-management support of people with stage 3 chronic kidney disease in primary care: study protocol for a randomized controlled trial

PubMed Central

2013-01-01

Background Improving the quality of care for people with vascular disease is a key priority. Chronic kidney disease (CKD) has recently been included as a target condition for general practices to add to registers of chronic conditions as part of the Quality and Outcome Framework. This paper outlines the implementation and evaluation of a self-management intervention involving an information guidebook, tailored access to local resources and telephone support for people with stage 3 chronic kidney disease. Methods/Design The study involves a multi-site, longitudinal patient-level randomized controlled trial. The study will evaluate the clinical use and cost-effectiveness of a complex self-management intervention for people with stage 3 chronic kidney disease in terms of self-management capacity, health-related quality of life and blood pressure control compared to care as usual. We describe the methods of the patient-level randomized controlled trial. Discussion The management of chronic kidney disease is a developing area of research. The BRinging Information and Guided Help Together (BRIGHT) trial aims to provide evidence that a complementary package of support for people with vascular disease that targets both clinical and social need broadens the opportunities of self-management support by addressing problems related to social disadvantage. Trial registration Trial registration reference: ISRCTN45433299 PMID:23356861

How Has the Economic Downturn Affected Communities and Implementation of Science-Based Prevention in the Randomized Trial of Communities That Care?

PubMed Central

Kuklinski, Margaret R.; Hawkins, J. David; Plotnick, Robert D.; Abbott, Robert D.; Reid, Carolina K.

2013-01-01

This study examined implications of the economic downturn that began in December 2007 for the Community Youth Development Study (CYDS), a longitudinal randomized controlled trial of the Communities That Care (CTC) prevention system. The downturn had the potential to affect the internal validity of the CYDS research design and implementation of science-based prevention in study communities. We used archival economic indicators and community key leader reports of economic conditions to assess the extent of the economic downturn in CYDS communities and potential internal validity threats. We also examined whether stronger economic downturn effects were associated with a decline in science-based prevention implementation. Economic indicators suggested the downturn affected CYDS communities to different degrees. We found no evidence of systematic differences in downturn effects in CTC compared to control communities that would threaten internal validity of the randomized trial. The Community Economic Problems scale was a reliable measure of community economic conditions, and it showed criterion validity in relation to several objective economic indicators. CTC coalitions continued to implement science-based prevention to a significantly greater degree than control coalitions 2 years after the downturn began. However, CTC implementation levels declined to some extent as unemployment, the percentage of students qualifying for free lunch, and community economic problems worsened. Control coalition implementation levels were not related to economic conditions before or after the downturn, but mean implementation levels of science-based prevention were also relatively low in both periods. PMID:23054169

A Longitudinal Assessment of the Effectiveness of a School-Based Mentoring Program in Middle School

ERIC Educational Resources Information Center

Nunez, Jose Carlos; Rosario, Pedro; Vallejo, Guillermo; Gonzalez-Pienda, Julio Antonio

2013-01-01

This work assessed the efficacy of a middle-school-based mentoring program designed to increase student use of self-regulated learning (SRL) strategies, self-efficacy for and the perceived usefulness of SRL as well as mathematics and language achievement. A longitudinal cluster randomized trial study design obtained evidence that found…

Longitudinal Associations between Adolescent Alcohol Use and Parents' Sources of Knowledge

ERIC Educational Resources Information Center

Stavrinides, Panayiotis; Georgiou, Stelios; Demetriou, Andreas

2010-01-01

The aim of this study was to test the direction of effect in the relationship between parents' sources of knowledge (parental monitoring and child disclosure) and adolescent alcohol use. The participants were 215 adolescents and their mothers, randomly selected from urban and rural areas in Cyprus. A 3-month, two-timepoint longitudinal design was…

Sensitivity Analysis of Mixed Models for Incomplete Longitudinal Data

ERIC Educational Resources Information Center

Xu, Shu; Blozis, Shelley A.

2011-01-01

Mixed models are used for the analysis of data measured over time to study population-level change and individual differences in change characteristics. Linear and nonlinear functions may be used to describe a longitudinal response, individuals need not be observed at the same time points, and missing data, assumed to be missing at random (MAR),…

Family and Psychosocial Risk Factors in a Longitudinal Epidemiological Study of Adolescents.

ERIC Educational Resources Information Center

Cuffe, Steven P.; McKeown, Robert E.; Addy, Cheryl L.; Garrison, Carol Z.

2005-01-01

Objective: To study the association of family and social risk factors with psychopathology in a longitudinal study of adolescents. Method: From 1986 to 1988, 3,419 seventh through ninth graders were screened with the Center for Epidemiologic Studies Depression Scale. The top decile scorers and a random sample of the remainder were interviewed…

A comparison of three random effects approaches to analyze repeated bounded outcome scores with an application in a stroke revalidation study.

PubMed

Molas, Marek; Lesaffre, Emmanuel

2008-12-30

Discrete bounded outcome scores (BOS), i.e. discrete measurements that are restricted on a finite interval, often occur in practice. Examples are compliance measures, quality of life measures, etc. In this paper we examine three related random effects approaches to analyze longitudinal studies with a BOS as response: (1) a linear mixed effects (LM) model applied to a logistic transformed modified BOS; (2) a model assuming that the discrete BOS is a coarsened version of a latent random variable, which after a logistic-normal transformation, satisfies an LM model; and (3) a random effects probit model. We consider also the extension whereby the variability of the BOS is allowed to depend on covariates. The methods are contrasted using a simulation study and on a longitudinal project, which documents stroke rehabilitation in four European countries using measures of motor and functional recovery. Copyright 2008 John Wiley & Sons, Ltd.

Factors Predicting Compliance to Ecological Momentary Assessment Among Adolescent Smokers

PubMed Central

2014-01-01

Introduction: Ecological momentary assessments (EMAs) are increasingly used in smoking research to understand contextual and individual differences related to smoking and changes in smoking. To date, there has been little detailed research into the predictors of EMA compliance. However, patterns or predictors of compliance may affect key relationships under investigation and introduce sources of bias in results. The purpose of this study was to investigate predictors of compliance to random prompts among a sample of adolescents who had ever smoked. Methods: Data for this study were drawn from a sample of 461 adolescents (9th and 10th graders at baseline) participating in a longitudinal study of smoking escalation. We examined 2 outcomes: subject-level EMA compliance (overall rate of compliance over a week-long EMA wave), and in-the-moment prompt-level compliance to the most proximal random prompt. We investigated several covariates including gender, race, smoking rate, alcohol use, psychological symptomatology, home composition, mood, social context, time in study, inter-prompt interval, and location. Results: At the overall subject level, higher mean negative affect, smoking rate, alcohol use, and male gender predicted lower compliance with random EMA prompts. At the prompt level, after controlling for significant subject-level predictors of compliance, increased positive affect, being outside of the home, and longer inter-prompt interval predicted lower momentary compliance. Conclusions: This study identifies several factors associated with overall and momentary EMA compliance among a sample of adolescents participating in a longitudinal study of smoking. We also propose a conceptual framework for investigating the contextual and momentary predictors of compliance within EMA studies. PMID:24097816

Case studies combined with or without concept maps improve critical thinking in hospital-based nurses: a randomized-controlled trial.

PubMed

Huang, Yu-Chuan; Chen, Hsing-Hsia; Yeh, Mei-Ling; Chung, Yu-Chu

2012-06-01

Critical thinking (CT) is essential to the exercise of professional judgment. As nurses face increasingly complex health-care situations, critical thinking can promote appropriate clinical decision-making and improve the quality of nursing care. This study aimed to evaluate the effects of a program of case studies, alone (CS) or combined with concept maps (CSCM), on improving CT in clinical nurses. The study was a randomized controlled trial. The experimental group participated in a 16-week CSCM program, whereas the control group participated in a CS program of equal duration. A randomized-controlled trial with a multistage randomization process was used to select and to assign participants, ultimately resulting in 67 nurses in each group. Data were collected before and after the program using the California Critical Thinking Skill Test (CCTST) and the California Critical Thinking Disposition Inventory (CCTDI). After the programs, there were significant differences between the two groups in the critical thinking skills of analysis, evaluation, inference, deduction, and induction. There was also an overall significant difference, and a significant difference in the specific disposition of open-mindedness. This study supports the application of case studies combined with concept maps as a hospital-based teaching strategy to promote development of critical thinking skills and encourage dispositions for nurses. The CSCM resulted in greater improvements in all critical thinking skills of as well as the overall and open-minded affective dispositions toward critical thinking, compared with the case studies alone. An obvious improvement in the CSCM participants was the analytic skill and disposition. Further longitudinal studies and data collection from multisite evaluations in a range of geographic locales are warranted. Copyright © 2012 Elsevier Ltd. All rights reserved.

Prevention of illicit drug use through a school-based program: results of a longitudinal, cluster-randomized controlled trial.

PubMed

Guo, Jong-Long; Lee, Tzu-Chi; Liao, Jung-Yu; Huang, Chiu-Mieh

2015-03-01

To evaluate the long-term effects of an illicit drug use prevention program for adolescents that integrates life skills into the theory of planned behavior. We conducted a cluster-randomized trial in which 24 participating schools were randomized to either an intervention group (12 schools, n = 1,176 students) or a control group (12 schools, n = 915 students). Participants were grade 7 students. The intervention comprised a main intervention of 10 sessions and two booster interventions. Booster 1 (four sessions) and booster 2 (two sessions) were performed at 6 months and 12 months, respectively, after completion of the main intervention. Assessments were made at baseline, after the main intervention, and after each booster session using specific questionnaires for measuring participants' attitudes, subjective norms, perceived behavioral control, and life skills. Retention rates were 71.9% (845/1,176) in the intervention group and 90.7% (830/915) in the control group after the 12-month follow-up. A significantly lower proportion of intervention group participants reported illicit drug use after the first and second booster sessions compared with control group participants (.1% vs. 1.7% and .2% vs. 1.7%, respectively; both p < .05). Attitudes, subjective norms, perceived behavioral control, life skills, and behavioral intention scores of the intervention group were significantly higher than those of control group after the first and second booster sessions (all p < .001), suggesting that intervention group students tended to avoid drug use. A drug use prevention program integrating life skills into the theory of planned behavior may be effective for reducing illicit drug use and improving planned behavior-related constructs in adolescents. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Differences between blood donors and a population sample: implications for case-control studies.

PubMed

Golding, Jean; Northstone, Kate; Miller, Laura L; Davey Smith, George; Pembrey, Marcus

2013-08-01

Selecting appropriate controls for studies of genetic variation in case series is important. The two major candidates involve the use of blood donors or a random sample of the population. We compare and contrast the two different populations of controls for studies of genetic variation using data from parents enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). In addition we compute different biases using a series of hypothetical assumptions. The study subjects who had been blood donors differed markedly from the general population in social, health-related, anthropometric, and personality-related variables. Using theoretical examples, we show that blood donors are a poor control group for non-genetic studies of diseases related to environmentally, behaviourally, or socially patterned exposures. However, we show that if blood donors are used as controls in genetic studies, these factors are unlikely to make a major difference in detecting true associations with relatively rare disorders (cumulative incidence through life of <10%). Nevertheless, for more common disorders, the reduction in accuracy resulting from the inclusion in any control population of individuals who have or will develop the disease in question can create a greater bias than can socially patterned factors. Information about the medical history of a control and the parents of the control (as a proxy for whether the control will develop the disease) is more important with regard to the choice of controls than whether the controls are a random population sample or blood donors.

Adult Attention-Deficit/Hyperactivity Disorder (ADHD) and Insomnia: an Update of the Literature.

PubMed

Wynchank, Dora; Bijlenga, Denise; Beekman, Aartjan T; Kooij, J J Sandra; Penninx, Brenda W

2017-10-30

Insomnia is diagnosed when there is dissatisfaction with sleep quantity or quality. It has a prevalence in the general population ranging from 31 to 56%. Insomnia has previously been associated with adult attention-deficit/hyperactivity disorder (ADHD). In this review, we address three topics: (1) the cross-sectional relationship between ADHD and insomnia in adulthood, (2) the longitudinal relationship between ADHD and insomnia, and (3) insomnia as a side effect of pharmacological treatments for adult ADHD. Three cross-sectional, clinical, and population studies report a prevalence of insomnia in ADHD adults ranging from 43 to 80%. Longitudinal evidence for a link between childhood-onset ADHD and insomnia at later age is mixed, with one study confirming and another study not supporting such a longitudinal association. In randomized, placebo-controlled trials, insomnia is reported significantly more often in the treatment arm than in the placebo arm. In varying percentages of trial participants, insomnia is a treatment-emergent adverse effect in triple-bead mixed amphetamine salts (40-45%), dasotraline (35-45%), lisdexamfetamine (10-19%), and extended-release methylphenidate (11%). Ten to seventeen percent of subjects in placebo-controlled trials of atomoxetine report insomnia, possibly related to poor metabolizer status. The mechanisms explaining the relationship between ADHD and sleep problems are incompletely understood, but both genetic and non-shared environmental influences may be involved. Adults with ADHD should be assessed for insomnia, which is frequently comorbid, and both conditions should be treated.

Jump starting skeletal health: a 4-year longitudinal study assessing the effects of jumping on skeletal development in pre and circum pubertal children.

PubMed

Gunter, Katherine; Baxter-Jones, Adam D G; Mirwald, Robert L; Almstedt, Hawley; Fuller, Arwen; Durski, Shantel; Snow, Christine

2008-04-01

Evidence suggests bone mineral increases attributable to exercise training prior to puberty may confer a significant advantage into adulthood. However, there is a dearth of supportive prospective longitudinal data. The purpose of this study was to assess bone mineral content (BMC) of the whole body (WB), total hip (TH), femoral neck (FN) and lumbar spine (LS) over four years in pre-pubertal boys and girls following a 7-month jumping intervention. The study population included 107 girls and 98 boys aged 8.6+/-0.88 years at baseline. Participating schools were randomly assigned as either intervention or control school. Children at the intervention school (n=101) participated in a jumping intervention embedded within the standard PE curriculum. The control school children (n=104) had similar exposure to PE without the jumping intervention. BMC was assessed by DXA at baseline, at 7-month post intervention, and annually thereafter for three years totaling 5 measurement opportunities. Multi-level random effects models were constructed and used to predict change from study entry in BMC parameters at each measurement occasion. A significant intervention effect was found at all bone sites. The effect was greatest immediately following the intervention (at 7 months) but still significant three years after the intervention. At 7 months, intervention participants had BMC values that were 7.9%, 8.4%, 7.7% and 7.3% greater than the controls at the LS, TH, FN and WB, respectively (p<0.05), when the confounders of age, maturity and tissue mass were controlled. Three years after the intervention had concluded the intervention group had 2.3%, 3.2%, 4.4% and 2.9% greater BMC than controls at the LS, TH, FN and WB respectively (p<0.05), when the confounders of age, maturity and tissue mass were controlled. This provides evidence that short-term high impact exercise in pre-puberty has a persistent effect over and above the effects of normal growth and development. If the benefits are sustained until BMC plateaus in early adulthood, this could have substantial effects on fracture risk.

14 CFR 23.145 - Longitudinal control.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Longitudinal control. 23.145 Section 23.145... Maneuverability § 23.145 Longitudinal control. (a) With the airplane as nearly as possible in trim at 1.3 VS1, it... application of single-handed control forces exceeding those specified in § 23.143(c). The trimming controls...

14 CFR 23.145 - Longitudinal control.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Longitudinal control. 23.145 Section 23.145... Maneuverability § 23.145 Longitudinal control. (a) With the airplane as nearly as possible in trim at 1.3 VS1, it... application of single-handed control forces exceeding those specified in § 23.143(c). The trimming controls...

14 CFR 23.145 - Longitudinal control.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Longitudinal control. 23.145 Section 23.145... Maneuverability § 23.145 Longitudinal control. (a) With the airplane as nearly as possible in trim at 1.3 VS1, it... application of single-handed control forces exceeding those specified in § 23.143(c). The trimming controls...

14 CFR 23.145 - Longitudinal control.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Longitudinal control. 23.145 Section 23.145... Maneuverability § 23.145 Longitudinal control. (a) With the airplane as nearly as possible in trim at 1.3 VS1, it... application of single-handed control forces exceeding those specified in § 23.143(c). The trimming controls...

Differential Susceptibility to Prevention: GABAergic, Dopaminergic, and Multilocus Effects

ERIC Educational Resources Information Center

Brody, Gene H.; Chen, Yi-fu; Beach, Steven R. H.

2013-01-01

Background: Randomized prevention trials provide a unique opportunity to test hypotheses about the interaction of genetic predispositions with contextual processes to create variations in phenotypes over time. Methods: Using two longitudinal, randomized prevention trials, molecular genetic and alcohol use outcome data were gathered from more than…

Measurement of human pilot dynamic characteristics in flight simulation

NASA Technical Reports Server (NTRS)

Reedy, James T.

1987-01-01

Fast Fourier Transform (FFT) and Least Square Error (LSE) estimation techniques were applied to the problem of identifying pilot-vehicle dynamic characteristics in flight simulation. A brief investigation of the effects of noise, input bandwidth and system delay upon the FFT and LSE techniques was undertaken using synthetic data. Data from a piloted simulation conducted at NASA Ames Research Center was then analyzed. The simulation was performed in the NASA Ames Research Center Variable Stability CH-47B helicopter operating in fixed-basis simulator mode. The piloting task consisted of maintaining the simulated vehicle over a moving hover pad whose motion was described by a random-appearing sum of sinusoids. The two test subjects used a head-down, color cathode ray tube (CRT) display for guidance and control information. Test configurations differed in the number of axes being controlled by the pilot (longitudinal only versus longitudinal and lateral), and in the presence or absence of an important display indicator called an 'acceleration ball'. A number of different pilot-vehicle transfer functions were measured, and where appropriate, qualitatively compared with theoretical pilot- vehicle models. Some indirect evidence suggesting pursuit behavior on the part of the test subjects is discussed.

Collateral benefits of the Family Check-Up on early childhood school readiness: indirect effects of parents' positive behavior support.

PubMed

Lunkenheimer, Erika S; Dishion, Thomas J; Shaw, Daniel S; Connell, Arin M; Gardner, Frances; Wilson, Melvin N; Skuban, Emily M

2008-11-01

The authors examined the longitudinal effects of the Family Check-Up (FCU) on parents' positive behavior support and children's school readiness competencies in early childhood. It was hypothesized that the FCU would promote language skills and inhibitory control in children at risk for behavior problems as an indirect outcome associated with targeted improvements in parents' positive behavior support. High-risk families in the Women, Infants, and Children Nutrition Program participated in a multisite preventive intervention study (N = 731) with 3 yearly assessments beginning at child age 2 years. Positive behavior support was measured using 4 indicators derived from at-home observations of parent-child interaction during semistructured tasks. Longitudinal structural equation models revealed that parents in families randomly assigned to the FCU showed improvements in positive behavior support from child age 2 to 3, which in turn promoted children's inhibitory control and language development from age 3 to 4, accounting for child gender, ethnicity, and parental education. Findings suggest that a brief, ecological preventive intervention supporting positive parenting practices can indirectly foster key facets of school readiness in children at risk.

Collateral Benefits of the Family Check-Up on Early Childhood School Readiness: Indirect Effects of Parents’ Positive Behavior Support

PubMed Central

Lunkenheimer, Erika S.; Dishion, Thomas J.; Shaw, Daniel S.; Connell, Arin M.; Gardner, Frances; Wilson, Melvin N.; Skuban, Emily M.

2009-01-01

The authors examined the longitudinal effects of the Family Check-Up (FCU) on parents’ positive behavior support and children’s school readiness competencies in early childhood. It was hypothesized that the FCU would promote language skills and inhibitory control in children at risk for behavior problems as an indirect outcome associated with targeted improvements in parents’ positive behavior support. High-risk families in the Women, Infants, and Children Nutrition Program participated in a multisite preventive intervention study (N = 731) with 3 yearly assessments beginning at child age 2 years. Positive behavior support was measured using 4 indicators derived from at-home observations of parent–child interaction during semistructured tasks. Longitudinal structural equation models revealed that parents in families randomly assigned to the FCU showed improvements in positive behavior support from child age 2 to 3, which in turn promoted children’s inhibitory control and language development from age 3 to 4, accounting for child gender, ethnicity, and parental education. Findings suggest that a brief, ecological preventive intervention supporting positive parenting practices can indirectly foster key facets of school readiness in children at risk. PMID:18999335

A Longitudinal Analysis of Antiretroviral Adherence Among Young Black Men Who Have Sex With Men.

PubMed

Voisin, Dexter R; Quinn, Katherine; Kim, Dong Ha; Schneider, John

2017-04-01

Young black men who have sex with men (YBMSM) experience poorer antiretroviral therapy (ART) medication adherence relative to their white counterparts. However, few studies have longitudinally examined factors that may correlate with various classifications of ART adherence among this population, which was the primary aim of this study. Project nGage was a randomized controlled trial conducted across five Chicago clinics from 2012 to 2015. Survey and medical records data were collected at baseline and 3- and 12-month periods to assess whether psychological distress, HIV stigma, substance use, family acceptance, social support, and self-efficacy predicted ART medication adherence among 92 YBMSM ages 16-29 years. Major results controlling for the potential effects of age, education level, employment, and intervention condition indicated that participants with high versus low medication adherence were less likely to report daily/weekly alcohol or marijuana use, had higher family acceptance, and exhibited greater self-efficacy. These findings identity important factors that can be targeted in clinical and program interventions to help improve ART medication adherence for YBMSM. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Preschool Gender-Typed Play Behavior at Age 3.5 Years Predicts Physical Aggression at Age 13 Years.

PubMed

Kung, Karson T F; Li, Gu; Golding, Jean; Hines, Melissa

2018-05-01

Gender differences in play behavior and physical aggression have been consistently reported. Theoretical perspectives concerning evolutionary, social, and social-cognitive mechanisms suggest that male-typical play behavior during childhood increases subsequent physical aggression. The evidence supporting these connections is limited, however. The present study investigated the association between gender-typed play behavior in early childhood and physical aggression in early adolescence using a sample drawn from a longitudinal, population study, the Avon Longitudinal Study of Parents and Children. Based on gender-typed play behavior as measured by the Pre-School Activities Inventory at age 3.5 years, samples of masculine (64 boys, 60 girls), feminine (80 boys, 66 girls), and randomly selected control children (55 boys, 67 girls) were recruited at age 13 years and administered the Reinisch Aggression Inventory. After controlling for a range of sociodemographic variables, maternal characteristics, and behavioral problems, including hyperactivity and conduct problems at age 3.5, significant group differences in physical aggression at age 13 were found among children classified as masculine, control, and feminine at age 3.5. Masculine children exhibited significantly more physical aggression than control children or feminine children, and control children exhibited significantly more physical aggression than feminine children. The association between gender-typed play behavior and physical aggression was not moderated by sex. These results suggest that the degree of childhood gender-typed play behavior independently predicts the degree of physical aggression at adolescence in boys and in girls.

Longitudinal Study of New and Prevalent Use of Self-Monitoring of Blood Glucose

PubMed Central

Karter, Andrew J.; Parker, Melissa M.; Moffet, Howard H.; Spence, Michele M.; Chan, James; Ettner, Susan L.; Selby, Joe V.

2008-01-01

OBJECTIVE We sought to assess longitudinal association between self-monitoring of blood glucose (SMBG) and glycemic control in diabetic patients from an integrated health plan (Kaiser Permanente Northern California). RESEARCH DESIGN AND METHODS Longitudinal analyses of glycemic control among 1) 16,091 patients initiating SMBG (new-user cohort) and 2) 15,347 ongoing users of SMBG (prevalent-user cohort). SMBG frequency was based on pharmacy use (number of blood glucose test strips dispensed), and glycemic control was based on HbA1c (A1C). In the new-user cohort, ANCOVA models (pre- and posttest design) were used to assess the effect of initiating SMBG. In the prevalent-user cohort, repeated-measure, mixed-effects models with random-intercept and time-dependent covariates were used to assess changes in SMBG and A1C. All models were stratified by therapy (no medications, oral agents only, or insulin) and adjusted for baseline A1C, sociodemographics, insulin injection frequency, comorbidity index, medication adherence, smoking status, health care use, and provider specialty. RESULTS Greater SMBG practice frequency among new users was associated with a graded decrease in A1C (relative to nonusers) regardless of diabetes therapy (P < 0.0001). Changes in SMBG frequency among prevalent users were associated with an inverse graded change in A1C only among pharmacologically treated patients (P < 0.0001). CONCLUSIONS These observational findings are consistent with short-term benefits of initiating SMBG practice for all patients but continuing benefits only for pharmacologically treated patients. Differences in effectiveness between new versus prevalent users of SMBG have implications for guideline development and interpretation of observational outcomes data. PMID:16873776

Compassion meditation enhances empathic accuracy and related neural activity

PubMed Central

Mascaro, Jennifer S.; Rilling, James K.; Tenzin Negi, Lobsang; Raison, Charles L.

2013-01-01

The ability to accurately infer others’ mental states from facial expressions is important for optimal social functioning and is fundamentally impaired in social cognitive disorders such as autism. While pharmacologic interventions have shown promise for enhancing empathic accuracy, little is known about the effects of behavioral interventions on empathic accuracy and related brain activity. This study employed a randomized, controlled and longitudinal design to investigate the effect of a secularized analytical compassion meditation program, cognitive-based compassion training (CBCT), on empathic accuracy. Twenty-one healthy participants received functional MRI scans while completing an empathic accuracy task, the Reading the Mind in the Eyes Test (RMET), both prior to and after completion of either CBCT or a health discussion control group. Upon completion of the study interventions, participants randomized to CBCT and were significantly more likely than control subjects to have increased scores on the RMET and increased neural activity in the inferior frontal gyrus (IFG) and dorsomedial prefrontal cortex (dmPFC). Moreover, changes in dmPFC and IFG activity from baseline to the post-intervention assessment were associated with changes in empathic accuracy. These findings suggest that CBCT may hold promise as a behavioral intervention for enhancing empathic accuracy and the neurobiology supporting it. PMID:22956676

Multiple Kernel Learning with Random Effects for Predicting Longitudinal Outcomes and Data Integration

PubMed Central

Chen, Tianle; Zeng, Donglin

2015-01-01

Summary Predicting disease risk and progression is one of the main goals in many clinical research studies. Cohort studies on the natural history and etiology of chronic diseases span years and data are collected at multiple visits. Although kernel-based statistical learning methods are proven to be powerful for a wide range of disease prediction problems, these methods are only well studied for independent data but not for longitudinal data. It is thus important to develop time-sensitive prediction rules that make use of the longitudinal nature of the data. In this paper, we develop a novel statistical learning method for longitudinal data by introducing subject-specific short-term and long-term latent effects through a designed kernel to account for within-subject correlation of longitudinal measurements. Since the presence of multiple sources of data is increasingly common, we embed our method in a multiple kernel learning framework and propose a regularized multiple kernel statistical learning with random effects to construct effective nonparametric prediction rules. Our method allows easy integration of various heterogeneous data sources and takes advantage of correlation among longitudinal measures to increase prediction power. We use different kernels for each data source taking advantage of the distinctive feature of each data modality, and then optimally combine data across modalities. We apply the developed methods to two large epidemiological studies, one on Huntington's disease and the other on Alzheimer's Disease (Alzheimer's Disease Neuroimaging Initiative, ADNI) where we explore a unique opportunity to combine imaging and genetic data to study prediction of mild cognitive impairment, and show a substantial gain in performance while accounting for the longitudinal aspect of the data. PMID:26177419

Longitudinal Examination of Aggression and Study Skills from Middle to High School: Implications for Dropout Prevention

ERIC Educational Resources Information Center

Orpinas, Pamela; Raczynski, Katherine; Hsieh, Hsien-Lin; Nahapetyan, Lusine; Horne, Arthur M.

2018-01-01

Background: High school completion provides health and economic benefits. The purpose of this study is to describe dropout rates based on longitudinal trajectories of aggression and study skills using teacher ratings. Methods: The sample consisted of 620 randomly selected sixth graders. Every year from Grade 6 to 12, a teacher completed a…

Contemporary Options for Longitudinal Follow-Up: Lessons Learned from a Cohort of Urban Adolescents

ERIC Educational Resources Information Center

Tobler, Amy L.; Komro, Kelli A.

2011-01-01

This study reports efforts to locate and survey participants in Project Northland Chicago (PNC), a longitudinal, group-randomized trial of an alcohol preventive intervention for racial/ethnic minority, urban, early-adolescents, 3-4 years following the end of the intervention. Data were collected annually among students from 6th-8th grade and then…

A Correlated Random Effects Model for Nonignorable Missing Data in Value-Added Assessment of Teacher Effects

ERIC Educational Resources Information Center

Karl, Andrew T.; Yang, Yan; Lohr, Sharon L.

2013-01-01

Value-added models have been widely used to assess the contributions of individual teachers and schools to students' academic growth based on longitudinal student achievement outcomes. There is concern, however, that ignoring the presence of missing values, which are common in longitudinal studies, can bias teachers' value-added scores.…

Computer Assisted English Language Learning in Costa Rican Elementary Schools: An Experimental Study

ERIC Educational Resources Information Center

Alvarez-Marinelli, Horacio; Blanco, Marta; Lara-Alecio, Rafael; Irby, Beverly J.; Tong, Fuhui; Stanley, Katherine; Fan, Yinan

2016-01-01

This study presents first-year findings of a 25-week longitudinal project derived from a two-year longitudinal randomized trial study at the elementary school level in Costa Rica on effective computer-assisted language learning (CALL) approaches in an English as a foreign language (EFL) setting. A pre-test-post-test experimental group design was…

Bridging the Gap: A Longitudinal Study of the Relationship between Pedagogical Continuity and Early Chinese Literacy Acquisition

ERIC Educational Resources Information Center

Li, Hui; Rao, Nirmala; Tse, Shek Kam

2011-01-01

This longitudinal study examined the relationship between pedagogical continuity in literacy education and early literacy development by comparing Chinese children in Hong Kong and Shenzhen. Stratified random sampling was used to select 24 preschool and Primary 1 classes in four communities catering to middle-class families in each city. The 24…

A Study of Ontogenetic and Generational Change in Adolescent Personality by Means of Multivariate Longitudinal Sequences: Phase II. Final Report.

ERIC Educational Resources Information Center

Nesselroade, John R.; Baltes, Paul B.

Assessment of the relationship between ontogenetic (individual) and generational (historical) change in adolescent personality development was the focus of this study. The total sample included 1000 male and female adolescents (ages 13-18) randomly drawn from 32 public school systems in West Virginia following a design using longitudinal sequences…

The Longitudinal Impact of a Universal School-Based Social-Emotional and Literacy Intervention on Classroom Climate and Teacher Processes and Practices

ERIC Educational Resources Information Center

Brown, Joshua L.; Jones, Stephanie M.; Aber, J. Lawrence

2010-01-01

This presentation capitalizes on a three-year, longitudinal, school-randomized trial of the 4Rs Program, a comprehensive, school-based social-emotional and literacy program for elementary schools, to test intervention induced changes in features of classroom climate and key dimensions of teacher affective and pedagogical processes and practices…

Differential Cost Avoidance and Successful Criminal Careers: Random or Rational?

ERIC Educational Resources Information Center

Kazemian, Lila; Le Blanc, Marc

2007-01-01

Using a sample of adjudicated French Canadian males from the Montreal Two Samples Longitudinal Study, this article investigates individual and social characteristics associated with differential cost avoidance. The main objective of this study is to determine whether such traits are randomly distributed across differential degrees of cost…

Mental skills training with basic combat training soldiers: A group-randomized trial.

PubMed

Adler, Amy B; Bliese, Paul D; Pickering, Michael A; Hammermeister, Jon; Williams, Jason; Harada, Coreen; Csoka, Louis; Holliday, Bernie; Ohlson, Carl

2015-11-01

Cognitive skills training has been linked to greater skills, self-efficacy, and performance. Although research in a variety of organizational settings has demonstrated training efficacy, few studies have assessed cognitive skills training using rigorous, longitudinal, randomized trials with active controls. The present study examined cognitive skills training in a high-risk occupation by randomizing 48 platoons (N = 2,432 soldiers) in basic combat training to either (a) mental skills training or (b) an active comparison condition (military history). Surveys were conducted at baseline and 3 times across the 10-week course. Multilevel mixed-effects models revealed that soldiers in the mental skills training condition reported greater use of a range of cognitive skills and increased confidence relative to those in the control condition. Soldiers in the mental skills training condition also performed better on obstacle course events, rappelling, physical fitness, and initial weapons qualification scores, although effects were generally moderated by gender and previous experience. Overall, effects were small; however, given the rigor of the design, the findings clearly contribute to the broader literature by providing supporting evidence that cognitive training skills can enhance performance in occupational and sports settings. Future research should address gender and experience to determine the need for targeting such training appropriately. (c) 2015 APA, all rights reserved).

A randomized controlled trial of home visits by neighborhood mentor mothers to improve children's nutrition in South Africa

PubMed Central

le Roux, Ingrid M.; le Roux, Karl; Mbeutu, Kwanie; Comulada, W. Scott; Desmond, Katherine A.; Rotheram-Borus, Mary Jane

2011-01-01

Malnourished children and babies with birth weights under 2500 g are at high risk for negative outcomes over their lifespans. Philani, a paraprofessional home visiting program, was developed to improve nutritional outcomes for young children in South Africa. One “mentor mother” was recruited from each of 37 neighborhoods in Cape Town, South Africa. Mentor mothers were trained to conduct home visits to weigh children under six years old and to support mothers to problem-solve life challenges, especially around nutrition. Households with underweight children were assigned randomly on a 2:1 ratio to the Philani program (n = 500) or to a standard care condition (n = 179); selection effects occurred and children in the intervention households weighed less at recruitment. Children were evaluated over a one-year period (n = 679 at recruitment and n = 638 with at least one follow-up; 94%). Longitudinal random effects models indicated that, over 12 months, the children in the intervention condition gained significantly more weight than children in the control condition. Mentor mothers who are positive peer deviants may be a viable strategy that is efficacious and can build community, and the use of mentor mothers for other problems in South Africa is discussed. PMID:22299019

Shaping long-term primate development: Telomere length trajectory as an indicator of early maternal maltreatment and predictor of future physiologic regulation.

PubMed

Drury, Stacy S; Howell, Brittany R; Jones, Christopher; Esteves, Kyle; Morin, Elyse; Schlesinger, Reid; Meyer, Jerrold S; Baker, Kate; Sanchez, Mar M

2017-12-01

The molecular, neurobiological, and physical health impacts of child maltreatment are well established, yet mechanistic pathways remain inadequately defined. Telomere length (TL) decline is an emerging molecular indicator of stress exposure with definitive links to negative health outcomes in maltreated individuals. The multiple confounders endemic to human maltreatment research impede the identification of causal pathways. This study leverages a unique randomized, cross-foster, study design in a naturalistic translational nonhuman primate model of infant maltreatment. At birth, newborn macaques were randomly assigned to either a maltreating or a competent control mother, balancing for sex, biological mother parenting history, and social rank. Offspring TL was measured longitudinally across the first 6 months of life (infancy) from peripheral blood. Hair cortisol accumulation was also determined at 6, 12, and 18 months of age. TL decline was greater in animals randomized to maltreatment, but also interacted with biological mother group. Shorter TL at 6 months was associated with higher mean cortisol levels through 18 months (juvenile period) when controlling for relevant covariates. These results suggest that even under the equivalent social, nutritional, and environmental conditions feasible in naturalistic translational nonhuman primate models, early adverse caregiving results in lasting molecular scars that foreshadow elevated health risk and physiologic dysregulation.

14 CFR 27.173 - Static longitudinal stability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Static longitudinal stability. 27.173... longitudinal stability. (a) The longitudinal control must be designed so that a rearward movement of the... the maneuvers specified in § 27.175(a) through (d), the slope of the control position versus airspeed...

14 CFR 29.173 - Static longitudinal stability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Static longitudinal stability. 29.173... Static longitudinal stability. (a) The longitudinal control must be designed so that a rearward movement... constant during the maneuvers specified in § 29.175(a) through (d), the slope of the control position...

Who Benefits from Gender Responsive Treatment? Accounting for Abuse History on Longitudinal Outcomes for Women in Prison.

PubMed

Saxena, Preeta; Messina, Nena; Grella, Christine E

2014-04-01

This study explores outcome variation among women offenders who participated in gender-responsive substance abuse treatment (GRT). In order to identify subgroups of participants that may differentially benefit from this treatment, secondary analyses examined the interaction between randomization into GRT and a history of abuse (physical/sexual) on depression and number of substances used post- treatment. The sample consisted of 115 incarcerated women assessed at baseline and 6- and 12-months post parole. Longitudinal regression showed that women reporting abuse randomized into GRT had significantly reduced odds of depression ( OR = .29, p < .05, 95% CI = .10 - .86) and lowered rates of number of substances used ( IRR = .52, p < .05, 95% CI = 0.28-0.98), in comparison to those who reported abuse and were randomized to the non-GRT group. GRT for women offenders who have experienced prior abuse would maximize the benefits of the trauma-informed, gender-sensitive intervention.

Evaluation of the Dogs, Physical Activity, and Walking (Dogs PAW) Intervention: A Randomized Controlled Trial.

PubMed

Richards, Elizabeth A; Ogata, Niwako; Cheng, Ching-Wei

2016-01-01

To facilitate physical activity (PA) adoption and maintenance, promotion of innovative population-level strategies that focus on incorporating moderate-intensity lifestyle PAs are needed. The purpose of this randomized controlled trial was to evaluate the Dogs, Physical Activity, and Walking intervention, a 3-month, social cognitive theory (SCT), e-mail-based PA intervention. In a longitudinal, repeated-measures design, 49 dog owners were randomly assigned to a control (n = 25) or intervention group (n = 24). The intervention group received e-mail messages (twice weekly for 4 weeks and weekly for 8 weeks) designed to influence SCT constructs of self-efficacy, self-regulation, outcome expectations and expectancies, and social support. At baseline and every 3 months through 1 year, participants completed self-reported questionnaires of individual, interpersonal, and PA variables. Linear mixed models were used to assess for significant differences in weekly minutes of dog walking and theoretical constructs between groups (intervention and control) across time. To test self-efficacy as a mediator of social support for dog walking, tests for mediation were conducted using the bootstrapping technique. With the exception of Month 9, participants in the intervention group accumulated significantly more weekly minutes of dog walking than the control group. On average, the intervention group accumulated 58.4 more minutes (SD = 18.1) of weekly dog walking than the control group (p < .05). Self-efficacy partially mediated the effect of social support variables on dog walking. Results indicate that a simple SCT-based e-mail intervention is effective in increasing and maintaining an increase in dog walking among dog owners at 12-month follow-up. In light of these findings, it may be advantageous to design dog walking interventions that focus on increasing self-efficacy for dog walking by fostering social support.

Randomized controlled trial of brief alcohol screening and intervention for college students for heavy-drinking mandated and volunteer undergraduates: 12-month outcomes.

PubMed

Terlecki, Meredith A; Buckner, Julia D; Larimer, Mary E; Copeland, Amy L

2015-03-01

This is the first randomized trial testing whether heavy-drinking undergraduates mandated to the Brief Alcohol Screening and Intervention for College Students (BASICS) program following a campus alcohol violation would benefit as much as heavy-drinking volunteers up to 1 year postintervention using control groups with high-risk drinkers to model disciplinary-related and naturalistic changes in drinking. Participants (61% male; 51% mandated; 84% Caucasian; M age = 20.14 years) were screened for heavy drinking and randomized to BASICS (n = 115) or assessment-only control (n = 110). Outcome measures (drinking, alcohol problems) were collected at baseline, 4 weeks, 3, 6, and 12 months postintervention. At 4 weeks postintervention, intent-to-treat multilevel longitudinal models showed that regardless of referral group (mandated or volunteer), BASICS significantly decreased weekly drinking, typical drinks, and peak drinks relative to controls (ds = .41-.92). BASICS had a large effect on decreases in alcohol problems (d = .87). At 12 months postintervention, BASICS participants (regardless of referral group) reported significantly fewer alcohol problems (d = .56) compared with controls. Significant long-term intervention gains for peak and typical drinks were sustained in both referral groups relative to controls (ds = .42; .11). Referral group had no significant main effect and did not interact with intervention condition to predict outcomes. Given that BASICS was associated with less drinking and fewer alcohol problems (even among heavier drinking mandated students up to 1 year postintervention), provision of BASICS-style programs within disciplinary settings may help reduce heavy and problematic drinking among at-risk students. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Testing the 'Teaching Kids to Cope with Anger' Youth Anger Intervention Program in a Rural School-based Sample.

PubMed

Puskar, Kathryn Rose; Ren, Dianxu; McFadden, Tricia

2015-03-01

The purpose of this paper is to report the longitudinal effects of the 'Teaching Kids to Cope with Anger' (TKC-A) program on self-reported anger in rural youth. Through a randomized controlled trial, 179 youths of 14-18 years of age, from three rural high schools, were randomized into a control (n  =  86) and an intervention group (n  =  93) for eight TKC-A weekly sessions. These students completed the STAXI-2 anger instrument questionnaires at baseline, post-intervention, 6 months, and at 1 year. T-test statistics were used to analyze and compare the control and intervention groups. Through analysis of the Anger Index sub-scale of the STAXI-2 at 1 year post-intervention, a significant difference was reported between the control and intervention group. Participants reported that the TKC-A intervention was helpful in coping with emotional, behavioral, and social aspects of anger. Future research may utilize the TKC-A with youth who have anger management problems. Psychiatric-mental health nurses can screen youth for anger and be cognizant of coping skills of youth, assess for anger problems and provide health education to youth about approaches for coping with anger.

Changes of loading tensile force-stretch relationships of rabbit mesenteric vein after 21 days of head-down rest

NASA Astrophysics Data System (ADS)

Yao, Yong-Jie; Sun, Hui-Pin; Yue, Yong; Sun, Xi-Qing; Wu, Xing-Yu

Changes of venous compliance may contribute to postflight orthostatic intolerance; however, direct animal studies to address the changes of venous compliance to microgravity have been rare. The purpose of this study was to determine compliance changes of mesenteric veins of rabbits after 21 days of head-down rest (HDR). Twenty-four healthy male New Zealand Rabbits were randomly divided into 21 days of HDR group, horizontal immobilization group (HIG) and control group (Ctrl), with eight in each. Loading tensile force-stretch relationships of mesenteric vein segments were constructed after 21 d HDR. With the increase of loading tensile force, both longitudinal and circumferential stretches of vein samples increased significantly. Under the same loading tensile force, mesenteric vein of the HDR showed significant increase both in circumferential stretch and longitudinal stretches compared to those of Ctrl group and HIG group. These results indicate that, a 21-day simulated weightlessness leads to increase of mesenteric venous compliance.

Peer influence processes for youth delinquency and depression.

PubMed

Reynolds, Andrew D; Crea, Thomas M

2015-08-01

This study explores the multiple factors that account for peer influence processes of adolescent delinquency and depression using data from Waves I and II of the National Longitudinal Study of Adolescent to Adult Health (Add Health). Random-effects longitudinal negative binomial models were used to predict depression and delinquency, controlling for social connection variables to account for selection bias. Findings suggest peer depression and delinquency are both predictive of youth delinquency, while peer influences of depression are much more modest. Youth who are more connected to parents and communities and who are more popular within their networks are more susceptible to peer influence, while self-regulating youth are less susceptible. We find support for theories of popularity-socialization as well as weak-ties in explaining social network factors that amplify or constrain peer influence. We argue that practitioners working with youth should consider network-informed interventions to improve program efficacy and avoid iatrogenic effects. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Do Older Drivers At-Risk for Crashes Modify Their Driving Over Time?

PubMed Central

Clay, Olivio J.; Edwards, Jerri D.; Ball, Karlene K.; Wadley, Virginia G.; Vance, David E.; Cissell, Gayla M.; Roenker, Daniel L.; Joyce, John J.

2009-01-01

Five-year driving habit trajectories among older adults (n = 645) at-risk for crashes were examined. Performance measures included Useful Field of View (UFOV). Motor-Free Visual Perception Test, Rapid Walk, and Foot Tap. Self-report measures included demographics and the Driving Habits Questionnaire. Longitudinal random-effects models revealed that drivers at-risk for subsequent crashes, based upon UFOV, regulated their driving more than the lower-risk participants. Restricted driving was present at baseline for the at-risk group and was observed in longitudinal trajectories that controlled for baseline differences. Results indicate that persons at-risk for subsequent crashes increasingly limit their driving over time. Despite this self-regulation, a larger sample of such older drivers was twice as likely to incur subsequent at-fault crashes. Results suggest that self-regulation among older drivers at-risk for crashes is an insufficient compensatory approach to eliminating increased crash risk. UFOV is a registered trademark of Visual Awareness, Inc. PMID:19196692

Clinical impact of negative-pressure wound therapy: a 1,126-patient observational prospective study.

PubMed

Téot, Luc; Guillot-Masanovic, Margot; Miquel, Pierre; Truchetet, François; Meaume, Sylvie; Dompmartin, Anne; Charles Kerihuel, Jean; Trial, Chloé; Faure, Christine

2014-01-01

Negative-pressure wound therapy (NPWT) was developed in the early 1990s and reported in 1997 by Argenta and Morykwas. Ignored at first, this technique progressively came to be considered as an outstanding advancement in reconstructive surgery. Several randomized controlled studies produced evidence for the effect of NPWT on promotion of granulation tissue formation and prevention of tissue damage and amputation. However, no important longitudinal study has yet produced clinical and economic data on the consequences of integrating NPWT into practice in multiple institutions. This prospective, comparative longitudinal study of NPWT as a clinical-practice innovation was conducted in 1,126 patients between March 2006 and June 2009 in 30 university and nonuniversity public and private hospitals in France. NPWT was proposed in a nonrandomized fashion for various clinical indications, and the patients were divided into two groups, one using NPWT, the second using standard care. Efficacy criteria were spontaneous closure, closure after surgical coverage using skin grafts or flaps, or achievement of 40% wound area regression. The results, observed in a pragmatic but not randomized study, are suggestive of a favorable impact of NPWT in multiple clinical situations. The significance of differences between surgical patients who underwent NPWT and those who did not was unclear, as NPWT had already been adopted by most of the surgical wards. © 2014 by the Wound Healing Society.

Effects of vibration therapy on hormone response and stress in severely disabled patients: a double-blind randomized placebo-controlled clinical trial.

PubMed

Seco, J; Rodríguez-Pérez, V; López-Rodríguez, A F; Torres-Unda, J; Echevarria, E; Díez-Alegre, M I; Ortega, A; Morán, P; Mendoza-Laíz, N; Abecia Inchaurregui, L C

2015-01-01

To assess the effects of vibration therapy (VT) on quality of life and hormone response in severely disabled patients compared with placebo. A longitudinal prospective, double-blind, randomized placebo-controlled trial, with pre and postintervention assessments. A total of 20 severely disabled individuals were recruited from a National Reference Centre in Spain: 13 (65%) men and 7 (35%) women, 45.5 ± 9.32 years of age (range 41: 22-63). We evaluated their physical stress and state anxiety. No statistically significant changes were found in the socio-psychological variables studied, while in the experimental group state anxiety decreased significantly with p < 0.01 (Z = 2.38; one-tailed p = .009) and, among the biological variables, the level of cortisol fell (p = 0.03). Short periods of exposure to low-frequency and low-amplitude local vibration are a safe and effective mechanical stimulus that can have a positive effect in terms of hormone response. VT can be considered to have an anti-stress effect. © 2013 Association of Rehabilitation Nurses.

Longitudinal follow-up comparison of educational interventions: multimedia textbook, traditional lecture, and printed textbook.

PubMed

D'Alessandro, D M; Kreiter, C D; Erkonen, W E; Winter, R J; Knapp, H R

1997-11-01

The goal of this prospective, interinstitutional study was to compare the long-term instructional effectiveness of a pediatric multimedia textbook (MMTB) to that of a standard lecture and a printed textbook. A randomized cohort of 89 3rd-year medical students from two institutions were initially evaluated from June 1992 to June 1993 and reevaluated in May 1994. Students were randomly assigned to one of four instructional groups: computer-aided instruction by means of MMTBs (n = 21), traditional lecture (n = 23), printed textbook (n = 19), and a control group (n = 26). After instruction, all groups were tested by means of a multiple choice test at the end of their pediatric clerkship; they were given this same test 11-22 months later. The long-term instructional effectiveness of the MMTB, printed textbook, and lecture were the same as that in the control group, as determined by analysis of variance of mean test scores. The educational advantage of MMTBs observed immediately after instruction was not detected 1 year later. Because attrition reduced statistical power, further research is necessary to determine how educational fading affects these instructional formats.

Extension of the Haseman-Elston regression model to longitudinal data.

PubMed

Won, Sungho; Elston, Robert C; Park, Taesung

2006-01-01

We propose an extension to longitudinal data of the Haseman and Elston regression method for linkage analysis. The proposed model is a mixed model having several random effects. As response variable, we investigate the sibship sample mean corrected cross-product (smHE) and the BLUP-mean corrected cross product (pmHE), comparing them with the original squared difference (oHE), the overall mean corrected cross-product (rHE), and the weighted average of the squared difference and the squared mean-corrected sum (wHE). The proposed model allows for the correlation structure of longitudinal data. Also, the model can test for gene x time interaction to discover genetic variation over time. The model was applied in an analysis of the Genetic Analysis Workshop 13 (GAW13) simulated dataset for a quantitative trait simulating systolic blood pressure. Independence models did not preserve the test sizes, while the mixed models with both family and sibpair random effects tended to preserve size well. Copyright 2006 S. Karger AG, Basel.

Application of an Extended Parabolic Equation to the Calculation of the Mean Field and the Transverse and Longitudinal Mutual Coherence Functions Within Atmospheric Turbulence

NASA Technical Reports Server (NTRS)

Manning, Robert M.

2005-01-01

Solutions are derived for the generalized mutual coherence function (MCF), i.e., the second order moment, of a random wave field propagating through a random medium within the context of the extended parabolic equation. Here, "generalized" connotes the consideration of both the transverse as well as the longitudinal second order moments (with respect to the direction of propagation). Such solutions will afford a comparison between the results of the parabolic equation within the pararaxial approximation and those of the wide-angle extended theory. To this end, a statistical operator method is developed which gives a general equation for an arbitrary spatial statistical moment of the wave field. The generality of the operator method allows one to obtain an expression for the second order field moment in the direction longitudinal to the direction of propagation. Analytical solutions to these equations are derived for the Kolmogorov and Tatarskii spectra of atmospheric permittivity fluctuations within the Markov approximation.

Multivariate Longitudinal Analysis with Bivariate Correlation Test

PubMed Central

Adjakossa, Eric Houngla; Sadissou, Ibrahim; Hounkonnou, Mahouton Norbert; Nuel, Gregory

2016-01-01

In the context of multivariate multilevel data analysis, this paper focuses on the multivariate linear mixed-effects model, including all the correlations between the random effects when the dimensional residual terms are assumed uncorrelated. Using the EM algorithm, we suggest more general expressions of the model’s parameters estimators. These estimators can be used in the framework of the multivariate longitudinal data analysis as well as in the more general context of the analysis of multivariate multilevel data. By using a likelihood ratio test, we test the significance of the correlations between the random effects of two dependent variables of the model, in order to investigate whether or not it is useful to model these dependent variables jointly. Simulation studies are done to assess both the parameter recovery performance of the EM estimators and the power of the test. Using two empirical data sets which are of longitudinal multivariate type and multivariate multilevel type, respectively, the usefulness of the test is illustrated. PMID:27537692

Multivariate Longitudinal Analysis with Bivariate Correlation Test.

PubMed

Adjakossa, Eric Houngla; Sadissou, Ibrahim; Hounkonnou, Mahouton Norbert; Nuel, Gregory

2016-01-01

In the context of multivariate multilevel data analysis, this paper focuses on the multivariate linear mixed-effects model, including all the correlations between the random effects when the dimensional residual terms are assumed uncorrelated. Using the EM algorithm, we suggest more general expressions of the model's parameters estimators. These estimators can be used in the framework of the multivariate longitudinal data analysis as well as in the more general context of the analysis of multivariate multilevel data. By using a likelihood ratio test, we test the significance of the correlations between the random effects of two dependent variables of the model, in order to investigate whether or not it is useful to model these dependent variables jointly. Simulation studies are done to assess both the parameter recovery performance of the EM estimators and the power of the test. Using two empirical data sets which are of longitudinal multivariate type and multivariate multilevel type, respectively, the usefulness of the test is illustrated.

Typology of alcohol users based on longitudinal patterns of drinking.

PubMed

Harrington, Magdalena; Velicer, Wayne F; Ramsey, Susan

2014-03-01

Worldwide, alcohol is the most commonly used psychoactive substance. However, heterogeneity among alcohol users has been widely recognized. This paper presents a typology of alcohol users based on an implementation of idiographic methodology to examine longitudinal daily and cyclic (weekly) patterns of alcohol use at the individual level. A secondary data analysis was performed on the pre-intervention data from a large randomized control trial. A time series analysis was performed at the individual level, and a dynamic cluster analysis was employed to identify homogenous longitudinal patterns of drinking behavior at the group level. The analysis employed 180 daily observations of alcohol use in a sample of 177 alcohol users. The first order autocorrelations ranged from -.76 to .72, and seventh order autocorrelations ranged from -.27 to .79. Eight distinct profiles of alcohol users were identified, each characterized by a unique configuration of first and seventh autoregressive terms and longitudinal trajectories of alcohol use. External validity of the profiles confirmed the theoretical relevance of different patterns of alcohol use. Significant differences among the eight subtypes were found on gender, marital status, frequency of drug use, lifetime alcohol dependence, family history of alcohol use and the Short Index of Problems. Our findings demonstrate that individuals can have very different temporal patterns of drinking behavior. The daily and cyclic patterns of alcohol use may be important for designing tailored interventions for problem drinkers. Copyright © 2013 Elsevier Ltd. All rights reserved.

Typology of Alcohol Users Based on Longitudinal Patterns of Drinking

PubMed Central

Harrington, Magdalena; Velicer, Wayne F.; Ramsey, Susan

2014-01-01

Objective Worldwide, alcohol is the most commonly used psychoactive substance. However, heterogeneity among alcohol users has been widely recognized. This paper presents a typology of alcohol users based on an implementation of idiographic methodology to examine longitudinal daily and cyclic (weekly) patterns of alcohol use at the individual level. Method A secondary data analysis was performed on the pre-intervention data from a large randomized control trial. A time series analysis was performed at the individual level, and a dynamic cluster analysis was employed to identify homogenous longitudinal patterns of drinking behavior at the group level. The analysis employed 180 daily observations of alcohol use in a sample of 177 alcohol users. Results The first order autocorrelations ranged from −.76 to .72, and seventh order autocorrelations ranged from −.27 to .79. Eight distinct profiles of alcohol users were identified, each characterized by a unique configuration of first and seventh autoregressive terms and longitudinal trajectories of alcohol use. External validity of the profiles confirmed the theoretical relevance of different patterns of alcohol use. Significant differences among the eight subtypes were found on gender, marital status, frequency of drug use, lifetime alcohol dependence, family history of alcohol use and the Short Index of Problems. Conclusions Our findings demonstrate that individuals can have very different temporal patterns of drinking behavior. The daily and cyclic patterns of alcohol use may be important for designing tailored interventions for problem drinkers. PMID:24333036

Pediatric advance care planning (pACP) for teens with cancer and their families: Design of a dyadic, longitudinal RCCT.

PubMed

Curtin, Katherine B; Watson, Anne E; Wang, Jichuan; Okonkwo, Obianuju C; Lyon, Maureen E

2017-11-01

Cancer is the leading cause of disease-related death for adolescents and young adults (AYAs) in the United States. Parents of AYAs with life-threatening illnesses have expressed the desire to talk to their children about end of life (EOL) care, yet, like caregivers of adult patients, struggle to initiate this conversation. Building Evidence for Effective Palliative/End of Life Care for Teens with Cancer is a longitudinal, randomized, controlled, single-blinded clinical trial aimed at evaluating the efficacy of FAmily CEntered disease-specific advance care planning (ACP) for teens with cancer (FACE-TC). A total of 130 dyads (260 subjects) composed of AYAs 14-20years old with cancer and their family decision maker (≥18years old) will be recruited from pediatric oncology programs at Akron Children's Hospital and St. Jude Children's Research Hospital. Dyads will be randomized to either the FACE-TC intervention or Treatment as Usual (TAU) control. FACE-TC intervention dyads will complete three 60-minute ACP sessions held at weekly intervals. Follow-up data will be collected at 3, 6, 12, and 18months post-intervention by a blinded research assistant (RA). The effects of FACE-TC on patient-family congruence in treatment preferences, quality of life (QOL), and advance directive completion will be analyzed. FACE-TC is an evidenced-based and patient-centered intervention that considers QOL and EOL care according to the AYA's representation of illness. The family is involved in the ACP process to facilitate shared decision making, increase understanding of the AYA's preferences, and make a commitment to honor the AYA's wishes. Copyright © 2017 Elsevier Inc. All rights reserved.

Prognosis of acute idiopathic neck pain is poor: a systematic review and meta-analysis.

PubMed

Hush, Julia M; Lin, C Christine; Michaleff, Zoe A; Verhagen, Arianne; Refshauge, Kathryn M

2011-05-01

To conduct a systematic review and meta-analysis on the prognosis of acute idiopathic neck pain and disability. EMBASE, CINAHL, Medline, AMED, PEDro, and CENTRAL were searched from inception to July 2009, limited to human studies. Reference lists of relevant systematic reviews were searched by hand. Search terms included: neck pain, prognosis, inception, cohort, longitudinal, observational, or prospective study and randomized controlled trial. Eligible studies were longitudinal cohort studies and randomized controlled trials with a no treatment or minimal treatment arm that recruited an inception cohort of acute idiopathic neck pain and reported pain or disability outcomes. Eligibility was determined by 2 authors independently. Seven of 20,085 references were included. Pain and disability data were extracted independently by 2 authors. Risk of bias was assessed independently by 2 authors. Statistical pooling showed a weighted mean pain score (0-100) of 64 (95% confidence interval [CI], 61-67) at onset and 35 (95% CI, 32-38) at 6.5 weeks. At 12 months, neck pain severity remained high at 42 (95% CI, 39-45). Disability reduced from a pooled weighted mean score (0-100) at onset of 30 (95% CI, 28-32) to 17 (95% CI, 15-19) by 6.5 weeks, without further improvement at 12 months. Studies varied in length of follow-up, design, and sample size. This review provides Level I evidence that the prognosis of acute idiopathic neck pain is worse than currently recognized. This evidence can guide primary care clinicians when providing prognostic information to patients. Further research to identify prognostic factors and long-term outcomes from inception cohorts would be valuable. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

A randomized controlled trial to evaluate the effectiveness of a cognitive behavioural group approach to improve patient adherence to peritoneal dialysis fluid restrictions: a pilot study.

PubMed

Hare, Jennifer; Clark-Carter, David; Forshaw, Mark

2014-03-01

Peritoneal dialysis (PD) requires patients to take an active role in their adherence to fluid restrictions. Although fluid non-adherence had been identified among this patient group, no specific interventions have been researched or published with in the PD population. The current study sought to investigate whether an applied cognitive behavioural therapy (CBT-based intervention) used among haemodialysis patients would improve fluid adherence among PD patients; utilizing clinical indicators used in practice. Fifteen PD patients identified as fluid non-adherent were randomly assigned to an intervention group (IG) or a deferred-entry control group (CG). The study ran for a total of 21 weeks, with five data collection points; at baseline, post-intervention and at three follow-up points; providing a RCT phase and a combined longitudinal analysis phase. The content of the group intervention encompassed educational, cognitive and behavioural components, aimed to assist patients' self-management of fluid. No significant differences in weight (kg) reduction were found in either phase and undesirable changes in blood pressure (BP) were observed. However, in the longitudinal phase, a statistically significant difference in oedematous status was observed at 6-week follow-up; which may be indicative of fluid adherence. Positive and significant differences were observed in the desired direction for measures of psychological well-being, quality of life and health beliefs; areas correlated with enhanced fluid adherence in other research. This study reveals encouraging and significant changes in predictors of fluid adherence. Although there were no significant changes in weight as a crude clinical measure of fluid intake, significant reductions in oedematous status were observed as a consequence of this CBT-based group intervention.

Behavior in children with Prader-Willi syndrome before and during growth hormone treatment: a randomized controlled trial and 8-year longitudinal study.

PubMed

Lo, Sin T; Siemensma, Elbrich P C; Festen, Dederieke A M; Collin, Philippe J L; Hokken-Koelega, Anita C S

2015-09-01

Information on behavior of children with Prader-Willi syndrome (PWS) and the effect of growth hormone (GH) treatment is scarce. Parents report less problem behavior during GH treatment. Forty-two pre-pubertal children, aged 3.5-14 years were studied in a randomized controlled GH trial (RCT) during 2 years, followed by a longitudinal study during 8 years of GH treatment. Behavior was measured annually by the Developmental Behavior Checklist for children with intellectual disability (DBC) and a Dutch questionnaire to evaluate social behavioral problems in children, the Children's Social Behavior Questionnaire (CSBQ). Problem behavior measured by the DBC in children with PWS was similar compared to peers with comparable intellectual disability. Scores on 'Social disabilities' subscale were however significantly higher compared to the DBC total score (p < 0.01). A lower IQ was associated with more self-absorbed behavior, more communication problems and more problem behavior in general. Problem behavior measured by the CSBQ was similar compared to peers with a comparable intellectual disability, but children with PWS scored significantly higher on the 'Not tuned', 'Understanding', and 'Stereotyped' subscales than the CSBQ total score (p < 0.05 for all subscales and p = 0.001 for the 'Not tuned'-subscale). There were no significant effects of GH treatment during the RCT and 8 years of GH treatment. Children with PWS showed similar problem behavior as a reference population with a comparable intellectual disability. Social problems were the most pronounced within-problem behavior in PWS. In contrast to our expectations and parents reports, our study shows no improvement but also no deterioration of behavioral problems in children with PWS during long-term GH treatment.

What It's Like to Grow Older: The Aging Perceptions of People with an Intellectual Disability in Ireland

ERIC Educational Resources Information Center

Burke, Eilish; McCarron, Mary; Carroll, Rachael; McGlinchey, Eimear; McCallion, Philip

2014-01-01

The Intellectual Disability Supplement to The Irish Longitudinal Study on Ageing is a national longitudinal study on the aging of people with an intellectual disability (ID) using a randomly selected sample of people with ID over the age of 40. In total, 367 people with an ID completed the aging perception self-report only section. Over 57% of…

Longitudinal Study of a Cooperation-Driven, Socio-Scientific Issue Intervention on Promoting Students' Critical Thinking and Self-Regulation in Learning Science

ERIC Educational Resources Information Center

Wang, Hsin-Hui; Chen, Hsiang-Ting; Lin, Huann-shyang; Huang, Yu-Ning; Hong, Zuway-R

2017-01-01

This longitudinal study explored the effects of a Cooperation-driven Socioscientific Issue (CDSSI) intervention on junior high school students' perceptions of critical thinking (CT) and self-regulation (SR) in Taiwan. Forty-nine grade 7 students were randomly selected as an experimental group (EG) to attend a 3-semester 72-hour intervention; while…

The Philadelphia Education Longitudinal Study (PELS): Report on the Transition to High School in the School District of Philadelphia.

ERIC Educational Resources Information Center

Neild, Ruth Curran; Weiss, Christopher C.

The Philadelphia Education Longitudinal Study (PELS) on the transition to ninth grade in Philadelphia highlights the high school choice process, course failure rates during ninth grade, and parents' responses to the transition to high school. The PELS study followed a city-wide random sample of public school students from the summer after eighth…

A random urine test can identify patients at risk of mesalamine non-adherence: a prospective study.

PubMed

Gifford, Anne E; Berg, Anders H; Lahiff, Conor; Cheifetz, Adam S; Horowitz, Gary; Moss, Alan C

2013-02-01

Mesalamine non-adherence is common among patients with ulcerative colitis (UC), and can be difficult to identify in practice. We sought to determine whether a random urine test for salicylates could be used as a marker of 5-aminosalicylic acid (5-ASA) ingestion and identify patients at risk of non-adherence. Our aim is to determine whether measurement of salicylates in a random urine sample correlates with 5-ASA levels, and predicts an individual's risk of mesalamine non-adherence. Prospective observational study. Urinary salicylates (by colorimetry) and 5-ASA (by liquid chromatography and tandem-mass spectrometry) were measured in a random urine sample at baseline in patients and controls. Mesalamine adherence was quantified by patient self-reports at enrollment and pharmacy refills of mesalamine over 6 months. A total of 93 patients with UC taking mesalamine maintenance therapy were prospectively enrolled from the clinic. Random urine salicylate levels (by colorimetry) were highly correlated with urine 5-ASA metabolite levels (by mass spectrometry; R2=0.9). A random urine salicylate level above 15 mg/dl distinguished patients who had recently taken mesalamine from controls (area under the curve value 0.9, sensitivity 95%, specificity 77%). A significant proportion of patients (27%) who self-identified as "high adherers" by an adherence questionnaire (Morisky Medication Adherence Scale-8) had random levels of urine salicylate below this threshold. These patients were at higher risk of objectively measured non-adherence to mesalamine over the subsequent 6 months (RR: 2.7, 95% CI: 1.1-7.0). A random urine salicylate level measured in the clinic can identify patients who have not recently taken mesalamine, and who are at higher risk of longitudinal non-adherence. This test could be used to screen patients who may warrant interventions to improve adherence and prevent disease relapse.

Model Selection with the Linear Mixed Model for Longitudinal Data

ERIC Educational Resources Information Center

Ryoo, Ji Hoon

2011-01-01

Model building or model selection with linear mixed models (LMMs) is complicated by the presence of both fixed effects and random effects. The fixed effects structure and random effects structure are codependent, so selection of one influences the other. Most presentations of LMM in psychology and education are based on a multilevel or…

Meat supplementation improves growth, cognitive, and behavioral outcomes in Kenyan children.

PubMed

Neumann, Charlotte G; Murphy, Suzanne P; Gewa, Connie; Grillenberger, Monika; Bwibo, Nimrod O

2007-04-01

A randomized, controlled school feeding study was conducted in rural Embu District, Kenya to test for a causal link between animal-source food intake and changes in micronutrient nutrition and growth, cognitive, and behavioral outcomes. Twelve primary schools were randomly assigned to 1 of 4 groups. Children in Standard I classes received the local plant-based dish githeri as a midmorning school snack supplemented with meat, milk, or fat added to equalize energy content in all feedings. The Control children received no feedings but participated in data collection. Main outcome measures assessed at baseline and longitudinally were 24-h food intake recall, anthropometry, cognitive function, physical activity, and behaviors during school free play. For cognitive function, the Meat group showed the steepest rate of increase on Raven's Progressive Matrices scores and in zone-wide school end-term total and arithmetic test scores. The Plain githeri and Meat groups performed better over time than the Milk and Control groups (P < 0.02-0.03) on arithmetic tests. The Meat group showed the greatest increase in percentage time in high levels of physical activity and in initiative and leadership behaviors compared with all other groups. For growth, in the Milk group only younger and stunted children showed a greater rate of gain in height. The Meat group showed near doubling of upper midarm muscle area, and the Milk group a smaller degree of increase. This is the first randomized, controlled feeding study to examine the effect of meat- vs. milk- vs. plant-based snacks on functional outcomes in children.

Regional gray matter volume increases following 7days of voluntary wheel running exercise: a longitudinal VBM study in rats.

PubMed

Sumiyoshi, Akira; Taki, Yasuyuki; Nonaka, Hiroi; Takeuchi, Hikaru; Kawashima, Ryuta

2014-09-01

The effects of physical exercise on brain morphology in rodents have been well documented in histological studies. However, to further understand when and where morphological changes occur in the whole brain, a noninvasive neuroimaging method allowing an unbiased, comprehensive, and longitudinal investigation of brain morphology should be used. In this study, we investigated the effects of 7days of voluntary wheel running exercise on regional gray matter volume (rGMV) using longitudinal voxel-based morphometry (VBM) in rats. Eighteen pairs of adult male naïve Wistar rats were randomized to the exercise or control condition (one rat for each condition from each pair). Each rat was scanned in a 7.0-T MRI scanner at three time points: before exercise, after 7days of exercise, and after 7days of follow-up. The T2-weighted MRI images were segmented using the rat brain tissue priors that were recently published by our laboratory, and the intra- and inter-subject template creation steps were followed. Longitudinal VBM analysis revealed significant increases in rGMV in the motor, somatosensory, association, and visual cortices in the exercise group. Among these brain regions, rGMV changes in the motor cortex were positively correlated with the total distance that was run during the 7days of exercise. In addition, the effects of 7days of exercise on rGMV persisted after 7days of follow-up. These results support the utility of a longitudinal VBM study in rats and provide new insights into experience-dependent structural brain plasticity in naïve adult animals. Copyright © 2014 Elsevier Inc. All rights reserved.

Methods for a longitudinal quantitative outcome with a multivariate Gaussian distribution multi-dimensionally censored by therapeutic intervention.

PubMed

Sun, Wanjie; Larsen, Michael D; Lachin, John M

2014-04-15

In longitudinal studies, a quantitative outcome (such as blood pressure) may be altered during follow-up by the administration of a non-randomized, non-trial intervention (such as anti-hypertensive medication) that may seriously bias the study results. Current methods mainly address this issue for cross-sectional studies. For longitudinal data, the current methods are either restricted to a specific longitudinal data structure or are valid only under special circumstances. We propose two new methods for estimation of covariate effects on the underlying (untreated) general longitudinal outcomes: a single imputation method employing a modified expectation-maximization (EM)-type algorithm and a multiple imputation (MI) method utilizing a modified Monte Carlo EM-MI algorithm. Each method can be implemented as one-step, two-step, and full-iteration algorithms. They combine the advantages of the current statistical methods while reducing their restrictive assumptions and generalizing them to realistic scenarios. The proposed methods replace intractable numerical integration of a multi-dimensionally censored MVN posterior distribution with a simplified, sufficiently accurate approximation. It is particularly attractive when outcomes reach a plateau after intervention due to various reasons. Methods are studied via simulation and applied to data from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications study of treatment for type 1 diabetes. Methods proved to be robust to high dimensions, large amounts of censored data, low within-subject correlation, and when subjects receive non-trial intervention to treat the underlying condition only (with high Y), or for treatment in the majority of subjects (with high Y) in combination with prevention for a small fraction of subjects (with normal Y). Copyright © 2013 John Wiley & Sons, Ltd.

Subject-specific longitudinal shape analysis by coupling spatiotemporal shape modeling with medial analysis

NASA Astrophysics Data System (ADS)

Hong, Sungmin; Fishbaugh, James; Rezanejad, Morteza; Siddiqi, Kaleem; Johnson, Hans; Paulsen, Jane; Kim, Eun Young; Gerig, Guido

2017-02-01

Modeling subject-specific shape change is one of the most important challenges in longitudinal shape analysis of disease progression. Whereas anatomical change over time can be a function of normal aging, anatomy can also be impacted by disease related degeneration. Anatomical shape change may also be affected by structural changes from neighboring shapes, which may cause non-linear variations in pose. In this paper, we propose a framework to analyze disease related shape changes by coupling extrinsic modeling of the ambient anatomical space via spatiotemporal deformations with intrinsic shape properties from medial surface analysis. We compare intrinsic shape properties of a subject-specific shape trajectory to a normative 4D shape atlas representing normal aging to isolate shape changes related to disease. The spatiotemporal shape modeling establishes inter/intra subject anatomical correspondence, which in turn enables comparisons between subjects and the 4D shape atlas, and also quantitative analysis of disease related shape change. The medial surface analysis captures intrinsic shape properties related to local patterns of deformation. The proposed framework jointly models extrinsic longitudinal shape changes in the ambient anatomical space, as well as intrinsic shape properties to give localized measurements of degeneration. Six high risk subjects and six controls are randomly sampled from a Huntington's disease image database for qualitative and quantitative comparison.

A Three-Year Longitudinal Study of Reading and Spelling Difficulty in Chinese Developmental Dyslexia: The Matter of Morphological Awareness.

PubMed

Tong, Xiuhong; McBride, Catherine; Lo, Jason Chor Ming; Shu, Hua

2017-11-01

In the present study, we used a three-time point longitudinal design to investigate the associations of morphological awareness to word reading and spelling in a small group of those with and without dyslexia taken from a larger sample of 164 Hong Kong Chinese children who remained in a longitudinal study across ages 6, 7 and 8. Among those 164 children, 15 had been diagnosed as having dyslexia by professional psychologists, and 15 other children manifested average reading ability and had been randomly selected from the sample for comparison. All children were administered a battery of tasks including Chinese character recognition, word dictation, morphological awareness, phonological awareness and rapid automatized naming. Multivariate analysis of variance and predictive discriminate analysis were performed to examine whether the dyslexic children showed differences in the cognitive-linguistic tasks in comparison with controls. Results suggested that the dyslexic groups had poorer performance in morphological awareness and RAN across all 3 years. However, phonological awareness was not stable in distinguishing the groups. Findings suggest that morphological awareness is a relatively strong correlate of spelling difficulties in Chinese, but phonological awareness is not. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Music training improves speech-in-noise perception: Longitudinal evidence from a community-based music program.

PubMed

Slater, Jessica; Skoe, Erika; Strait, Dana L; O'Connell, Samantha; Thompson, Elaine; Kraus, Nina

2015-09-15

Music training may strengthen auditory skills that help children not only in musical performance but in everyday communication. Comparisons of musicians and non-musicians across the lifespan have provided some evidence for a "musician advantage" in understanding speech in noise, although reports have been mixed. Controlled longitudinal studies are essential to disentangle effects of training from pre-existing differences, and to determine how much music training is necessary to confer benefits. We followed a cohort of elementary school children for 2 years, assessing their ability to perceive speech in noise before and after musical training. After the initial assessment, participants were randomly assigned to one of two groups: one group began music training right away and completed 2 years of training, while the second group waited a year and then received 1 year of music training. Outcomes provide the first longitudinal evidence that speech-in-noise perception improves after 2 years of group music training. The children were enrolled in an established and successful community-based music program and followed the standard curriculum, therefore these findings provide an important link between laboratory-based research and real-world assessment of the impact of music training on everyday communication skills. Copyright © 2015 Elsevier B.V. All rights reserved.

Does oral language underpin the development of later behavior problems? A longitudinal meta-analysis.

PubMed

Chow, Jason C; Ekholm, Erik; Coleman, Heather

2018-05-24

The purpose of this article is to estimate the overall weighted mean effect of the relation between early language skills and later behavior problems in school-aged children. A systematic literature search yielded 19,790 unduplicated reports, and a structured search strategy and identification procedure yielded 25 unique data sets, with 114 effect sizes for analysis. Eligible reports were then coded, and effect sizes were extracted and synthesized via robust variance estimation and random-effects meta-analytic techniques. The overall correlation between early language and later behavior problems was negative and small (r = -.14, 95% confidence interval [CI] [-.16, -.11]), and controlling for demographic variables did not reduce the magnitude of the inverse relationship between language skill and problem behavior (r = -.16). Moderator analyses identified receptive language, parent-reported behavior measures, gender, and age as significant predictors of the association between language and behavior. This article corroborates the consistent findings of previous meta-analytic and longitudinal studies and further identifies areas, particularly around measurement, for future research. Furthermore, prospective longitudinal evaluations of the relations between language deficits and behavior problems with different types of measures (teacher-/parent-report, direct assessment, classroom observation) is warranted. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A structured framework for assessing sensitivity to missing data assumptions in longitudinal clinical trials.

PubMed

Mallinckrodt, C H; Lin, Q; Molenberghs, M

2013-01-01

The objective of this research was to demonstrate a framework for drawing inference from sensitivity analyses of incomplete longitudinal clinical trial data via a re-analysis of data from a confirmatory clinical trial in depression. A likelihood-based approach that assumed missing at random (MAR) was the primary analysis. Robustness to departure from MAR was assessed by comparing the primary result to those from a series of analyses that employed varying missing not at random (MNAR) assumptions (selection models, pattern mixture models and shared parameter models) and to MAR methods that used inclusive models. The key sensitivity analysis used multiple imputation assuming that after dropout the trajectory of drug-treated patients was that of placebo treated patients with a similar outcome history (placebo multiple imputation). This result was used as the worst reasonable case to define the lower limit of plausible values for the treatment contrast. The endpoint contrast from the primary analysis was - 2.79 (p = .013). In placebo multiple imputation, the result was - 2.17. Results from the other sensitivity analyses ranged from - 2.21 to - 3.87 and were symmetrically distributed around the primary result. Hence, no clear evidence of bias from missing not at random data was found. In the worst reasonable case scenario, the treatment effect was 80% of the magnitude of the primary result. Therefore, it was concluded that a treatment effect existed. The structured sensitivity framework of using a worst reasonable case result based on a controlled imputation approach with transparent and debatable assumptions supplemented a series of plausible alternative models under varying assumptions was useful in this specific situation and holds promise as a generally useful framework. Copyright © 2012 John Wiley & Sons, Ltd.

Histomorphological and immunofluorescence evaluation of clear corneal incisions after microcoaxial phacoemulsification with 2.2 mm and 1.8 mm systems.

PubMed

Vasavada, Abhay R; Johar, Kaid; Praveen, Mamidipudi R; Vasavada, Viraj A; Arora, Anshul I

2013-04-01

To compare changes in the incision's histomorphology and denaturation of collagen I in rabbit eyes having microcoaxial phacoemulsification through 2.2 mm and 1.8 mm incision-compatible systems. Randomized experimental trial. Iladevi Cataract & IOL Research Centre, Ahmedabad, India. Thirty rabbit eyes were randomized into Group 1 (microcoaxial phacoemulsification through 2.2 mm incisions using Infiniti system [torsional ultrasound]) and Group 2 (microcoaxial phacoemulsification through 1.8 mm incisions using Stellaris system [longitudinal ultrasound]). Each group was then divided into 3 subgroups of 5 eyes each based on 1 of the 3 intervention options: phacoemulsification only, intraocular lens (IOL) insertion only, and phacoemulsification with IOL insertion. Left eyes were randomized for microcoaxial phacoemulsification, and right eyes were treated as controls. After phacoemulsification, eyes in Group 1 showed loss of epithelium at the roof of the incisions and Descemet membrane detachment at the floor of the incisions. These findings did not change after IOL insertion. After phacoemulsification, eyes in Group 2 showed loss of epithelium, but Descemet membrane remained attached. There was a longitudinal split in the incision's stroma in the direction of internal entry. The stromal damage increased after IOL implantation. Immunofluorescence studies showed no obvious irregularities in the arrangement of collagen I in either group. A dot blot analysis showed significant denaturation of collagen I in Group 2. The histomorphology of the 2.2 mm system incision showed localized Descemet membrane detachment and endothelial cell loss. The 1.8 mm system incision showed exaggerated stromal damage after IOL insertion. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Impact exercise increases BMC during growth: an 8-year longitudinal study.

PubMed

Gunter, Katherine; Baxter-Jones, Adam Dg; Mirwald, Robert L; Almstedt, Hawley; Fuchs, Robyn K; Durski, Shantel; Snow, Christine

2008-07-01

Our aim was to assess BMC of the hip over 8 yr in prepubertal children who participated in a 7-mo jumping intervention compared with controls who participated in a stretching program of equal duration. We hypothesized that jumpers would gain more BMC than control subjects. The data reported come from two cohorts of children who participated in separate, but identical, randomized, controlled, school-based impact exercise interventions and reflect those subjects who agreed to long-term follow-up (N = 57; jumpers = 33, controls = 24; 47% of the original participants). BMC was assessed by DXA at baseline, 7 and 19 mo after intervention, and annually thereafter for 5 yr (eight visits over 8 yr). Multilevel random effects models were constructed and used to predict change in BMC from baseline at each measurement occasion. After 7 mo, those children that completed high-impact jumping exercises had 3.6% more BMC at the hip than control subjects whom completed nonimpact stretching activities (p < 0.05) and 1.4% more BMC at the hip after nearly 8 yr (BMC adjusted for change in age, height, weight, and physical activity; p < 0.05). This provides the first evidence of a sustained effect on total hip BMC from short-term high-impact exercise undertaken in early childhood. If the benefits are sustained into young adulthood, effectively increasing peak bone mass, fracture risk in the later years could be reduced.

Intermittent slow sand filtration for preventing diarrhoea among children in Kenyan households using unimproved water sources: randomized controlled trial.

PubMed

Tiwari, Sangya-Sangam K; Schmidt, Wolf-Peter; Darby, Jeannie; Kariuki, Z G; Jenkins, Marion W

2009-11-01

Measure effectiveness of intermittent slow sand filtration for reducing child diarrhoea among households using unimproved water sources in rural Kenya. A randomized controlled trail was conducted among populations meeting a high-risk profile for child diarrhoea from drinking river water in the River Njoro watershed. Intervention households (30) were provided the concrete BioSand Filter and instructed on filter use and maintenance. Control households (29) continued normal practices. Longitudinal monthly monitoring of diarrhoea (seven-day daily prevalence recall) and of influent, effluent, and drinking water quality for fecal coliform was conducted for 6 months. Intervention households had better drinking water quality than control households (fecal coliform geometric mean, 30.0 CFU vs. 89.0 CFU/100 ml, P < 0.001) and reported significantly fewer diarrhoea days (86 days over 626 child-weeks) compared to controls (203 days over 558 child-weeks) among children up to 15 (age-adjusted RR 0.46; 95 % CI = 0.22, 0.96). Greater child diarrhoea reduction due to the intervention (age-adjusted RR 0.23, 95 % CI = 0.10, 0.51) was observed among the sub-group using unimproved water sources all of the time. Intermittent slow sand filtration, a non-commercial technology, produces similar observed effects on child diarrhoea as commercial POU products, adding to the range of effective options for poor populations (chlorination, ceramic filtration, solar disinfection, flocculation/disinfection).

Longitudinal vortex control - Techniques and applications (The 32nd Lanchester Lecture)

NASA Technical Reports Server (NTRS)

Bushnell, D. M.

1992-01-01

A summary is presented of vortex control applications and current techniques for the control of longitudinal vortices produced by bodies, leading edges, tips and intersections. Vortex control has up till now been performed by many approaches in an empirical fashion, assisted by the essentially inviscid nature of much of longitudinal vortex behavior. Attention is given to Reynolds number sensitivities, vortex breakdown and interactions, vortex control on highly swept wings, and vortex control in juncture flows.

Longitudinal changes of angle configuration in primary angle-closure suspects: the Zhongshan Angle-Closure Prevention Trial.

PubMed

Jiang, Yuzhen; Chang, Dolly S; Zhu, Haogang; Khawaja, Anthony P; Aung, Tin; Huang, Shengsong; Chen, Qianyun; Munoz, Beatriz; Grossi, Carlota M; He, Mingguang; Friedman, David S; Foster, Paul J

2014-09-01

To determine longitudinal changes in angle configuration in the eyes of primary angle-closure suspects (PACS) treated by laser peripheral iridotomy (LPI) and in untreated fellow eyes. Longitudinal cohort study. Primary angle-closure suspects aged 50 to 70 years were enrolled in a randomized, controlled clinical trial. Each participant was treated by LPI in 1 randomly selected eye, with the fellow eye serving as a control. Angle width was assessed in a masked fashion using gonioscopy and anterior segment optical coherence tomography (AS-OCT) before and at 2 weeks, 6 months, and 18 months after LPI. Angle width in degrees was calculated from Shaffer grades assessed under static gonioscopy. Angle configuration was also evaluated using angle opening distance (AOD250, AOD500, AOD750), trabecular-iris space area (TISA500, TISA750), and angle recess area (ARA) measured in AS-OCT images. No significant difference was found in baseline measures of angle configuration between treated and untreated eyes. At 2 weeks after LPI, the drainage angle on gonioscopy widened from a mean of 13.5° at baseline to a mean of 25.7° in treated eyes, which was also confirmed by significant increases in all AS-OCT angle width measures (P<0.001 for all variables). Between 2 weeks and 18 months after LPI, a significant decrease in angle width was observed over time in treated eyes (P<0.001 for all variables), although the change over the first 5.5 months was not statistically significant for angle width measured under gonioscopy (P = 0.18), AOD250 (P = 0.167) and ARA (P = 0.83). In untreated eyes, angle width consistently decreased across all follow-up visits after LPI, with a more rapid longitudinal decrease compared with treated eyes (P values for all variables ≤0.003). The annual rate of change in angle width was equivalent to 1.2°/year (95% confidence interval [CI], 0.8-1.6) in treated eyes and 1.6°/year (95% CI, 1.3-2.0) in untreated eyes (P<0.001). Angle width of treated eyes increased markedly after LPI, remained stable for 6 months, and then decreased significantly by 18 months after LPI. Untreated eyes experienced a more consistent and rapid decrease in angle width over the same time period. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Increasing Water Intake of Children and Parents in the Family Setting: A Randomized, Controlled Intervention Using Installation Theory.

PubMed

Lahlou, Saadi; Boesen-Mariani, Sabine; Franks, Bradley; Guelinckx, Isabelle

2015-01-01

On average, children and adults in developed countries consume too little water, which can lead to negative health consequences. In a one-year longitudinal field experiment in Poland, we compared the impact of three home-based interventions on helping children and their parents/caregivers to develop sustainable increased plain water consumption habits. Fluid consumption of 334 children and their caregivers were recorded over one year using an online specific fluid dietary record. They were initially randomly allocated to one of the three following conditions: Control, Information (child and carer received information on the health benefits of water), or Placement (in addition to information, free small bottles of still water for a limited time period were delivered at home). After three months, half of the non-controls were randomly assigned to Community (child and caregiver engaged in an online community forum providing support on water consumption). All conditions significantly increased the water consumption of children (by 21.9-56.7%) and of adults (by 22-89%). Placement + Community generated the largest effects. Community enhanced the impact of Placement for children and parents, as well as the impact of Information for parents but not children. The results suggest that the family setting offers considerable scope for successful installation of interventions encouraging children and caregivers to develop healthier consumption habits, in mutually reinforcing ways. Combining information, affordances, and social influence gives the best, and most sustainable, results. © 2015 S. Karger AG, Basel.

Impact of a fictional reading intervention on empathy development in student pharmacists.

PubMed

Collins, Karin L; Zweber, Ann; Irwin, Adriane N

2017-05-01

Determine the impact of a short longitudinal literary fiction intervention on empathy development in student pharmacists as measured by the Jefferson Scale of Empathy - Health Profession Students (JSE-HPS) version. Twenty-one student pharmacists were randomized to an intervention consisting of reading short excerpts of literary fiction over eight weeks (n=11) or a control group not participating in the intervention (n=10). Both groups completed the JSE-HPS at baseline and completion of the literary intervention. Categorical data were compared using a chi-square or Fisher's exact test, and continuous data were compared using paired or independent t-tests for within and across group comparisons respectively. JSE-HPS scores increased in the intervention group (112.1±10.7 to 116.1±7.4; p=0.201) while they decreased in the control group (118.7±12.6 to 113.0±15.9; p=0.188). Changes across groups were not statistically significant (p=0.061). Students randomized to an eight-week literature intervention demonstrated a non-statistically significant increase in empathy as measured by the JSE-HPS questionnaire. Similar increases were not observed in students randomized to a control group. As a result, this intervention may represent a novel way to foster empathy in student pharmacists using an intervention requiring few resources. Further research is needed with larger sample sizes, ideally across multiple institutions, in order to validate the effectiveness of this intervention. Copyright © 2017 Elsevier Inc. All rights reserved.

14 CFR 25.231 - Longitudinal stability and control.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Longitudinal stability and control. 25.231... Characteristics § 25.231 Longitudinal stability and control. (a) Landplanes may have no uncontrollable tendency to... on concrete, to maintain any attitude up to thrust line level, at 75 percent of V SR 1. (b) For...

14 CFR 25.231 - Longitudinal stability and control.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Longitudinal stability and control. 25.231... Characteristics § 25.231 Longitudinal stability and control. (a) Landplanes may have no uncontrollable tendency to... on concrete, to maintain any attitude up to thrust line level, at 75 percent of V SR 1. (b) For...

14 CFR 25.231 - Longitudinal stability and control.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Longitudinal stability and control. 25.231... Characteristics § 25.231 Longitudinal stability and control. (a) Landplanes may have no uncontrollable tendency to... on concrete, to maintain any attitude up to thrust line level, at 75 percent of V SR 1. (b) For...

14 CFR 25.231 - Longitudinal stability and control.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Longitudinal stability and control. 25.231... Characteristics § 25.231 Longitudinal stability and control. (a) Landplanes may have no uncontrollable tendency to... on concrete, to maintain any attitude up to thrust line level, at 75 percent of V SR 1. (b) For...

77 FR 20885 - Agency Information Collection (Vocational Rehabilitation and Employment Longitudinal Study Survey...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-06

... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-New (VR&E Longitudinal Study Survey)] Agency... Building, Room 10235, Washington, DC 20503 (202) 395-7316. Please refer to ``OMB Control No. 2900-New (VR&E....gov . Please refer to ``OMB Control No. 2900-New (VR&E Longitudinal Study Survey)''. SUPPLEMENTARY...

Reducing self-objectification: are dissonance-based methods a possible approach?

PubMed

Becker, Carolyn Black; Hill, Kaitlin; Greif, Rebecca; Han, Hongmei; Stewart, Tiffany

2013-01-01

Previous research has documented that self-objectification is associated with numerous negative outcomes including body shame, eating disorder (ED) pathology, and negative affect. This exploratory open study investigated whether or not an evidence-based body image improvement program that targets thin-ideal internalization in university women also reduces self-objectification. A second aim of the study was to determine if previous findings showing that body shame mediated the relationship between self-objectification and eating disorder pathology at a single time point (consistent with self-objectification theory) but did not mediate longitudinally (inconsistent with self-objectification theory) would be replicated in a new sample under novel conditions. Ninety-six university women completed a peer-led dissonance-based intervention, along with assessment measures at pre-, post-intervention, 8-week and 8-month follow-up. To address the open trial nature of this study, a planned manipulation check was included to make sure that peer-led dissonance decreased thin-ideal internalization, body dissatisfaction, eating disorder pathology, and negative affect with effect sizes being similar to past randomized controlled trials. We hypothesized that all three subscales of the Objectified Body Consciousness Scale (i.e., self-surveillance, body shame, and appearance control beliefs) would be reduced. In addition, we hypothesized that body shame would mediate the relationship between self-objectification (i.e., self-surveillance) and eating disorder pathology at a both at a single time point and longitudinally. The planned manipulation check supported the interpretation that peer-led dissonance in this study largely yielded comparable changes to past controlled trials. In terms of changes in dependent variables, results supported all hypotheses with the exception of body shame, which remained unchanged. With regards to the mediation analyses, our first (cross-sectional) hypothesis but not our second (longitudinal) was supported. Findings provide preliminary support for the use of dissonance interventions in reducing self-surveillance and body control beliefs. Results for body shame and the mediation analyses suggest that greater scrutiny of the body shame construct is warranted.

The Effect of Cognitive Therapy on Structural Social Capital: Results From a Randomized Controlled Trial Among Sexual Violence Survivors in the Democratic Republic of the Congo

PubMed Central

Bolton, Paul A.; Annan, Jeannie; Kaysen, Debra; Robinette, Katie; Cetinoglu, Talita; Wachter, Karin; Bass, Judith K.

2014-01-01

Objectives. We evaluated changes in social capital following group-based cognitive processing therapy (CPT) for female survivors of sexual violence. Methods. We compared CPT with individual support in a cluster-randomized trial in villages in South Kivu province, Democratic Republic of the Congo. Local psychosocial assistants delivered the interventions from April through July 2011. We evaluated differences between CPT and individual support conditions for structural social capital (i.e., time spent with nonkin social network, group membership and participation, and the size of financial and instrumental support networks) and emotional support seeking. We analyzed intervention effects with longitudinal random effects models. Results. We obtained small to medium effect size differences for 2 study outcomes. Women in the CPT villages increased group membership and participation at 6-month follow-up and emotional support seeking after the intervention compared with women in the individual support villages. Conclusions. Results support the efficacy of group CPT to increase dimensions of social capital among survivors of sexual violence in a low-income conflict-affected context. PMID:25033113

Sample size determination for GEE analyses of stepped wedge cluster randomized trials.

PubMed

Li, Fan; Turner, Elizabeth L; Preisser, John S

2018-06-19

In stepped wedge cluster randomized trials, intact clusters of individuals switch from control to intervention from a randomly assigned period onwards. Such trials are becoming increasingly popular in health services research. When a closed cohort is recruited from each cluster for longitudinal follow-up, proper sample size calculation should account for three distinct types of intraclass correlations: the within-period, the inter-period, and the within-individual correlations. Setting the latter two correlation parameters to be equal accommodates cross-sectional designs. We propose sample size procedures for continuous and binary responses within the framework of generalized estimating equations that employ a block exchangeable within-cluster correlation structure defined from the distinct correlation types. For continuous responses, we show that the intraclass correlations affect power only through two eigenvalues of the correlation matrix. We demonstrate that analytical power agrees well with simulated power for as few as eight clusters, when data are analyzed using bias-corrected estimating equations for the correlation parameters concurrently with a bias-corrected sandwich variance estimator. © 2018, The International Biometric Society.

The relationship between working conditions and self-rated health among medical doctors: evidence from seven waves of the Medicine In Australia Balancing Employment and Life (Mabel) survey.

PubMed

Milner, Allison; Witt, Katrina; Spittal, Matthew J; Bismark, Marie; Graham, Melissa; LaMontagne, Anthony D

2017-08-29

Psychosocial job stressors, such as low control and high demands, have been found to influence the health and wellbeing of doctors. However, past research in this area has relied on cross-sectional data, which limits causal inferences about the influence of psychosocial job stressors on health. In this study, we examine this relationship longitudinally while also assessing whether the relationship between psychosocial job stressors and health is modified by gender. The data source was seven annual waves of the Medicine in Australia: Balancing Employment and Life (MABEL) survey. The outcome was self-rated health (measured using the SF-12), and key exposures reflected job control, job demands, work-life balance variables, employment arrangements, and aggression experienced at work. We used longitudinal fixed and random effects regression models to assess within and between-person changes in health. Excessive job demands, low job control, feelings of not being rewarded at work, and work-life imbalance were associated with higher within-person odds of poorer self-rated health. Gender differences were apparent. For female doctors, work arrangements and work-life imbalance were associated with poorer self-rated health whilst task-based job stressors were associated with poorer self-rated health in male doctors. These results suggest the importance of addressing adverse working environments among doctors. Not applicable.

Mathematical modelling of active safety system functions as tools for development of driverless vehicles

NASA Astrophysics Data System (ADS)

Ryazantsev, V.; Mezentsev, N.; Zakharov, A.

2018-02-01

This paper is dedicated to a solution of the issue of synthesis of the vehicle longitudinal dynamics control functions (acceleration and deceleration control) based on the element base of the vehicle active safety system (ESP) - driverless vehicle development tool. This strategy helps to reduce time and complexity of integration of autonomous motion control systems (AMCS) into the vehicle architecture and allows direct control of actuators ensuring the longitudinal dynamics control, as well as reduction of time for calibration works. The “vehicle+wheel+road” longitudinal dynamics control is complicated due to the absence of the required prior information about the control object. Therefore, the control loop becomes an adaptive system, i.e. a self-adjusting monitoring system. Another difficulty is the driver’s perception of the longitudinal dynamics control process in terms of comfort. Traditionally, one doesn’t pay a lot of attention to this issue within active safety systems, and retention of vehicle steerability, controllability and stability in emergency situations are considered to be the quality criteria. This is mainly connected to its operational limits, since it is activated only in critical situations. However, implementation of the longitudinal dynamics control in the AMCS poses another challenge for the developers - providing the driver with comfortable vehicle movement during acceleration and deceleration - while the possible highest safety level in terms of the road grip is provided by the active safety system (ESP). The results of this research are: universal active safety system - AMCS interaction interface; block diagram for the vehicle longitudinal acceleration and deceleration control as one of the active safety system’s integrated functions; ideology of adaptive longitudinal dynamics control, which enables to realize the deceleration and acceleration requested by the AMCS; algorithms synthesised; analytical experiments proving the efficiency and practicability of the chosen concept.

Feasibility, acceptability and preliminary psychological benefits of mindfulness meditation training in a sample of men diagnosed with prostate cancer on active surveillance: results from a randomized controlled pilot trial.

PubMed

Victorson, David; Hankin, Vered; Burns, James; Weiland, Rebecca; Maletich, Carly; Sufrin, Nathaniel; Schuette, Stephanie; Gutierrez, Bruriah; Brendler, Charles

2017-08-01

In a pilot randomized controlled trial, examine the feasibility and preliminary efficacy of an 8-week, mindfulness training program (Mindfulness Based Stress Reduction) in a sample of men on active surveillance on important psychological outcomes including prostate cancer anxiety, uncertainty intolerance and posttraumatic growth. Men were randomized to either mindfulness (n = 24) or an attention control arm (n = 19) and completed self-reported measures of prostate cancer anxiety, uncertainty intolerance, global quality of life, mindfulness and posttraumatic growth at baseline, 8 weeks, 6 months and 12 months. Participants in the mindfulness arm demonstrated significant decreases in prostate cancer anxiety and uncertainty intolerance, and significant increases in mindfulness, global mental health and posttraumatic growth. Participants in the control condition also demonstrated significant increases in mindfulness over time. Longitudinal increases in posttraumatic growth were significantly larger in the mindfulness arm than they were in the control arm. While mindfulness training was found to be generally feasible and acceptable among participants who enrolled in the 8-week intervention as determined by completion rates and open-ended survey responses, the response rate between initial enrollment and the total number of men approached was lower than desired (47%). While larger sample sizes are necessary to examine the efficacy of mindfulness training on important psychological outcomes, in this pilot study posttraumatic growth was shown to significantly increase over time for men in the treatment group. Mindfulness training has the potential to help men cope more effectively with some of the stressors and uncertainties associated with active surveillance. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

A pilot randomized controlled trial of time-intensive cognitive-behaviour therapy for postpartum obsessive-compulsive disorder: effects on maternal symptoms, mother-infant interactions and attachment.

PubMed

Challacombe, F L; Salkovskis, P M; Woolgar, M; Wilkinson, E L; Read, J; Acheson, R

2017-06-01

There is increasing recognition that perinatal anxiety disorders are both common and potentially serious for mother and child. Obsessive-compulsive disorder (OCD) can be triggered or exacerbated in the postpartum period, with mothers reporting significant effects on parenting tasks. However, there is little evidence concerning their effective treatment or the impact of successful treatment on parenting. A total of 34 mothers with OCD and a baby of 6 months old were randomized into either time-intensive cognitive-behaviour therapy (iCBT) or treatment as usual (TAU). iCBT took place after randomization at 6 months postpartum and was completed by 9 months. Maternal symptomatology, sensitivity in mother-infant interactions and parenting were assessed at baseline and reassessed at 12 months postpartum. At 12 months attachment was also assessed using Ainsworth's Strange Situation Procedure. A healthy control group of mothers and infants (n = 37) underwent the same assessments as a benchmark. iCBT was successful in ameliorating maternal symptoms of OCD (controlled effect size = 1.31-1.90). However, mother-infant interactions were unchanged by treatment and remained less sensitive in both OCD groups than a healthy control group. The distribution of attachment categories was similar across both clinical groups and healthy controls with approximately 72% classified as secure in each group. iCBT is an effective intervention for postpartum OCD. Sensitive parenting interactions are affected by the presence of postpartum OCD and this is not improved by successful treatment of OCD symptoms. However, the overall attachment bond appears to be unaffected. Longitudinal studies are needed to explore the impact of postpartum OCD as the child develops.

Nurse Case Management and Housing Interventions Reduce Allergen Exposures: The Milwaukee Randomized Controlled Trial

PubMed Central

Breysse, Jill; Wendt, Jean; Dixon, Sherry; Murphy, Amy; Wilson, Jonathan; Meurer, John; Cohn, Jennifer; Jacobs, David E.

2011-01-01

Objective We examined the impact of a combination of home environmental interventions and nurse case management services on total settled dust loadings and on allergen concentrations in the homes of asthmatic children. Methods Using a randomized longitudinal controlled trial study design, we randomly assigned homes of asthmatic children in Milwaukee to either a control (n=64) or an intervention (n=57) group. Control group homes received a visual assessment, education, bed/pillow dust mite encasings, and treatment of lead-based paint hazards. The intervention group received these same services plus nurse case management that included tailored, individual asthma action plans, provision of minor home repairs, home cleaning using special vacuuming and wet washing, and integrated pest management. Dust vacuum samples were collected from measured surface areas of floors in the TV room, kitchen, and child's bedroom at baseline and at three-, six-, and 12-month follow-up visits. Dust loading (mass per surface area) is a means of measuring total dust and the total amount of allergen present. Results For the intervention group, geometric mean dust loadings declined significantly from baseline (39 milligrams per square foot [mg/ft2]) to post-intervention (11 mg/ft2) (p<0.001). Baseline dust loading, treatment group, visit, and season were significant predictors of follow-up dust loadings. Mean post-intervention dust loadings were 72% higher in the control group. The total amount of allergen in settled house dust declined significantly following the intervention because total dust loading declined; the concentration of allergens in settled dust did not change significantly. Conclusion The combination of nurse case management and home environmental interventions promotes collaboration between health and housing professionals and is effective in reducing exposures to allergens in settled dust. PMID:21563716

Voice Disorders in Teacher Students-A Prospective Study and a Randomized Controlled Trial.

PubMed

Ohlsson, Ann-Christine; Andersson, Eva M; Södersten, Maria; Simberg, Susanna; Claesson, Silwa; Barregård, Lars

2016-11-01

Teachers are at risk of developing voice disorders, but longitudinal studies on voice problems among teachers are lacking. The aim of this randomized trial was to investigate long-term effects of voice education for teacher students with mild voice problems. In addition, vocal health was examined prospectively in a group of students without voice problems. First-semester students answered three questionnaires: one about background factors, one about voice symptoms (Screen6), and the Voice Handicap Index. Students with voice problems according to the questionnaire results were randomized to a voice training group or a control group. At follow-up in the sixth semester, all students answered Screen6 again together with four questions about factors that could have affected vocal health during their teacher education. The training group and the control group also answered the Voice Handicap Index a second time. At follow-up, 400 students remained in the study: 27 in the training group, 54 in the control group, and 319 without voice problems at baseline. Voice problems had decreased somewhat more in the training group than in the control group, but the difference was not statistically significant (P = 0.1). However, subgroup analyses showed significantly larger improvement among the students in the group with complete participation in the training program compared with the group with incomplete participation. Of the 319 students without voice problems at baseline, 14% had developed voice problems. Voice problems often develop in teacher students. Despite extensive dropout, our results support the hypothesis that voice education for teacher students has a preventive effect. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Influence of short-term selenium supplementation on the natural course of Hashimoto's thyroiditis: clinical results of a blinded placebo-controlled randomized prospective trial.

PubMed

Esposito, D; Rotondi, M; Accardo, G; Vallone, G; Conzo, G; Docimo, G; Selvaggi, F; Cappelli, C; Chiovato, L; Giugliano, D; Pasquali, D

2017-01-01

The real efficacy of selenium supplementation in Hashimoto's thyroiditis (HT) is still an unresolved issue. We studied the short-term effect of L-selenomethionine on the thyroid function in euthyroid patients with HT. Our primary outcome measures were TSH, thyroid hormones, thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TGAb) levels and thyroid echogenicity after 6 months of L-selenomethionine treatment. The secondary outcome measure was serum CXCL10 levels. In a placebo-controlled randomized prospective study, we have enrolled untreated euthyroid patients with HT. Seventy-six patients were randomly assigned to receive L-selenomethionine 166 µg/die (SE n = 38) or placebo (controls n = 38) for 6 months. TSH, free T 4 (FT 4 ), free T 3 (FT 3 ), TPOAb and CXCL10 serum levels were assayed at time 0, after 3 and 6 months. An ultrasound examination of the left and right thyroid lobe in transverse and longitudinal sections was performed. A rectangular region, the region of interest, was selected for analysis. TSH, FT4, FT3, TPOAb, thyroid echogenicity and CXCL10 were not statistically different between SE and control groups at time 0, after 3 and 6 months. In the SE group, FT 4 levels were significantly decreased (P < 0.03) after 3 months, while FT 3 increased (P < 0.04) after 3 and 6 months versus baseline values. In the control group, the FT 3 decreased after 3 and 6 months (P < 0.02) compared to baseline. The short-term L-selenomethionine supplementation has a limited impact on the natural course in euthyroid HT. Our results tip the balance toward the ineffectiveness of short-term L-selenomethionine supplementation in HT.

Medical decision-making capacity in mild cognitive impairment: a 3-year longitudinal study.

PubMed

Okonkwo, O C; Griffith, H R; Copeland, J N; Belue, K; Lanza, S; Zamrini, E Y; Harrell, L E; Brockington, J C; Clark, D; Raman, R; Marson, D C

2008-11-04

To investigate longitudinal change in the medical decision-making capacity (MDC) of patients with amnestic mild cognitive impairment (MCI) under different consent standards. Eighty-eight healthy older controls and 116 patients with MCI were administered the Capacity to Consent to Treatment Instrument at baseline and at 1 to 3 (mean = 1.7) annual follow-up visits thereafter. Covariate-adjusted random coefficient regressions were used to examine differences in MDC trajectories across MCI and control participants, as well as to investigate the impact of conversion to Alzheimer disease on MCI patients' MDC trajectories. At baseline, MCI patients performed significantly below controls only on the three clinically relevant standards of appreciation, reasoning, and understanding. Compared with controls, MCI patients experienced significant declines over time on understanding but not on any other consent standard. Conversion affected both the elevation (a decrease in performance) and slope (acceleration in subsequent rate of decline) of MCI patients' MDC trajectories on understanding. A trend emerged for conversion to be associated with a performance decrease on reasoning in the MCI group. Medical decision-making capacity (MDC) decline in mild cognitive impairment (MCI) is a relatively slow but detectable process. Over a 3-year period, patients with amnestic MCI show progressive decline in the ability to understand consent information. This decline accelerates after conversion to Alzheimer disease (AD), reflecting increasing vulnerability to decisional impairment. Clinicians and researchers working with MCI patients should give particular attention to the informed consent process when conversion to AD is suspected or confirmed.

Stereotyped motor behaviors associated with autism in high-risk infants: a pilot videotape analysis of a sibling sample.

PubMed

Loh, Alvin; Soman, Teesta; Brian, Jessica; Bryson, Susan E; Roberts, Wendy; Szatmari, Peter; Smith, Isabel M; Zwaigenbaum, Lonnie

2007-01-01

This study examined motor behaviors in a longitudinal cohort of infant siblings of children with autism. Stereotypic movements and postures occurring during standardized observational assessments at 12 and 18 months were coded from videotapes. Participants included eight infant siblings later diagnosed with autism spectrum disorder (ASD), a random sample of nine non-diagnosed siblings, and 15 controls. Videos were coded blind to diagnostic group. At 12 and 18 months the ASD group "arm waved" more frequently and at 18 months, one posture ("hands to ears") was more frequently observed in the ASD and non-diagnosed group compared to the controls. Overall, the siblings subsequently diagnosed with ASD and the comparison groups had considerable overlap in their repertoires of stereotyped behaviors.

Housing First, Consumer Choice, and Harm Reduction for Homeless Individuals With a Dual Diagnosis

PubMed Central

Tsemberis, Sam; Gulcur, Leyla; Nakae, Maria

2004-01-01

Objectives. We examined the longitudinal effects of a Housing First program for homeless, mentally ill individuals’ on those individuals’ consumer choice, housing stability, substance use, treatment utilization, and psychiatric symptoms. Methods. Two hundred twenty-five participants were randomly assigned to receive housing contingent on treatment and sobriety (control) or to receive immediate housing without treatment prerequisites (experimental). Interviews were conducted every 6 months for 24 months. Results. The experimental group obtained housing earlier, remained stably housed, and reported higher perceived choice. Utilization of substance abuse treatment was significantly higher for the control group, but no differences were found in substance use or psychiatric symptoms. Conclusions. Participants in the Housing First program were able to obtain and maintain independent housing without compromising psychiatric or substance abuse symptoms. PMID:15054020

Longitudinal analysis of the strengths and difficulties questionnaire scores of the Millennium Cohort Study children in England using M-quantile random-effects regression.

PubMed

Tzavidis, Nikos; Salvati, Nicola; Schmid, Timo; Flouri, Eirini; Midouhas, Emily

2016-02-01

Multilevel modelling is a popular approach for longitudinal data analysis. Statistical models conventionally target a parameter at the centre of a distribution. However, when the distribution of the data is asymmetric, modelling other location parameters, e.g. percentiles, may be more informative. We present a new approach, M -quantile random-effects regression, for modelling multilevel data. The proposed method is used for modelling location parameters of the distribution of the strengths and difficulties questionnaire scores of children in England who participate in the Millennium Cohort Study. Quantile mixed models are also considered. The analyses offer insights to child psychologists about the differential effects of risk factors on children's outcomes.

A varying-coefficient method for analyzing longitudinal clinical trials data with nonignorable dropout

PubMed Central

Forster, Jeri E.; MaWhinney, Samantha; Ball, Erika L.; Fairclough, Diane

2011-01-01

Dropout is common in longitudinal clinical trials and when the probability of dropout depends on unobserved outcomes even after conditioning on available data, it is considered missing not at random and therefore nonignorable. To address this problem, mixture models can be used to account for the relationship between a longitudinal outcome and dropout. We propose a Natural Spline Varying-coefficient mixture model (NSV), which is a straightforward extension of the parametric Conditional Linear Model (CLM). We assume that the outcome follows a varying-coefficient model conditional on a continuous dropout distribution. Natural cubic B-splines are used to allow the regression coefficients to semiparametrically depend on dropout and inference is therefore more robust. Additionally, this method is computationally stable and relatively simple to implement. We conduct simulation studies to evaluate performance and compare methodologies in settings where the longitudinal trajectories are linear and dropout time is observed for all individuals. Performance is assessed under conditions where model assumptions are both met and violated. In addition, we compare the NSV to the CLM and a standard random-effects model using an HIV/AIDS clinical trial with probable nonignorable dropout. The simulation studies suggest that the NSV is an improvement over the CLM when dropout has a nonlinear dependence on the outcome. PMID:22101223

Multilevel Models for Intensive Longitudinal Data with Heterogeneous Autoregressive Errors: The Effect of Misspecification and Correction with Cholesky Transformation

PubMed Central

Jahng, Seungmin; Wood, Phillip K.

2017-01-01

Intensive longitudinal studies, such as ecological momentary assessment studies using electronic diaries, are gaining popularity across many areas of psychology. Multilevel models (MLMs) are most widely used analytical tools for intensive longitudinal data (ILD). Although ILD often have individually distinct patterns of serial correlation of measures over time, inferences of the fixed effects, and random components in MLMs are made under the assumption that all variance and autocovariance components are homogenous across individuals. In the present study, we introduced a multilevel model with Cholesky transformation to model ILD with individually heterogeneous covariance structure. In addition, the performance of the transformation method and the effects of misspecification of heterogeneous covariance structure were investigated through a Monte Carlo simulation. We found that, if individually heterogeneous covariances are incorrectly assumed as homogenous independent or homogenous autoregressive, MLMs produce highly biased estimates of the variance of random intercepts and the standard errors of the fixed intercept and the fixed effect of a level 2 covariate when the average autocorrelation is high. For intensive longitudinal data with individual specific residual covariance, the suggested transformation method showed lower bias in those estimates than the misspecified models when the number of repeated observations within individuals is 50 or more. PMID:28286490

Effectiveness of skill-based substance abuse intervention among male adolescents in an Islamic country: case of the Islamic Republic of Iran.

PubMed

Allahverdipour, Hamid; Bazargan, Mohsen; Farhadinasab, Abdollah; Hidarnia, Alireza; Bashirian, Saeed

2009-01-01

The prevalence of substance abuse among adolescents from low- and middle-income countries is increasing drastically and requires immediate intervention. The objective of this longitudinal quasi-experimental panel study was to design and implement a skill-based intervention to prevent and reduce substance use among urban adolescents who attended 2 randomly selected high-schools in Tehran, Iran. One-year post intervention data show that substance abuse, knowledge, attitudes, peer resistance skills, level of self-control, self-efficacy, and perceived susceptibility among intervention group were significantly improved, whereas level of self control and attitudes against substance abuse among the control group deteriorated. To efficiently prevent substance abuse among youth primary preventive interventions should be implemented before onset of substance abuse to improve resistance skills and provide adolescents with information and skills needed to develop anti-drug norms.

The effect of massage on heart rate variability in preterm infants.

PubMed

Smith, S L; Lux, R; Haley, S; Slater, H; Beachy, J; Beechy, J; Moyer-Mileur, L J

2013-01-01

To test the hypothesis that massage would improve autonomic nervous system (ANS) function as measured by heart rate variability (HRV) in preterm infants. Medically stable, 29- to 32-week preterm infants (17 massage, 20 control) were enrolled in a masked, randomized longitudinal study. Licensed massage therapists provided the massage or control condition twice a day for 4 weeks. Weekly HRV, a measure of ANS development and function, was analyzed using SPSS generalized estimating equations. Infant characteristics were similar between groups. HRV improved in massaged infants but not in the control infants (P<0.05). Massaged males had a greater improvement in HRV than females (P<0.05). HRV in massaged infants was on a trajectory comparable to term-born infants by study completion. Massage-improved HRV in a homogeneous sample of hospitalized, medically stable, preterm male infants and may improve infant response to exogenous stressors. We speculate that massage improves ANS function in these infants.

Multivariate longitudinal data analysis with mixed effects hidden Markov models.

PubMed

Raffa, Jesse D; Dubin, Joel A

2015-09-01

Multiple longitudinal responses are often collected as a means to capture relevant features of the true outcome of interest, which is often hidden and not directly measurable. We outline an approach which models these multivariate longitudinal responses as generated from a hidden disease process. We propose a class of models which uses a hidden Markov model with separate but correlated random effects between multiple longitudinal responses. This approach was motivated by a smoking cessation clinical trial, where a bivariate longitudinal response involving both a continuous and a binomial response was collected for each participant to monitor smoking behavior. A Bayesian method using Markov chain Monte Carlo is used. Comparison of separate univariate response models to the bivariate response models was undertaken. Our methods are demonstrated on the smoking cessation clinical trial dataset, and properties of our approach are examined through extensive simulation studies. © 2015, The International Biometric Society.

A Fast EM Algorithm for Fitting Joint Models of a Binary Response and Multiple Longitudinal Covariates Subject to Detection Limits

PubMed Central

Bernhardt, Paul W.; Zhang, Daowen; Wang, Huixia Judy

2014-01-01

Joint modeling techniques have become a popular strategy for studying the association between a response and one or more longitudinal covariates. Motivated by the GenIMS study, where it is of interest to model the event of survival using censored longitudinal biomarkers, a joint model is proposed for describing the relationship between a binary outcome and multiple longitudinal covariates subject to detection limits. A fast, approximate EM algorithm is developed that reduces the dimension of integration in the E-step of the algorithm to one, regardless of the number of random effects in the joint model. Numerical studies demonstrate that the proposed approximate EM algorithm leads to satisfactory parameter and variance estimates in situations with and without censoring on the longitudinal covariates. The approximate EM algorithm is applied to analyze the GenIMS data set. PMID:25598564

Longitudinal Change in Telomere Length and the Chronic Stress Response in a Randomized Pilot Biobehavioral Clinical Study: Implications for Cancer Prevention

PubMed Central

Biegler, Kelly A.; Anderson, Amanda K. L.; Wenzel, Lari B.; Osann, Kathryn; Nelson, Edward L.

2015-01-01

Shortened telomere length is associated with increased cancer incidence and mortality. Populations experiencing chronic stress have accelerated telomere shortening. In this exploratory study, we examined associations between longitudinal changes in patient reported outcomes (PRO) of psychologic distress and peripheral blood mononuclear cell (PBMC) telomere length to test the hypothesis that modulation of the chronic stress response would also modulate telomere dynamics. Archived PBMC specimens (N = 22) were analyzed from a completed and reported randomized, longitudinal trial that showed a psychosocial telephone counseling intervention improved quality of life (QOL) and modulated stress-associated biomarkers in cervical cancer survivors. PROs and biospecimens were collected at baseline and 4 months postenrollment. Telomere length of archived PBMCs was evaluated using the flow-FISH assay. Longitudinal changes in psychologic distress, measured by the Brief Symptom Inventory-18, were significantly associated with increased telomere length within the CD14+ (monocyte) population (r = 0.46, P = 0.043); a similar trend was observed for the CD14− population. Longitudinal changes in telomere length of the CD14− subset, primarily T lymphocytes, were associated with longitudinal increases in the naive T-cell population (r = 0.49, P = 0.052). Alterations in the chronic stress response were associated with modulation of telomere length in PBMCs, with evidence for mobilization of “younger” cells from progenitor populations. These data provide preliminary support for the (i) capacity to modulate the chronic stress response and the associated accelerated telomere shortening, (ii) inclusion of telomere length in the biobehavioral paradigm, and (iii) potential link between the chronic stress response and biologic mechanisms responsible for genomic integrity and carcinogenesis. PMID:22827974

A suicide education programme for nurses to educate the family caregivers of suicidal individuals: a longitudinal study.

PubMed

Sun, Fan-Ko; Chiang, Chun-Ying; Yu, Pei-Jane; Lin, Ching-Hsing

2013-10-01

Family members lack the ability to care for suicidal relatives. Nurses have a responsibility to improve family members' ability to care for their suicidal relatives. The aims of this study were to design a suicide education programme for nurses to educate family caregivers and to evaluate the longitudinal (12 months after the educational programme) effects of a suicide care education programme on the ability of families to care for suicidal relatives. A randomised controlled trial was conducted. The study population (n=61) was composed of the family caregivers of suicidal individuals. Several caregivers (n=26) were randomly allocated to an experimental group who attended a two-hour suicide care education programme, and the other caregivers (n=35) represented a control group who did not attend the education programme. All of the participants were given a questionnaire at baseline, 3 months, and 12 months during the period from 2009 to 2011. The results of the longitudinal effects of the suicide care education programme demonstrated that there were statistically significant differences after the educational programme as compared to before the programme with regard to "seeking assistance from resources" and the ability to care for those who were once suicidal. The longitudinal results of both groups showed that there was a significant difference in terms of "caring ability" at 12 months. The results of a multiple linear regression analysis indicated that evaluations performed at the three-month time point were able to effectively predict success in "seeking assistance from resources", "caring ability"; caring ability was also significantly improved among those who engaged in the educational programme at the 12-month time point. The suicide care education programme had long-term effects for family caregivers caring for their suicidal relatives. Nurses could employ this suicide care education programme to improve the ability of family caregivers to care for their suicidal relatives. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Safety and efficacy of antihypertensive prescription at emergency department discharge.

PubMed

Brody, Aaron; Rahman, Tahsin; Reed, Brian; Millis, Scott; Ference, Brian; Flack, John M; Levy, Phillip D

2015-05-01

Poor blood pressure (BP) control is a primary risk factor for target organ damage in the heart, brain, and kidney. Uncontrolled hypertension is common among emergency department (ED) patients, particularly in underresourced settings, but it is unclear what role ED providers should play in the management of chronic antihypertensive therapy. The objective was to evaluate the safety and efficacy of prescribing antihypertensive therapy from the ED. This was a retrospective study of data pooled from two prospective, longitudinal, randomized controlled trials, both of which enrolled ED patients with asymptomatic hypertension. Antihypertensives were prescribed at emergency physician discretion, and this was not related to randomization arm. Demographic data, BP at screening and randomization visit, and data on adverse effects potentially related to antihypertensive therapy were compiled. Means were compared using Student's t-tests, and proportions were compared using chi-square tests. The effect of antihypertensive therapy on BP control was further analyzed using multivariable regression modeling controlling for age, race, sex, hypertension history, study cohort, and ED BP. Data were abstracted for 217 subjects. The median interval from ED visit to randomization was 12 days. Seventy-six subjects (35%) received one or more prescriptions for antihypertensive therapy. Age, sex, race, hypertension history, and mean duration of hypertension were equivalent between groups. Although mean ED BP was higher among those who received prescriptions, the mean systolic BP (sBP) reduction from ED to randomization was significantly greater (difference = 19 mm Hg, 95% confidence interval = 12 to 26 mm Hg). No patient in either group had an sBP less than 100 mm Hg at randomization. On multiple regression modeling, randomization sBP reduction was independently associated with antihypertensive prescription (p = 0.001). The incidence of adverse effects was equivalent and low in both groups. No new neurological deficits, ischemic events, or life-threatening anaphylactic reactions were reported in either group. Prescription of antihypertensive medication from the ED is associated with significantly lower sBP at short-term outpatient follow-up. Antihypertensive therapy was not associated with an increased incidence of adverse events, and BP reduction did not exceed potentially harmful levels. Initiation of chronic antihypertensive therapy in the ED is safe and effective and may be a reasonable consideration for at-risk populations. © 2015 by the Society for Academic Emergency Medicine.

Performance of time-varying predictors in multilevel models under an assumption of fixed or random effects.

PubMed

Baird, Rachel; Maxwell, Scott E

2016-06-01

Time-varying predictors in multilevel models are a useful tool for longitudinal research, whether they are the research variable of interest or they are controlling for variance to allow greater power for other variables. However, standard recommendations to fix the effect of time-varying predictors may make an assumption that is unlikely to hold in reality and may influence results. A simulation study illustrates that treating the time-varying predictor as fixed may allow analyses to converge, but the analyses have poor coverage of the true fixed effect when the time-varying predictor has a random effect in reality. A second simulation study shows that treating the time-varying predictor as random may have poor convergence, except when allowing negative variance estimates. Although negative variance estimates are uninterpretable, results of the simulation show that estimates of the fixed effect of the time-varying predictor are as accurate for these cases as for cases with positive variance estimates, and that treating the time-varying predictor as random and allowing negative variance estimates performs well whether the time-varying predictor is fixed or random in reality. Because of the difficulty of interpreting negative variance estimates, 2 procedures are suggested for selection between fixed-effect and random-effect models: comparing between fixed-effect and constrained random-effect models with a likelihood ratio test or fitting a fixed-effect model when an unconstrained random-effect model produces negative variance estimates. The performance of these 2 procedures is compared. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Intelligent vehicle safety control strategy in various driving situations

NASA Astrophysics Data System (ADS)

Moon, Seungwuk; Cho, Wanki; Yi, Kyongsu

2010-12-01

This paper describes a safety control strategy for intelligent vehicles with the objective of optimally coordinating the throttle, brake, and active front steering actuator inputs to obtain both lateral stability and longitudinal safety. The control system consists of a supervisor, control algorithms, and a coordinator. From the measurement and estimation signals, the supervisor determines the active control modes among normal driving, longitudinal safety, lateral stability, and integrated safety control mode. The control algorithms consist of longitudinal and lateral stability controllers. The longitudinal controller is designed to improve the driver's comfort during normal, safe-driving situations, and to avoid rear-end collision in vehicle-following situations. The lateral stability controller is designed to obtain the required manoeuvrability and to limit the vehicle body's side-slip angle. To obtain both longitudinal safety and lateral stability control in various driving situations, the coordinator optimally determines the throttle, brake, and active front steering inputs based on the current status of the subject vehicle. Closed-loop simulations with the driver-vehicle-controller system are conducted to investigate the performance of the proposed control strategy. From these simulation results, it is shown that the proposed control algorithm assists the driver in combined severe braking/large steering manoeuvring so that the driver can maintain good manoeuvrability and prevent the vehicle from crashing in vehicle-following situations.

Fractional Brownian motion and multivariate-t models for longitudinal biomedical data, with application to CD4 counts in HIV-positive patients.

PubMed

Stirrup, Oliver T; Babiker, Abdel G; Carpenter, James R; Copas, Andrew J

2016-04-30

Longitudinal data are widely analysed using linear mixed models, with 'random slopes' models particularly common. However, when modelling, for example, longitudinal pre-treatment CD4 cell counts in HIV-positive patients, the incorporation of non-stationary stochastic processes such as Brownian motion has been shown to lead to a more biologically plausible model and a substantial improvement in model fit. In this article, we propose two further extensions. Firstly, we propose the addition of a fractional Brownian motion component, and secondly, we generalise the model to follow a multivariate-t distribution. These extensions are biologically plausible, and each demonstrated substantially improved fit on application to example data from the Concerted Action on SeroConversion to AIDS and Death in Europe study. We also propose novel procedures for residual diagnostic plots that allow such models to be assessed. Cohorts of patients were simulated from the previously reported and newly developed models in order to evaluate differences in predictions made for the timing of treatment initiation under different clinical management strategies. A further simulation study was performed to demonstrate the substantial biases in parameter estimates of the mean slope of CD4 decline with time that can occur when random slopes models are applied in the presence of censoring because of treatment initiation, with the degree of bias found to depend strongly on the treatment initiation rule applied. Our findings indicate that researchers should consider more complex and flexible models for the analysis of longitudinal biomarker data, particularly when there are substantial missing data, and that the parameter estimates from random slopes models must be interpreted with caution. © 2015 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

REACTOR CONTROL DEVICE

DOEpatents

Kaufman, H.B.; Weiss, A.A.

1959-08-18

A shadow control device for controlling a nuclear reactor is described. The device comprises a series of hollow neutron-absorbing elements arranged in groups, each element having a cavity for substantially housing an adjoining element and a longitudinal member for commonly supporting the groups of elements. Longitudinal actuation of the longitudinal member distributes the elements along its entire length in which position maximum worth is achieved.

On Models for Binomial Data with Random Numbers of Trials

PubMed Central

Comulada, W. Scott; Weiss, Robert E.

2010-01-01

Summary A binomial outcome is a count s of the number of successes out of the total number of independent trials n = s + f, where f is a count of the failures. The n are random variables not fixed by design in many studies. Joint modeling of (s, f) can provide additional insight into the science and into the probability π of success that cannot be directly incorporated by the logistic regression model. Observations where n = 0 are excluded from the binomial analysis yet may be important to understanding how π is influenced by covariates. Correlation between s and f may exist and be of direct interest. We propose Bayesian multivariate Poisson models for the bivariate response (s, f), correlated through random effects. We extend our models to the analysis of longitudinal and multivariate longitudinal binomial outcomes. Our methodology was motivated by two disparate examples, one from teratology and one from an HIV tertiary intervention study. PMID:17688514

Stress and burnout in anaesthesia: a real world problem?

PubMed

Rama-Maceiras, Pablo; Jokinen, Johanna; Kranke, Peter

2015-04-01

Stress and burnout have arisen as relevant problems to the healthcare workers and the health systems themselves. As anaesthesiologists work in stressful areas of the hospitals, we are exposed to these problems. In this review, we summarize recent studies regarding stress and burnout, exploring possible solutions. Almost 50% of anaesthesiologists scored positive for some of the burnout domains in different surveys, with one-third reporting high levels. The management of this problem not only needs an institutional but also an individual approach. Some recent randomized clinical trials and longitudinal studies suggest that there is some benefit of using several techniques to control stress, although benefits are still modest and most of the studies are based on transversal surveys and self-reported questionnaires. There is a lack of definitive evidence to guide the management of stress and burnout in medical professions in general and in anaesthesiology in particular. Longitudinal and interventional studies are needed to better determine ways of action. In the meantime, creating a positive work climate and institutional support as well as promoting control over one's job and the autonomy of employees are the most recommended strategies. Workers should also learn how to cope with stressors and practice personal strategies of wellness and resilience to fight against burnout.

Effect of music care on depression and behavioral problems in elderly people with dementia in Taiwan: a quasi-experimental, longitudinal study.

PubMed

Wang, Su-Chin; Yu, Ching-Len; Chang, Su-Hsien

2017-02-01

The purpose was to examine the effectiveness of music care on cognitive function, depression, and behavioral problems among elderly people with dementia in long-term care facilities in Taiwan. The study had a quasi-experimental, longitudinal research design and used two groups of subjects. Subjects were not randomly assigned to experimental group (n = 90) or comparison group (n = 56). Based on Bandura's social cognition theory, subjects in the experimental group received Kagayashiki music care (KMC) twice per week for 24 weeks. Subjects in the comparison group were provided with activities as usual. Results found, using the control score of the Clifton Assessment Procedures for the Elderly Behavior Rating Scale (baseline) and time of attending KMC activities as a covariate, the two groups of subjects had statistically significant differences in the mini-mental state examination (MMSE). Results also showed that, using the control score of the Cornell Scale for Depression in Dementia (baseline) and MMSE (baseline) as a covariate, the two groups of subjects had statistically significant differences in the Clifton Assessment Procedures for the Elderly Behavior Rating Scale. These findings provide information for staff caregivers in long-term care facilities to develop a non-invasive care model for elderly people with dementia to deal with depression, anxiety, and behavioral problems.

Video game training and the reward system.

PubMed

Lorenz, Robert C; Gleich, Tobias; Gallinat, Jürgen; Kühn, Simone

2015-01-01

Video games contain elaborate reinforcement and reward schedules that have the potential to maximize motivation. Neuroimaging studies suggest that video games might have an influence on the reward system. However, it is not clear whether reward-related properties represent a precondition, which biases an individual toward playing video games, or if these changes are the result of playing video games. Therefore, we conducted a longitudinal study to explore reward-related functional predictors in relation to video gaming experience as well as functional changes in the brain in response to video game training. Fifty healthy participants were randomly assigned to a video game training (TG) or control group (CG). Before and after training/control period, functional magnetic resonance imaging (fMRI) was conducted using a non-video game related reward task. At pretest, both groups showed strongest activation in ventral striatum (VS) during reward anticipation. At posttest, the TG showed very similar VS activity compared to pretest. In the CG, the VS activity was significantly attenuated. This longitudinal study revealed that video game training may preserve reward responsiveness in the VS in a retest situation over time. We suggest that video games are able to keep striatal responses to reward flexible, a mechanism which might be of critical value for applications such as therapeutic cognitive training.

Longitudinal analysis of physical activity, fluid intake, and graft function among kidney transplant recipients

PubMed Central

Gordon, Elisa J.; Prohaska, Thomas R.; Gallant, Mary P.; Sehgal, Ashwini R.; Strogatz, David; Yucel, Recai; Conti, David; Siminoff, Laura A.

2010-01-01

Summary Self-care is recommended to kidney transplant recipients as a vital component to maintain long-term graft function. However, little is known about the effects of physical activity, fluid intake, and smoking history on graft function. This longitudinal study examined the relationship between self-care practices on graft function among 88 new kidney transplant recipients in Chicago, IL and Albany, NY between 2005 and 2008. Participants were interviewed, completed surveys, and medical charts were abstracted. Physical activity, fluid intake, and smoking history at baseline were compared with changes in estimated glomerular filtration rate (eGFR) (every 6 months up to 1 year) using bivariate and multivariate regression analysis, while controlling for sociodemographic and clinical transplant variables. Multivariate analyses revealed that greater physical activity was significantly (P < 0.05) associated with improvement in GFR at 6 months; while greater physical activity, absence of smoking history, and nonwhite ethnicity were significant (P < 0.05) predictors of improvement in GFR at 12 months. These results suggest that increasing physical activity levels in kidney recipients may be an effective behavioral measure to help ensure graft functioning. Our findings suggest the need for a randomized controlled trial of exercise, fluid intake, and smoking history on GFR beyond 12 months. PMID:19619168

Longitudinal analysis of physical activity, fluid intake, and graft function among kidney transplant recipients.

PubMed

Gordon, Elisa J; Prohaska, Thomas R; Gallant, Mary P; Sehgal, Ashwini R; Strogatz, David; Yucel, Recai; Conti, David; Siminoff, Laura A

2009-10-01

Self-care is recommended to kidney transplant recipients as a vital component to maintain long-term graft function. However, little is known about the effects of physical activity, fluid intake, and smoking history on graft function. This longitudinal study examined the relationship between self-care practices on graft function among 88 new kidney transplant recipients in Chicago, IL and Albany, NY between 2005 and 2008. Participants were interviewed, completed surveys, and medical charts were abstracted. Physical activity, fluid intake, and smoking history at baseline were compared with changes in estimated glomerular filtration rate (eGFR) (every 6 months up to 1 year) using bivariate and multivariate regression analysis, while controlling for sociodemographic and clinical transplant variables. Multivariate analyses revealed that greater physical activity was significantly (P < 0.05) associated with improvement in GFR at 6 months; while greater physical activity, absence of smoking history, and nonwhite ethnicity were significant (P < 0.05) predictors of improvement in GFR at 12 months. These results suggest that increasing physical activity levels in kidney recipients may be an effective behavioral measure to help ensure graft functioning. Our findings suggest the need for a randomized controlled trial of exercise, fluid intake, and smoking history on GFR beyond 12 months.

Video game training and the reward system

PubMed Central

Lorenz, Robert C.; Gleich, Tobias; Gallinat, Jürgen; Kühn, Simone

2015-01-01

Video games contain elaborate reinforcement and reward schedules that have the potential to maximize motivation. Neuroimaging studies suggest that video games might have an influence on the reward system. However, it is not clear whether reward-related properties represent a precondition, which biases an individual toward playing video games, or if these changes are the result of playing video games. Therefore, we conducted a longitudinal study to explore reward-related functional predictors in relation to video gaming experience as well as functional changes in the brain in response to video game training. Fifty healthy participants were randomly assigned to a video game training (TG) or control group (CG). Before and after training/control period, functional magnetic resonance imaging (fMRI) was conducted using a non-video game related reward task. At pretest, both groups showed strongest activation in ventral striatum (VS) during reward anticipation. At posttest, the TG showed very similar VS activity compared to pretest. In the CG, the VS activity was significantly attenuated. This longitudinal study revealed that video game training may preserve reward responsiveness in the VS in a retest situation over time. We suggest that video games are able to keep striatal responses to reward flexible, a mechanism which might be of critical value for applications such as therapeutic cognitive training. PMID:25698962

Effect of radioactive iodine-induced hypothyroidism on longitudinal bone growth during puberty in immature female rats.

PubMed

Choi, Hyeonhae; Ryu, Ki-Young; Roh, Jaesook; Bae, Jaeman

2018-05-22

Thyroid cancer in children, the most common endocrine malignancy, shows aggressive behavior and has a high recurrence rate after surgical ablation. Radioactive iodine (RAI) treatment is the most effective primary modality for medical ablation of juvenile thyroid cancer, and leads to intentional hypothyroidism. Although several negative impacts of hypothyroidism have been reported in children in response to other antithyroid agents, the combined effects of RAI exposure and hypothyroidism, on growing bones specifically, are unknown. In this study, we investigated the effect of RAI-induced hypothyroidism on the long bones during the pubertal growth spurt using immature female rats. Female Sprague-Dawley rats were randomly divided into a control group, and an RAI-treated group fed with RAI (0.37 MBq/g body weight) twice via gavage. After 4 weeks, we observed a significantly-reduced serum free thyroxine level in the RAI group. The latter group also displayed decreased body weight gain compared to the control. In addition, the lengths of long bones, such as the leg bones and vertebral column, as well as bone mineral content, were reduced in the RAI-treated animals. Our results confirm the negative impacts of RAI-induced thyroid deficiency during puberty on longitudinal bone growth and bone mineralization.

Ankle manual therapy for individuals with post-acute ankle sprains: description of a randomized, placebo-controlled clinical trial.

PubMed

Davenport, Todd E; Kulig, Kornelia; Fisher, Beth E

2010-10-19

Ankle sprains are common within the general population and can result in prolonged disablement. Limited talocrural dorsiflexion range of motion (DF ROM) is a common consequence of ankle sprain. Limited talocrural DF ROM may contribute to persistent symptoms, disability, and an elevated risk for re-injury. As a result, many health care practitioners use hands-on passive procedures with the intention of improving talocrural joint DF ROM in individuals following ankle sprains. Dosage of passive hands-on procedures involves a continuum of treatment speeds. Recent evidence suggests both slow- and fast-speed treatments may be effective to address disablement following ankle sprains. However, these interventions have yet to be longitudinally compared against a placebo study condition. We developed a randomized, placebo-controlled clinical trial designed to test the hypotheses that hands-on treatment procedures administered to individuals following ankle sprains during the post-acute injury period can improve short-, intermediate-, and long-term disablement, as well as reduce the risk for re-injury. This study is designed to measure the clinical effects of hands-on passive stretching treatment procedures directed to the talocrural joint that vary in treatment speed during the post-acute injury period, compared to hands-on placebo control intervention. http://www.clinicaltrials.gov identifier NCT00888498.

Repair of surgical wounds in rats using a 10% unripe Musa sapientum peel gel.

PubMed

Von Atzingen, Dênia Amélia Novato Castelli; Mendonça, Adriana Rodrigues dos Anjos; Mesquita Filho, Marcos; Alvarenga, Vinícius Alves; Assis, Vinícius Almeida; Penazzo, Afonso Esteves; Muzetti, Julio Henrique; Rezende, Thaisa Sousa

2015-09-01

To investigate the efficacy of a 10% gel of unripe banana (Musa sapientum) peel in treating surgical wounds in rats. A longitudinal, prospective, randomized triple-blind study was conducted with 60 Wistar rats (Rattus norvegicus albinus) weighing approximately 400g. The animals were randomly divided into: control group (treated with gel containing no active ingredient) and study group (treated with 10% gel of unripe banana peel). The gel was applied every three days to a 4x4-cm surgical wound created on the back of each animal (day 0) in both groups. Tissue samples were collected for histological analysis on days 14, 21 and 28. On day 14, more extensive vascular proliferation (p=0.023), presence of mononuclear cells (p=0.000), fibroblast proliferation (p=0.012), re-epithelialization (p=0.000), and decreased presence of polymorphonuclear cells (p=0.010) were observed in the study group than in controls. No significant between-group difference in the presence of polymorphonuclear cells was found on day 21. Fibroblast proliferation was significantly greater (p=0.006) in the study group than in the control group on day 28. The 10% gel of unripe banana peel showed anti-inflammatory activity and stimulated wound healing in rat skin when compared with a gel containing no active ingredient.

Effectiveness of heat moisture exchangers (hmes) in preventing perioperative hypothermia among adult patients undergoing abdominal surgery under general endotracheal anaesthesia.

PubMed

Anaegbu, Nc; Olatosi, Oj; Tobi, Ku

2013-01-01

Heat Moisture Exchangers (HMEs) conserve heat and moisture during expiration and make this available to inspired gases during subsequent inspiration. We sought to evaluate the effectiveness of HMEs in the prevention of perioperative hypothermia in patients scheduled for abdominal surgery under general anaesthesia relaxant technique with endotrachael intubation (GART.) Lagos University Teaching Hospital, in Modular theatre, Anaesthesia unit. The study was a randomized, controlled, longitudinal, interventional study Methods: 100 ASA I, II and III patients aged 18 to 65 years scheduled for abdominal surgery under GART were randomly assigned to 2 groups, groups H and C. Group H had HMEs, while group C served as controls. Core temperature measured using tympanic probe was every 10 minutes till end of anaesthesia Data from total 99 patients, 49 in group H and 50 in group C were eventually analysed. Although patients in both groups developed hypothermia in the course of anaesthesia, core temperature was significantly lower p< 0.05 after one hour in the control group than the intervention group. The use of HMEs during general anaesthesia with endotrachael intubation did not prevent hypothermia but resulted in higher core temperature and should be part of a multimodal approach in the prevention of perioperative hypothermia. Heat Moisture Exchangers, General endotracheal anaesthesia, Hypothermia, abdominal surgery.

The effect of Early Head Start on child welfare system involvement: A first look at longitudinal child maltreatment outcomes☆

PubMed Central

Green, Beth L.; Ayoub, Catherine; Bartlett, Jessica Dym; Von Ende, Adam; Furrer, Carrie; Chazan-Cohen, Rachel; Vallotton, Claire; Klevens, Joanne

2015-01-01

The high societal and personal costs of child maltreatment make identification of effective early prevention programs a high research priority. Early Head Start (EHS), a dual generational program serving low-income families with children prenatally through age three years, is one of the largest federally funded programs for infants and toddlers in the United States. A national randomized trial found EHS to be effective in improving parent and child outcomes, but its effectiveness in reducing child maltreatment was not assessed. The current study used administrative data from state child welfare agencies to examine the impact of EHS on documented abuse and neglect among children from seven of the original seventeen programs in the national EHS randomized controlled trial. Results indicated that children in EHS had significantly fewer child welfare encounters between the ages of five and nine years than did children in the control group, and that EHS slowed the rate of subsequent encounters. Additionally, compared to children in the control group, children in EHS were less likely to have a substantiated report of physical or sexual abuse, but more likely to have a substantiated report of neglect. These findings suggest that EHS may be effective in reducing child maltreatment among low-income children, in particular, physical and sexual abuse. PMID:26744550

A Systematic Review and Meta-analysis of the Association Between Giardia lamblia and Endemic Pediatric Diarrhea in Developing Countries

PubMed Central

Muhsen, Khitam; Levine, Myron M.

2012-01-01

We performed a systematic literature review and meta-analysis examining the association between diarrhea in young children in nonindustrialized settings and Giardia lamblia infection. Eligible were case/control and longitudinal studies that defined the outcome as acute or persistent (>14 days) diarrhea, adjusted for confounders and lasting for at least 1 year. Data on G. lamblia detection (mainly in stools) from diarrhea patients and controls without diarrhea were abstracted. Random effects model meta-analysis obtained pooled odds ratios (ORs) and 95% confidence intervals (CIs). Twelve nonindustrialized-setting acute pediatric diarrhea studies met the meta-analysis inclusion criteria. Random-effects model meta-analysis of combined results (9774 acute diarrhea cases and 8766 controls) yielded a pooled OR of 0.60 (95% CI, .38–.94; P = .03), indicating that G. lamblia was not associated with acute diarrhea. However, limited data suggest that initial Giardia infections in early infancy may be positively associated with diarrhea. Meta-analysis of 5 persistent diarrhea studies showed a pooled OR of 3.18 (95% CI, 1.50–6.76; P < .001), positively linking Giardia with that syndrome. The well-powered Global Enteric Multicenter Study (GEMS) is prospectively addressing the association between G. lamblia infection and diarrhea in children in developing countries. PMID:23169940

A model for incomplete longitudinal multivariate ordinal data.

PubMed

Liu, Li C

2008-12-30

In studies where multiple outcome items are repeatedly measured over time, missing data often occur. A longitudinal item response theory model is proposed for analysis of multivariate ordinal outcomes that are repeatedly measured. Under the MAR assumption, this model accommodates missing data at any level (missing item at any time point and/or missing time point). It allows for multiple random subject effects and the estimation of item discrimination parameters for the multiple outcome items. The covariates in the model can be at any level. Assuming either a probit or logistic response function, maximum marginal likelihood estimation is described utilizing multidimensional Gauss-Hermite quadrature for integration of the random effects. An iterative Fisher-scoring solution, which provides standard errors for all model parameters, is used. A data set from a longitudinal prevention study is used to motivate the application of the proposed model. In this study, multiple ordinal items of health behavior are repeatedly measured over time. Because of a planned missing design, subjects answered only two-third of all items at a given point. Copyright 2008 John Wiley & Sons, Ltd.

Impact of a parent-child sexual communication campaign: results from a controlled efficacy trial of parents.

PubMed

Davis, Kevin C; Blitstein, Jonathan L; Evans, W Douglas; Kamyab, Kian

2010-07-21

Prior research supports the notion that parents have the ability to influence their children's decisions regarding sexual behavior. Yet parent-based approaches to curbing teen pregnancy and STDs have been relatively unexplored. The Parents Speak Up National Campaign (PSUNC) is a multimedia campaign that attempts to fill this void by targeting parents of teens to encourage parent-child communication about waiting to have sex. The campaign follows a theoretical framework that identifies cognitions that are targeted in campaign messages and theorized to influence parent-child communication. While a previous experimental study showed PSUNC messages to be effective in increasing parent-child communication, it did not address how these effects manifest through the PSUNC theoretical framework. The current study examines the PSUNC theoretical framework by 1) estimating the impact of PSUNC on specific cognitions identified in the theoretical framework and 2) examining whether those cognitions are indeed associated with parent-child communication Our study consists of a randomized efficacy trial of PSUNC messages under controlled conditions. A sample of 1,969 parents was randomly assigned to treatment (PSUNC exposure) and control (no exposure) conditions. Parents were surveyed at baseline, 4 weeks, 6 months, 12 months, and 18 months post-baseline. Linear regression procedures were used in our analyses. Outcome variables included self-efficacy to communicate with child, long-term outcome expectations that communication would be successful, and norms on appropriate age for sexual initiation. We first estimated multivariable models to test whether these cognitive variables predict parent-child communication longitudinally. Longitudinal change in each cognitive variable was then estimated as a function of treatment condition, controlling for baseline individual characteristics. Norms related to appropriate age for sexual initiation and outcome expectations that communication would be successful were predictive of parent-child communication among both mothers and fathers. Treatment condition mothers exhibited larger changes than control mothers in both of these cognitive variables. Fathers exhibited no exposure effects. Results suggest that within a controlled setting, the "wait until older norm" and long-term outcome expectations were appropriate cognitions to target and the PSUNC media materials were successful in impacting them, particularly among mothers. This study highlights the importance of theoretical frameworks for parent-focused campaigns that identify appropriate behavioral precursors that are both predictive of a campaign's distal behavioral outcome and sensitive to campaign messages.

Buffering Syndemic Effects in a Sexual Risk-Reduction Intervention for Male Clients of Female Sex Workers: Results From a Randomized Controlled Trial.

PubMed

Pitpitan, Eileen V; Strathdee, Steffanie A; Semple, Shirley J; Chavarin, Claudia V; Magis-Rodriguez, Carlos; Patterson, Thomas L

2015-09-01

We sought to test the efficacy of a sexual risk intervention for male clients of female sex workers (FSWs) and examine whether efficacy was moderated by syndemic risk. From 2010 to 2014, we conducted a 2-arm randomized controlled trial (60-minute, theory-based, safer sex intervention versus a didactic time-equivalent attention control) that included 400 male clients of FSWs on the US-Mexico border with follow-up at 4, 8, and 12 months. We measured 5 syndemic risk factors, including substance use and depression. Primary outcomes were sexually transmitted infections incidence and total unprotected sex with FSWs. Although participants in both groups became safer, there was no significant difference in behavior change between groups. However, baseline syndemic risk moderated intervention efficacy. At baseline, there was a positive association between syndemic risk and unprotected sex. Then at 12 months, longitudinal analyses showed the association depended on intervention participation (B = -0.71; 95% confidence interval [CI] = -1.22, -0.20; P = .007). Among control participants there still existed this modest association (B = 0.36; 95% CI = -0.49, 1.22; P = .09); among intervention participants there was a significant negative association (B = -0.35; 95% CI = -0.63, -0.06; P = .02). A brief intervention might attenuate syndemic risks among clients of FSWs. Other populations experiencing syndemic problems may also benefit from such programs.

Changing friend selection in middle school: A social network analysis of a randomized intervention study designed to prevent adolescent problem behavior

PubMed Central

DeLay, Dawn; Ha, Thao; Van Ryzin, Mark; Winter, Charlotte; Dishion, Thomas J.

2015-01-01

Adolescent friendships that promote problem behavior are often chosen in middle school. The current study examines the unintended impact of a randomized school based intervention on the selection of friends in middle school, as well as on observations of deviant talk with friends five years later. Participants included 998 middle school students (526 boys and 472 girls) recruited at the onset of middle school (age 11-12 years) from three public middle schools participating in the Family Check-up model intervention. The current study focuses only on the effects of the SHAPe curriculum—one level of the Family Check-up model—on friendship choices. Participants nominated friends and completed measures of deviant peer affiliation. Approximately half of the sample (n=500) was randomly assigned to the intervention and the other half (n=498) comprised the control group within each school. The results indicate that the SHAPe curriculum affected friend selection within School 1, but not within Schools 2 or 3. The effects of friend selection in School 1 translated into reductions in observed deviancy training five years later (age 16-17 years). By coupling longitudinal social network analysis with a randomized intervention study the current findings provide initial evidence that a randomized public middle school intervention can disrupt the formation of deviant peer groups and diminish levels of adolescent deviance five years later. PMID:26377235

The impact of sedimentary anisotropy on solute mixing in stacked scour-pool structures

NASA Astrophysics Data System (ADS)

Bennett, Jeremy P.; Haslauer, Claus P.; Cirpka, Olaf A.

2017-04-01

The spatial variability of hydraulic conductivity is known to have a strong impact on solute spreading and mixing. In most investigations, its local anisotropy has been neglected. Recent studies have shown that spatially varying orientation in sedimentary anisotropy can lead to twisting flow enhancing transverse mixing, but most of these studies used geologically implausible geometries. We use an object-based approach to generate stacked scour-pool structures with either isotropic or anisotropic filling which are typically reported in glacial outwash deposits. We analyze how spatially variable isotropic conductivity and variation of internal anisotropy in these features impacts transverse plume deformation and both longitudinal and transverse spreading and mixing. In five test cases, either the scalar values of conductivity or the spatial orientation of its anisotropy is varied between the scour-pool structures. Based on 100 random configurations, we compare the variability of velocity components, stretching and folding metrics, advective travel-time distributions, one and two-particle statistics in advective-dispersive transport, and the flux-related dilution indices for steady state advective-dispersive transport among the five test cases. Variation in the orientation of internal anisotropy causes strong variability in the lateral velocity components, which leads to deformation in transverse directions and enhances transverse mixing, whereas it hardly affects the variability of the longitudinal velocity component and thus longitudinal spreading and mixing. The latter is controlled by the spatial variability in the scalar values of hydraulic conductivity. Our results demonstrate that sedimentary anisotropy is important for transverse mixing, whereas it may be neglected when considering longitudinal spreading and mixing.

Longitudinal Associations Between Observed and Perceived Neighborhood Food Availability and Body Mass Index in a Multiethnic Urban Sample.

PubMed

Zenk, Shannon N; Mentz, Graciela; Schulz, Amy J; Johnson-Lawrence, Vicki; Gaines, Causandra R

2017-02-01

Blacks, Hispanics, and women of lower socioeconomic status tend to have a higher risk of obesity. Numerous studies over the past decade examined the role of the neighborhood food environment in body weight. However, few were longitudinal. This longitudinal study examined whether multiple measures of neighborhood food availability were associated with body mass index (BMI) in a predominately Black and Hispanic adult sample living in low- to moderate-income urban neighborhoods. This longitudinal study used two waves of data (2002, 2008), including interviewer-measured height and weight, from a community survey of adults ( n = 219). In both 2002 and 2008, multiple measures characterized neighborhood food availability: GIS-derived availability of retail food outlets (large grocery store, small grocery store, convenience store, liquor stores), observed fruit and vegetable availability (count of stores selling 10 or more fresh fruit or vegetable varieties), and perceived fruit and vegetable access. Random intercept models estimated multivariable associations, controlling for individual-level demographics and neighborhood median household income. Small grocery store availability was associated with 1.22-unit increase in BMI ( p = .047), while each unit increase in perceived fruit and vegetable access was associated with a 0.69-unit decrease in BMI ( p = .055). BMI was not associated with large grocery store, convenience store, or liquor store availability, or with observed fruit and vegetable availability. Findings suggest that improving the neighborhood food environment, particularly at small grocery stores, may help urban residents living in low- to moderate-income neighborhoods achieve healthier body weights over time.

Renal sympathetic denervation inhibits the development of left ventricular mechanical dyssynchrony during the progression of heart failure in dogs.

PubMed

Hu, Wei; Zhao, Qing-yan; Yu, Sheng-bo; Sun, Bin; Chen, Liao; Cao, Sheng; Guo, Rui-qiang

2014-11-22

The purpose of this study was to investigate whether transcatheter renal sympathetic denervation (RSD) interfere with the development of left ventricular (LV) mechanical dyssynchrony during the progression of heart failure (HF). Nineteen beagles were randomly divided into sham-operated group (six dogs), control group (seven dogs), and RSD group (six dogs). Sham-operated group were implanted with pacemakers without pacing; Control group were implanted with pacemakers and underwent 3 weeks of rapid right ventricular pacing; and RSD group underwent catheter-based RSD bilaterally and were simultaneously implanted with pacemakers. Both LV strain and LV dyssynchrony were analyzed via 2D speckle-tracking strain echocardiography to evaluate LV function. Longitudinal dyssynchrony was determined as the standard deviation for time-to-peak speckle-tracking strain on apical 4- and 2-chamber views. Radial and circumferential dyssynchrony was determined as the standard deviation for time-to-peak speckle-tracking strain in mid- and base-LV short-axis views. Each myocardial function was also evaluated by averaging the peak systolic strains. LV systolic pressure (LVSP) and LV end-diastolic pressure (LVEDP) were measured. The LV interstitial fibrosis was determined by histological analysis. Plasma angiotensin II (Ang II), aldosterone and norepinephrine (NE) levels were also measured. After 3 weeks, all of the dogs in both the control and RSD groups showed greater LV end-diastolic volume compared with the sham-operated group; however, the dogs in the RSD group had a higher LV ejection fraction (LVEF) than the dogs in the control group (p<0.001). The LV systolic strains were higher in the RSD group than in the control group (p<0.001 for longitudinal, circumferential and radial strain, respectively). The levels of LV dyssynchrony were lower in the RSD group than in the control group (p<0.001 for longitudinal, circumferential and radial dyssynchrony, respectively). Compared with dogs with control alone, RSD dogs had lower LV end-diastolic pressures and less fibrous tissue. The levels of plasma Ang II, aldosterone and NE were lower in the RSD group than in the control group. RSD inhibites the development of left ventricular mechanical dyssynchrony during the progression of heart failure in dogs.

Effect of food prices on the prevalence of obesity among young adults.

PubMed

Han, E; Powell, L M

2011-03-01

To examine the extent to which various food prices were associated with the obesity status of young adults. Retrospective cohort study of 6537 men and 5324 women in the USA using panel data from the Monitoring the Future Surveys (1992-2003), which were merged with two food-at-home and one food-away-from-home price measures from the American Chamber of Commerce Researchers Association. Longitudinal individual random effect and fixed effect models were estimated. This study found that food prices did not have a significant effect on the prevalence of obesity among young female adults. For young adult men, an individual random effect estimator suggested that a 10% increase in the price of fast food was associated with a 13.2% decrease in the probability of obesity, but this effect lost its economic and statistical significance once individual fixed effects were controlled for in the estimation. Overall, the results imply that observed time-varying individual characteristics, such as working status, marital status and school enrolment status, may over-ride the effect of changes in food prices for young adults. More research employing longitudinal data is necessary to determine if food subsidies or taxes, particularly soft drink and fast food taxes or subsidies for fruit and vegetables, could be effective policy measures to curtail the increasing prevalence of obesity among young adults. Copyright © 2010 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Cancer-related fatigue: Mechanisms, risk factors, and treatments

PubMed Central

Bower, Julienne E.

2015-01-01

Fatigue is one of the most common and distressing side effects of cancer and its treatment, and may persist for years after treatment completion in otherwise healthy survivors. Cancer-related fatigue causes disruption in all aspects of quality of life and may be a risk factor for reduced survival. The prevalence and course of fatigue in cancer patients has been well characterized, and there is growing understanding of underlying biological mechanisms. Inflammation has emerged as a key biological pathway for cancer-related fatigue, with studies documenting links between markers of inflammation and fatigue before, during, and particularly after treatment. There is considerable variability in the experience of cancer-related fatigue that is not explained by disease- or treatment-related characteristics, suggesting that host factors may play an important role in the development and persistence of this symptom. Indeed, longitudinal studies have begun to identify genetic, biological, psychosocial, and behavioral risk factors for cancer-related fatigue. Given the multi-factorial nature of cancer-related fatigue, a variety of intervention approaches have been examined in randomized controlled trials, including physical activity, psychosocial, mind-body, and pharmacological treatments. Although there is currently no gold standard for treating fatigue, several of these approaches have shown beneficial effects and can be recommended to patients. This report provides a state of the science review of mechanisms, risk factors, and interventions for cancer-related fatigue, with a focus on recent longitudinal studies and randomized trials that have targeted fatigued patients. PMID:25113839

Longitudinal predictors of colorectal cancer screening among participants in a randomized controlled trial.

PubMed

Murphy, Caitlin C; Vernon, Sally W; Haddock, Nicole M; Anderson, Melissa L; Chubak, Jessica; Green, Beverly B

2014-09-01

Few studies use longitudinal data to identify predictors of colorectal cancer screening (CRCS). We examined predictors of (1) initial CRCS during the first year of a randomized trial, and (2) repeat CRCS during the second year of the trial among those that completed FOBT in Year 1. The sample comprised 1247 participants of the Systems of Support to Increase Colorectal Cancer Screening (SOS) Trial (Group Health Cooperative, August 2008 to November 2011). Potential predictors of CRCS were identified with logistic regression and included sociodemographics, health history, and validated scales of psychosocial constructs. Prior CRCS (OR 2.64, 95% CI 1.99-3.52) and intervention group (Automated: OR 2.06 95% CI 1.43-2.95; Assisted: OR 4.03, 95% CI 2.69-6.03; Navigated: OR 5.64, 95% CI 3.74-8.49) were predictors of CRCS completion at Year 1. For repeat CRCS at Year 2, prior CRCS at baseline (OR 1.97, 95% CI 1.25-3.11), intervention group (Automated: OR 9.27, 95% CI 4.56-18.82; Assisted: OR 11.17, 95% CI 5.44-22.94; Navigated: OR 13.10, 95% CI 6.33-27.08), and self-efficacy (OR 1.32, 95% CI 1.00-1.73) were significant predictors. Self-efficacy and prior CRCS are important predictors of future screening behavior. CRCS completion increased when access barriers were removed through interventions. Copyright © 2014 Elsevier Inc. All rights reserved.

Longitudinal Evaluation of a Scale-up Model for Teaching Mathematics with Trajectories and Technologies: Persistence of Effects in the Third Year

ERIC Educational Resources Information Center

Clements, Douglas H.; Sarama, Julie; Wolfe, Christopher B.; Spitler, Mary Elaine

2013-01-01

Using a cluster randomized trial design, we evaluated the persistence of effects of a research-based model for scaling up educational interventions. The model was implemented in 42 schools in two city districts serving low-resource communities, randomly assigned to three conditions. In pre-kindergarten, the two experimental interventions were…

Estimates of Intraclass Correlation Coefficients from Longitudinal Group-Randomized Trials of Adolescent HIV/STI/Pregnancy Prevention Programs

ERIC Educational Resources Information Center

Glassman, Jill R.; Potter, Susan C.; Baumler, Elizabeth R.; Coyle, Karin K.

2015-01-01

Introduction: Group-randomized trials (GRTs) are one of the most rigorous methods for evaluating the effectiveness of group-based health risk prevention programs. Efficiently designing GRTs with a sample size that is sufficient for meeting the trial's power and precision goals while not wasting resources exceeding them requires estimates of the…

Log-gamma linear-mixed effects models for multiple outcomes with application to a longitudinal glaucoma study

PubMed Central

Zhang, Peng; Luo, Dandan; Li, Pengfei; Sharpsten, Lucie; Medeiros, Felipe A.

2015-01-01

Glaucoma is a progressive disease due to damage in the optic nerve with associated functional losses. Although the relationship between structural and functional progression in glaucoma is well established, there is disagreement on how this association evolves over time. In addressing this issue, we propose a new class of non-Gaussian linear-mixed models to estimate the correlations among subject-specific effects in multivariate longitudinal studies with a skewed distribution of random effects, to be used in a study of glaucoma. This class provides an efficient estimation of subject-specific effects by modeling the skewed random effects through the log-gamma distribution. It also provides more reliable estimates of the correlations between the random effects. To validate the log-gamma assumption against the usual normality assumption of the random effects, we propose a lack-of-fit test using the profile likelihood function of the shape parameter. We apply this method to data from a prospective observation study, the Diagnostic Innovations in Glaucoma Study, to present a statistically significant association between structural and functional change rates that leads to a better understanding of the progression of glaucoma over time. PMID:26075565

Experiential versus rational training: a comparison of student attitudes toward homosexuality.

PubMed

Guth, Lorraine J; Lopez, David F; Rojas, Julio; Clements, Kimberly D; Tyler, J Michael

2004-01-01

Based on Epstein's (1994a) cognitive-experiential self-theory, two new training interventions were designed to teach students about gay, lesbian and bisexual issues. The efficacy of these theoretically based interventions was assessed in a short-term (7-week, three occasion) longitudinal study. Fifty undergraduate psychology students were randomly assigned to one of three treatment groups: Rational Training, Experiential Training, or Control Group. A residualized change score procedure was used to analyze change in levels of sexual prejudice and affect across the three types of measurement (pre-test, post-test, and follow-up). A 3 (Rational Training, Experiential Training, Control Group) x 2 (Low Sexual Prejudice, High Sexual Prejudice) MANOVA revealed that after the training, participants in the Experiential Group (affective training) had more accepting attitudes toward homosexuality compared to the Control Group. In addition, participants in the Experiential Group experienced more positive affect compared to the Rational and Control Groups and experienced more negative affect compared to the Rational Group. Findings are discussed and suggestions for future research are provided.

77 FR 2349 - Proposed Information Collection (Vocational Rehabilitation and Employment Longitudinal Study...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-17

... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-New (VR&E Longitudinal Study Survey... Rehabilitation and Employment (VR&E) Program. DATES: Written comments and recommendations on the proposed [[Page... . Please refer to ``OMB Control No. 2900--New (VR&E Longitudinal Study Survey)'' in any correspondence...

Remote magnetic control of a wireless capsule endoscope in the esophagus is safe and feasible: results of a randomized, clinical trial in healthy volunteers.

PubMed

Keller, Jutta; Fibbe, Christiane; Volke, Frank; Gerber, Jeremy; Mosse, Alexander C; Reimann-Zawadzki, Meike; Rabinovitz, Elisha; Layer, Peter; Swain, Paul

2010-11-01

Remote control of esophageal capsule endoscopes could enhance diagnostic accuracy. To assess the safety and efficacy of remote magnetic manipulation of a modified capsule endoscope (magnetic maneuverable capsule [MMC]; Given Imaging Ltd, Yoqneam, Israel) in the esophagus of healthy humans. Randomized, controlled trial. Academic hospital. This study involved 10 healthy volunteers. All participants swallowed a conventional capsule (ESO2; Given Imaging) and a capsule endoscope with magnetic material, the MMC, which is activated by a thermal switch, in random order (1 week apart). An external magnetic paddle (EMP; Given Imaging) was used to manipulate the MMC within the esophageal lumen. MMC responsiveness was evaluated on a screen showing the MMC film in real time. Safety and tolerability of the procedure (questionnaire), responsiveness of the MMC to the EMP, esophageal transit time, and visualization of the Z-line. No adverse events occurred apart from mild retrosternal pressure (n = 5). The ability to rotate the MMC around its longitudinal axis and to tilt it by defined movements of the EMP was clearly demonstrated in 9 volunteers. Esophageal transit time was highly variable for both capsules (MMC, 111-1514 seconds; ESO2, 47-1474 seconds), but the MMC stayed longer in the esophagus in 8 participants (P < .01). Visualization of the Z-line was more efficient with the ESO2 (inspection of 73% ± 18% of the circumference vs 33% ± 27%, P = .01). Magnetic forces were not strong enough to hold the MMC against peristalsis when the capsule approached the gastroesophageal junction. Remote control of the MMC in the esophagus of healthy volunteers is safe and feasible, but higher magnetic forces may be needed. Copyright © 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Yoga decreases kyphosis in senior women and men with adult onset hyperkyphosis: results of a randomized controlled trial

PubMed Central

Greendale, Gail A.; Huang, Mei-Hua; Karlamangla, Arun S.; Seeger, Leanne; Crawford, Sybil

2013-01-01

Objective To assess whether a specifically designed Yoga intervention can reduce hyperkyphosis. Design A 6-month, 2 group, randomized, controlled, single masked trial. Setting Community research unit. Participants 118 women and men aged >60 years with kyphosis angle >40 degrees. Major exclusions were: serious medical comorbidity; use of assistive device; unable to hear or see adequately for participation; or unable to pass a physical safety screen. Intervention The active treatment group attended hour-long Yoga classes, 3 days per week, for 24 weeks. The control group attended a monthly luncheon/seminar and received mailings. Measurements Primary outcomes were change (baseline to 6 months) in Debrunner kyphometer-assessed kyphosis angle, standing height, timed chair stands, functional reach and walking speed. Secondary outcomes were change in: kyphosis index, flexicurve kyphosis angle, the Rancho Bernardo Blocks posture assessment and health-related quality of life (HRQOL). Results Compared to control participants, those randomized to Yoga experienced a 4.4% improvement in flexicurve kyphosis angle (p=0.006) and a 5% improvement in kyphosis index (p=0.004). The intervention did not result in statistically significant improvement in Debrunner kyphometer angle, measured physical performance or in self-assessed HRQOL (each p>0.1). Conclusion The decrease in flexicurve kyphosis angle in the Yoga treatment group shows that hyperkyphosis is remediable, a critical first step in the pathway to treating or preventing this condition. Larger, more definitive studies of Yoga or other interventions for hyperkyphosis should be considered. Targeting individuals with more malleable spines and using longitudinally precise measures of kyphosis could strengthen the treatment effect. PMID:19682114

Longitudinal Stability and Control Characteristics at Transonic Speeds of a 1/30-Scale Model of the Republic XF-103 Airplane

NASA Technical Reports Server (NTRS)

Luoma, Arvo A.

1954-01-01

The longitudinal stability and control characteristics of a 1/30-scale model of the Republic XF-103 airplane were investigated in the Langley 8-foot transonic tunnel. The effect of speed brakes located at the end of the fuselage was also investigated. The main part of the investigation was made with internal flow in the model, but some data were obtained with no internal flow. The longitudinal stability and control at transonic-speeds appeared satisfactory. The transonic drag rise was small. The speed brakes had no adverse effects on longitudinal stability.

Randomized Controlled Trial of Group-Based Culturally Specific Cognitive Behavioral Therapy Among African American Smokers.

PubMed

Webb Hooper, Monica; Antoni, Michael H; Okuyemi, Kolawole; Dietz, Noella A; Resnicow, Ken

2017-03-01

This study tested the efficacy of group-based culturally specific cognitive behavioral therapy (CBT) for smoking cessation among low-income African Americans. Participants (N = 342; 63.8% male; M = 49.5 years old; M cigarettes per day = 18) were randomly assigned to eight sessions of group-based culturally specific or standard CBT, plus 8 weeks of transdermal nicotine patches. Biochemically verified 7-day point prevalence abstinence (ppa) was assessed at the end-of-therapy (ie, CBT) (EOT), and 3-, 6-, and 12-month follow-ups. Primary outcomes were the longitudinal intervention effect over the 12-month follow-up period, and 7-day ppa at the 6-month follow-up. Secondary outcomes included 7-day ppa at the EOT and 12-month follow-up, and intervention ratings. Generalized linear mixed modeling tested the longitudinal effect and logistic regression tested effects at specific timepoints. Generalized linear mixed modeling demonstrated a longitudinal effect of intervention condition. Specifically, 7-day ppa was two times (P = .02) greater following culturally specific CBT versus standard CBT when tested across all timepoints. Analyses by timepoint found no significant difference at 6 or 12 months, yet culturally specific CBT was efficacious at the EOT (62.5% vs. 51.5% abstinence, P = .05) and the 3-month follow-up (36.4% vs. 22.9% abstinence, P = .007). Finally, intervention ratings in both conditions were high, with no significant differences. Culturally specific CBT had a positive longitudinal effect on smoking cessation compared to a standard approach; however, the effects were driven by short-term successes. We recommend the use of group-based culturally specific CBT in this population when possible, and future research on methods to prevent long-term relapse. Culturally specific interventions are one approach to address smoking-related health disparities; however, evidence for their efficacy in African Americans is equivocal. Moreover, the methodological limitations of the existing literature preclude an answer to this fundamental question. We found a positive longitudinal effect of culturally specific CBT versus standard CBT for smoking cessation across the follow-up period. Analyses by assessment point revealed that the overall effect was driven by early successes. Best practices for treating tobacco use in this population should attend to ethnocultural factors, but when this is not possible, standard CBT is an alternative approach for facilitating long-term abstinence. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Does Assessing Suicidality Frequently and Repeatedly Cause Harm? A Randomized Control Study

PubMed Central

Law, Mary Kate; Furr, R. Michael; Arnold, Elizabeth Mayfield; Mneimne, Malek; Jaquett, Caroline; Fleeson, William

2015-01-01

Assessing suicidality is common in mental health practice and is fundamental to suicide research. Although necessary, there is significant concern that such assessments have unintended harmful consequences. Using a longitudinal randomized control design, we evaluated whether repeated and frequent assessments of suicide-related thoughts and behaviors negatively affected individuals, including those at-risk for suicide-related outcomes. Adults (N = 282), including many diagnosed with Borderline Personality Disorder (BPD), were recruited through psychiatric outpatient clinics and from the community at large, and were randomly assigned to assessment groups. A Control Assessment group responded to questions regarding negative psychological experiences several times each day during a 2-week Main Observation phase. During the same observation period, an Intensive Suicide Assessment group responded to the same questions, along with questions regarding suicidal behavior and ideation. Negative psychological outcomes were measured during the Main Observation phase (for BPD symptoms unrelated to suicide and for BPD-relevant emotions) and/or at the end of each week during the Main Observation phase and monthly for 6 months thereafter (for all outcomes, including suicidal ideation and behavior). Results revealed little evidence that intensive suicide assessment triggered negative outcomes, including suicidal ideation or behavior, even among people with BPD. A handful of effects did reach or approach significance, though these were temporary and non-robust. However, given the seriousness of some outcomes, we recommend that researchers or clinicians who implement experience sampling methods including suicide-related items carefully consider the benefits of asking about suicide and to inform participants about possible risks. PMID:25894705

Self-efficacy is associated with increased food security in novel food pantry program.

PubMed

Martin, Katie S; Colantonio, Angela G; Picho, Katherine; Boyle, Katie E

2016-12-01

We examined the effect of a novel food pantry intervention (Freshplace) that includes client-choice and motivational interviewing on self-efficacy and food security in food pantry clients. The study was designed as a randomized control trial. Participants were recruited over one year from traditional food pantries in Hartford, CT. Participants were randomized to Freshplace or traditional food pantries (controls) and data collection occurred at baseline with quarterly follow-ups for 18 months. Food security was measured using the USDA 18-item Food Security Module. A newly developed scale was utilized to measure self-efficacy. Scale reliability was measured using a Cronbach alpha test; validity was measured via correlating with a related variable. Analyses included chi-square tests for bivariate analyses and hierarchical linear modeling for longitudinal analyses. A total of 227 adults were randomized to the Freshplace intervention ( n =112) or control group ( n =115). The overall group was 60% female, 73% Black, mean age=51. The new self-efficacy scale showed good reliability and validity. Self-efficacy was significantly inversely associated with very low food security ( p <.05). Being in the Freshplace intervention ( p =.01) and higher self-efficacy ( p =.04) were independently associated with decreased very low food security. The traditional food pantry model fails to recognize the influence of self-efficacy on a person's food security. A food pantry model with client-choice, motivational interviewing and targeted referral services can increase self-efficacy of clients. Prioritizing the self-efficacy of clients over the efficiency of pantry operations is required to increase food security among disadvantaged populations.

Does assessing suicidality frequently and repeatedly cause harm? A randomized control study.

PubMed

Law, Mary Kate; Furr, R Michael; Arnold, Elizabeth Mayfield; Mneimne, Malek; Jaquett, Caroline; Fleeson, William

2015-12-01

Assessing suicidality is common in mental health practice and is fundamental to suicide research. Although necessary, there is significant concern that such assessments have unintended harmful consequences. Using a longitudinal randomized control design, the authors evaluated whether repeated and frequent assessments of suicide-related thoughts and behaviors negatively affected individuals, including those at-risk for suicide-related outcomes. Adults (N = 282), including many diagnosed with borderline personality disorder (BPD), were recruited through psychiatric outpatient clinics and from the community at large, and were randomly assigned to assessment groups. A control assessment group responded to questions regarding negative psychological experiences several times each day during a 2-week main observation phase. During the same observation period, an intensive suicide assessment group responded to the same questions, along with questions regarding suicidal behavior and ideation. Negative psychological outcomes were measured during the main observation phase (for BPD symptoms unrelated to suicide and for BPD-relevant emotions) and/or at the end of each week during the main observation phase and monthly for 6 months thereafter (for all outcomes, including suicidal ideation and behavior). Results revealed little evidence that intensive suicide assessment triggered negative outcomes, including suicidal ideation or behavior, even among people with BPD. A handful of effects did reach or approach significance, though these were temporary and nonrobust. However, given the seriousness of some outcomes, the authors recommend that researchers or clinicians who implement experience sampling methods including suicide-related items carefully consider the benefits of asking about suicide and to inform participants about possible risks. (c) 2015 APA, all rights reserved).

Community-based intermittent mass testing and treatment for malaria in an area of high transmission intensity, western Kenya: study design and methodology for a cluster randomized controlled trial.

PubMed

Samuels, Aaron M; Awino, Nobert; Odongo, Wycliffe; Abong'o, Benard; Gimnig, John; Otieno, Kephas; Shi, Ya Ping; Were, Vincent; Allen, Denise Roth; Were, Florence; Sang, Tony; Obor, David; Williamson, John; Hamel, Mary J; Patrick Kachur, S; Slutsker, Laurence; Lindblade, Kim A; Kariuki, Simon; Desai, Meghna

2017-06-07

Most human Plasmodium infections in western Kenya are asymptomatic and are believed to contribute importantly to malaria transmission. Elimination of asymptomatic infections requires active treatment approaches, such as mass testing and treatment (MTaT) or mass drug administration (MDA), as infected persons do not seek care for their infection. Evaluations of community-based approaches that are designed to reduce malaria transmission require careful attention to study design to ensure that important effects can be measured accurately. This manuscript describes the study design and methodology of a cluster-randomized controlled trial to evaluate a MTaT approach for malaria transmission reduction in an area of high malaria transmission. Ten health facilities in western Kenya were purposively selected for inclusion. The communities within 3 km of each health facility were divided into three clusters of approximately equal population size. Two clusters around each health facility were randomly assigned to the control arm, and one to the intervention arm. Three times per year for 2 years, after the long and short rains, and again before the long rains, teams of community health volunteers visited every household within the intervention arm, tested all consenting individuals with malaria rapid diagnostic tests, and treated all positive individuals with an effective anti-malarial. The effect of mass testing and treatment on malaria transmission was measured through population-based longitudinal cohorts, outpatient visits for clinical malaria, periodic population-based cross-sectional surveys, and entomological indices.

Handling Qualities of a Large Civil Tiltrotor in Hover using Translational Rate Command

NASA Technical Reports Server (NTRS)

Malpica, Carlos A.; Theodore, Colin R.; Lawrence, Ben; Lindsey, James; Blanken, Chris

2012-01-01

A Translational Rate Command (TRC) control law has been developed to enable low speed maneuvering of a large civil tiltrotor with minimal pitch changes by means of automatic nacelle angle deflections for longitudinal velocity control. The nacelle actuator bandwidth required to achieve Level 1 handling qualities in hover and the feasibility of additional longitudinal cyclic control to augment low bandwidth nacelle actuation were investigated. A frequency-domain handling qualities criterion characterizing TRC response in terms of bandwidth and phase delay was proposed and validated against a piloted simulation conducted on the NASA-Ames Vertical Motion Simulator. Seven experimental test pilots completed evaluations in the ADS-33E-PRF Hover Mission Task Element (MTE) for a matrix of nacelle actuator bandwidths, equivalent rise times and control response sensitivities, and longitudinal cyclic control allocations. Evaluated against this task, longitudinal phase delay shows the Level 1 boundary is around 0.4 0.5 s. Accordingly, Level 1 handling qualities were achieved either with a nacelle actuator bandwidth greater than 4 rad/s, or by employing longitudinal cyclic control to augment low bandwidth nacelle actuation.

An advanced stochastic model for threshold crossing studies of rotor blade vibrations.

NASA Technical Reports Server (NTRS)

Gaonkar, G. H.; Hohenemser, K. H.

1972-01-01

A stochastic model to analyze turbulence-excited rotor blade vibrations, previously described by Gaonkar et al. (1971), is generalized to include nonuniformity of the atmospheric turbulence velocity across the rotor disk in the longitudinal direction. The results of the presented analysis suggest that the nonuniformity of the vertical turbulence over the rotor disk is of little influence on the random blade flapping response, at least as far as longitudinal nonuniformity is concerned.

The Myth of Blunted Gamers: No Evidence for Desensitization in Empathy for Pain after a Violent Video Game Intervention in a Longitudinal fMRI Study on Non-Gamers.

PubMed

Kühn, Simone; Kugler, Dimitrij; Schmalen, Katharina; Weichenberger, Markus; Witt, Charlotte; Gallinat, Jürgen

2018-01-31

It is a common concern in the research field and the community that habitual violent video gaming reduces empathy for pain in its players. However, previous fMRI studies have only compared habitual game players against control participants cross-sectionally. However the observed pattern of results may be due to a priori differences in people who become gamers and who not. In order to derive the causal conclusion that violent video game play causes desensitisation, longitudinal studies are needed. Therefore we conducted a longitudinal fMRI intervention study over 16 weeks. Participants were randomly assigned to 1) play a violent video game (Grand Theft Auto 5), 2) perform a social life simulation game (The Sims 3) 30 min/day for 8 weeks, 3) serve as passive control. To assess empathy processing, participants were exposed to painful and non-painful stimuli (e.g. someone cutting a cucumber with or without hurting herself) either as real photographs or video-game like depictions in a 3T MRI scanner before and after the training intervention as well as two months after training. We did not find any evidence for desensitization in the empathy network for pain in the violent video game group at any time point. The present results provide strong evidence against the frequently proclaimed negative effects of playing violent video games and will therefore help to communicate a more realistic scientific perspective of the effects of violent video gaming in real life. © 2018 The Author(s). Published by S. Karger AG, Basel.

State observer-based sliding mode control for semi-active hydro-pneumatic suspension

NASA Astrophysics Data System (ADS)

Ren, Hongbin; Chen, Sizhong; Zhao, Yuzhuang; Liu, Gang; Yang, Lin

2016-02-01

This paper proposes an improved virtual reference model for semi-active suspension to coordinate the vehicle ride comfort and handling stability. The reference model combines the virtues of sky-hook with ground-hook control logic, and the hybrid coefficient is tuned according to the longitudinal and lateral acceleration so as to improve the vehicle stability especially in high-speed condition. Suspension state observer based on unscented Kalman filter is designed. A sliding mode controller (SMC) is developed to track the states of the reference model. The stability of the SMC strategy is proven by means of Lyapunov function taking into account the nonlinear damper characteristics and sprung mass variation of the vehicle. Finally, the performance of the controller is demonstrated under three typical working conditions: the random road excitation, speed bump road and sharp acceleration and braking. The simulation results indicated that, compared with the traditional passive suspension, the proposed control algorithm can offer a better coordination between vehicle ride comfort and handling stability. This approach provides a viable alternative to costlier active suspension control systems for commercial vehicles.

Modeling Longitudinal Data Containing Non-Normal Within Subject Errors

NASA Technical Reports Server (NTRS)

Feiveson, Alan; Glenn, Nancy L.

2013-01-01

The mission of the National Aeronautics and Space Administration’s (NASA) human research program is to advance safe human spaceflight. This involves conducting experiments, collecting data, and analyzing data. The data are longitudinal and result from a relatively few number of subjects; typically 10 – 20. A longitudinal study refers to an investigation where participant outcomes and possibly treatments are collected at multiple follow-up times. Standard statistical designs such as mean regression with random effects and mixed–effects regression are inadequate for such data because the population is typically not approximately normally distributed. Hence, more advanced data analysis methods are necessary. This research focuses on four such methods for longitudinal data analysis: the recently proposed linear quantile mixed models (lqmm) by Geraci and Bottai (2013), quantile regression, multilevel mixed–effects linear regression, and robust regression. This research also provides computational algorithms for longitudinal data that scientists can directly use for human spaceflight and other longitudinal data applications, then presents statistical evidence that verifies which method is best for specific situations. This advances the study of longitudinal data in a broad range of applications including applications in the sciences, technology, engineering and mathematics fields.

Morgantown Personal Rapid Transit Longitudinal Control System Design Summary

DOT National Transportation Integrated Search

1975-12-01

Experience with the longitudinal control system used on each vehicle in the Morgantown Personal Rapid Transit System has shown that nonlinearities and variations in control system parameters can significantly affect performance if such characteristic...

Self-blood pressure monitoring in an urban, ethnically diverse population: a randomized clinical trial utilizing the electronic health record.

PubMed

Yi, Stella S; Tabaei, Bahman P; Angell, Sonia Y; Rapin, Anne; Buck, Michael D; Pagano, William G; Maselli, Frank J; Simmons, Alvaro; Chamany, Shadi

2015-03-01

Hypertension is a leading risk factor for cardiovascular disease. Although control rates have improved over time, racial/ethnic disparities in hypertension control persist. Self-blood pressure monitoring, by itself, has been shown to be an effective tool in predominantly white populations, but less studied in minority, urban communities. These types of minimally intensive approaches are important to test in all populations, especially those experiencing related health disparities, for broad implementation with limited resources. The New York City Health Department in partnership with community clinic networks implemented a randomized clinical trial (n=900, 450 per arm) to investigate the effectiveness of self-blood pressure monitoring in medically underserved and largely black and Hispanic participants. Intervention participants received a home blood pressure monitor and training on use, whereas control participants received usual care. After 9 months, systolic blood pressure decreased (intervention, 14.7 mm Hg; control, 14.1 mm Hg; P=0.70). Similar results were observed when incorporating longitudinal data and calculating a mean slope over time. Control was achieved in 38.9% of intervention and 39.1% of control participants at the end of follow-up; the time-to-event experience of achieving blood pressure control in the intervention versus control groups were not different from each other (logrank P value =0.91). Self-blood pressure monitoring was not shown to improve control over usual care in this largely minority, urban population. The patient population in this study, which included a high proportion of Hispanics and uninsured persons, is understudied. Results indicate these groups may have additional meaningful barriers to achieving blood pressure control beyond access to the monitor itself. http://clinicaltrials.gov. Unique Identifier: NCT01123577. © 2015 American Heart Association, Inc.

Comparing meta-analysis and ecological-longitudinal analysis in time-series studies. A case study of the effects of air pollution on mortality in three Spanish cities

PubMed Central

Saez, M; Figueiras, A; Ballester, F; Perez-Hoyos, S; Ocana, R; Tobias, A

2001-01-01

STUDY OBJECTIVE—The objective of this paper is to introduce a different approach, called the ecological-longitudinal, to carrying out pooled analysis in time series ecological studies. Because it gives a larger number of data points and, hence, increases the statistical power of the analysis, this approach, unlike conventional ones, allows the complementation of aspects such as accommodation of random effect models, of lags, of interaction between pollutants and between pollutants and meteorological variables, that are hardly implemented in conventional approaches.
DESIGN—The approach is illustrated by providing quantitative estimates of the short-term effects of air pollution on mortality in three Spanish cities, Barcelona, Valencia and Vigo, for the period 1992-1994. Because the dependent variable was a count, a Poisson generalised linear model was first specified. Several modelling issues are worth mentioning. Firstly, because the relations between mortality and explanatory variables were non-linear, cubic splines were used for covariate control, leading to a generalised additive model, GAM. Secondly, the effects of the predictors on the response were allowed to occur with some lag. Thirdly, the residual autocorrelation, because of imperfect control, was controlled for by means of an autoregressive Poisson GAM. Finally, the longitudinal design demanded the consideration of the existence of individual heterogeneity, requiring the consideration of mixed models.
MAIN RESULTS—The estimates of the relative risks obtained from the individual analyses varied across cities, particularly those associated with sulphur dioxide. The highest relative risks corresponded to black smoke in Valencia. These estimates were higher than those obtained from the ecological-longitudinal analysis. Relative risks estimated from this latter analysis were practically identical across cities, 1.00638 (95% confidence intervals 1.0002, 1.0011) for a black smoke increase of 10 µg/m3 and 1.00415 (95% CI 1.0001, 1.0007) for a increase of 10 µg/m3 of sulphur dioxide. Because the statistical power is higher than in the individual analysis more interactions were statistically significant, especially those among air pollutants and meteorological variables.
CONCLUSIONS—Air pollutant levels were related to mortality in the three cities of the study, Barcelona, Valencia and Vigo. These results were consistent with similar studies in other cities, with other multicentric studies and coherent with both, previous individual, for each city, and multicentric studies for all three cities.


Keywords: air pollution; mortality; longitudinal studies PMID:11351001

Experimental research on the stability and the multilongitudinal mode interference of bidirectional outputs of LD-pumped solid state ring laser

NASA Astrophysics Data System (ADS)

Wan, Shunping; Tian, Qian; Sun, Liqun; Yao, Minyan; Mao, Xianhui; Qiu, Hongyun

2004-05-01

This paper reports an experimental research on the stability of bidirectional outputs and multi-longitudinal mode interference of laser diode end-pumped Nd:YVO4 solid-state ring laser (DPSSL). The bidirectional, multi-longitudinal and TEM00 mode continuous wave outputs are obtained and the output powers are measured and their stabilities are analyzed respectively. The spectral characteristic of the outputs is measured. The interfering pattern of the bidirectional longitudinal mode outputs is obtained and analyzed in the condition of the ring cavity with rotation velocity. The movement of the interfering fringe of the multi-longitudinal modes is very sensitive to the deformation of the setup base and the fluctuation of the intracavity air, but is stationary or randomly dithers when the stage is rotating.

Effectiveness and sustainability of the ViSC Social Competence Program to prevent cyberbullying and cyber-victimization: Class and individual level moderators.

PubMed

Gradinger, Petra; Yanagida, Takuya; Strohmeier, Dagmar; Spiel, Christiane

2016-01-01

We investigated whether the general anti-bullying program ViSC sustainably prevents cyberbullying and cyber-victimization. A longitudinal randomized control group design was used to examine (i) program effectiveness immediately after a 1 year implementation phase and (ii) sustainable program effects 6 months later taking several moderators on the class level (class climate and ethnic diversity) and on the individual level (gender, age, internet usage, traditional bullying/victimization) into account. Effectiveness (e.g., the change between waves 2 and 1) was examined in 2,042 students (47.6% girls), aged 11.7 years (SD = 0.88) enrolled in 18 schools and 103 classes. Sustainability (e.g., the change between waves 3 and 2) was examined in a sub-sample of 6 schools and 35 classes comprising 659 students. The self-assessment multiple-item scales showed longitudinal and multiple group invariance. Factor scores were extracted to compute difference scores for effectiveness (Posttest minus Pretest) and sustainability (Follow-up test minus Posttest) for cyberbullying and cyber-victimization. Multilevel Modeling was applied to examine (i) the effectiveness and (ii) the sustainability of the ViSC intervention controlling for several individual and class level variables. Controlling for covariates, it was demonstrated that the ViSC program is effective in preventing cyberbullying and cyber-victimization and that the effects are sustainable after 6 months. The consequences for cyberbullying prevention are discussed. © 2016 Wiley Periodicals, Inc.

Full drive-by-wire dynamic control for four-wheel-steer all-wheel-drive vehicles

NASA Astrophysics Data System (ADS)

Fahimi, Farbod

2013-03-01

Most of the controllers introduced for four-wheel-steer (4WS) vehicles are derived with the assumption that the longitudinal speed of the vehicle is constant. However, in real applications, the longitudinal speed varies, and the longitudinal, lateral, and yaw dynamics are coupled. In this paper, the longitudinal dynamics of the vehicle as well as its lateral and yaw motions are controlled simultaneously. This way, the effect of driving/braking forces of the tires on the lateral and yaw motions of the vehicle are automatically included in the control laws. To address the dynamic parameter uncertainty of the vehicle, a chatter-free variable structure controller is introduced. Elimination of chatter is achieved by introducing a dynamically adaptive boundary layer thickness. It is shown via simulations that the proposed control approach performs more robustly than the controllers developed based on dynamic models, in which longitudinal speed is assumed to be constant, and only lateral speed and yaw rate are used as system states. Furthermore, this approach supports all-wheel-drive vehicles. Front-wheel-drive or rear-wheel-drive vehicles are also supported as special cases of an all-wheel-drive vehicle.

Total energy based flight control system

NASA Technical Reports Server (NTRS)

Lambregts, Antonius A. (Inventor)

1985-01-01

An integrated aircraft longitudinal flight control system uses a generalized thrust and elevator command computation (38), which accepts flight path angle, longitudinal acceleration command signals, along with associated feedback signals, to form energy rate error (20) and energy rate distribution error (18) signals. The engine thrust command is developed (22) as a function of the energy rate distribution error and the elevator position command is developed (26) as a function of the energy distribution error. For any vertical flight path and speed mode the outerloop errors are normalized (30, 34) to produce flight path angle and longitudinal acceleration commands. The system provides decoupled flight path and speed control for all control modes previously provided by the longitudinal autopilot, autothrottle and flight management systems.

Socio-demographic and clinical profiles of paranoid and nonparanoid schizophrenia: a prospective, multicenter study in China.

PubMed

Xiang, Yu-Tao; Wang, Chuan-Yue; Chiu, Helen F K; Weng, Yong-Zhen; Bo, Qi-Jing; Chan, Sandra S M; Lee, Edwin H M; Ungvari, Gabor S

2011-07-01

This study aimed to explore the socio-demographic and clinical characteristics of paranoid and nonparanoid subtypes of schizophrenia. In a multicenter, randomized, controlled, longitudinal study, 374 clinically stable schizophrenia patients were interviewed at entry with standardized assessment instruments and followed for 12-26 months. In the multivariate analysis, male sex, married marital status, urban abode, and more frequent relapse over the study period were independently associated with paranoid schizophrenia. The socio-demographic and clinical characteristics of Chinese patients with the paranoid subtype of schizophrenia are different from those of their Caucasian counterparts who are more likely to be women and have a better outcome. © 2010 Wiley Periodicals, Inc.

A school-based supplementary food programme in rural Kenya did not reduce children's intake at home.

PubMed

Gewa, Constance A; Murphy, Suzanne P; Weiss, Robert E; Neumann, Charlotte G

2013-04-01

To examine changes in energy intake along with markers of dietary quality (animal-source energy and protein intakes) among household members in the presence of supplementary school feeding in rural Kenya. A 2-year, longitudinal, randomized controlled feeding intervention study. Kyeni South Division, Embu District, Kenya. A total of 182 schoolchildren and selected household members. There was no evidence that schoolchildren who received supplementary snacks at school experienced reduced intakes at home or that intakes by other family members were increased at the expense of the schoolchild's intake. This analysis highlights a number of factors useful in planning for supplementary feeding interventions in rural Kenya and similar communities.

Wind-tunnel tests of a 1/4 scale model of the Bell XS-1 transonic airplane. 1: Longitudinal stability and control characteristics

NASA Technical Reports Server (NTRS)

Donlan, C. J.; Kemp, W. B., Jr.; Polhamus, E. C.

1976-01-01

A 1/4 scale model of the Bell XS-1 transonic aircraft was tested in the Langley 300 mile-per-hour 7 by 10 foot tunnel to determine its low speed longitudinal stability and control characteristics. Pertinent longitudinal flying qualities expected of the XS-1 research airplane were estimated from the results of these tests including the effects of compressibility likely to be encountered at speeds below the force break. It appears that the static longitudinal stability and elevator control power will be adequate, but that the elevator control force gradient in steady flight will be undesirably low for all configurations. It is suggested that a centering spring be incorporated in the elevator control system of the airplane in order to increase the control force gradient in steady flight and in maneuvers.

The impact of victim-focused outreach on criminal legal system outcomes following police-reported intimate partner abuse.

PubMed

DePrince, Anne P; Belknap, Joanne; Labus, Jennifer S; Buckingham, Susan E; Gover, Angela R

2012-08-01

Randomized control designs have been used in the public health and psychological literatures to examine the relationship between victim outreach following intimate partner abuse (IPA) and various outcomes. These studies have largely relied on samples drawn from health providers and shelters to examine outcomes outside the criminal legal system. Based on the positive findings from this body of research, we expected that a victim-focused, community-coordinated outreach intervention would improve criminal legal system outcomes. The current study used a randomized, longitudinal design to recruit 236 ethnically diverse women with police-reported IPA to compare treatment-as-usual with an innovative community-coordinated, victim-focused outreach program. Findings indicated that the outreach program was effective in increasing women's engagement with prosecution tasks as well as likelihood of taking part in prosecution of their abusers. Results were particularly robust among women marginalized by ethnicity and class, and those still living with their abusers after the target incident.

14 CFR 125.225 - Flight data recorders.

Code of Federal Regulations, 2014 CFR

2014-01-01

... acceleration; (5) Heading; (6) Time of each radio transmission to or from air traffic control; (7) Pitch attitude; (8) Roll attitude; (9) Longitudinal acceleration; (10) Control column or pitch control surface... control; (7) Pitch attitude; (8) Roll attitude; (9) Longitudinal acceleration; (10) Pitch trim position...

Telehealth Coaching: Impact on Dietary and Physical Activity Contributions to Bone Health During a Military Deployment.

PubMed

Frank, Laura L; McCarthy, Mary S

2016-05-01

To examine the difference in bone health and body composition via blood biomarkers, bone mineral density, anthropometrics and dietary intake following deployment to Afghanistan among soldiers randomized to receive telehealth coaching promoting nutrition and exercise. This was a prospective, longitudinal, cluster-randomized, controlled trial with repeated measures in 234 soldiers. Measures included heel bone scan for bone mineral density, blood biomarkers for bone formation, resorption, and turnover, body composition via Futrex, resting metabolic rate via MedGem, physical activity using the Baecke Habitual Physical Activity Questionnaire, and dietary intake obtained from the Block Food Frequency Questionnaire. There were significant increases in body fat (p = 0.00035), osteocalcin (0.0152), and sports index (p = 0.0152) for the telehealth group. No other statistically significant differences were observed between groups. Vitamin D intake among soldiers was ≤ 35% of the suggested Dietary Reference Intakes for age. A 9-month deployment to Afghanistan increased body fat, bone turnover, and physical activity among soldiers randomized to receive telehealth strategies to build bone with nutrition and exercise. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Benefit-Cost Analysis of a Randomized Evaluation of Communities That Care: Monetizing Intervention Effects on the Initiation of Delinquency and Substance Use Through Grade 12.

PubMed

Kuklinski, Margaret R; Fagan, Abigail A; Hawkins, J David; Briney, John S; Catalano, Richard F

2015-06-01

To determine whether the Communities That Care (CTC) prevention system is a cost-beneficial intervention. Data were from a longitudinal panel of 4,407 youth participating in a randomized controlled trial including 24 towns in 7 states, matched in pairs within state and randomly assigned to condition. Significant differences favoring intervention youth in sustained abstinence from delinquency, alcohol use, and tobacco use through Grade 12 were monetized and compared to economic investment in CTC. CTC was estimated to produce $4,477 in benefits per youth (discounted 2011 dollars). It cost $556 per youth to implement CTC for 5 years. The net present benefit was $3,920. The benefit-cost ratio was $8.22 per dollar invested. The internal rate of return was 21%. Risk that investment would exceed benefits was minimal. Investment was expected to be recouped within 9 years. Sensitivity analyses in which effects were halved yielded positive cost-beneficial results. CTC is a cost-beneficial, community-based approach to preventing initiation of delinquency, alcohol use, and tobacco use. CTC is estimated to generate economic benefits that exceed implementation costs when disseminated with fidelity in communities.

Assessing the effectiveness of household-level focal mass drug administration and community-wide mass drug administration for reducing malaria parasite infection prevalence and incidence in Southern Province, Zambia: study protocol for a community randomized controlled trial.

PubMed

Eisele, Thomas P; Silumbe, Kafula; Finn, Timothy; Chalwe, Victor; Kamuliwo, Mukalwa; Hamainza, Busiku; Moonga, Hawela; Bennett, Adam; Yukich, Josh; Keating, Joseph; Steketee, Richard W; Miller, John M

2015-08-13

Mass drug administration (MDA) and focal MDA (fMDA) using dihydroartemisinin plus piperaquine (DHAp), represent two strategies to maximize the use of existing information to achieve greater clearance of human infection and reduce the parasite reservoir, and provide longer chemoprophylactic protection against new infections. The primary aim of this study is to quantify the relative effectiveness of MDA and fMDA with DHAp against no mass treatment (standard of care) for reducing Plasmodium falciparum prevalence and incidence. The study will be conducted along Lake Kariba in Southern Province, Zambia; an area of low to moderate malaria transmission and high coverage of vector control. A community randomized controlled trial (CRCT) of 60 health facility catchment areas (HFCAs) will be used to evaluate the impact of two rounds of MDA and fMDA interventions, relative to a control of no mass treatment, stratified by high and low transmission. Community residents in MDA HFCAs will be treated with DHAp at the end of the dry season (round one: November to December 2014) and the beginning of the rainy season (round two: February to March 2015). Community residents in fMDA HFCAs will be tested during the same two rounds for malaria parasites with a rapid diagnostic test; all positive individuals and all individuals living in their household will be treated with DHAp. Primary outcomes include malaria parasite prevalence (n = 5,640 children aged one month to under five-years-old), as measured by pre- and post-surveys, and malaria parasite infection incidence (n = 2,250 person-years among individuals aged three months and older), as measured by a monthly longitudinal cohort. The study is powered to detect approximately a 50 % relative reduction in these outcomes between each intervention group versus the control. Strengths of this trial include: a robust study design (CRCT); cross-sectional parasite surveys as well as a longitudinal cohort; and stratification of high and low transmission areas. Primary limitations include: statistical power to detect only a 50 % reduction in primary outcomes within high and low transmission strata; potential for contamination; and potential for misclassification of exposure. Identifier: Clinicaltrials.gov: NCT02329301 . Registration date: 30 December 2014.

Greater diet quality is associated with more optimal glycemic control in a longitudinal study of youth with type 1 diabetes.

PubMed

Nansel, Tonja R; Lipsky, Leah M; Liu, Aiyi

2016-07-01

Despite the centrality of nutrition in the management of type 1 diabetes, the association of diet quality and macronutrient distribution with glycemic control is ambiguous. This study examined longitudinally the association of dietary intake with multiple indicators of glycemic control in youth with type 1 diabetes participating in a behavioral nutrition intervention study. Participants in a randomized clinical trial of a behavioral nutrition intervention [n = 136; mean ± SD age: 12.8 ± 2.6 y; glycated hemoglobin (HbA1c): 8.1% ± 1.0%; 69.1% using an insulin pump] completed 3-d diet records at baseline and months 3, 6, 9, 12, and 18; masked continuous glucose monitoring (CGM) data were obtained concurrently with the use of the Medtronic iPro CGM system. HbA1c was obtained every 3 mo; 1,5-anhydroglucitol was obtained every 6 mo. Linear mixed-effects regression models estimated associations of time-varying dietary intake variables with time-varying glycemic control indicators, controlling for age, height, weight, sex, Tanner stage, diabetes duration, regimen, frequency of blood glucose monitoring, physical activity, and treatment assignment. HbA1c was associated inversely with carbohydrate and natural sugar, and positively with protein and unsaturated fat. 1,5-Anhydroglucitol was associated positively with fiber intake and natural sugar. Greater glycemic control as indicated by ≥1 CGM variable was associated with higher Healthy Eating Index-2005, whole plant food density, fiber, carbohydrate, and natural sugar and lower glycemic index and unsaturated fat. Both overall diet quality and macronutrient distribution were associated with more optimal glycemic control. Associations were more consistent for CGM variables obtained concurrently with dietary intake than for biomarkers of longer-term glycemic control. These findings suggest that glycemic control may be improved by increasing intake of high-fiber, low glycemic-index, carbohydrate-containing foods. This trial was registered at clinicaltrials.gov as NCT00999375. © 2016 American Society for Nutrition.

Entry dynamics of space shuttle orbiter with longitudinal stability and control uncertainties at supersonic and hypersonic speeds

NASA Technical Reports Server (NTRS)

Stone, H. W.; Powell, R. W.

1977-01-01

A six-degree-of-freedom simulation analysis was conducted to examine the effects of longitudinal static aerodynamic stability and control uncertainties on the performance of the space shuttle orbiter automatic (no manual inputs) entry guidance and control systems. To establish the acceptable boundaries, the static aerodynamic characteristics were varied either by applying a multiplier to the aerodynamic parameter or by adding an increment. With either of two previously identified control system modifications included, the acceptable longitudinal aerodynamic boundaries were determined.

Saving and Empowering Young Lives in Europe (SEYLE): a randomized controlled trial

PubMed Central

2010-01-01

Background There have been only a few reports illustrating the moderate effectiveness of suicide-preventive interventions in reducing suicidal behavior, and, in most of those studies, the target populations were primarily adults, whereas few focused on adolescents. Essentially, there have been no randomized controlled studies comparing the efficacy, cost-effectiveness and cultural adaptability of suicide-prevention strategies in schools. There is also a lack of information on whether suicide-preventive interventions can, in addition to preventing suicide, reduce risk behaviors and promote healthier ones as well as improve young people's mental health. The aim of the SEYLE project, which is funded by the European Union under the Seventh Framework Health Program, is to address these issues by collecting baseline and follow-up data on health and well-being among European adolescents and compiling an epidemiological database; testing, in a randomized controlled trial, three different suicide-preventive interventions; evaluating the outcome of each intervention in comparison with a control group from a multidisciplinary perspective; as well as recommending culturally adjusted models for promoting mental health and preventing suicidal behaviors. Methods and design The study comprises 11,000 adolescents emitted from randomized schools in 11 European countries: Austria, Estonia, France, Germany, Hungary, Ireland, Israel, Italy, Romania, Slovenia and Spain, with Sweden serving as the scientific coordinating center. Each country performs three active interventions and one minimal intervention as a control group. The active interventions include gatekeeper training (QPR), awareness training on mental health promotion for adolescents, and screening for at-risk adolescents by health professionals. Structured questionnaires are utilized at baseline, 3- and 12-month follow-ups in order to assess changes. Discussion Although it has been reported that suicide-preventive interventions can be effective in decreasing suicidal behavior, well-documented and randomized studies are lacking. The effects of such interventions in terms of combating unhealthy lifestyles in young people, which often characterize suicidal individuals, have never been reported. We know that unhealthy and risk-taking behaviors are detrimental to individuals' current and future health. It is, therefore, crucial to test well-designed, longitudinal mental health-promoting and suicide-preventive interventions by evaluating the implications of such activities for reducing unhealthy and risk behaviors while concurrently promoting healthy ones. Trial registration The German Clinical Trials Register, DRKS00000214. PMID:20388196

Saving and empowering young lives in Europe (SEYLE): a randomized controlled trial.

PubMed

Wasserman, Danuta; Carli, Vladimir; Wasserman, Camilla; Apter, Alan; Balazs, Judit; Bobes, Julia; Bracale, Renata; Brunner, Romuald; Bursztein-Lipsicas, Cendrine; Corcoran, Paul; Cosman, Doina; Durkee, Tony; Feldman, Dana; Gadoros, Julia; Guillemin, Francis; Haring, Christian; Kahn, Jean-Pierre; Kaess, Michael; Keeley, Helen; Marusic, Dragan; Nemes, Bogdan; Postuvan, Vita; Reiter-Theil, Stella; Resch, Franz; Sáiz, Pilar; Sarchiapone, Marco; Sisask, Merike; Varnik, Airi; Hoven, Christina W

2010-04-13

There have been only a few reports illustrating the moderate effectiveness of suicide-preventive interventions in reducing suicidal behavior, and, in most of those studies, the target populations were primarily adults, whereas few focused on adolescents. Essentially, there have been no randomized controlled studies comparing the efficacy, cost-effectiveness and cultural adaptability of suicide-prevention strategies in schools. There is also a lack of information on whether suicide-preventive interventions can, in addition to preventing suicide, reduce risk behaviors and promote healthier ones as well as improve young people's mental health.The aim of the SEYLE project, which is funded by the European Union under the Seventh Framework Health Program, is to address these issues by collecting baseline and follow-up data on health and well-being among European adolescents and compiling an epidemiological database; testing, in a randomized controlled trial, three different suicide-preventive interventions; evaluating the outcome of each intervention in comparison with a control group from a multidisciplinary perspective; as well as recommending culturally adjusted models for promoting mental health and preventing suicidal behaviors. The study comprises 11,000 adolescents emitted from randomized schools in 11 European countries: Austria, Estonia, France, Germany, Hungary, Ireland, Israel, Italy, Romania, Slovenia and Spain, with Sweden serving as the scientific coordinating center. Each country performs three active interventions and one minimal intervention as a control group. The active interventions include gatekeeper training (QPR), awareness training on mental health promotion for adolescents, and screening for at-risk adolescents by health professionals. Structured questionnaires are utilized at baseline, 3- and 12-month follow-ups in order to assess changes. Although it has been reported that suicide-preventive interventions can be effective in decreasing suicidal behavior, well-documented and randomized studies are lacking. The effects of such interventions in terms of combating unhealthy lifestyles in young people, which often characterize suicidal individuals, have never been reported. We know that unhealthy and risk-taking behaviors are detrimental to individuals' current and future health. It is, therefore, crucial to test well-designed, longitudinal mental health-promoting and suicide-preventive interventions by evaluating the implications of such activities for reducing unhealthy and risk behaviors while concurrently promoting healthy ones. The German Clinical Trials Register, DRKS00000214.

14 CFR 25.145 - Longitudinal control.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Longitudinal control. 25.145 Section 25.145... control. (a) It must be possible, at any point between the trim speed prescribed in § 25.103(b)(6) and..., no change in trim control, or exertion of more than 50 pounds control force (representative of the...

14 CFR 25.145 - Longitudinal control.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Longitudinal control. 25.145 Section 25.145... control. (a) It must be possible, at any point between the trim speed prescribed in § 25.103(b)(6) and..., no change in trim control, or exertion of more than 50 pounds control force (representative of the...

Longitudinal Emergency Medical Technician Attributes and Demographic Study (LEADS) Design and Methodology.

PubMed

Levine, Roger

2016-12-01

The objective of this study is to describe the Longitudinal Emergency Medical Technician (EMT) Attributes and Demographic Study (LEADS) design, instrument development, pilot testing, sampling procedures, and data collection methodology. Response rates are provided, along with results of follow-up surveys of non-responders (NRs) and a special survey of Emergency Medical Services (EMS) professionals who were not nationally certified. Annual surveys from 1999 to 2008 were mailed out to a random, stratified sample of nationally registered EMT-Basics and Paramedics. Survey weights were developed to reflect each respondent's probability of selection. A special survey of NRs was mailed out to individuals who did not respond to the annual survey to estimate the probable extent and direction of response bias. Individuals who indicated they were no longer in the profession were mailed a special exit survey to determine their reasons for leaving EMS. Given the large number of comparisons between NR and regular (annual) survey respondents, it is not surprising that some statistically significant differences were found. In general, there were few differences. However, NRs tended to report higher annual EMS incomes, were younger, healthier, more physically fit, and were more likely to report that they were not practicing EMS. Comparisons of the nationally certified EMS professionals with EMS professionals who were not nationally certified indicated that nationally certified EMS providers were younger, had less EMS experiences, earned less, were more likely to be female and work for private EMS services, and less likely to work for fire-based services. These differences may reflect state and local policy and practice, since many states and local agencies do not require maintenance of national certification as a requirement to practice. When these differences were controlled for statistically, there were few systematic differences between non-nationally certified and nationally certified EMS professionals. The LEADS study is the only national, randomized, and longitudinal data source for studying EMS professionals in the United States. Although not without flaws, this study remains an excellent source of information about EMS provider demographics, attributes, attitudes, workplace issues and concerns, and how the profession has changed from 1999 to 2008. Levine R . Longitudinal Emergency Medical Technician Attributes and Demographic Study (LEADS) design and methodology. Prehosp Disaster Med. 2016;31(Suppl. 1):s7-s17.

Semiparametric Bayesian classification with longitudinal markers

PubMed Central

De la Cruz-Mesía, Rolando; Quintana, Fernando A.; Müller, Peter

2013-01-01

Summary We analyse data from a study involving 173 pregnant women. The data are observed values of the β human chorionic gonadotropin hormone measured during the first 80 days of gestational age, including from one up to six longitudinal responses for each woman. The main objective in this study is to predict normal versus abnormal pregnancy outcomes from data that are available at the early stages of pregnancy. We achieve the desired classification with a semiparametric hierarchical model. Specifically, we consider a Dirichlet process mixture prior for the distribution of the random effects in each group. The unknown random-effects distributions are allowed to vary across groups but are made dependent by using a design vector to select different features of a single underlying random probability measure. The resulting model is an extension of the dependent Dirichlet process model, with an additional probability model for group classification. The model is shown to perform better than an alternative model which is based on independent Dirichlet processes for the groups. Relevant posterior distributions are summarized by using Markov chain Monte Carlo methods. PMID:24368871

For God (or) country: the hydraulic relation between government instability and belief in religious sources of control.

PubMed

Kay, Aaron C; Shepherd, Steven; Blatz, Craig W; Chua, Sook Ning; Galinsky, Adam D

2010-11-01

It has been recently proposed that people can flexibly rely on sources of control that are both internal and external to the self to satisfy the need to believe that their world is under control (i.e., that events do not unfold randomly or haphazardly). Consistent with this, past research demonstrates that, when personal control is threatened, people defend external systems of control, such as God and government. This theoretical perspective also suggests that belief in God and support for governmental systems, although seemingly disparate, will exhibit a hydraulic relationship with one another. Using both experimental and longitudinal designs in Eastern and Western cultures, the authors demonstrate that experimental manipulations or naturally occurring events (e.g., electoral instability) that lower faith in one of these external systems (e.g., the government) lead to subsequent increases in faith in the other (e.g., God). In addition, mediation and moderation analyses suggest that specific concerns with order and structure underlie these hydraulic effects. Implications for the psychological, sociocultural, and sociopolitical underpinnings of religious faith, as well as system justification theory, are discussed.

Prevention of Alzheimer disease

PubMed Central

Scalco, Monica Zavaloni; van Reekum, Robert

2006-01-01

OBJECTIVE To review the evidence regarding prevention of Alzheimer disease (AD) in order to highlight the role of family medicine. QUALITY OF EVIDENCE Most of the evidence relating to prevention of AD is derived from observational (cross-sectional, case-control, or longitudinal) studies. Evidence from randomized controlled trials (RCTs) is available only for blood pressure control and for hormone replacement therapy for menopausal women. MAIN MESSAGE Many preventive approaches to AD have been identified, but no RCTs support their efficacy. Evidence from RCTs supports the effectiveness of blood pressure control in reducing incidence of AD, but demonstrates that postmenopausal women’s use of estrogen is ineffective in reducing it. Observational studies suggest that some preventive approaches, such as healthy lifestyle, ongoing education, regular physical activity, and cholesterol control, play a role in prevention of AD. These approaches can and should be used for every patient because they carry no significant risk. Currently, no effective pharmacologic interventions have been researched enough to support their use in prevention of AD. CONCLUSION Health professionals should educate patients, especially patients at higher risk of AD, about preventive strategies and potentially modifiable risk factors. PMID:16529393

Using Random Forest Models to Predict Organizational Violence

NASA Technical Reports Server (NTRS)

Levine, Burton; Bobashev, Georgly

2012-01-01

We present a methodology to access the proclivity of an organization to commit violence against nongovernment personnel. We fitted a Random Forest model using the Minority at Risk Organizational Behavior (MAROS) dataset. The MAROS data is longitudinal; so, individual observations are not independent. We propose a modification to the standard Random Forest methodology to account for the violation of the independence assumption. We present the results of the model fit, an example of predicting violence for an organization; and finally, we present a summary of the forest in a "meta-tree,"

Improving the Rank Precision of Population Health Measures for Small Areas with Longitudinal and Joint Outcome Models

PubMed Central

Athens, Jessica K.; Remington, Patrick L.; Gangnon, Ronald E.

2015-01-01

Objectives The University of Wisconsin Population Health Institute has published the County Health Rankings since 2010. These rankings use population-based data to highlight health outcomes and the multiple determinants of these outcomes and to encourage in-depth health assessment for all United States counties. A significant methodological limitation, however, is the uncertainty of rank estimates, particularly for small counties. To address this challenge, we explore the use of longitudinal and pooled outcome data in hierarchical Bayesian models to generate county ranks with greater precision. Methods In our models we used pooled outcome data for three measure groups: (1) Poor physical and poor mental health days; (2) percent of births with low birth weight and fair or poor health prevalence; and (3) age-specific mortality rates for nine age groups. We used the fixed and random effects components of these models to generate posterior samples of rates for each measure. We also used time-series data in longitudinal random effects models for age-specific mortality. Based on the posterior samples from these models, we estimate ranks and rank quartiles for each measure, as well as the probability of a county ranking in its assigned quartile. Rank quartile probabilities for univariate, joint outcome, and/or longitudinal models were compared to assess improvements in rank precision. Results The joint outcome model for poor physical and poor mental health days resulted in improved rank precision, as did the longitudinal model for age-specific mortality rates. Rank precision for low birth weight births and fair/poor health prevalence based on the univariate and joint outcome models were equivalent. Conclusion Incorporating longitudinal or pooled outcome data may improve rank certainty, depending on characteristics of the measures selected. For measures with different determinants, joint modeling neither improved nor degraded rank precision. This approach suggests a simple way to use existing information to improve the precision of small-area measures of population health. PMID:26098858

Bayesian inference for two-part mixed-effects model using skew distributions, with application to longitudinal semicontinuous alcohol data.

PubMed

Xing, Dongyuan; Huang, Yangxin; Chen, Henian; Zhu, Yiliang; Dagne, Getachew A; Baldwin, Julie

2017-08-01

Semicontinuous data featured with an excessive proportion of zeros and right-skewed continuous positive values arise frequently in practice. One example would be the substance abuse/dependence symptoms data for which a substantial proportion of subjects investigated may report zero. Two-part mixed-effects models have been developed to analyze repeated measures of semicontinuous data from longitudinal studies. In this paper, we propose a flexible two-part mixed-effects model with skew distributions for correlated semicontinuous alcohol data under the framework of a Bayesian approach. The proposed model specification consists of two mixed-effects models linked by the correlated random effects: (i) a model on the occurrence of positive values using a generalized logistic mixed-effects model (Part I); and (ii) a model on the intensity of positive values using a linear mixed-effects model where the model errors follow skew distributions including skew- t and skew-normal distributions (Part II). The proposed method is illustrated with an alcohol abuse/dependence symptoms data from a longitudinal observational study, and the analytic results are reported by comparing potential models under different random-effects structures. Simulation studies are conducted to assess the performance of the proposed models and method.

Comparing the Psychometric Properties of Two Physical Activity Self-Efficacy Instruments in Urban, Adolescent Girls: Validity, Measurement Invariance, and Reliability

PubMed Central

Voskuil, Vicki R.; Pierce, Steven J.; Robbins, Lorraine B.

2017-01-01

Aims: This study compared the psychometric properties of two self-efficacy instruments related to physical activity. Factorial validity, cross-group and longitudinal invariance, and composite reliability were examined. Methods: Secondary analysis was conducted on data from a group randomized controlled trial investigating the effect of a 17-week intervention on increasing moderate to vigorous physical activity among 5th–8th grade girls (N = 1,012). Participants completed a 6-item Physical Activity Self-Efficacy Scale (PASE) and a 7-item Self-Efficacy for Exercise Behaviors Scale (SEEB) at baseline and post-intervention. Confirmatory factor analyses for intervention and control groups were conducted with Mplus Version 7.4 using robust weighted least squares estimation. Model fit was evaluated with the chi-square index, comparative fit index, and root mean square error of approximation. Composite reliability for latent factors with ordinal indicators was computed from Mplus output using SAS 9.3. Results: Mean age of the girls was 12.2 years (SD = 0.96). One-third of the girls were obese. Girls represented a diverse sample with over 50% indicating black race and an additional 19% identifying as mixed or other race. Both instruments demonstrated configural invariance for simultaneous analysis of cross-group and longitudinal invariance based on alternative fit indices. However, simultaneous metric invariance was not met for the PASE or the SEEB instruments. Partial metric invariance for the simultaneous analysis was achieved for the PASE with one factor loading identified as non-invariant. Partial metric invariance was not met for the SEEB. Longitudinal scalar invariance was achieved for both instruments in the control group but not the intervention group. Composite reliability for the PASE ranged from 0.772 to 0.842. Reliability for the SEEB ranged from 0.719 to 0.800 indicating higher reliability for the PASE. Reliability was more stable over time in the control group for both instruments. Conclusions: Results suggest that the intervention influenced how girls responded to indicator items. Neither of the instruments achieved simultaneous metric invariance making it difficult to assess mean differences in PA self-efficacy between groups. PMID:28824487

Reducing self-objectification: are dissonance-based methods a possible approach?

PubMed Central

2013-01-01

Background Previous research has documented that self-objectification is associated with numerous negative outcomes including body shame, eating disorder (ED) pathology, and negative affect. This exploratory open study investigated whether or not an evidence-based body image improvement program that targets thin-ideal internalization in university women also reduces self-objectification. A second aim of the study was to determine if previous findings showing that body shame mediated the relationship between self-objectification and eating disorder pathology at a single time point (consistent with self-objectification theory) but did not mediate longitudinally (inconsistent with self-objectification theory) would be replicated in a new sample under novel conditions. Methods Ninety-six university women completed a peer-led dissonance-based intervention, along with assessment measures at pre-, post-intervention, 8-week and 8-month follow-up. To address the open trial nature of this study, a planned manipulation check was included to make sure that peer-led dissonance decreased thin-ideal internalization, body dissatisfaction, eating disorder pathology, and negative affect with effect sizes being similar to past randomized controlled trials. We hypothesized that all three subscales of the Objectified Body Consciousness Scale (i.e., self-surveillance, body shame, and appearance control beliefs) would be reduced. In addition, we hypothesized that body shame would mediate the relationship between self-objectification (i.e., self-surveillance) and eating disorder pathology at a both at a single time point and longitudinally. Results The planned manipulation check supported the interpretation that peer-led dissonance in this study largely yielded comparable changes to past controlled trials. In terms of changes in dependent variables, results supported all hypotheses with the exception of body shame, which remained unchanged. With regards to the mediation analyses, our first (cross-sectional) hypothesis but not our second (longitudinal) was supported. Conclusions Findings provide preliminary support for the use of dissonance interventions in reducing self-surveillance and body control beliefs. Results for body shame and the mediation analyses suggest that greater scrutiny of the body shame construct is warranted. PMID:24999392

Longitudinal assessment of excessive daytime sleepiness in early Parkinson's disease.

PubMed

Amara, Amy W; Chahine, Lama M; Caspell-Garcia, Chelsea; Long, Jeffrey D; Coffey, Christopher; Högl, Birgit; Videnovic, Aleksandar; Iranzo, Alex; Mayer, Geert; Foldvary-Schaefer, Nancy; Postuma, Ron; Oertel, Wolfgang; Lasch, Shirley; Marek, Ken; Simuni, Tanya

2017-08-01

Excessive daytime sleepiness (EDS) is common and disabling in Parkinson's disease (PD). Predictors of EDS are unclear, and data on biological correlates of EDS in PD are limited. We investigated clinical, imaging and biological variables associated with longitudinal changes in sleepiness in early PD. The Parkinson's Progression Markers Initiative is a prospective cohort study evaluating progression markers in participants with PD who are unmedicated at baseline (n=423) and healthy controls (HC; n=196). EDS was measured with the Epworth Sleepiness Scale (ESS). Clinical, biological and imaging variables were assessed for associations with EDS for up to 3 years. A machine learning approach (random survival forests) was used to investigate baseline predictors of incident EDS. ESS increased in PD from baseline to year 3 (mean±SD 5.8±3.5 to 7.55±4.6, p<0.0001), with no change in HC. Longitudinally, EDS in PD was associated with non-tremor dominant phenotype, autonomic dysfunction, depression, anxiety and probable behaviour disorder, but not cognitive dysfunction or motor severity. Dopaminergic therapy was associated with EDS at years 2 and 3, as dose increased. EDS was also associated with presynaptic dopaminergic dysfunction, whereas biofluid markers at year 1 showed no significant associations with EDS. A predictive index for EDS was generated, which included seven baseline characteristics, including non-motor symptoms and cerebrospinal fluid phosphorylated-tau/total-tau ratio. In early PD, EDS increases significantly over time and is associated with several clinical variables. The influence of dopaminergic therapy on EDS is dose dependent. Further longitudinal analyses will better characterise associations with imaging and biomarkers. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Anharmonic longitudinal motion of bases and dynamics of nonlinear excitation in DNA.

PubMed

Di Garbo, Angelo

2016-01-01

The dynamics of the transcription bubble in DNA is studied by using a nonlinear model in which torsional and longitudinal conformations of the biomolecule are coupled. In the absence of forcing and dissipation the torsional dynamics is described by a perturbed kink of the Sine-Gordon DNA model, while the longitudinal conformational energy propagate as phonons. It was found that for random initial conditions of the longitudinal conformational field the presence of the kink promotes the creation of phonons propagating along the chain axis. Moreover, the presence of forcing, describing the active role of RNA polymerase, determines in agreement to the experimental data a modulation of the velocity of the transcription bubble. Lastly, it was shown that the presence of dissipation impacts the dynamic of the phonon by reducing the amplitude of the corresponding conformational field. On the contrary, dissipation and forcing modulate the velocity of the transcription bubble alone.

Heller myotomy versus Heller myotomy with Dor fundoplication for achalasia: long-term symptomatic follow-up of a prospective randomized controlled trial.

PubMed

Kummerow Broman, Kristy; Phillips, Sharon E; Faqih, Adil; Kaiser, Joan; Pierce, Richard A; Poulose, Benjamin K; Richards, William O; Sharp, Kenneth W; Holzman, Michael D

2018-04-01

Our prior randomized controlled trial of Heller myotomy alone versus Heller plus Dor fundoplication for achalasia from 2000 to 2004 demonstrated comparable postoperative resolution of dysphagia but less gastroesophageal reflux after Heller plus Dor. Patient-reported outcomes are needed to determine whether the findings are sustained long-term. We actively engaged participants from the prior randomized cohort, making up to six contact attempts per person using telephone, mail, and electronic messaging. We collected patient-reported measures of dysphagia and gastroesophageal reflux using the Dysphagia Score and the Gastroesophageal Reflux Disease-Health-Related Quality of Life (GERD-HRQL) instrument. Patient-reported re-interventions for dysphagia were verified by obtaining longitudinal medical records. Among living participants, 27/41 (66%) were contacted and all completed the follow-up study at a mean of 11.8 years postoperatively. Median Dysphagia Scores and GERD-HRQL scores were slightly worse for Heller than Heller plus Dor but were not statistically different (6 vs 3, p = 0.08 for dysphagia, 15 vs 13, p = 0.25 for reflux). Five patients in the Heller group and 6 in Heller plus Dor underwent re-intervention for dysphagia with most occurring more than five years postoperatively. One patient in each group underwent redo Heller myotomy and subsequent esophagectomy. Nearly all patients (96%) would undergo operation again. Long-term patient-reported outcomes after Heller alone and Heller plus Dor for achalasia are comparable, providing support for either procedure.

Comparing meta-analysis and ecological-longitudinal analysis in time-series studies. A case study of the effects of air pollution on mortality in three Spanish cities.

PubMed

Saez, M; Figueiras, A; Ballester, F; Pérez-Hoyos, S; Ocaña, R; Tobías, A

2001-06-01

The objective of this paper is to introduce a different approach, called the ecological-longitudinal, to carrying out pooled analysis in time series ecological studies. Because it gives a larger number of data points and, hence, increases the statistical power of the analysis, this approach, unlike conventional ones, allows the complementation of aspects such as accommodation of random effect models, of lags, of interaction between pollutants and between pollutants and meteorological variables, that are hardly implemented in conventional approaches. The approach is illustrated by providing quantitative estimates of the short-term effects of air pollution on mortality in three Spanish cities, Barcelona, Valencia and Vigo, for the period 1992-1994. Because the dependent variable was a count, a Poisson generalised linear model was first specified. Several modelling issues are worth mentioning. Firstly, because the relations between mortality and explanatory variables were non-linear, cubic splines were used for covariate control, leading to a generalised additive model, GAM. Secondly, the effects of the predictors on the response were allowed to occur with some lag. Thirdly, the residual autocorrelation, because of imperfect control, was controlled for by means of an autoregressive Poisson GAM. Finally, the longitudinal design demanded the consideration of the existence of individual heterogeneity, requiring the consideration of mixed models. The estimates of the relative risks obtained from the individual analyses varied across cities, particularly those associated with sulphur dioxide. The highest relative risks corresponded to black smoke in Valencia. These estimates were higher than those obtained from the ecological-longitudinal analysis. Relative risks estimated from this latter analysis were practically identical across cities, 1.00638 (95% confidence intervals 1.0002, 1.0011) for a black smoke increase of 10 microg/m(3) and 1.00415 (95% CI 1.0001, 1.0007) for a increase of 10 microg/m(3) of sulphur dioxide. Because the statistical power is higher than in the individual analysis more interactions were statistically significant, especially those among air pollutants and meteorological variables. Air pollutant levels were related to mortality in the three cities of the study, Barcelona, Valencia and Vigo. These results were consistent with similar studies in other cities, with other multicentric studies and coherent with both, previous individual, for each city, and multicentric studies for all three cities.

Tracking control of WMRs on loose soil based on mixed H2/H∞ control with longitudinal slip ratio estimation

NASA Astrophysics Data System (ADS)

Gao, Haibo; Chen, Chao; Ding, Liang; Li, Weihua; Yu, Haitao; Xia, Kerui; Liu, Zhen

2017-11-01

Wheeled mobile robots (WMRs) often suffer from the longitudinal slipping when moving on the loose soil of the surface of the moon during exploration. Longitudinal slip is the main cause of WMRs' delay in trajectory tracking. In this paper, a nonlinear extended state observer (NESO) is introduced to estimate the longitudinal velocity in order to estimate the slip ratio and the derivative of the loss of velocity which are used in modelled disturbance compensation. Owing to the uncertainty and disturbance caused by estimation errors, a multi-objective controller using the mixed H2/H∞ method is employed to ensure the robust stability and performance of the WMR system. The final inputs of the trajectory tracking consist of the feedforward compensation, compensation for the modelled disturbances and designed multi-objective control inputs. Finally, the simulation results demonstrate the effectiveness of the controller, which exhibits a satisfactory tracking performance.

Changing Friend Selection in Middle School: A Social Network Analysis of a Randomized Intervention Study Designed to Prevent Adolescent Problem Behavior.

PubMed

DeLay, Dawn; Ha, Thao; Van Ryzin, Mark; Winter, Charlotte; Dishion, Thomas J

2016-04-01

Adolescent friendships that promote problem behavior are often chosen in middle school. The current study examines the unintended impact of a randomized school-based intervention on the selection of friends in middle school, as well as on observations of deviant talk with friends 5 years later. Participants included 998 middle school students (526 boys and 472 girls) recruited at the onset of middle school (age 11-12 years) from three public middle schools participating in the Family Check-up model intervention. The current study focuses only on the effects of the SHAPe curriculum-one level of the Family Check-up model-on friendship choices. Participants nominated friends and completed measures of deviant peer affiliation. Approximately half of the sample (n = 500) was randomly assigned to the intervention, and the other half (n = 498) comprised the control group within each school. The results indicate that the SHAPe curriculum affected friend selection within school 1 but not within schools 2 or 3. The effects of friend selection in school 1 translated into reductions in observed deviancy training 5 years later (age 16-17 years). By coupling longitudinal social network analysis with a randomized intervention study, the current findings provide initial evidence that a randomized public middle school intervention can disrupt the formation of deviant peer groups and diminish levels of adolescent deviance 5 years later.

F-16 Simulator for Man-in-the-Loop Testing of Aircraft Control Systems (SIMTACS).

DTIC Science & Technology

1987-12-01

Figures Figure Page 2.1. General Hardware Arrangement..................... 12 3.1. DFCS Longitudinal Control Block Diagram .... 21 3.2. DFCS Gain...Functions for Longitudinal Control 22 3.3. DFCS Lateral-Directional Control Block Diagram........................................... 23 3.4. DFCS Gain...Functions for Lateral-Directional Control........................................... 24 3.5. DFCS Control Surface Mixer....................... 25 3.6

Vitamin D levels and risk for periodontal disease: A systematic review.

PubMed

Pinto, J P N S; Goergen, J; Muniz, F W M G; Haas, A N

2018-06-01

To evaluate the existing evidence supporting or refuting the following questions: (i) Do patients with lower vitamin D levels have higher risk for periodontal disease? (ii) Are periodontal treatment outcomes improved by the adjuvant supplementation of vitamin D or by elevated serum vitamin D levels? MEDLINE, SCOPUS, EMBASE and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched up to September 2017. Studies were included if they had measured serum vitamin D levels or vitamin D intake and any periodontal parameter. Overall, 27 studies were included (13 cross-sectional studies, 6 case-control studies, 5 cohort studies, 2 randomized clinical trials and 1 case series study). Sixty-five percent of the cross-sectional studies reported significant associations between low vitamin D levels and poor periodontal parameters. None of the observational longitudinal studies found that periodontal disease progression could be attributed to lower vitamin D levels. No interventional studies that evaluated the use of vitamin D supplementation as a solely adjuvant to periodontal treatment was found. No meta-analysis was performed due to high variability across studies. The data to support or refute the association between vitamin D levels and periodontal disease are inconclusive at the moment. More rigorously designed longitudinal studies with standardized definitions of periodontal disease and vitamin D are necessary. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A randomized waitlist-controlled trial of culturally sensitive relationship education for male same-sex couples.

PubMed

Whitton, Sarah W; Weitbrecht, Eliza M; Kuryluk, Amanda D; Hutsell, David W

2016-09-01

Relationship education, effective in improving relationship quality among different-sex couples, represents a promising and nonstigmatizing approach to promoting the health and stability of same-sex couples. A new culturally sensitive relationship education program was developed specifically for male same-sex couples, which includes adaptations of evidence-based strategies to build core relationship skills (e.g., communication skills training) and newly developed content to address unique challenges faced by this group (e.g., discrimination; low social support). A small randomized waitlist-control trial (N = 20 couples) was conducted to evaluate the program. To assess program efficacy, dyadic longitudinal data (collected at pre- and postprogram and 3-month follow-up) were analyzed using multilevel models that accounted for nonindependence in data from indistinguishable dyads. Results indicated significant program effects in comparison to waitlist controls on couple constructive and destructive communication, perceived stress, and relationship satisfaction. Gains in each of these areas were maintained at 3-month follow-up. Although there was no evidence of within-person program effects on social support, satisfaction, or relationship instability immediately postprogram, all 3 showed within-person improvements by follow-up. Ratings of program satisfaction were high. In summary, study findings support the feasibility, acceptability, and initial efficacy of the program and highlight the potential value of culturally sensitive adaptations of relationship education for same-sex couples. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Effect of poverty reduction program on nutritional status of the extreme poor in Bangladesh.

PubMed

Jalal, Chowdhury S B; Frongillo, Edward A

2013-12-01

Poverty alleviation programs for the extreme poor improve participants' economic status and may impact other important outcomes that are seldom evaluated. A program targeted to the extreme poor by BRAG, a development organization in Bangladesh, has been successful in significantly alleviating extreme poverty. We hypothesized that the program also improved the nutritional status of women and preschool children. A nonequivalent control, pre- and posttest quasi-experimental design that was longitudinal at the village level was used to test the hypotheses. Data were collected from a random sample of 4,131 children and 3,551 women from 3,409 households in 159 villages of 3 northern districts of Bangladesh in 2002 and 2006. Linear mixed random-intercept models accounted for clustering effects and potential confounders. The weight-for-height of children between 24 and 35 months of age from program households was significantly higher (p < .05) than that of children from control households. We found no significant differences between control and program households in three other growth and body-composition indicators in three other age categories of preschool children or in women. These results are important, as this is a large-scale program that has already been extended to more than half the country. The findings will contribute to judging the cost-benefit and cost-effectiveness of the program and in garnering support for the expansion of such programs.

Ankle manual therapy for individuals with post-acute ankle sprains: description of a randomized, placebo-controlled clinical trial

PubMed Central

2010-01-01

Background Ankle sprains are common within the general population and can result in prolonged disablement. Limited talocrural dorsiflexion range of motion (DF ROM) is a common consequence of ankle sprain. Limited talocrural DF ROM may contribute to persistent symptoms, disability, and an elevated risk for re-injury. As a result, many health care practitioners use hands-on passive procedures with the intention of improving talocrural joint DF ROM in individuals following ankle sprains. Dosage of passive hands-on procedures involves a continuum of treatment speeds. Recent evidence suggests both slow- and fast-speed treatments may be effective to address disablement following ankle sprains. However, these interventions have yet to be longitudinally compared against a placebo study condition. Methods/Design We developed a randomized, placebo-controlled clinical trial designed to test the hypotheses that hands-on treatment procedures administered to individuals following ankle sprains during the post-acute injury period can improve short-, intermediate-, and long-term disablement, as well as reduce the risk for re-injury. Discussion This study is designed to measure the clinical effects of hands-on passive stretching treatment procedures directed to the talocrural joint that vary in treatment speed during the post-acute injury period, compared to hands-on placebo control intervention. Trial Registration http://www.clinicaltrials.gov identifier NCT00888498. PMID:20958995

Reducing Violence by Transforming Neighborhoods: A Natural Experiment in Medellín, Colombia

PubMed Central

Cerdá, Magdalena; Morenoff, Jeffrey D.; Hansen, Ben B.; Tessari Hicks, Kimberly J.; Duque, Luis F.; Restrepo, Alexandra; Diez-Roux, Ana V.

2012-01-01

Neighborhood-level interventions provide an opportunity to better understand the impact that neighborhoods have on health. In 2004, municipal authorities in Medellín, Colombia, built a public transit system to connect isolated low-income neighborhoods to the city’s urban center. Transit-oriented development was accompanied by municipal investment in neighborhood infrastructure. In this study, the authors examined the effects of this exogenous change in the built environment on violence. Neighborhood conditions and violence were assessed in intervention neighborhoods (n = 25) and comparable control neighborhoods (n = 23) before (2003) and after (2008) completion of the transit project, using a longitudinal sample of 466 residents and homicide records from the Office of the Public Prosecutor. Baseline differences between these groups were of the same magnitude as random assignment of neighborhoods would have generated, and differences that remained after propensity score matching closely resembled imbalances produced by paired randomization. Permutation tests were used to estimate differential change in the outcomes of interest in intervention neighborhoods versus control neighborhoods. The decline in the homicide rate was 66% greater in intervention neighborhoods than in control neighborhoods (rate ratio = 0.33, 95% confidence interval: 0.18, 0.61), and resident reports of violence decreased 75% more in intervention neighborhoods (odds ratio = 0.25, 95% confidence interval 0.11, 0.67). These results show that interventions in neighborhood physical infrastructure can reduce violence. PMID:22472117

Antiretroviral treatment is associated with iron deficiency in HIV-infected Malawian women that is mitigated with supplementation, but is not associated with infant iron deficiency during 24 weeks of exclusive breastfeeding

PubMed Central

Widen, Elizabeth M; Bentley, Margaret E; Chasela, Charles S; Kayira, Dumbani; Flax, Valerie L; Kourtis, Athena P; Ellington, Sascha R; Kacheche, Zebrone; Tegha, Gerald; Jamieson, Denise J; van der Horst, Charles M; Allen, Lindsay H; Shahab-Ferdows, Setareh; Adair, Linda S

2015-01-01

Objective In resource-limited settings without safe alternatives to breastfeeding, the WHO recommends exclusive breastfeeding and antiretroviral (ARV) prophylaxis. Given the high prevalence of anemia among HIV-infected women, mothers and their infants (via fetal iron accretion) may be at risk of iron deficiency. We assessed the effects of maternal micronutrient-fortified lipid-based nutrient supplements (LNS) and maternal ARV treatment or infant ARV prophylaxis on maternal and infant iron status during exclusive breastfeeding from birth to 24 weeks. Methods The Breastfeeding, Antiretrovirals, and Nutrition Study was a randomized controlled trial conducted in Lilongwe, Malawi from 2004-2010. HIV-infected mothers (CD4>200 cells/ul) and their infants were randomly assigned to 28-week interventions: maternal-LNS/maternal-ARV (n=424), maternal-LNS/infant-ARV (n=426), maternal-LNS (n=334), maternal-ARV (n=425), infant-ARV (n=426), or control (n=334). Longitudinal models tested intervention effects on hemoglobin (Hb). In a subsample (n=537) with multiple iron indicators, intervention effects on Hb, transferrin receptors (TfR) and ferritin were tested with linear and Poisson regression. Results In longitudinal models, LNS effects on maternal and infant Hb were minimal. In subsample mothers, maternal ARVs were associated with tissue iron depletion (TfR>8.3 mg/L) (Risk ratio (RR): 3.1, p<0.01), but not in ARV-treated mothers receiving LNS (p=0.17). LNS without ARVs, was not associated with iron deficiency or anemia (p>0.1). In subsample infants, interventions were not associated with impaired iron status (all p-values>0.1). Conclusions Maternal ARV treatment with protease inhibitors is associated with maternal tissue iron depletion; but LNS mitigates adverse effects. ARVs do not appear to influence infant iron status; however, extended use needs to be evaluated. PMID:25723140

Relationship Between Attitudes and Beliefs and Physical Activity in Older Adults With Knee Pain: Secondary Analysis of a Randomized Controlled Trial.

PubMed

Quicke, Jonathan G; Foster, Nadine E; Ogollah, Reuben O; Croft, Peter R; Holden, Melanie A

2017-08-01

To investigate how attitudes and beliefs about exercise relate to physical activity behavior in older adults with knee pain attributable to osteoarthritis (OA). We conducted secondary data analyses of a randomized controlled trial of exercise interventions (ISRCTN: 93634563). Participants were adults ≥45 years old with knee pain attributable to OA (n = 514). Crude and adjusted cross-sectional and longitudinal associations between baseline Self-Efficacy for Exercise (SEE), Positive Outcome Expectations for Exercise (POEE), Negative Outcome Expectations for Exercise scores, and physical activity level, at baseline, 3 months, and 6 months (measured by self-report using the Physical Activity Scale for the Elderly [PASE]), and important increases in physical activity level (from baseline to 6-month followup) were investigated using multiple linear and logistic regression. Cross-sectional associations were found between SEE and PASE scores (β = 4.14 [95% confidence interval (95% CI) 0.26, 8.03]) and POEE and PASE scores (β = 16.71 [95% CI 1.87, 31.55]), adjusted for sociodemographic and clinical covariates. Longitudinal associations were found between baseline SEE and PASE scores at 3 months (β = 4.95 [95% CI 1.02, 8.87]) and 6 months β = 3.71 (0.26, 7.16), and baseline POEE and PASE at 3 months (β = 34.55 [95% CI 20.13, 48.97]) and 6 months (β = 25.74 [95% CI 11.99, 39.49]), adjusted for baseline PASE score and intervention arm. However, no significant associations with important increases in physical activity level were found. Greater exercise self-efficacy and more positive exercise outcome expectations were associated with higher current and future physical activity levels. These may be targets for interventions aimed at increasing physical activity. © 2017 The Authors. Arthritis Care & Research published by Wiley Periodicals, Inc. on behalf of American College of Rheumatology.

Relationship Between Attitudes and Beliefs and Physical Activity in Older Adults With Knee Pain: Secondary Analysis of a Randomized Controlled Trial

PubMed Central

Foster, Nadine E.; Ogollah, Reuben O.; Croft, Peter R.; Holden, Melanie A.

2017-01-01

Objective To investigate how attitudes and beliefs about exercise relate to physical activity behavior in older adults with knee pain attributable to osteoarthritis (OA). Methods We conducted secondary data analyses of a randomized controlled trial of exercise interventions (ISRCTN: 93634563). Participants were adults ≥45 years old with knee pain attributable to OA (n = 514). Crude and adjusted cross‐sectional and longitudinal associations between baseline Self‐Efficacy for Exercise (SEE), Positive Outcome Expectations for Exercise (POEE), Negative Outcome Expectations for Exercise scores, and physical activity level, at baseline, 3 months, and 6 months (measured by self‐report using the Physical Activity Scale for the Elderly [PASE]), and important increases in physical activity level (from baseline to 6‐month followup) were investigated using multiple linear and logistic regression. Results Cross‐sectional associations were found between SEE and PASE scores (β = 4.14 [95% confidence interval (95% CI) 0.26, 8.03]) and POEE and PASE scores (β = 16.71 [95% CI 1.87, 31.55]), adjusted for sociodemographic and clinical covariates. Longitudinal associations were found between baseline SEE and PASE scores at 3 months (β = 4.95 [95% CI 1.02, 8.87]) and 6 months β = 3.71 (0.26, 7.16), and baseline POEE and PASE at 3 months (β = 34.55 [95% CI 20.13, 48.97]) and 6 months (β = 25.74 [95% CI 11.99, 39.49]), adjusted for baseline PASE score and intervention arm. However, no significant associations with important increases in physical activity level were found. Conclusion Greater exercise self‐efficacy and more positive exercise outcome expectations were associated with higher current and future physical activity levels. These may be targets for interventions aimed at increasing physical activity. PMID:27696795

A randomized longitudinal dietary intervention study during pregnancy: effects on fish intake, phospholipids, and body composition.

PubMed

Bosaeus, Marja; Hussain, Aysha; Karlsson, Therese; Andersson, Louise; Hulthén, Lena; Svelander, Cecilia; Sandberg, Ann-Sofie; Larsson, Ingrid; Ellegård, Lars; Holmäng, Agneta

2015-01-02

Fish and meat intake may affect gestational weight gain, body composition and serum fatty acids. We aimed to determine whether a longitudinal dietary intervention during pregnancy could increase fish intake, affect serum phospholipid fatty acids, gestational weight gain and body composition changes during pregnancy in women of normal weight participating in the Pregnancy Obesity Nutrition and Child Health study. A second aim was to study possible effects in early pregnancy of fish intake and meat intake, respectively, on serum phospholipid fatty acids, gestational weight gain, and body composition changes during pregnancy. In this prospective, randomized controlled study, women were allocated to a control group or to a dietary counseling group that focused on increasing fish intake. Fat mass and fat-free mass were measured by air-displacement plethysmography. Reported intake of fish and meat was collected from a baseline population and from a subgroup of women who participated in each trimester of their pregnancies. Serum levels of phospholipid arachidonic acid (s-ARA), eicosapentaenoic acid (s-EPA), and docosahexaenoic acid (s-DHA) were measured during each trimester. Weekly fish intake increased only in the intervention group (n = 18) from the first to the second trimester (median difference 113 g, p = 0.03) and from the first to the third trimester (median difference 75 g, p = 0.01). In the first trimester, fish intake correlated with s-EPA (r = 0.36, p = 0.002, n = 69) and s-DHA (r = 0.34, p = 0.005, n = 69), and meat intake correlated with s-ARA (r = 0.28, p = 0.02, n = 69). Fat-free mass gain correlated with reported meat intake in the first trimester (r = 0.39, p = 0.01, n = 45). Dietary counseling throughout pregnancy could help women increase their fish intake. Intake of meat in early pregnancy may increase the gain in fat-free mass during pregnancy.

Two-Year Longitudinal Analysis of a Cluster Randomized Trial of Physical Activity Promotion by General Practitioners

PubMed Central

Grandes, Gonzalo; Sanchez, Alvaro; Montoya, Imanol; Ortega Sanchez-Pinilla, Ricardo; Torcal, Jesús

2011-01-01

Background We evaluate the effectiveness of a physical activity promotion programme carried out by general practitioners with inactive patients in routine care. Methods and Findings Pragmatic, cluster randomised clinical trial conducted in eleven public primary care centres in Spain. Fifty-six general practitioners (GPs) were randomly assigned to intervention (29) or standard care (27) groups. They assessed the physical activity level of a systematic sample of patients in routine practice and recruited 4317 individuals (2248 intervention and 2069 control) who did not meet minimum physical activity recommendations. Intervention GPs provided advice to all patients and a physical activity prescription to the subgroup attending an additional appointment (30%). A third of these prescriptions were opportunistically repeated. Control GPs provided standard care. Primary outcome measure was the change in self-reported physical activity from baseline to six, 12 and 24 months. Secondary outcomes included cardiorespiratory fitness and health-related quality of life. A total of 3691 patients (85%) were included in the longitudinal analysis and overall trends over the whole 24 month follow-up were significantly better in the intervention group (p<0.01). The greatest differences with the control group were observed at six months (adjusted difference 1.7 MET*hr/wk [95% CI, 0.8 to 2.6], 25 min/wk [95% CI, 11.3 to 38.4], and a 5.3% higher percentage of patients meeting minimum recommendations [95% CI: 2.1% to 8.8%] NNT = 19). These differences were not statistically significant at 12 and 24 months. No differences were found in secondary outcomes. A significant difference was maintained until 24 months in the proportion of patients achieving minimum recommendation in the subgroup that received a repeat prescription (adjusted difference 10.2%, 95% CI 1.5% to 19.4%). Conclusions General practitioners are effective at increasing the level of physical activity among their inactive patients during the initial six-months of an intervention but this effect wears off at 12 and 24 months. Only in the subgroup of patients receiving repeat prescriptions of physical activity is the effect maintained in long-term. Trial Registration clinicaltrials.gov NCT00131079 PMID:21479243

Cognitive Training Sustainably Improves Executive Functioning in Middle-Aged Industry Workers Assessed by Task Switching: A Randomized Controlled ERP Study

PubMed Central

Gajewski, Patrick D.; Freude, Gabriele; Falkenstein, Michael

2017-01-01

Recently, we reported results of a cross-sectional study investigating executive functions in dependence of aging and type of work. That study showed deficits in performance and electrophysiological activity in middle-aged workers with long-term repetitive and unchallenging work. Based on these findings, we conducted a longitudinal study that aimed at ameliorating these cognitive deficits by means of a trainer-guided cognitive training (CT) in 57 further middle-aged workers with repetitive type of work from the same factory. This study was designed as a randomized controlled trail with pre- (t1), post- (t2), and a 3-month follow-up (t3) measure. The waiting control group was trained between t2 and t3. The training lasted 3 months (20 sessions) and was evaluated with the same task switching paradigm used in the previous cross-sectional study. The CT improved performance in accuracy at the behavioral level and affected the electrophysiological correlates of retrieval of stimulus-response sets (P2), response selection (N2), and error detection (Ne), thus unveiling the neuronal background of the behavioral effects. The same training effects were observed in the waiting control group after CT at t3. Moreover, at t3, most of the behavioral and electrophysiological training-induced changes were found stable. Hence, CT appears to be an important intervention for compensating cognitive deficits in executive functions in middle-aged employees with cognitively unchallenging work. PMID:28275347

Assessment of the effect of pelvic floor exercises on pelvic floor muscle strength using ultrasonography in patients with urinary incontinence: a prospective randomized controlled trial

PubMed Central

Tosun, Ozge Celiker; Solmaz, Ulas; Ekin, Atalay; Tosun, Gokhan; Gezer, Cenk; Ergenoglu, Ahmet Mete; Yeniel, Ahmet Ozgur; Mat, Emre; Malkoc, Mehtap; Askar, Niyazi

2016-01-01

[Purpose] The aim of this study was to evaluate whether the effect of pelvic floor exercises on pelvic floor muscle strength could be detected via ultrasonography in patients with urinary incontinence. [Subjects and Methods] Of 282 incontinent patients, 116 participated in the study and were randomly divided into a pelvic floor muscle training (n=65) group or control group (n=51). The pelvic floor muscle training group was given pelvic floor exercise training for 12 weeks. Both groups were evaluated at the beginning of the study and after 12 weeks. Abdominal ultrasonography measurements in transverse and longitudinal planes, the PERFECT scheme, perineometric evaluation, the stop test, the stress test, and the pad test were used to assess pelvic floor muscle strength in all cases. [Results] After training, the PERFECT, perineometry and transabdominal ultrasonography measurements were found to be significantly improved, and the stop test and pad test results were significantly decreased in the pelvic floor muscle training group, whereas no difference was observed in the control group. There was a positive correlation between the PERFECT force measurement scale and ultrasonography force measurement scale before and after the intervention in the control and pelvic floor muscle training groups (r=0.632 and r=0.642, respectively). [Conclusion] Ultrasonography can be used as a noninvasive method to identify the change in pelvic floor muscle strength with exercise training. PMID:27065519

The effect of massage on heart rate variability in preterm infants

PubMed Central

Smith, SL.; Lux, R.; Haley, S.; Slater, H.; Beechy, J.; Moyer-Mileur, LJ.

2012-01-01

Objective To test the hypothesis that massage would improve autonomic nervous system (ANS) function as measured by heart rate variability (HRV) in preterm infants. Study Design Medically stable, 29- to 32-week preterm infants (17 massage, 20 control) were enrolled in a masked, randomized longitudinal study. Licensed massage therapists provided the massage or control condition twice a day for 4 weeks. Weekly HRV, a measure of ANS development and function, was analyzed using SPSS generalized estimating equations. Results Infant characteristics were similar between groups. HRV improved in massaged infants but not in the control infants (P<0.05). Massaged males had a greater improvement in HRV than females (P<0.05). HRV in massaged infants was on a trajectory comparable to term-born infants by study completion. Conclusion Massage-improved HRV in a homogeneous sample of hospitalized, medically stable, preterm male infants and may improve infant response to exogenous stressors. We speculate that massage improves ANS function in these infants. PMID:22538325

A spiritual-hypnosis assisted treatment of children with PTSD after the 2002 Bali terrorist attack.

PubMed

Lesmana, C B J; Suryani, L K; Jensen, G D; Tiliopoulos, Niko

2009-07-01

The aim of this study was to assess the effectiveness of a spiritual-hypnosis assisted therapy (SHAT) for treatment of posttraumatic stress disorder (PTSD) in children. All children, age 6-12 years (N=226; 52.7% females), who experienced the terrorist bomb blasts in Bali in 2002, and subsequently were diagnosed with PTSD were studied, through a longitudinal, quasi-experimental (pre-post test), single-blind, randomized control design. Of them, 48 received group SHAT (treatment group), and 178 did not receive any therapy (control group). Statistically significant results showed that SHAT produced a 77.1% improvement rate, at a two-year follow up, compared to 24% in the control group, while at the same time, the mean PTSD symptom score differences were significantly lower in the former group. We conclude that the method of spiritual-hypnosis is highly effective, economic, and easily implemented, and has a potential for therapy of PTSD in other cultures or other catastrophic life-threatening events.

A longitudinal experimental study comparing the effectiveness of happiness-enhancing strategies in Anglo Americans and Asian Americans.

PubMed

Boehm, Julia K; Lyubomirsky, Sonja; Sheldon, Kennon M

2011-11-01

Growing evidence suggests that well-being interventions can be effective. However, it is unclear whether happiness-increasing practices are equally effective for individuals from different cultural backgrounds. To investigate this question, Anglo Americans and predominantly foreign-born Asian Americans were randomly assigned to express optimism, convey gratitude, or list their past experiences (control group). Multilevel analyses indicated that participants in the optimism and gratitude conditions reported enhanced life satisfaction relative to those in the control condition. However, Anglo Americans in the treatment conditions demonstrated larger increases in life satisfaction relative to Asian Americans, while both cultural groups in the control condition showed the least improvement. These results are consistent with the idea that the value individualist cultures place on self-improvement and personal agency bolsters the efforts of Anglo Americans to become more satisfied, whereas collectivist cultures' de-emphasis of self-focus and individual goals interferes with the efforts of Asian Americans to pursue enhanced well-being.

Promoting employee health by integrating health protection, health promotion, and continuous improvement: a longitudinal quasi-experimental intervention study.

PubMed

von Thiele Schwarz, Ulrica; Augustsson, Hanna; Hasson, Henna; Stenfors-Hayes, Terese

2015-02-01

To test the effects of integrating health protection and health promotion with a continuous improvement system (Kaizen) on proximal employee outcomes (health promotion, integration, and Kaizen) and distal outcomes (workability, productivity, self-rated health and self-rated sickness absence). Twelve units in a county hospital in Sweden were randomized to control or intervention groups using a quasiexperimental study design. All staff (approximately 500) provided self-ratings in questionnaires at baseline, and a 12- and 24-month follow-up (response rate, 79% to 87.5%). There was a significant increase in the proximal outcomes over time in the intervention group compared with the control group, and a trend toward improvement in the distal outcomes workability and productivity. Integration seems to promote staff engagement in health protection and promotion, as well as to improve their understanding of the link between work and health.

An Efficacy Trial of Carescapes: Home-Based Child-Care Practices and Children's Social Outcomes.

PubMed

Rusby, Julie C; Jones, Laura B; Crowley, Ryann; Smolkowski, Keith

2016-07-01

This study reported findings from a longitudinal randomized controlled trial of Carescapes, a professional development program for home-based child-care providers in promoting children's social competence. Participants included 134 child-care providers and 310 children, ages 3-5 years, in Oregon. The Carescapes intervention group made significant improvements in observed caregiver responsiveness and monitoring, and showed decreased caregiver-reported child problem behavior and improved parent-reported peer relationships compared to the control group. Increased caregiver-reported cooperation skills were found for the intervention group at follow-up. No differences in condition were found for kindergarten teacher-reported social-behavioral, classroom, and academic skills. Moderation effects on children's behavior and peer relations were found for child age and exposure to the intervention child care. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

A longitudinal examination of factors associated with social support satisfaction among HIV-positive young Black men who have sex with men.

PubMed

McCullagh, Charlotte; Quinn, Katherine; Voisin, Dexter R; Schneider, John

2017-12-01

This study examined the long-term predictors of social support satisfaction among HIV-positive young Black men who have sex with men (YBMSM). Data were collected across three waves between October 2012 and November 2014 as part of the baseline assessment from Project nGage, a preliminary efficacy randomized control study examining the role of social support in improving HIV care among YBMSM. The sample included 92 YBMSM aged 18-29. Major results controlling for age, education and intervention effects indicated that psychological health, social network size, and education at baseline predicted differences in social support satisfaction at Wave 3, with no significant effects based on length of HIV diagnosis. Therefore, interventions that are intended to promote the quality of life for YBMSM and their engagement and retention in HIV care must focus on their psychological health concerns and network size.

Building better bones in childhood: a randomized controlled study to test the efficacy of a dietary intervention program to increase calcium intake.

PubMed

Weber, D R; Stark, L J; Ittenbach, R F; Stallings, V A; Zemel, B S

2017-06-01

Many children do not consume the recommended daily allowance of calcium. Inadequate calcium intake in childhood may limit bone accrual. The objective of this study was to determine if a behavioral modification and nutritional education (BM-NE) intervention improved dietary calcium intake and bone accrual in children. 139 (86 female) healthy children, 7-10 years of age, were enrolled in this randomized controlled trial conducted over 36 months. Participants randomized to the BM-NE intervention attended five sessions over a 6-week period designed to increase calcium intake to 1500 mg/day. Participants randomized to the usual care (UC) group received a single nutritional counseling session. The Calcium Counts Food Frequency Questionnaire was used to assess calcium intake; dual energy X-ray absorptiometry was used to assess areal bone mineral density (aBMD) and bone mineral content (BMC). Longitudinal mixed effects models were used to assess for an effect of the intervention on calcium intake, BMC and aBMD. BM-NE participants had greater increases in calcium intake that persisted for 12 months following the intervention compared with UC. The intervention had no effect on BMC or aBMD accrual. Secondary analyses found a negative association between calcium intake and adiposity such that greater calcium intake was associated with lesser gains in body mass index and fat mass index. A family-centered BM-NE intervention program in healthy children was successful in increasing calcium intake for up to 12 months but had no effect on bone accrual. A beneficial relationship between calcium intake and adiposity was observed and warrants future study.

Evaluation of a cancer patient navigation program ("Onkolotse") in terms of hospitalization rates, resource use and healthcare costs: rationale and design of a randomized, controlled study.

PubMed

Porzig, Ralf; Neugebauer, Sina; Heckmann, Thomas; Adolf, Daniela; Kaskel, Peter; Froster, Ursula G

2018-06-05

Concepts for the nursing and care of cancer patients through a "navigation service" have attracted much interest. However, there is still room for improvement in terms of their funding and coverage. The Saxon Cancer Society designed a prospective, randomized, multicenter, longitudinal study with a view to determining the positive effects of a cancer patient navigator program. The objective of this ongoing study is to evaluate the impact of the cancer patient navigation program on cancer patients and cost bearers in Germany. The study population in this evaluation comprises cancer patients with gastric carcinoma, pancreatic carcinoma, colorectal cancer, melanoma or gynecological cancer who have been hospitalized at least once at one of the study centers as well as their relatives, outpatient and inpatient physicians, and cancer nurses. It is planned to randomize 340 cancer patients (stomach, colonic/rectal cancer, gynecological cancer, melanoma) at five centers to an intervention group (care by patient navigators based on standardized operating procedures) or a control group in a one-to-one ratio. The primary target parameter is the number of hospitalizations within the 12-month intervention period. The participants are asked to complete various questionnaires on patient-related outcomes at baseline and at 3 and 12 months (SF 36, HADS, PAM 13, and others). Data on drug therapy, utilization of health services, and medical expenses will also be analyzed. For the first time, the study will provide data on the effectiveness of a patient support program in cancer care in Germany from a randomized trial with a high level of evidence. The study has been registered under DRKS00013199 in the German Clinical Trials Register.

Longitudinal outcomes of children with pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS).

PubMed

Leon, Jill; Hommer, Rebecca; Grant, Paul; Farmer, Cristan; D'Souza, Precilla; Kessler, Riley; Williams, Kyle; Leckman, James F; Swedo, Susan

2018-05-01

Little is known about the natural history of children with pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS). This study prospectively followed 33 children with PANDAS for up to 4.8 years (mean 3.3 ± 0.7 years) after enrollment in a 24-week randomized, double-blind, placebo-controlled trial of intravenous immunoglobulin (IVIG) (N = 35). Fourteen of eighteen children randomized to placebo received open label IVIG 6 weeks after the blinded infusion, so follow-up results reported below largely reflect outcomes in a population of children who received at least one dose of IVIG. Telephone interviews with the parents of participants found that at the time of phone follow-up, 29 (88%) were not experiencing clinically significant obsessive-compulsive symptoms. During the interim period (6-57 months after entering the clinical trial), 24 (72%) had experienced at least one exacerbation of PANDAS symptoms, with a median of one exacerbation per child (range 1-12; interquartile range 0-3). A variety of treatment modalities, including antibiotics, IVIG, psychiatric medications, cognitive behavioral therapy, and others, were used to treat these exacerbations, and were often used in combination. The outcomes of this cohort are better than those previously reported for childhood-onset OCD, which may support conceptualization of PANDAS as a subacute illness similar to Sydenham chorea. However, some children developed a chronic course of illness, highlighting the need for research that identifies specific symptoms or biomarkers that can be used to predict the longitudinal course of symptoms in PANDAS.

Time Course of Atrophic Remodeling: Effects of Exercise on Cardiac Morpology and Function

NASA Technical Reports Server (NTRS)

Scott, J. M.; Martin, D.; Caine, T.; Matz, T.; Ploutz-Snyder, L. L.

2014-01-01

Early and consistent evaluation of cardiac morphology and function throughout an atrophic stimulus is critically important for the design and optimization of interventions. Exercise training is one intervention that has been shown to confer favorable improvements in LV mass and function during unloading. However, the format and intensity of exercise required to induce optimal cardiac improvements has not been investigated. PURPOSE: This randomized, controlled trial was designed to 1) comprehensively characterize the time course of unloading-induced morpho-functional remodeling, and 2) examine the effects of high intensity exercise training on cardiac structural and functional parameters during unloading. METHODS: Twenty six subjects completed 70 days of head down tilt bed rest (HDBR): 17 were randomized to exercise training (ExBR) and 9 remained sedentary. Exercise consisted of integrated high intensity, continuous, and resistance exercise. We assessed cardiac morphology (left ventricular mass; LVM) and function (speckle-tracking assessment of longitudinal, radial, and circumferential strain and twist) before (BR-2), during (BR7,21,31,70), and following (BR+0, +3) HDBR. Cardiorespiratory fitness (VO2max) was evaluated before (BR- 3), during (BR4,25,46,68) and following (BR+0) HDBR. RESULTS: Sedentary HDBR resulted in a progressive decline in LVM, longitudinal, radial, and circumferential strain, and an increase in twist. ExBR mitigated decreases in LVM and function. Change in twist was significantly related to change in VO2max (R=0.68, p<0.01). CONCLUSIONS: Alterations in cardiac morphology and function begin early during unloading. High-intensity exercise attenuates atrophic morphological and functional remodeling.

Emergency Department Alcohol Intervention: Effects on Dating Violence and Depression.

PubMed

Ngo, Quyen M; Eisman, Andria B; Walton, Maureen A; Kusunoki, Yasamin; Chermack, Stephen T; Singh, Vijay; Cunningham, Rebecca

2018-06-05

With this study, we examined secondary outcomes of an emergency department (ED)-based brief intervention (BI) on dating violence perpetration and victimization and depression symptoms over 3, 6, and 12 months. ED patients (14-20 years) were screened for risk drinking. Patients who received positive screen results were randomly assigned to a computer BI ( n = 277), therapist BI ( n = 278), or control condition ( n = 281). After the 3-month assessment, participants were randomly assigned to receive the post-ED BI or control condition. BIs were used to address alcohol consumption and consequences (eg, dating violence and depression symptoms) by using motivational interviewing. A total of 836 patients were enrolled in the randomized controlled trial of 4389 patients screened and 1054 who reported risky drinking. Regression models were used to examine longitudinal effects of the alcohol BI on dating violence perpetration, dating violence victimization, and depression symptoms. The therapist BI resulted in a significant reduction of dating violence perpetration up to 12 months (incidence rate ratio [IRR] = 0.53; 95% confidence interval [CI]: 0.37-0.77) and depression symptoms up to 3 months (IRR = 0.85; 95% CI: 0.72-1.00) after the intervention. Computer BI resulted in a reduction of dating violence perpetration (IRR = 0.52; 95% CI: 0.35-0.76) and depression symptoms (IRR = 0.78; 95% CI: 0.66-0.94) 6 months postintervention. Post-ED BIs were associated with lower perpetration at 12 months and lower victimization at 6 and 12 months, irrespective of BI intervention randomization at baseline; however, they did not affect depression symptoms. A single-session ED BI revealed previously to show promise in reducing underage drinking also demonstrates promise in preventing dating violence perpetration and depression symptoms. These technology-enhanced BIs could be particularly helpful given the potential for more efficient resource usage and ease of future implementation. Copyright © 2018 by the American Academy of Pediatrics.

Kidney function changes with aging in adults: comparison between cross-sectional and longitudinal data analyses in renal function assessment.

PubMed

Chung, Sang M; Lee, David J; Hand, Austin; Young, Philip; Vaidyanathan, Jayabharathi; Sahajwalla, Chandrahas

2015-12-01

The study evaluated whether the renal function decline rate per year with age in adults varies based on two primary statistical analyses: cross-section (CS), using one observation per subject, and longitudinal (LT), using multiple observations per subject over time. A total of 16628 records (3946 subjects; age range 30-92 years) of creatinine clearance and relevant demographic data were used. On average, four samples per subject were collected for up to 2364 days (mean: 793 days). A simple linear regression and random coefficient models were selected for CS and LT analyses, respectively. The renal function decline rates per year were 1.33 and 0.95 ml/min/year for CS and LT analyses, respectively, and were slower when the repeated individual measurements were considered. The study confirms that rates are different based on statistical analyses, and that a statistically robust longitudinal model with a proper sampling design provides reliable individual as well as population estimates of the renal function decline rates per year with age in adults. In conclusion, our findings indicated that one should be cautious in interpreting the renal function decline rate with aging information because its estimation was highly dependent on the statistical analyses. From our analyses, a population longitudinal analysis (e.g. random coefficient model) is recommended if individualization is critical, such as a dose adjustment based on renal function during a chronic therapy. Copyright © 2015 John Wiley & Sons, Ltd.

A longitudinal multilevel CFA-MTMM model for interchangeable and structurally different methods

PubMed Central

Koch, Tobias; Schultze, Martin; Eid, Michael; Geiser, Christian

2014-01-01

One of the key interests in the social sciences is the investigation of change and stability of a given attribute. Although numerous models have been proposed in the past for analyzing longitudinal data including multilevel and/or latent variable modeling approaches, only few modeling approaches have been developed for studying the construct validity in longitudinal multitrait-multimethod (MTMM) measurement designs. The aim of the present study was to extend the spectrum of current longitudinal modeling approaches for MTMM analysis. Specifically, a new longitudinal multilevel CFA-MTMM model for measurement designs with structurally different and interchangeable methods (called Latent-State-Combination-Of-Methods model, LS-COM) is presented. Interchangeable methods are methods that are randomly sampled from a set of equivalent methods (e.g., multiple student ratings for teaching quality), whereas structurally different methods are methods that cannot be easily replaced by one another (e.g., teacher, self-ratings, principle ratings). Results of a simulation study indicate that the parameters and standard errors in the LS-COM model are well recovered even in conditions with only five observations per estimated model parameter. The advantages and limitations of the LS-COM model relative to other longitudinal MTMM modeling approaches are discussed. PMID:24860515

Providing intensive addiction/housing case management to homeless veterans enrolled in addictions treatment: A randomized controlled trial.

PubMed

Malte, Carol A; Cox, Koriann; Saxon, Andrew J

2017-05-01

This study sought to determine whether homeless veterans entering Veterans Affairs (VA) substance use treatment randomized to intensive addiction/housing case management (AHCM) had improved housing, substance use, mental health, and functional outcomes and lower acute health care utilization, compared to a housing support group (HSG) control. Homeless veterans (n = 181) entering outpatient VA substance use treatment were randomized to AHCM and HSG and received treatment for 12 months. AHCM provided individualized housing, substance use and mental health case management, life skills training, and community outreach. The control condition was a weekly drop-in housing support group. Adjusted longitudinal analyses compared groups on baseline to month 12 change in percentage of days housed and functional status, substance use, and mental health outcomes (36-Item Short-Form Health Survey; Addiction Severity Index [ASI]). Negative binomial regression models compared groups on health care utilization. Both conditions significantly increased percentage of days housed, with no differences detected between conditions. In total, 74 (81.3%) AHCM and 64 (71.1%) HSG participants entered long-term housing (odds ratio = 1.9, 95% confidence interval [0.9, 4.0], p = .088). HSG participants experienced a greater decrease in emergency department visits than AHCM (p = .037), whereas AHCM participants remained in substance use treatment 52.7 days longer (p = .005) and had greater study treatment participation (p < .001) than HSG. ASI alcohol composite scores improved more for HSG than AHCM (p = .006), and both conditions improved on ASI drug and psychiatric scores and alcohol/drug abstinence. AHCM did not demonstrate overarching benefits beyond standard VA housing and substance use care. For those veterans not entering or losing long-term housing, different approaches to outreach and ongoing intervention are required. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Effect of an environmental school-based obesity prevention program on changes in body fat and body weight: a randomized trial.

PubMed

Williamson, Donald A; Champagne, Catherine M; Harsha, David W; Han, Hongmei; Martin, Corby K; Newton, Robert L; Sothern, Melinda S; Stewart, Tiffany M; Webber, Larry S; Ryan, Donna H

2012-08-01

This study tested the efficacy of two school-based programs for prevention of body weight/fat gain in comparison to a control group, in all participants and in overweight children. The Louisiana (LA) Health study utilized a longitudinal, cluster randomized three-arm controlled design, with 28 months of follow-up. Children (N = 2,060; mean age = 10.5 years, SD = 1.2) from rural communities in grades 4-6 participated in the study. Seventeen school clusters (mean = 123 children/cluster) were randomly assigned to one of three prevention arms: (i) primary prevention (PP), an environmental modification (EM) program, (ii) primary + secondary prevention (PP+SP), the environmental program with an added classroom and internet education component, or (iii) control (C). Primary outcomes were changes in percent body fat and BMI z scores. Secondary outcomes were changes in behaviors related to energy balance. Comparisons of PP, PP+SP, and C on changes in body fat and BMI z scores found no differences. PP and PP+SP study arms were combined to create an EM arm. Relative to C, EM decreased body fat for boys (-1.7 ± 0.38% vs. -0.14 ± 0.69%) and attenuated fat gain for girls (2.9 ± 0.22% vs. 3.93 ± 0.37%), but standardized effect sizes were relatively small (<0.30). In conclusion, this school-based EM programs had modest beneficial effects on changes in percent body fat. Addition of a classroom/internet program to the environmental program did not enhance weight/fat gain prevention, but did impact physical activity and social support in overweight children.

Low-dose naltrexone for the treatment of fibromyalgia: findings of a small, randomized, double-blind, placebo-controlled, counterbalanced, crossover trial assessing daily pain levels.

PubMed

Younger, Jarred; Noor, Noorulain; McCue, Rebecca; Mackey, Sean

2013-02-01

To determine whether low dosages (4.5 mg/day) of naltrexone reduce fibromyalgia severity as compared with the nonspecific effects of placebo. In this replication and extension study of a previous clinical trial, we tested the impact of low-dose naltrexone on daily self-reported pain. Secondary outcomes included general satisfaction with life, positive mood, sleep quality, and fatigue. Thirty-one women with fibromyalgia participated in the randomized, double-blind, placebo-controlled, counterbalanced, crossover study. During the active drug phase, participants received 4.5 mg of oral naltrexone daily. An intensive longitudinal design was used to measure daily levels of pain. When contrasting the condition end points, we observed a significantly greater reduction of baseline pain in those taking low-dose naltrexone than in those taking placebo (28.8% reduction versus 18.0% reduction; P = 0.016). Low-dose naltrexone was also associated with improved general satisfaction with life (P = 0.045) and with improved mood (P = 0.039), but not improved fatigue or sleep. Thirty-two percent of participants met the criteria for response (defined as a significant reduction in pain plus a significant reduction in either fatigue or sleep problems) during low-dose naltrexone therapy, as contrasted with an 11% response rate during placebo therapy (P = 0.05). Low-dose naltrexone was rated equally tolerable as placebo, and no serious side effects were reported. The preliminary evidence continues to show that low-dose naltrexone has a specific and clinically beneficial impact on fibromyalgia pain. The medication is widely available, inexpensive, safe, and well-tolerated. Parallel-group randomized controlled trials are needed to fully determine the efficacy of the medication. Copyright © 2013 by the American College of Rheumatology.

Measuring Clinical Decision Support Influence on Evidence-Based Nursing Practice.

PubMed

Cortez, Susan; Dietrich, Mary S; Wells, Nancy

2016-07-01

To measure the effect of clinical decision support (CDS) on oncology nurse evidence-based practice (EBP).
. Longitudinal cluster-randomized design.
. Four distinctly separate oncology clinics associated with an academic medical center.
. The study sample was comprised of randomly selected data elements from the nursing documentation software. The data elements were patient-reported symptoms and the associated nurse interventions. The total sample observations were 600, derived from a baseline, posteducation, and postintervention sample of 200 each (100 in the intervention group and 100 in the control group for each sample).
. The cluster design was used to support randomization of the study intervention at the clinic level rather than the individual participant level to reduce possible diffusion of the study intervention. An elongated data collection cycle (11 weeks) controlled for temporary increases in nurse EBP related to the education or CDS intervention.
. The dependent variable was the nurse evidence-based documentation rate, calculated from the nurse-documented interventions. The independent variable was the CDS added to the nursing documentation software.
. The average EBP rate at baseline for the control and intervention groups was 27%. After education, the average EBP rate increased to 37%, and then decreased to 26% in the postintervention sample. Mixed-model linear statistical analysis revealed no significant interaction of group by sample. The CDS intervention did not result in an increase in nurse EBP.
. EBP education increased nurse EBP documentation rates significantly but only temporarily. Nurses may have used evidence in practice but may not have documented their interventions.
. More research is needed to understand the complex relationship between CDS, nursing practice, and nursing EBP intervention documentation. CDS may have a different effect on nurse EBP, physician EBP, and other medical professional EBP.

Measuring Outcomes of Digital Technology-Assisted Nursing Postpartum: A Randomized Controlled Trial.

PubMed

Mccarter, Deborah E; Demidenko, Eugene; Hegel, Mark T

2018-05-17

To determine if delivering electronic messages from nurses during the first six months postpartum is feasible, acceptable and effective in improving mood and decreasing parenting stress. Competing demands during the postpartum hospitalization make focused time for nurses to provide education and support difficult. Unmet needs following discharge may increase the incidence of postpartum depression. Untreated depression negatively affects families, especially for vulnerable women with limited access to health care. This is a longitudinal cohort study in three phases. Feasibility and acceptability were assessed during Phases 1 & 2. Phase 3 is a randomized controlled trial (RCT) with three conditions. This protocol was approved by the Institutional Review Board of the maternity hospital on 12 May 2015 and reviewed annually. Women are enrolled during the maternity hospitalization, after which randomization occurs. The control group receives usual care. Intervention I participants receive a standardized electronic message four times/week for six months postpartum. Intervention II participants receive the messages and the option to request a call from a nurse. Electronic surveys at 3 weeks, 3 months and 6 months postpartum measure depressive symptoms using the Edinburgh Postnatal Depression Scale and parenting stress using the Parenting Stress Index-Short form. Patient satisfaction, nursing time and expertise required are also measured. Phase 1 and 2 have demonstrated the intervention is feasible and acceptable to women. Phase 3 enrollment is completed, and the last follow-up surveys were emailed to participants in February 2018. Results will help inform efforts to continue nursing care after hospital discharge. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Clinical efficacy of a xenogeneic collagen matrix in augmenting keratinized mucosa around implants: a randomized controlled prospective clinical trial.

PubMed

Lorenzo, Ramón; García, Virginia; Orsini, Marco; Martin, Conchita; Sanz, Mariano

2012-03-01

The aim of this controlled randomized clinical trial was to evaluate the efficacy of a xenogeneic collagen matrix (CM) to augment the keratinized tissue around implants supporting prosthetic restorations at 6 months when compared with the standard treatment, the connective tissue autograft, CTG). This randomized longitudinal parallel controlled clinical trial studied 24 patients with at least one location with minimal keratinized tissue (≤1 mm). The 6-month width of keratinized tissue. As secondary outcomes the esthetic outlook, the maintenance of peri-implant mucosal health and the patient morbidity were assessed pre-operatively and 1, 3, and 6 months post-operatively. At 6 months, Group CTG attained a mean width of keratinized tissue of 2.75 (1.5) mm, while the corresponding figure in Group CM was 2.8 (0.4) mm, the inter-group differences not being statistically significant. The surgical procedure in both groups did not alter significantly the mucosal health in the affected abutments. There was a similar esthetic result and significant increase in the vestibular depth in both groups as a result of the surgery. In the CM group it changed from 2.2 (3.3) to 5.1 (2.5) mm at 6 months. The patients treated with the CM referred less pain, needed less pain medication, and the surgical time was shorter, although these differences were not statistically significant when compared with the CTG group. These results prove that this new CM was as effective and predictable as the CTG for attaining a band of keratinized tissue. © 2011 John Wiley & Sons A/S.

Effect of an Environmental School-based Obesity Prevention Program On Changes in Body Fat and Body Weight: A Randomized Trial

PubMed Central

Williamson, D.A.; Champagne, C.M.; Harsha, D.; Han, H.; Martin, C.K.; Newton, R.L.; Sothern, M.; Stewart, T.M.; Webber, L.S.; Ryan, D.

2012-01-01

This study tested the efficacy of two school-based programs for prevention of body weight/fat gain in comparison to a control group, in all participants and in overweight children. The Louisiana (LA) Health study utilized a longitudinal, cluster randomized 3-arm controlled design, with 28 months of follow-up. Children (N=2060; M age = 10.5 years, SD = 1.2) from rural communities in Grades 4 to 6 participated in the study. 17 school clusters (M = 123 children/cluster) were randomly assigned to one of three prevention arms: 1) Primary Prevention (PP), an environmental modification program, 2) Primary + Secondary Prevention (PP+SP), the environmental program with an added classroom and internet education component, or 3) Control (C). Primary outcomes were changes in percent body fat and body mass index z scores. Secondary outcomes were changes in behaviors related to energy balance. Comparisons of PP, PP+SP, and C on changes in body fat and BMI z scores found no differences. PP and PP+SP study arms were combined to create an environmental modification arm (EM). Relative to C, EM decreased body fat for boys (−1.7% ± 0.38% versus −0.14% ± 0.69%) and attenuated fat gain for girls (2.9% ± 0.22% versus 3.93% ± 0.37%), but standardized effect sizes were relatively small (< 0.30). In conclusion, this school-based environmental modification programs had modest beneficial effects on changes in percent body fat. Addition of a classroom/internet program to the environmental program did not enhance weight/fat gain prevention, but did impact physical activity and social support in overweight children. PMID:22402733

A Multifactorial Weight Reduction Programme for Children with Overweight and Asthma: A Randomized Controlled Trial

PubMed Central

Willeboordse, Maartje; van de Kant, Kim D. G.; Tan, Frans E. S.; Mulkens, Sandra; Schellings, Julia; Crijns, Yvonne; van der Ploeg, Liesbeth; van Schayck, Constant P.; Dompeling, Edward

2016-01-01

Background There is increasing evidence that obesity is related to asthma development and severity. However, it is largely unknown whether weight reduction can influence asthma management, especially in children. Objective To determine the effects of a multifactorial weight reduction intervention on asthma management in overweight/obese children with (a high risk of developing) asthma. Methods An 18-month weight-reduction randomized controlled trial was conducted in 87 children with overweight/obesity and asthma. Every six months, measurements of anthropometry, lung function, lifestyle parameters and inflammatory markers were assessed. Analyses were performed with linear mixed models for longitudinal analyses. Results After 18 months, the body mass index-standard deviation score decreased by -0.14±0.29 points (p<0.01) in the intervention group and -0.12±0.34 points (p<0.01) in the control group. This change over time did not differ between groups (p>0.05). Asthma features (including asthma control and asthma-related quality of life) and lung function indices (static and dynamic) improved significantly over time in both groups. The FVC% predicted improved over time by 10.1 ± 8.7% in the intervention group (p<0.001), which was significantly greater than the 6.1 ± 8.4% in the control group (p<0.05). Conclusions & clinical relevance Clinically relevant improvements in body weight, lung function and asthma features were found in both the intervention and control group, although some effects were more pronounced in the intervention group (FVC, asthma control, and quality of life). This implies that a weight reduction intervention could be clinically beneficial for children with asthma. Trial Registration ClinicalTrials.gov NCT00998413 PMID:27294869

A review of the handling of missing longitudinal outcome data in clinical trials

PubMed Central

2014-01-01

The aim of this review was to establish the frequency with which trials take into account missingness, and to discover what methods trialists use for adjustment in randomised controlled trials with longitudinal measurements. Failing to address the problems that can arise from missing outcome data can result in misleading conclusions. Missing data should be addressed as a means of a sensitivity analysis of the complete case analysis results. One hundred publications of randomised controlled trials with longitudinal measurements were selected randomly from trial publications from the years 2005 to 2012. Information was extracted from these trials, including whether reasons for dropout were reported, what methods were used for handing the missing data, whether there was any explanation of the methods for missing data handling, and whether a statistician was involved in the analysis. The main focus of the review was on missing data post dropout rather than missing interim data. Of all the papers in the study, 9 (9%) had no missing data. More than half of the papers included in the study failed to make any attempt to explain the reasons for their choice of missing data handling method. Of the papers with clear missing data handling methods, 44 papers (50%) used adequate methods of missing data handling, whereas 30 (34%) of the papers used missing data methods which may not have been appropriate. In the remaining 17 papers (19%), it was difficult to assess the validity of the methods used. An imputation method was used in 18 papers (20%). Multiple imputation methods were introduced in 1987 and are an efficient way of accounting for missing data in general, and yet only 4 papers used these methods. Out of the 18 papers which used imputation, only 7 displayed the results as a sensitivity analysis of the complete case analysis results. 61% of the papers that used an imputation explained the reasons for their chosen method. Just under a third of the papers made no reference to reasons for missing outcome data. There was little consistency in reporting of missing data within longitudinal trials. PMID:24947664

The combined effects of job demand and control, effort-reward imbalance and work-family conflicts on the risk of major depressive episode: a 4-year longitudinal study.

PubMed

Nigatu, Yeshambel T; Wang, JianLi

2018-01-01

Work-related psychosocial factors may precipitate the onset of depression. In occupational mental health research, there are three widely used theoretical models, namely, job demand and control (JD-C), effort-reward imbalance (ERI) and work-family conflicts (WFC). However, the interaction between these models and their combined effect on the risk of major depression in the workplace is largely unknown. The aim of this study is to examine the longitudinal combined effects of JD-C, ERI and WFC on the risk of major depression in the working population. Longitudinal data (2008-2013) were collected on randomly selected participants (n=4200) from the working population of the province of Alberta, Canada, at baseline and 1-, 2-, 3- and 4-year follow-up. Data about JD-C, ERI, WFC and major depression were collected by trained interviewers using a computer-assisted telephone interviewing method. Generalised estimating equations for longitudinal modelling were used. There was an independent association between high ERI and high WFC at t x and major depression at t x+1 (OR 1.56, 95% CI 1.25 to 1.96; OR 1.33, 95% CI 1.16 to 1.52), respectively. The combined effects of JD-C and ERI, ERI and WFC, and WFC and JD-C on the risk of major depression were as follows: OR 1.71, 95% CI 1.22 to 2.42, OR 2.47, 95% CI 1.99 to 3.49 and OR 2.21, 95% CI 1.48 to 3.30, respectively. The relative excess risks attributable to the interactions were statistically non-significant. Work-related psychosocial factors are associated with increased risk of major depression over time, but their combined effect is not synergistic. The effects of the factors depicted in the three occupational health models on the risk of major depression appear to be additive. © 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.

At the Frontiers of Modeling Intensive Longitudinal Data: Dynamic Structural Equation Models for the Affective Measurements from the COGITO Study.

PubMed

Hamaker, E L; Asparouhov, T; Brose, A; Schmiedek, F; Muthén, B

2018-04-06

With the growing popularity of intensive longitudinal research, the modeling techniques and software options for such data are also expanding rapidly. Here we use dynamic multilevel modeling, as it is incorporated in the new dynamic structural equation modeling (DSEM) toolbox in Mplus, to analyze the affective data from the COGITO study. These data consist of two samples of over 100 individuals each who were measured for about 100 days. We use composite scores of positive and negative affect and apply a multilevel vector autoregressive model to allow for individual differences in means, autoregressions, and cross-lagged effects. Then we extend the model to include random residual variances and covariance, and finally we investigate whether prior depression affects later depression scores through the random effects of the daily diary measures. We end with discussing several urgent-but mostly unresolved-issues in the area of dynamic multilevel modeling.

No efficacy for silicone gel sheeting in prevention of abnormal scar formation in children with cancer: a randomized controlled trial.

PubMed

Braam, Katja I; Kooijmans, Esmee C M; van Dulmen-den Broeder, Eline; Veening, Margreet A; Schouten-van Meeteren, Antoinette Y N; Verhaegen, Pauline D H M; Kaspers, Gertjan J L; Niessen, Frank B; Heij, Hugo A

2015-04-01

Placement of a totally implantable venous access device in children with cancer often leads to hypertrophic scars after its removal. This study investigates whether the use of silicone gel sheets has a beneficial effect on scar outcome in children with cancer. In a three-arm randomized controlled trial, the effects of use of silicone gel sheets for 2 and 6 months were assessed and compared with no intervention in children with cancer after removal of the totally implantable venous access device. Silicone gel sheets were first administered 14 days after surgery. The 1-year follow-up included measurements at seven time points. Next to scar size assessment, the modified Vancouver Scar Scale was used to assess scar outcome. Thirty-six children participated. For hypertrophy, no significant differences were found between the two intervention groups and the control group. However, at 1-year follow-up, the 2-month application group showed significantly smaller scars compared with the group receiving silicone gel sheet treatment for 6 months (p = 0.04), but not when compared with the control group (p = 0.22). Longitudinal multilevel analyses could not confirm these findings and showed no significant intervention effects on both outcomes. This study provides no strong evidence to support the use of silicone gel sheets after totally implantable venous access device removal in children with cancer. There seems to be a small benefit for scar width with application for 2 months. However, for hypertrophy, the scar outcome shows no significant difference between the control group and the 2-month and 6-month treatment groups.

Using spaced retrieval and Montessori-based activities in improving eating ability for residents with dementia.

PubMed

Lin, Li-Chan; Huang, Ya-Ju; Su, Su-Gen; Watson, Roger; Tsai, Belina W-J; Wu, Shiao-Chi

2010-10-01

To construct a training protocol for spaced retrieval (SR) and to investigate the effectiveness of SR and Montessori-based activities in decreasing eating difficulty in older residents with dementia. A single evaluator, blind, and randomized control trial was used. Eighty-five residents with dementia were chosen from three special care units for residents with dementia in long-term care facilities in Taiwan. To avoid any confounding of subjects, the three institutions were randomized into three groups: spaced retrieval, Montessori-based activities, and a control group. The invention consisted of three 30-40 min sessions per week, for 8 weeks. After receiving the intervention, the Edinburgh Feeding Evaluation in Dementia (EdFED) scores and assisted feeding scores for the SR and Montessori-based activity groups were significantly lower than that of the control group. However, the frequencies of physical assistance and verbal assistance for the Montessori-based activity group after intervention were significantly higher than that of the control group, which suggests that residents who received Montessori-based activity need more physical and verbal assistance during mealtimes. In terms of the effects of nutritional status after intervention, Mini-Nutritional Assessment (MNA) in the SR group was significantly higher than that of the control group. This study confirms the efficacy of SR and Montessori-based activities for eating difficulty and eating ability. A longitudinal study to follow the long-term effects of SR and Montessori-based activities on eating ability and nutritional status is recommended. Copyright © 2010 John Wiley & Sons, Ltd.

“Computerized Counseling Reduces HIV-1 Viral Load and Sexual Transmission Risk: Findings from a Randomized Controlled Trial”

PubMed Central

KURTH, Ann E.; SPIELBERG, Freya; CLELAND, Charles M.; LAMBDIN, Barrot; BANGSBERG, David R.; FRICK, Pamela A.; SEVERYNEN, Anneleen O.; CLAUSEN, Marc; NORMAN, Robert G.; LOCKHART, David; SIMONI, Jane M.; HOLMES, King K.

2014-01-01

Objective Evaluate a computerized intervention supporting antiretroviral therapy (ART) adherence and HIV transmission prevention. Design Longitudinal RCT. Settings An academic HIV clinic and a community-based organization in Seattle. Subjects 240 HIV-positive adults on ART; 209 completed nine-month follow-up (87% retention). Intervention Randomization to computerized counseling or assessment-only, 4 sessions over 9 months. Main Outcome Measures HIV-1 viral suppression, and self-reported ART adherence, and transmission risks, compared using generalized estimating equations. Results Overall, intervention participants had reduced viral load (VL): mean 0.17 log10 decline, versus 0.13 increase in controls, p = 0.053, and significant difference in ART adherence baseline to 9 months (p = 0.046). Their sexual transmission risk behaviors decreased (OR = 0.55, p = 0.020), a reduction not seen among controls (OR = 1.1, p = 0.664), and a significant difference in change (p = 0.040). Intervention effect was driven by those most in need: among those with detectable virus at baseline (>30 copies/milliliter, n=89), intervention effect was mean 0.60 log10 VL decline versus 0.15 increase in controls, p=0.034. ART adherence at the final follow-up was 13 points higher among intervention participants versus controls, p = 0.038. Conclusions Computerized counseling is promising for integrated ART adherence and safer sex, especially for individuals with problems in these areas. This is the first intervention to report improved ART adherence, viral suppression, and reduced secondary sexual transmission risk behavior. PMID:24384803

Teaching Medical Students to Help Patients Quit Smoking: Outcomes of a 10-School Randomized Controlled Trial.

PubMed

Ockene, Judith K; Hayes, Rashelle B; Churchill, Linda C; Crawford, Sybil L; Jolicoeur, Denise G; Murray, David M; Shoben, Abigail B; David, Sean P; Ferguson, Kristi J; Huggett, Kathryn N; Adams, Michael; Okuliar, Catherine A; Gross, Robin L; Bass, Pat F; Greenberg, Ruth B; Leone, Frank T; Okuyemi, Kola S; Rudy, David W; Waugh, Jonathan B; Geller, Alan C

2016-02-01

Early in medical education, physicians must develop competencies needed for tobacco dependence treatment. To assess the effect of a multi-modal tobacco dependence treatment curriculum on medical students' counseling skills. A group-randomized controlled trial (2010-2014) included ten U.S. medical schools that were randomized to receive either multi-modal tobacco treatment education (MME) or traditional tobacco treatment education (TE). Students from the classes of 2012 and 2014 at ten medical schools participated. Students from the class of 2012 (N = 1345) completed objective structured clinical examinations (OSCEs), and 50 % (N = 660) were randomly selected for pre-intervention evaluation. A total of 72.9 % of eligible students (N = 1096) from the class of 2014 completed an OSCE and 69.7 % (N = 1047) completed pre and post surveys. The MME included a Web-based course, a role-play classroom demonstration, and a clerkship booster session. Clerkship preceptors in MME schools participated in an academic detailing module and were encouraged to be role models for third-year students. The primary outcome was student tobacco treatment skills using the 5As measured by an objective structured clinical examination (OSCE) scored on a 33-item behavior checklist. Secondary outcomes were student self-reported skills for performing 5As and pharmacotherapy counseling. Although the difference was not statistically significant, MME students completed more tobacco counseling behaviors on the OSCE checklist (mean 8.7 [SE 0.6] vs. mean 8.0 [SE 0.6], p = 0.52) than TE students. Several of the individual Assist and Arrange items were significantly more likely to have been completed by MME students, including suggesting behavioral strategies (11.8 % vs. 4.5 %, p < 0.001) and providing information regarding quitline (21.0 % vs. 3.8 %, p < 0.001). MME students reported higher self-efficacy for Assist, Arrange, and Pharmacotherapy counseling items (ps ≤0.05). Inclusion of only ten schools limits generalizability. Subsequent interventions should incorporate lessons learned from this first randomized controlled trial of a multi-modal longitudinal tobacco treatment curriculum in multiple U.S. medical schools. NIH Trial Registry Number: NCT01905618.

Examining the Variability of Sleep Patterns during Treatment for Chronic Insomnia: Application of a Location-Scale Mixed Model.

PubMed

Ong, Jason C; Hedeker, Donald; Wyatt, James K; Manber, Rachel

2016-06-15

The purpose of this study was to introduce a novel statistical technique called the location-scale mixed model that can be used to analyze the mean level and intra-individual variability (IIV) using longitudinal sleep data. We applied the location-scale mixed model to examine changes from baseline in sleep efficiency on data collected from 54 participants with chronic insomnia who were randomized to an 8-week Mindfulness-Based Stress Reduction (MBSR; n = 19), an 8-week Mindfulness-Based Therapy for Insomnia (MBTI; n = 19), or an 8-week self-monitoring control (SM; n = 16). Sleep efficiency was derived from daily sleep diaries collected at baseline (days 1-7), early treatment (days 8-21), late treatment (days 22-63), and post week (days 64-70). The behavioral components (sleep restriction, stimulus control) were delivered during late treatment in MBTI. For MBSR and MBTI, the pre-to-post change in mean levels of sleep efficiency were significantly larger than the change in mean levels for the SM control, but the change in IIV was not significantly different. During early and late treatment, MBSR showed a larger increase in mean levels of sleep efficiency and a larger decrease in IIV relative to the SM control. At late treatment, MBTI had a larger increase in the mean level of sleep efficiency compared to SM, but the IIV was not significantly different. The location-scale mixed model provides a two-dimensional analysis on the mean and IIV using longitudinal sleep diary data with the potential to reveal insights into treatment mechanisms and outcomes. © 2016 American Academy of Sleep Medicine.

Do behavioral scientists really understand HIV-related sexual risk behavior? A systematic review of longitudinal and experimental studies predicting sexual behavior.

PubMed

Huebner, David M; Perry, Nicholas S

2015-10-01

Behavioral interventions to reduce sexual risk behavior depend on strong health behavior theory. By identifying the psychosocial variables that lead causally to sexual risk, theories provide interventionists with a guide for how to change behavior. However, empirical research is critical to determining whether a particular theory adequately explains sexual risk behavior. A large body of cross-sectional evidence, which has been reviewed elsewhere, supports the notion that certain theory-based constructs (e.g., self-efficacy) are correlates of sexual behavior. However, given the limitations of inferring causality from correlational research, it is essential that we review the evidence from more methodologically rigorous studies (i.e., longitudinal and experimental designs). This systematic review identified 44 longitudinal studies in which investigators attempted to predict sexual risk from psychosocial variables over time. We also found 134 experimental studies (i.e., randomized controlled trials of HIV interventions), but of these only 9 (6.7 %) report the results of mediation analyses that might provide evidence for the validity of health behavior theories in predicting sexual behavior. Results show little convergent support across both types of studies for most traditional, theoretical predictors of sexual behavior. This suggests that the field must expand the body of empirical work that utilizes the most rigorous study designs to test our theoretical assumptions. The inconsistent results of existing research would indicate that current theoretical models of sexual risk behavior are inadequate, and may require expansion or adaptation.

Depression and family interaction among low-income, predominantly hispanic cancer patients: a longitudinal analysis.

PubMed

Oh, Hyunsung; Ell, Kathleen; Subica, Andrew

2014-02-01

Among cancer patients, family interaction has been associated with depression. According to the stress generation theory, depression among cancer patients triggers stressful interpersonal events that contribute to poor family interactions and additional depression. This conflict may occur with a spouse/partner or other family member, including extended family. This study evaluated the longitudinal association between depression and marital and family conflict among low-income, predominantly Hispanic cancer patients. Data were collected during a randomized controlled clinical trial of depression treatment among 472 low-income cancer patients with baseline depression scores of 10 or more on the Patient Health Questionnaire-9 and whose depression symptoms and negative family interactions were assessed at baseline and at 6, 12, 18, and 24 months. Considering that not all participants were in an intimate relationship, only 237 participants were included in the analysis of marital conflict. Mixed linear modeling with and without decomposition of between- and within-person variability was conducted to examine the longitudinal association between family interaction and depression. Overall, family conflict was significantly associated with changes in depression over time, and marital conflict was significantly associated with mean depression levels over 2 years. In addition, within-subject change in both marital and family conflict was significantly associated with within-patient deviation from average depression levels. Findings provide evidence of an association between depression and negative family interaction among depressed cancer patients. Cancer patients with clinically significant depressive symptoms may benefit from clinical assessment and psychotherapy relevant to family interaction.

Circle of life: rationale, design, and baseline results of an HIV prevention intervention among young American Indian adolescents of the Northern Plains.

PubMed

Kaufman, Carol E; Mitchell, Christina M; Beals, Janette; Desserich, Jennifer A; Wheeler, Cindy; Keane, Ellen M; Whitesell, Nancy Rumbaugh; Sam, Angela; Sedey, Cory

2010-03-01

In spite of significant disparities in sexual health outcomes for American Indian youth, no studies exist examining the effectiveness of HIV-prevention interventions. Circle of Life is an HIV-prevention intervention specifically developed for American Indian middle-school youth. We describe the rationale, methodology, and baseline results of a longitudinal randomized trial of Circle of Life conducted among American Indian youth aged 11-15 in a reservation community. The innovative design includes two pre-intervention waves to determine patterns of behavior prior to the intervention that might be associated with a differential impact of the intervention on sexual risk. We used one-way analysis of variance and chi-square tests to test for significant differences between randomized group assignment at each baseline wave and generalized estimating equations (GEE) to test significant differences in the rate of change in outcomes by group longitudinally. We present the collaborative and adaptive strategies for consenting, assenting, and data collection methodology in this community. Achieved response rates are comparable to other similar studies. Results from the two baseline waves indicate that few outcomes significantly varied by randomized intervention assignment. Ten percent of youth reported having had sex at Wave 1, rising to 15% at Wave 2. Among those who had had sex, the majority (>70%) reported using a condom at last sex. The project is well positioned to carry out the longitudinal assessments of the intervention to determine the overall impact of the Circle of Life and the differential impact by pre-intervention patterns of behavior across youth.

A Two-Step Approach for Analysis of Nonignorable Missing Outcomes in Longitudinal Regression: an Application to Upstate KIDS Study.

PubMed

Liu, Danping; Yeung, Edwina H; McLain, Alexander C; Xie, Yunlong; Buck Louis, Germaine M; Sundaram, Rajeshwari

2017-09-01

Imperfect follow-up in longitudinal studies commonly leads to missing outcome data that can potentially bias the inference when the missingness is nonignorable; that is, the propensity of missingness depends on missing values in the data. In the Upstate KIDS Study, we seek to determine if the missingness of child development outcomes is nonignorable, and how a simple model assuming ignorable missingness would compare with more complicated models for a nonignorable mechanism. To correct for nonignorable missingness, the shared random effects model (SREM) jointly models the outcome and the missing mechanism. However, the computational complexity and lack of software packages has limited its practical applications. This paper proposes a novel two-step approach to handle nonignorable missing outcomes in generalized linear mixed models. We first analyse the missing mechanism with a generalized linear mixed model and predict values of the random effects; then, the outcome model is fitted adjusting for the predicted random effects to account for heterogeneity in the missingness propensity. Extensive simulation studies suggest that the proposed method is a reliable approximation to SREM, with a much faster computation. The nonignorability of missing data in the Upstate KIDS Study is estimated to be mild to moderate, and the analyses using the two-step approach or SREM are similar to the model assuming ignorable missingness. The two-step approach is a computationally straightforward method that can be conducted as sensitivity analyses in longitudinal studies to examine violations to the ignorable missingness assumption and the implications relative to health outcomes. © 2017 John Wiley & Sons Ltd.

Effects of Simulated Interventions to Improve School Entry Academic Skills on Socioeconomic Inequalities in Educational Achievement

PubMed Central

Chittleborough, Catherine R; Mittinty, Murthy N; Lawlor, Debbie A; Lynch, John W

2014-01-01

Randomized controlled trial evidence shows that interventions before age 5 can improve skills necessary for educational success; the effect of these interventions on socioeconomic inequalities is unknown. Using trial effect estimates, and marginal structural models with data from the Avon Longitudinal Study of Parents and Children (n = 11,764, imputed), simulated effects of plausible interventions to improve school entry academic skills on socioeconomic inequality in educational achievement at age 16 were examined. Progressive universal interventions (i.e., more intense intervention for those with greater need) to improve school entry academic skills could raise population levels of educational achievement by 5% and reduce absolute socioeconomic inequality in poor educational achievement by 15%. PMID:25327718

A longitudinal study of youth assets, neighborhood conditions, and youth sexual behaviors.

PubMed

Oman, Roy F; Vesely, Sara K; Aspy, Cheryl B; Tolma, Eleni L; Gavin, Lorrie; Bensyl, Diana M; Mueller, Trisha; Fluhr, Janene D

2013-06-01

To prospectively determine whether individual, family, and community assets help youth to delay initiation of sexual intercourse (ISI); and for youth who do initiate intercourse, to use birth control and avoid pregnancy. The potential influence of neighborhood conditions was also investigated. The Youth Asset Study was a 4-year longitudinal study involving 1,089 youth (mean age = 14.2 years, standard deviation = 1.6; 53% female; 40% white, 28% Hispanic, 23% African American, 9% other race) and their parents. Participants were living in randomly selected census tracts. We accomplished recruitment via door-to-door canvassing. We interviewed one youth and one parent from each household annually. We assessed 17 youth assets (e.g., responsible choices, family communication) believed to influence behavior at multiple levels via in-person interviews methodology. Trained raters who conducted annual windshield tours assessed neighborhood conditions. Cox proportional hazard or marginal logistic regression modeling indicated that 11 assets (e.g., family communication, school connectedness) were significantly associated with reduced risk for ISI; seven assets (e.g., educational aspirations for the future, responsible choices) were significantly associated with increased use of birth control at last sex; and 10 assets (e.g., family communication, school connectedness) were significantly associated with reduced risk for pregnancy. Total asset score was significantly associated with all three outcomes. Positive neighborhood conditions were significantly associated with increased birth control use, but not with ISI or pregnancy. Programming to strengthen youth assets may be a promising strategy for reducing youth sexual risk behaviors. Copyright © 2013 Society for Adolescent Health and Medicine. All rights reserved.

Early Head Growth in Infants at Risk of Autism: A Baby Siblings Research Consortium Study

PubMed Central

Zwaigenbaum, Lonnie; Young, Gregory S.; Stone, Wendy L.; Dobkins, Karen; Ozonoff, Sally; Brian, Jessica; Bryson, Susan E.; Carver, Leslie J.; Hutman, Ted; Iverson, Jana M.; Landa, Rebecca J.; Messinger, Daniel

2014-01-01

Objective: While early brain overgrowth is frequently reported in autism spectrum disorder (ASD), the relationship between ASD and head circumference (HC) is less clear, with inconsistent findings from longitudinal studies that include community controls. Our aim was to examine whether head growth in the first 3 years differed between children with ASD from a high-risk (HR) sample of infant siblings of children with ASD (by definition, multiplex), HR siblings not diagnosed with ASD, and low-risk (LR) controls. Method: Participants included 442 HR and 253 LR infants from 12 sites of the international Baby Siblings Research Consortium. Longitudinal HC data were obtained prospectively, supplemented by growth records. Random effects non-linear growth models were used to compare HC in HR infants and LR infants. Additional comparisons were conducted with the HR group stratified by diagnostic status at age 3: ASD (n=77), developmental delay (DD; n=32), and typical development (TD; n=333). Nonlinear growth models were also developed for height to assess general overgrowth associated with ASD. Results: There was no overall difference in head circumference growth over the first 3 years between HR and LR infants, although secondary analyses suggested possible increased total growth in HR infants, reflected by the model asymptote. Analyses stratifying the HR group by 3-year outcomes did not detect differences in head growth or height between HR infants who developed ASD and those who did not, nor between infants with ASD and LR controls. Conclusion: Head growth was uninformative as an ASD risk marker within this HR cohort. PMID:25245349

14 CFR 25.201 - Stall demonstration.

Code of Federal Regulations, 2010 CFR

2010-01-01

...; or (3) The pitch control reaches the aft stop and no further increase in pitch attitude occurs when... steady rate of speed reduction can be established, apply the longitudinal control so that the speed... flight stalls, apply the longitudinal control to achieve airspeed deceleration rates up to 3 knots per...

14 CFR 25.201 - Stall demonstration.

Code of Federal Regulations, 2012 CFR

2012-01-01

...; or (3) The pitch control reaches the aft stop and no further increase in pitch attitude occurs when... steady rate of speed reduction can be established, apply the longitudinal control so that the speed... flight stalls, apply the longitudinal control to achieve airspeed deceleration rates up to 3 knots per...

14 CFR 25.201 - Stall demonstration.

Code of Federal Regulations, 2014 CFR

2014-01-01

...; or (3) The pitch control reaches the aft stop and no further increase in pitch attitude occurs when... steady rate of speed reduction can be established, apply the longitudinal control so that the speed... flight stalls, apply the longitudinal control to achieve airspeed deceleration rates up to 3 knots per...

14 CFR 25.201 - Stall demonstration.

Code of Federal Regulations, 2011 CFR

2011-01-01

...; or (3) The pitch control reaches the aft stop and no further increase in pitch attitude occurs when... steady rate of speed reduction can be established, apply the longitudinal control so that the speed... flight stalls, apply the longitudinal control to achieve airspeed deceleration rates up to 3 knots per...

14 CFR 25.201 - Stall demonstration.

Code of Federal Regulations, 2013 CFR

2013-01-01

...; or (3) The pitch control reaches the aft stop and no further increase in pitch attitude occurs when... steady rate of speed reduction can be established, apply the longitudinal control so that the speed... flight stalls, apply the longitudinal control to achieve airspeed deceleration rates up to 3 knots per...

Longitudinal Effects of Perceived Control on Academic Achievement

ERIC Educational Resources Information Center

You, Sukkyung; Hong, Sehee; Ho, Hsiu-Zu

2011-01-01

It is well established that perceived control plays an important role in student academic achievement, but little is known about its longitudinal stability, ethnic variation, and developmental effects on subsequent achievement during adolescence. Findings from this study indicated (a) perceived control remains stable during adolescence for each of…

76 FR 46213 - National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-02

... design and application of traffic control devices, this Manual should not be considered a substitute for... retroreflectivity of longitudinal pavement markings. The deadline for comments to that docket has passed and the... the proposed revisions regarding maintaining minimum retroreflectivity of longitudinal pavement...

The manual control of vehicles undergoing slow transitions in dynamic characteristics

NASA Technical Reports Server (NTRS)

Moriarty, T. E.

1974-01-01

The manual control was studied of a vehicle with slowly time-varying dynamics to develop analytic and computer techniques necessary for the study of time-varying systems. The human operator is considered as he controls a time-varying plant in which the changes are neither abrupt nor so slow that the time variations are unimportant. An experiment in which pilots controlled the longitudinal mode of a simulated time-varying aircraft is described. The vehicle changed from a pure double integrator to a damped second order system, either instantaneously or smoothly over time intervals of 30, 75, or 120 seconds. The regulator task consisted of trying to null the error term resulting from injected random disturbances with bandwidths of 0.8, 1.4, and 2.0 radians per second. Each of the twelve experimental conditons was replicated ten times. It is shown that the pilot's performance in the time-varying task is essentially equivalent to his performance in stationary tasks which correspond to various points in the transition. A rudimentary model for the pilot-vehicle-regulator is presented.

Worksite Tobacco Prevention: A Randomized, Controlled Trial of Adoption, Dissemination Strategies, and Aggregated Health-Related Outcomes across Companies.

PubMed

Friedrich, Verena; Brügger, Adrian; Bauer, Georg F

2015-01-01

Evidence based public health requires knowledge about successful dissemination of public health measures. This study analyses (a) the changes in worksite tobacco prevention (TP) in the Canton of Zurich, Switzerland, between 2007 and 2009; (b1) the results of a multistep versus a "brochure only" dissemination strategy; (b2) the results of a monothematic versus a comprehensive dissemination strategy that aim to get companies to adopt TP measures; and (c) whether worksite TP is associated with health-related outcomes. A longitudinal design with randomized control groups was applied. Data on worksite TP and health-related outcomes were gathered by a written questionnaire (baseline n = 1627; follow-up n = 1452) and analysed using descriptive statistics, nonparametric procedures, and ordinal regression models. TP measures at worksites improved slightly between 2007 and 2009. The multistep dissemination was superior to the "brochure only" condition. No significant differences between the monothematic and the comprehensive dissemination strategies were observed. However, improvements in TP measures at worksites were associated with improvements in health-related outcomes. Although dissemination was approached at a mass scale, little change in the advocated adoption of TP measures was observed, suggesting the need for even more aggressive outreach or an acceptance that these channels do not seem to be sufficiently effective.

Evaluation of complex community-based childhood obesity prevention interventions.

PubMed

Karacabeyli, D; Allender, S; Pinkney, S; Amed, S

2018-05-16

Multi-setting, multi-component community-based interventions have shown promise in preventing childhood obesity; however, evaluation of these complex interventions remains a challenge. The objective of the study is to systematically review published methodological approaches to outcome evaluation for multi-setting community-based childhood obesity prevention interventions and synthesize a set of pragmatic recommendations. MEDLINE, CINAHL and PsycINFO were searched from inception to 6 July 2017. Papers were included if the intervention targeted children ≤18 years, engaged at least two community sectors and described their outcome evaluation methodology. A single reviewer conducted title and abstract scans, full article review and data abstraction. Directed content analysis was performed by three reviewers to identify prevailing themes. Thirty-three studies were included, and of these, 26 employed a quasi-experimental design; the remaining were randomized control trials. Body mass index was the most commonly measured outcome, followed by health behaviour change and psychosocial outcomes. Six themes emerged, highlighting advantages and disadvantages of active vs. passive consent, quasi-experimental vs. randomized control trials, longitudinal vs. repeat cross-sectional designs and the roles of process evaluation and methodological flexibility in evaluating complex interventions. Selection of study designs and outcome measures compatible with community infrastructure, accompanied by process evaluation, may facilitate successful outcome evaluation. © 2018 World Obesity Federation.

Using social-emotional and character development to improve academic outcomes: a matched-pair, cluster-randomized controlled trial in low-income, urban schools

PubMed Central

Lewis, Kendra M.; DuBois, David L.; Acock, Alan; Vuchinich, Samuel; Silverthorn, Naida; Snyder, Frank J.; Day, Joseph; Ji, Peter; Flay, Brian R.

2013-01-01

BACKGROUND School-based social-emotional and character development (SECD) programs can influence not only SECD, but also academic-related outcomes. This study evaluated the impact of one SECD program, Positive Action (PA), on educational outcomes among low-income, urban youth. METHODS The longitudinal study used a matched-pair, cluster-randomized controlled design. Student-reported disaffection with learning and academic grades, and teacher ratings of academic ability and motivation were assessed for a cohort followed from grades 3 to 8. Aggregate school records were used to assess standardized test performance (for entire school, cohort, and demographic subgroups) and absenteeism (entire school). Multilevel growth-curve analyses tested program effects. RESULTS PA significantly improved growth in academic motivation and mitigated disaffection with learning. There was a positive impact of PA on absenteeism and marginally significant impact on math performance of all students. There were favorable program effects on reading for African American boys and cohort students transitioning between grades 7 and 8, and on math for girls and low-income students. CONCLUSIONS A school-based SECD program was found to influence academic outcomes among students living in low-income, urban communities. Future research should examine mechanisms by which changes in SECD influence changes in academic outcomes. PMID:24138347

Stochastic resonance training reduces musculoskeletal symptoms in metal manufacturing workers: a controlled preventive intervention study.

PubMed

Burger, Christian; Schade, Volker; Lindner, Christina; Radlinger, Lorenz; Elfering, Achim

2012-01-01

This study examined the effects of stochastic resonance whole-body vibration training on work-related musculoskeletal symptoms and accidents. Participants were white and blue-collar employees of a Swiss metal manufacturer (N=38), and participation was voluntary. The study was designed as a switching-replications longitudinal trial with randomized group allocation. The randomized controlled cross-over design consisted of two groups each given four weeks of exercise and no intervention during a second four-week period. Outcome was measured on a daily basis with questionnaires. Three components constituted musculoskeletal symptoms: musculoskeletal pain, related function limitations and musculoskeletal well-being. Accidents were assessed by ratings for balance and daily near-accidents. For statistical analysis, a mixed model was calculated. At the end of the training period musculoskeletal pain and related function limitation were significantly reduced, whereas musculoskeletal well-being had significantly increased. For function limitation and musculoskeletal well-being, change over time was linear. There was no effect on balance or near-accidents. Stochastic resonance whole-body vibration was found to be effective in the prevention of work-related musculoskeletal symptoms. It is well suited for the use in a work environment since it requires very little effort in terms of infrastructure, time and investment from participants.

Effectiveness of self-management promotion educational program among diabetic patients based on health belief model

PubMed Central

Jalilian, Farzad; Motlagh, Fazel Zinat; Solhi, Mahnaz; Gharibnavaz, Hasan

2014-01-01

Introduction: Diabetes is a chronic disease; it can cause serious complications. Diabetes self-management is essential for prevention of disease complications. This study was conducted to evaluate self-management promotion educational program intervention efficiency among diabetic patients in Iran and health belief model (HBM) was applied as a theoretical framework. Materials and Methods: Overall, 120 Type 2 diabetic patients referred to rural health centers in Gachsaran, Iran participated in this study as randomly divided into intervention and control group. This was a longitudinal randomized pre- and post-test series control group design panel study to implement a behavior modification based intervention to promotion self-management among diabetic patients. Cross-tabulation and t-test by using SPSS statistical package, version 16 was used for the statistical analysis. Results: Mean age was 55.07 years (SD = 9.94, range: 30-70). Our result shows significant improvements in average response for susceptibility, severity, benefit and self-management among intervention group. Additionally, after intervention, average response of the barrier to self-management was decreased among intervention group. Conclusion: Our result showed education program based on HBM was improve of self-management and seems implementing these programs can be effective in the and prevention of diabetes complications. PMID:24741654

Novel approaches for the management of tendinopathy.

PubMed

Maffulli, Nicola; Longo, Umile Giuseppe; Denaro, Vincenzo

2010-11-03

Tendinopathy is a failed healing response of the tendon. Despite an abundance of therapeutic options, very few randomized prospective, placebo-controlled trials have been carried out to assist physicians in choosing the best evidence-based management. Eccentric exercises have been proposed to promote collagen fiber cross-link formation within the tendon, thereby facilitating tendon remodeling. Overall results suggest a trend for a positive effect of eccentric exercises, with no reported adverse effects. Combining eccentric training and shock wave therapy produces higher success rates compared with eccentric loading alone or shock wave therapy alone. The use of injectable substances such as platelet-rich plasma, autologous blood, polidocanol, corticosteroids, and aprotinin in and around tendons is popular, but there is minimal clinical evidence to support their use. The aim of operative treatment is to excise fibrotic adhesions, remove areas of failed healing, and make multiple longitudinal incisions in the tendon to detect intratendinous lesions and to restore vascularity and possibly stimulate the remaining viable cells to initiate cell matrix response and healing. New operative procedures include endoscopy, electrocoagulation, and minimally invasive stripping. The aim of these techniques is to disrupt the abnormal neoinnervation to interfere with the pain sensation caused by tendinopathy. Randomized controlled trials are necessary to better clarify the best therapeutic options for the management of tendinopathy.

Using social-emotional and character development to improve academic outcomes: a matched-pair, cluster-randomized controlled trial in low-income, urban schools.

PubMed

Bavarian, Niloofar; Lewis, Kendra M; Dubois, David L; Acock, Alan; Vuchinich, Samuel; Silverthorn, Naida; Snyder, Frank J; Day, Joseph; Ji, Peter; Flay, Brian R

2013-11-01

School-based social-emotional and character development (SECD) programs can influence not only SECD but also academic-related outcomes. This study evaluated the impact of one SECD program, Positive Action (PA), on educational outcomes among low-income, urban youth. The longitudinal study used a matched-pair, cluster-randomized controlled design. Student-reported disaffection with learning and academic grades, and teacher ratings of academic ability and motivation were assessed for a cohort followed from grades 3 to 8. Aggregate school records were used to assess standardized test performance (for entire school, cohort, and demographic subgroups) and absenteeism (entire school). Multilevel growth-curve analyses tested program effects. PA significantly improved growth in academic motivation and mitigated disaffection with learning. There was a positive impact of PA on absenteeism and marginally significant impact on math performance of all students. There were favorable program effects on reading for African American boys and cohort students transitioning between grades 7 and 8, and on math for girls and low-income students. A school-based SECD program was found to influence academic outcomes among students living in low-income, urban communities. Future research should examine mechanisms by which changes in SECD influence changes in academic outcomes. © 2013, American School Health Association.

Acute and Chronic Effects of Endurance Running on Inflammatory Markers: A Systematic Review

PubMed Central

Barros, Edilberto S.; Nascimento, Dahan C.; Prestes, Jonato; Nóbrega, Otávio T.; Córdova, Claúdio; Sousa, Fernando; Boullosa, Daniel A.

2017-01-01

In order to understand the effect of endurance running on inflammation, it is necessary to quantify the extent to which acute and chronic running affects inflammatory mediators. The aim of this study was to summarize the literature on the effects of endurance running on inflammation mediators. Electronic searches were conducted on PubMED and Science Direct with no limits of date and language of publication. Randomized controlled trials (RCTs) and non-randomized controlled trials (NRCTs) investigating the acute and chronic effects of running on inflammation markers in runners were reviewed by two researchers for eligibility. The modified Downs and Black checklist for the assesssments of the methodological quality of studies was subsequently used. Fifty-one studies were finally included. There were no studies with elite athletes. Only two studies were chronic interventions. Results revealed that acute and chronic endurance running may affect anti- and pro-inflammatory markers but methodological differences between studies do not allow comparisons or generalization of the results. The information provided in this systematic review would help practitioners for better designing further studies while providing reference values for a better understanding of inflammatory responses after different running events. Further longitudinal studies are needed to identify the influence of training load parameters on inflammatory markers in runners of different levels and training background. PMID:29089897

Worksite Tobacco Prevention: A Randomized, Controlled Trial of Adoption, Dissemination Strategies, and Aggregated Health-Related Outcomes across Companies

PubMed Central

Friedrich, Verena; Brügger, Adrian; Bauer, Georg F.

2015-01-01

Evidence based public health requires knowledge about successful dissemination of public health measures. This study analyses (a) the changes in worksite tobacco prevention (TP) in the Canton of Zurich, Switzerland, between 2007 and 2009; (b1) the results of a multistep versus a “brochure only” dissemination strategy; (b2) the results of a monothematic versus a comprehensive dissemination strategy that aim to get companies to adopt TP measures; and (c) whether worksite TP is associated with health-related outcomes. A longitudinal design with randomized control groups was applied. Data on worksite TP and health-related outcomes were gathered by a written questionnaire (baseline n = 1627; follow-up n = 1452) and analysed using descriptive statistics, nonparametric procedures, and ordinal regression models. TP measures at worksites improved slightly between 2007 and 2009. The multistep dissemination was superior to the “brochure only” condition. No significant differences between the monothematic and the comprehensive dissemination strategies were observed. However, improvements in TP measures at worksites were associated with improvements in health-related outcomes. Although dissemination was approached at a mass scale, little change in the advocated adoption of TP measures was observed, suggesting the need for even more aggressive outreach or an acceptance that these channels do not seem to be sufficiently effective. PMID:26504778

Coffee, caffeine, and sleep: A systematic review of epidemiological studies and randomized controlled trials.

PubMed

Clark, Ian; Landolt, Hans Peter

2017-02-01

Caffeine is the most widely consumed psychoactive substance in the world. It is readily available in coffee and other foods and beverages, and is used to mitigate sleepiness, enhance performance, and treat apnea in premature infants. This review systematically explores evidence from epidemiological studies and randomized controlled trials as to whether coffee and caffeine have deleterious effects on sleep. Caffeine typically prolonged sleep latency, reduced total sleep time and sleep efficiency, and worsened perceived sleep quality. Slow-wave sleep and electroencephalographic (EEG) slow-wave activity were typically reduced, whereas stage-1, wakefulness, and arousals were increased. Dose- and timing-response relationships were established. The sleep of older adults may be more sensitive to caffeine compared to younger adults. Pronounced individual differences are also present in young people, and genetic studies isolated functional polymorphisms of genes implicated in adenosine neurotransmission and metabolism contributing to individual sensitivity to sleep disruption by caffeine. Most studies were conducted in male adults of Western countries, which limits the generalizability of the findings. Given the importance of good sleep for general health and functioning, longitudinal investigations aimed at establishing possible causal relationships among coffee- and caffeine-induced changes in sleep quality and health development are warranted. Copyright © 2016 Elsevier Ltd. All rights reserved.

Giant transversal particle diffusion in a longitudinal magnetic ratchet.

PubMed

Tierno, Pietro; Reimann, Peter; Johansen, Tom H; Sagués, Francesc

2010-12-03

We study the transversal motion of paramagnetic particles on a uniaxial garnet film, exhibiting a longitudinal ratchet effect in the presence of an oscillating magnetic field. Without the field, the thermal diffusion coefficient obtained by video microscopy is D(0) ≈ 3 × 10(-4)  μm2/s. With the field, the transversal diffusion exhibits a giant enhancement by almost four decades and a pronounced maximum as a function of the driving frequency. We explain the experimental findings with a theoretical interpretation in terms of random disorder effects within the magnetic film.

Interviewer effects on non-response propensity in longitudinal surveys: a multilevel modelling approach

PubMed Central

Vassallo, Rebecca; Durrant, Gabriele B; Smith, Peter W F; Goldstein, Harvey

2015-01-01

The paper investigates two different multilevel approaches, the multilevel cross-classified and the multiple-membership models, for the analysis of interviewer effects on wave non-response in longitudinal surveys. The models proposed incorporate both interviewer and area effects to account for the non-hierarchical structure, the influence of potentially more than one interviewer across waves and possible confounding of area and interviewer effects arising from the non-random allocation of interviewers across areas. The methods are compared by using a data set: the UK Family and Children Survey. PMID:25598587

An Investigation of the Aerodynamic Characteristics of an 0.08-Scale Model of the Chance Vought XF7U-1 Airplane in the Langley High-Speed 7- by 10-Foot Tunnel. Part III - Longitudinal-Control Characteristics TED No. NACA DE308. Part 3; Longitudinal-Control Characteristics, TED No. NACA DE308

NASA Technical Reports Server (NTRS)

Kuhn, Richard E.; King, Thomas J., Jr.

1947-01-01

Tests have been conducted in the Langley high speed 7- by 10-foot tunnel over a Mach number range from 0.40 to 0.91 to determine the stability and control characteristics of an 0,08-scale model of the Chance Vought XF7U-1 airplane. The longitudinal-control characteristics of the complete model are presented in the present report with a limited analysis of the results.

Analysis of in-trail following dynamics of CDTI-equipped aircraft. [Cockpit Displays of Traffic Information

NASA Technical Reports Server (NTRS)

Sorensen, J. A.; Goka, T.

1982-01-01

In connection with the necessity to provide greater terminal area capacity, attention is given to approaches in which the required increase in capacity will be obtained by making use of more automation and by involving the pilot to a larger degree in the air traffic control (ATC) process. It was recommended that NASA should make extensive use of its research aircraft and cockpit simulators to assist the FAA in examining the capabilities and limitations of cockpit displays of traffic information (CDTI). A program was organized which utilizes FAA ATC (ground-based) simulators and NASA aircraft and associated cockpit simulators in a research project which explores applications of the CDTI system. The present investigation is concerned with several questions related to the CDTI-based terminal area traffic tactical control concepts. Attention is given to longitudinal separation criteria, a longitudinal following model, longitudinal capture, combined longitudinal/vertical control, and lateral control.

Distinguishing between tectonic and lithologic controls on bedrock channel longitudinal profiles using cosmogenic 10Be erosion rates and channel steepness index

USGS Publications Warehouse

Cyr, Andrew J.; Granger, Darryl E.; Olivetti, Valerio; Molin, Paola

2014-01-01

Knickpoints in fluvial channel longitudinal profiles and channel steepness index values derived from digital elevation data can be used to detect tectonic structures and infer spatial patterns of uplift. However, changes in lithologic resistance to channel incision can also influence the morphology of longitudinal profiles. We compare the spatial patterns of both channel steepness index and cosmogenic 10Be-determined erosion rates from four landscapes in Italy, where the geology and tectonics are well constrained, to four theoretical predictions of channel morphologies, which can be interpreted as the result of primarily tectonic or lithologic controls. These data indicate that longitudinal profile forms controlled by unsteady or nonuniform tectonics can be distinguished from those controlled by nonuniform lithologic resistance. In each landscape the distribution of channel steepness index and erosion rates is consistent with model predictions and demonstrates that cosmogenic nuclide methods can be applied to distinguish between these two controlling factors.

Living with systemic lupus erythematosus in the developing world.

PubMed

Phuti, A; Schneider, M; Tikly, M; Hodkinson, B

2018-03-26

Most of our understanding of SLE and its negative impact originates from developed countries. This review aims to collate existing literature on Health-Related Quality of Life (HRQoL) in SLE patients living in developing countries to identify the gaps for the focus of future research. A narrative literature review was compiled using selected MeSH terms to search EBSCOHOST for articles published between January 1975 and February 2018 pertaining to HRQoL in SLE patients in developing countries. 31 studies from 11 countries were included for analysis. Only one longitudinal, one randomized controlled trial (RCT), one qualitative study, and two intervention studies were found. High disease activity and organ damage were associated with poor functional ability, mental health and low socio-economic status (SES). Poor SES is a recurring theme in developing countries, and worsens all SLE outcomes by reducing access to healthcare, mental, social and emotional support systems. In developing countries, SLE has a globally negative impact on patients' HRQoL, similar to that seen in developed countries. There is an urgent need for more HRQoL studies, and in particular, longitudinal, qualitative and interventional studies in these countries to investigate unmet needs, and to explore novel strategies to improve patient outcomes.

Why do boys eat less fruit and vegetables than girls?

PubMed

Bere, Elling; Brug, Johannes; Klepp, Knut-Inge

2008-03-01

To explore why boys eat less fruit and vegetables (F&V) than girls, using longitudinal data following pupils from the age of 12.5 to 15.5 years, including perceived accessibility, modelling, intention, preferences, self-efficacy and knowledge of recommendations as potential mediators. A longitudinal study, based on data collected among the control schools within the intervention project 'Fruits and Vegetables Make the Marks'. This sample contains 896 6th and 7th graders from 20 randomly selected elementary schools within two Norwegian counties. Questionnaires were administered in May 2002 and May 2005 (when the participants were in 9th and 10th grade in 18 secondary elementary schools). In single mediation analyses all determinants mediated parts of the gender difference, but only preferences decreased the gender difference to a level below statistical significance. Preferences alone explained 81% of the gender difference. In the multiple mediation analyses, the six mediators together explained 91% of the gender difference, but only preferences and perceived accessibility contributed uniquely to the explanation, with 25% and 10% respectively. Preference appears as the strongest mediator of the difference in F&V intakes between boys and girls. Further research should explore why girls like F&V more than boys.

E-Rehabilitation - an Internet and mobile phone based tailored intervention to enhance self-management of cardiovascular disease: study protocol for a randomized controlled trial.

PubMed

Antypas, Konstantinos; Wangberg, Silje C

2012-07-09

Cardiac rehabilitation is very important for the recovery and the secondary prevention of cardiovascular disease, and one of its main strategies is to increase the level of physical activity. Internet and mobile phone based interventions have been successfully used to help people to achieve this. One of the components that are related to the efficacy of these interventions is tailoring of content to the individual. This trial is studying the effect of a longitudinally tailored Internet and mobile phone based intervention that is based on models of health behaviour, on the level of physical activity and the adherence to the intervention, as an extension of a face-to-face cardiac rehabilitation stay. A parallel group, cluster randomized controlled trial. The study population is adult participants of a cardiac rehabilitation programme in Norway with home Internet access and mobile phone, who in monthly clusters are randomized to the control or the intervention condition. Participants have access to a website with information regarding cardiac rehabilitation, an online discussion forum and an online activity calendar. Those randomized to the intervention condition, receive in addition tailored content based on models of health behaviour, through the website and mobile text messages. The objective is to assess the effect of the intervention on maintenance of self-management behaviours after the rehabilitation stay. Main outcome is the level of physical activity one month, three months and one year after the end of the cardiac rehabilitation programme. The randomization of clusters is based on a true random number online service, and participants, investigators and outcome assessor are blinded to the condition of the clusters. The study suggests a theory-based intervention that combines models of health behaviour in an innovative way, in order to tailor the delivered content. The users have been actively involved in its design, and because of the use of Open-Source software, the intervention can easily and at low-cost be reproduced and expanded by others. Challenges are the recruitment in the elderly population and the possible underrepresentation of women in the study sample. Funding by Northern Norway Regional Health Authority. Trial registry http://www.clinicaltrials.gov: NCT01223170.

Happiness as a motivator: positive affect predicts primary control striving for career and educational goals.

PubMed

Haase, Claudia M; Poulin, Michael J; Heckhausen, Jutta

2012-08-01

What motivates individuals to invest time and effort and overcome obstacles (i.e., strive for primary control) when pursuing important goals? We propose that positive affect predicts primary control striving for career and educational goals, and we explore the mediating role of control beliefs. In Study 1, positive affect predicted primary control striving for career goals in a two-wave longitudinal study of a U.S. sample. In Study 2, positive affect predicted primary control striving for career and educational goals and objective career outcomes in a six-wave longitudinal study of a German sample. Control beliefs partially mediated the longitudinal associations with primary control striving. Thus, when individuals experience positive affect, they become more motivated to invest time and effort, and overcome obstacles when pursuing their goals, in part because they believe they have more control over attaining their goals.

Chondron curvature mapping in growth plate cartilage under compressive loading.

PubMed

Vendra, Bhavya B; Roan, Esra; Williams, John L

2018-05-18

The physis, or growth plate, is a layer of cartilage responsible for long bone growth. It is organized into reserve, proliferative and hypertrophic zones. Unlike the reserve zone where chondrocytes are randomly arranged, either singly or in pairs, the proliferative and hypertrophic chondrocytes are arranged within tubular structures called chondrons. In previous studies, the strain patterns within the compressed growth plate have been reported to be nonuniform and inhomogeneous, with an apparent random pattern in compressive strains and a localized appearance of tensile strains. In this study we measured structural deformations along the entire lengths of chondrons when the physis was subjected to physiological (20%) and hyper-physiological (30% and 40%) levels of compression. This provided a means to interpret the apparent random strain patterns seen in texture correlation maps in terms of bending deformations of chondron structures and provided a physical explanation for the inhomogeneous and nonuniform strain patterns reported in previous studies. We observed relatively large bending deformations (kinking) of the chondron structures at the interface of the reserve and proliferative zones during compression. Bending in this region may induce dividing cells to align longitudinally to maintain column formation and drive longitudinal growth. Copyright © 2018 Elsevier Ltd. All rights reserved.

Not merely a question of self-control: The longitudinal effects of overeating behaviors, diet quality and physical activity on dieters' perceived diet success.

PubMed

Keller, Carmen; Hartmann, Christina

2016-12-01

This longitudinal study was conducted between 2010 (T1) and 2014 (T2) on a random sample from the general Swiss population (N = 2781, 46% male). Results showed that dieters (restrained eaters) who reported lack of success in T2 were overweight in T1, had higher levels of emotional and external eating, overeating, and ambivalence toward eating palatable food in T1, and a significantly increased body mass index (BMI) in the period between T1 and T2. Dieters who reported success in T2 had maintained a normal BMI between T1 and T2, had a higher diet quality in T1 and had maintained regular physical activity for at least one year before T2. The logistic regression revealed that high levels of dispositional self-control provided the most important predictor of being a successful dieter. When controlling for dispositional self-control, high levels of emotional eating, overeating, and ambivalence in T1, together with increases in these levels between T1 and T2, were associated with a decreased likelihood of being a successful dieter in T2. High levels of diet quality in T1 and the maintenance of regular physical activity were associated with an increased likelihood of being a successful dieter in T2. Results suggest that diet success and failure is a long-term phenomenon, partly but not fully explained by dispositional self-control. Independent of self-control persistent patterns of overeating due to emotional eating and ambivalent feelings toward eating palatable food, also explain long-term diet failure. A high diet quality and maintenance of regular physical activity accounted for dieters' long-term success. This is the first study that examined the long-term psychological and behavioral characteristics of successful and unsuccessful restrained eaters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Estimating onset time from longitudinal and cross-sectional data with an application to estimating gestational age from longitudinal maternal anthropometry during pregnancy and neonatal anthropometry at birth.

PubMed

Ortega-Villa, Ana Maria; Grantz, Katherine L; Albert, Paul S

2018-06-01

Determining the date of conception is important for estimating gestational age and monitoring whether the fetus and mother are on track in their development and pregnancy. Various methods based on ultrasound have been proposed for dating a pregnancy in high resource countries. However, such techniques may not be available in under-resourced countries. We develop a shared random parameter model for estimating the date of conception using longitudinal assessment of multiple maternal anthropometry and cross-sectional neonatal anthropometry. The methodology is evaluated with a training-test set paradigm as well as with simulations to examine the robustness of the method to model misspecification. We illustrate this new methodology with data from the NICHD Fetal Growth Studies.

Accelerated telomere shortening: Tracking the lasting impact of early institutional care at the cellular level.

PubMed

Humphreys, Kathryn L; Esteves, Kyle; Zeanah, Charles H; Fox, Nathan A; Nelson, Charles A; Drury, Stacy S

2016-12-30

Studies examining the association between early adversity and longitudinal changes in telomere length within the same individual are rare, yet are likely to provide novel insight into the subsequent lasting effects of negative early experiences. We sought to examine the association between institutional care history and telomere shortening longitudinally across middle childhood and into adolescence. Buccal DNA was collected 2-4 times, between the ages of 6 and 15 years, in 79 children enrolled in the Bucharest Early Intervention Project (BEIP), a longitudinal study exploring the impact of early institutional rearing on child health and development. Children with a history of early institutional care (n=50) demonstrated significantly greater telomere shortening across middle childhood and adolescence compared to never institutionalized children (n=29). Among children with a history of institutional care, randomization to high quality foster care was not associated with differential telomere attrition across development. Cross-sectional analysis of children randomized to the care as usual group indicated shorter telomere length was associated with greater percent of the child's life spent in institutional care up to age 8. These results suggest that early adverse care from severe psychosocial deprivation may be embedded at the molecular genetic level through accelerated telomere shortening. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Accelerated telomere shortening: Tracking the lasting impact of early institutional care at the cellular level

PubMed Central

Humphreys, Kathryn L.; Esteves, Kyle; Zeanah, Charles H; Fox, Nathan A; Nelson, Charles A.; Drury, Stacy S.

2016-01-01

Studies examining the association between early adversity and longitudinal changes in telomere length within the same individual are rare, yet are likely to provide novel insight into the subsequent lasting effects of negative early experiences. We sought to examine the association between institutional care history and telomere shortening longitudinally across middle childhood and into adolescence. Buccal DNA was collected 2 to 4 times, between the ages of 6 and 15 years, in 79 children enrolled in the Bucharest Early Intervention Project (BEIP), a longitudinal study exploring the impact of early institutional rearing on child health and development. Children with a history of early institutional care (n=50) demonstrated significantly greater telomere shortening across middle childhood and adolescence compared to never institutionalized children (n=29). Among children with a history of institutional care, randomization to high quality foster care was not associated with differential telomere attrition across development. Cross-sectional analysis of children randomized to the care as usual group indicated shorter telomere length was associated with greater percent of the child’s life spent in institutional care up to age 8. These results suggest that early adverse care from severe psychosocial deprivation may be embedded at the molecular genetic level through accelerated telomere shortening. PMID:27677058

Benefit-Cost Analysis of a Randomized Evaluation of Communities That Care: Monetizing Intervention Effects on the Initiation of Delinquency and Substance Use Through Grade 12

PubMed Central

Kuklinski, Margaret R.; Fagan, Abigail A.; Hawkins, J. David; Briney, John S.; Catalano, Richard F.

2015-01-01

Objective To determine whether the Communities That Care (CTC) prevention system is a cost-beneficial intervention. Methods Data were from a longitudinal panel of 4,407 youth participating in a randomized controlled trial including 24 towns in 7 states, matched in pairs within state and randomly assigned to condition. Significant differences favoring intervention youth in sustained abstinence from delinquency, alcohol use, and tobacco use through Grade 12 were monetized and compared to economic investment in CTC. Results CTC was estimated to produce $4,477 in benefits per youth (discounted 2011 dollars). It cost $556 per youth to implement CTC for 5 years. The net present benefit was $3,920. The benefit-cost ratio was $8.22 per dollar invested. The internal rate of return was 21%. Risk that investment would exceed benefits was minimal. Investment was expected to be recouped within 9 years. Sensitivity analyses in which effects were halved yielded positive cost-beneficial results. Conclusions CTC is a cost-beneficial, community-based approach to preventing initiation of delinquency, alcohol use, and tobacco use. CTC is estimated to generate economic benefits that exceed implementation costs when disseminated with fidelity in communities. PMID:26213527

77 FR 39344 - Agency Information (Post-9/11 GI Bill Education Longitudinal Study Survey) Activity Under OMB Review

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-02

... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-New (Post-9/11 GI Bill Longitudinal Study Survey)] Agency Information (Post-9/11 GI Bill Education Longitudinal Study Survey) Activity Under OMB...-9/11 GI Bill Longitudinal Study Survey) in any correspondence For Further Information or a Copy of...

Centrifugal Expansion of Fundus Autofluorescence Patterns in Stargardt Disease Over Time

PubMed Central

Cukras, Catherine A.; Wong, Wai T.; Caruso, Rafael; Cunningham, Denise; Zein, Wadih; Sieving, Paul

2012-01-01

Objective Changing lipofuscin and melanin content in RPE cells has been hypothesized to contribute to Stargardt disease pathogenesis. Longitudinal study of autofluorescence in Stargardt disease which reflect changing fluorophore compositions can reveal aspects of disease progression not previously evident. Method We examined the temporal-spatial patterns of fundus autofluorescence with excitation at both 488 nm (standard fundus autofluorescence, FAF) and 795nm (near infrared autofluorescence, NIA) in a longitudinal case series involving 8 eyes of 4 patients (range of follow-up = 11 to 57 months; mean = 39 months). Image processing was performed to analyze spatial and temporal cross-modality associations. Results Longitudinal FAF imaging of fleck lesions revealed hyperautofluorescent lesions that extended in a centrifugal direction from the fovea with time. Patterns of spread were non-random and followed a radial path that leaves behind a trail of diminishing autofluorescence. Longitudinal NIA imaging also demonstrated centrifugal lesion spread, but with fewer hyperautofluorescent lesions, suggestive of more transient hyperautofluorescence and more rapid decay at longer wavelengths. FAF and NIA abnormalities were spatially correlated to each other, and together reflect systematic progressions in fleck distribution and fluorophore composition occurring during the natural history of the disease. Conclusion Stargardt disease fleck lesions do not evolve randomly in location but instead follow consistent patterns of radial expansion and a systematic decay of autofluorescence that reflect changing lipofuscin and melanin compositions in RPE cells. These progressive foveal-to-peripheral changes are helpful in elucidating molecular and cellular mechanisms underlying Stargardt disease and may constitute potential outcome measures in clinical trials. PMID:21987580

Family planning to promote physical activity: a randomized controlled trial protocol.

PubMed

Quinlan, Alison; Rhodes, Ryan E; Blanchard, Chris M; Naylor, Patti-Jean; Warburton, Darren E R

2015-10-05

Physical activity is associated with the reduction of several chronic conditions in adults. Additionally, physical activity is extremely important for children for their development and cognitive functioning and also to create a physically active lifestyle that continues into adulthood. Despite the known benefits of physical activity, only one in five adults are achieving the public health recommendations of 150 minutes of moderate-to-vigorous physical activity per week and only 13 % of boys and 6 % of girls between the ages of 5 and 17 years are meeting the guidelines of 60 minutes per day. This study aims to evaluate whether a planning condition improves adherence to regular physical activity compared to an education-only control condition among families. Families are eligible if there is at least one child between the ages of 6 and 12 years who is not meeting the Canadian Physical Activity Guidelines. A six-month longitudinal randomized controlled trial will be used to compare the two conditions. Materials will be delivered at baseline with 'booster' sessions at six weeks and three months. Participants will be assessed at baseline and at six months with a fitness test, as well as questionnaires and accelerometery at baseline, six weeks, three months and six months. A total of 137 families have been recruited thus far from Greater Victoria. This study is ongoing and recruitment will continue until December 2015 with the target goal of reaching 160 families. This protocol describes the implementation of a randomized controlled trial that utilizes planning strategies to try and increase physical activity among families. Research findings could be useful in public health in providing effective strategies to families to help decrease sedentary lifestyles. Additionally, findings may help to inform future interventions aimed at increasing physical activity among families. This trial was registered on June 5, 2012 with the Clinical Trials Registry maintained by the National Library of Medicine at the National Institutes of Health. The registration ID is NCT01882192.

Assessment of the effect of population and diary sampling methods on estimation of school-age children exposure to fine particles.

PubMed

Che, W W; Frey, H Christopher; Lau, Alexis K H

2014-12-01

Population and diary sampling methods are employed in exposure models to sample simulated individuals and their daily activity on each simulation day. Different sampling methods may lead to variations in estimated human exposure. In this study, two population sampling methods (stratified-random and random-random) and three diary sampling methods (random resampling, diversity and autocorrelation, and Markov-chain cluster [MCC]) are evaluated. Their impacts on estimated children's exposure to ambient fine particulate matter (PM2.5 ) are quantified via case studies for children in Wake County, NC for July 2002. The estimated mean daily average exposure is 12.9 μg/m(3) for simulated children using the stratified population sampling method, and 12.2 μg/m(3) using the random sampling method. These minor differences are caused by the random sampling among ages within census tracts. Among the three diary sampling methods, there are differences in the estimated number of individuals with multiple days of exposures exceeding a benchmark of concern of 25 μg/m(3) due to differences in how multiday longitudinal diaries are estimated. The MCC method is relatively more conservative. In case studies evaluated here, the MCC method led to 10% higher estimation of the number of individuals with repeated exposures exceeding the benchmark. The comparisons help to identify and contrast the capabilities of each method and to offer insight regarding implications of method choice. Exposure simulation results are robust to the two population sampling methods evaluated, and are sensitive to the choice of method for simulating longitudinal diaries, particularly when analyzing results for specific microenvironments or for exposures exceeding a benchmark of concern. © 2014 Society for Risk Analysis.

A Joint Model for Longitudinal Measurements and Survival Data in the Presence of Multiple Failure Types

PubMed Central

Elashoff, Robert M.; Li, Gang; Li, Ning

2009-01-01

Summary In this article we study a joint model for longitudinal measurements and competing risks survival data. Our joint model provides a flexible approach to handle possible nonignorable missing data in the longitudinal measurements due to dropout. It is also an extension of previous joint models with a single failure type, offering a possible way to model informatively censored events as a competing risk. Our model consists of a linear mixed effects submodel for the longitudinal outcome and a proportional cause-specific hazards frailty submodel (Prentice et al., 1978, Biometrics 34, 541-554) for the competing risks survival data, linked together by some latent random effects. We propose to obtain the maximum likelihood estimates of the parameters by an expectation maximization (EM) algorithm and estimate their standard errors using a profile likelihood method. The developed method works well in our simulation studies and is applied to a clinical trial for the scleroderma lung disease. PMID:18162112

Extending cluster Lot Quality Assurance Sampling designs for surveillance programs

PubMed Central

Hund, Lauren; Pagano, Marcello

2014-01-01

Lot quality assurance sampling (LQAS) has a long history of applications in industrial quality control. LQAS is frequently used for rapid surveillance in global health settings, with areas classified as poor or acceptable performance based on the binary classification of an indicator. Historically, LQAS surveys have relied on simple random samples from the population; however, implementing two-stage cluster designs for surveillance sampling is often more cost-effective than simple random sampling. By applying survey sampling results to the binary classification procedure, we develop a simple and flexible non-parametric procedure to incorporate clustering effects into the LQAS sample design to appropriately inflate the sample size, accommodating finite numbers of clusters in the population when relevant. We use this framework to then discuss principled selection of survey design parameters in longitudinal surveillance programs. We apply this framework to design surveys to detect rises in malnutrition prevalence in nutrition surveillance programs in Kenya and South Sudan, accounting for clustering within villages. By combining historical information with data from previous surveys, we design surveys to detect spikes in the childhood malnutrition rate. PMID:24633656

Altering school climate through school-wide Positive Behavioral Interventions and Supports: findings from a group-randomized effectiveness trial.

PubMed

Bradshaw, Catherine P; Koth, Christine W; Thornton, Leslie A; Leaf, Philip J

2009-06-01

Positive Behavioral Interventions and Supports (PBIS) is a universal, school-wide prevention strategy that is currently implemented in over 7,500 schools to reduce disruptive behavior problems. The present study examines the impact of PBIS on staff reports of school organizational health using data from a group-randomized controlled effectiveness trial of PBIS conducted in 37 elementary schools. Longitudinal multilevel analyses on data from 2,596 staff revealed a significant effect of PBIS on the schools' overall organizational health, resource influence, staff affiliation, and academic emphasis over the 5-year trial; the effects on collegial leadership and institutional integrity were significant when implementation fidelity was included in the model. Trained schools that adopted PBIS the fastest tended to have higher levels of organizational health at baseline, but the later-implementing schools tended to experience the greatest improvements in organizational health after implementing PBIS. This study indicated that changes in school organizational health are important consequences of the PBIS whole-school prevention model, and may in turn be a potential contextual mediator of the effect of PBIS on student performance.

Extending cluster lot quality assurance sampling designs for surveillance programs.

PubMed

Hund, Lauren; Pagano, Marcello

2014-07-20

Lot quality assurance sampling (LQAS) has a long history of applications in industrial quality control. LQAS is frequently used for rapid surveillance in global health settings, with areas classified as poor or acceptable performance on the basis of the binary classification of an indicator. Historically, LQAS surveys have relied on simple random samples from the population; however, implementing two-stage cluster designs for surveillance sampling is often more cost-effective than simple random sampling. By applying survey sampling results to the binary classification procedure, we develop a simple and flexible nonparametric procedure to incorporate clustering effects into the LQAS sample design to appropriately inflate the sample size, accommodating finite numbers of clusters in the population when relevant. We use this framework to then discuss principled selection of survey design parameters in longitudinal surveillance programs. We apply this framework to design surveys to detect rises in malnutrition prevalence in nutrition surveillance programs in Kenya and South Sudan, accounting for clustering within villages. By combining historical information with data from previous surveys, we design surveys to detect spikes in the childhood malnutrition rate. Copyright © 2014 John Wiley & Sons, Ltd.

A Longitudinal Study on Resting State Functional Connectivity in Behavioral Variant Frontotemporal Dementia and Alzheimer's Disease.

PubMed

Hafkemeijer, Anne; Möller, Christiane; Dopper, Elise G P; Jiskoot, Lize C; van den Berg-Huysmans, Annette A; van Swieten, John C; van der Flier, Wiesje M; Vrenken, Hugo; Pijnenburg, Yolande A L; Barkhof, Frederik; Scheltens, Philip; van der Grond, Jeroen; Rombouts, Serge A R B

2017-01-01

Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) are the most common types of early-onset dementia. We applied longitudinal resting state functional magnetic resonance imaging (fMRI) to delineate functional brain connections relevant for disease progression and diagnostic accuracy. We used two-center resting state fMRI data of 20 AD patients (65.1±8.0 years), 12 bvFTD patients (64.7±5.4 years), and 22 control subjects (63.8±5.0 years) at baseline and 1.8-year follow-up. We used whole-network and voxel-based network-to-region analyses to study group differences in functional connectivity at baseline and follow-up, and longitudinal changes in connectivity within and between groups. At baseline, connectivity between paracingulate gyrus and executive control network, between cuneal cortex and medial visual network, and between paracingulate gyrus and salience network was higher in AD compared with controls. These differences were also present after 1.8 years. At follow-up, connectivity between angular gyrus and right frontoparietal network, and between paracingulate gyrus and default mode network was lower in bvFTD compared with controls, and lower compared with AD between anterior cingulate gyrus and executive control network, and between lateral occipital cortex and medial visual network. Over time, connectivity decreased in AD between precuneus and right frontoparietal network and in bvFTD between inferior frontal gyrus and left frontoparietal network. Longitudinal changes in connectivity between supramarginal gyrus and right frontoparietal network differ between both patient groups and controls. We found disease-specific brain regions with longitudinal connectivity changes. This suggests the potential of longitudinal resting state fMRI to delineate regions relevant for disease progression and for diagnostic accuracy, although no group differences in longitudinal changes in the direct comparison of AD and bvFTD were found.

A cognitive behavioral group approach to enhance adherence to hemodialysis fluid restrictions: a randomized controlled trial.

PubMed

Sharp, John; Wild, Matt R; Gumley, Andrew I; Deighan, Christopher J

2005-06-01

Adhering to fluid restrictions represents one of the most difficult aspects of the hemodialysis treatment regimen. This report describes a randomized controlled trial of a group-based cognitive behavioral intervention aimed at improving fluid-restriction adherence in patients receiving hemodialysis. It was hypothesized that the intervention would improve adherence, measured by means of interdialytic weight gain (IWG), without impacting negatively on psychosocial functioning. Fifty-six participants receiving hemodialysis from 4 renal outpatient settings were randomly assigned to an immediate-treatment group (ITG; n = 29) or deferred-treatment group (DTG; n = 27). Participants were assessed at baseline, posttreatment, and follow-up stages. Treatment consisted of a 4-week intervention using educational, cognitive, and behavioral strategies to enhance effective self-management of fluid consumption. No significant difference in mean IWGs was found between the ITG and DTG during the acute-phase analysis (F(1,54) = 0.03; P > 0.05). However, in longitudinal analysis, there was a significant main effect for mean IWG (F(1.76,96.80) = 9.10; P < 0.001) and a significant difference between baseline and follow-up IWG values (t55 = 3.85; P < 0.001), reflecting improved adherence over time. No adverse effects of treatment were indicated through measures of psychosocial functioning. Some significant changes were evidenced in cognitions thought to be important in mediating behavioral change. The current study provides evidence for the feasibility and effectiveness of applying group-based cognitive behavior therapy to enhance adherence to hemodialysis fluid restrictions. Results are discussed in the context of the study's methodological limitations.

Mindfulness-based Intervention for Female Adolescents with Chronic Pain: A Pilot Randomized Trial

PubMed Central

Chadi, Nicholas; McMahon, Audrey; Vadnais, Majorie; Malboeuf-Hurtubise, Catherine; Djemli, Anissa; Dobkin, Patricia L.; Lacroix, Jacques; Luu, Thuy Mai; Haley, Nancy

2016-01-01

Objective To test the feasibility of a randomized-controlled trial measuring the impact of an adapted mindfulness-based intervention (MBI) in female adolescents with chronic pain. Methods This was a single center, single-blind, prospective, experimental, longitudinal trial conducted in a pediatric tertiary care center. Participants had a history of chronic pain during at least three months. They were randomized into an intervention group or a wait-list control group. Both groups successively followed an adapted eight-week MBI designed specifically for adolescents with chronic pain. Pre-determined criteria were established to assess the feasibility, validity and acceptability of the study model. Data evaluating changes in quality of life, depression, anxiety, pain perception, psychological distress and salivary cortisol were collected throughout the 4-month study period. Results Nineteen female participants completed the study and had a mean age of 15.8 years (range 13.9 -17.8). Attrition rate was low (17%). Attendance to mindfulness sessions (84%) and compliance to study protocol (100%) were high. All participants reported a positive change in the way they coped with pain. No changes in quality of life, depression, anxiety, pain perception, and psychological distress were detected. Significant reductions in pre-and post-mindfulness session salivary cortisol levels were observed (p<0.001). Conclusions Mindfulness is a promising therapeutic approach for which limited data exist in adolescents with chronic pain. Our study indicates the feasibility of conducting such interventions in teenage girls. A large trial is needed to demonstrate the efficacy and bio-physiological impacts of MBIs in teenagers with chronic pain. PMID:27924146

Patient Navigation in Medically Underserved Areas study design: A trial with implications for efficacy, effect modification, and full continuum assessment.

PubMed

Molina, Yamile; Glassgow, Anne E; Kim, Sage J; Berrios, Nerida M; Pauls, Heather; Watson, Karriem S; Darnell, Julie S; Calhoun, Elizabeth A

2017-02-01

The Patient Navigation in Medically Underserved Areas study objectives are to assess if navigation improves: 1) care uptake and time to diagnosis; and 2) outcomes depending on patients' residential medically underserved area (MUA) status. Secondary objectives include the efficacy of navigation across 1) different points of the care continuum among patients diagnosed with breast cancer; and 2) multiple regular screening episodes among patients who did not obtain breast cancer diagnoses. Our randomized controlled trial was implemented in three community hospitals in South Chicago. Eligible participants were: 1) female, 2) 18+years old, 3) not pregnant, 4) referred from a primary care provider for a screening or diagnostic mammogram based on an abnormal clinical breast exam. Participants were randomized to 1) control care or 2) receive longitudinal navigation, through treatment if diagnosed with cancer or across multiple years if asymptomatic, by a lay health worker. Participants' residential areas were identified as: 1) established MUA (before 1998), 2) new MUA (after 1998), 3) eligible/but not designated as MUA, and 4) affluent/ineligible for MUA. Primary outcomes include days to initially recommended care after randomization and days to diagnosis for women with abnormal results. Secondary outcomes concern days to treatment initiation following a diagnosis and receipt of subsequent screening following normal/benign results. This intervention aims to assess the efficacy of patient navigation on breast cancer care uptake across the continuum. If effective, the program may improve rates of early cancer detection and breast cancer morbidity. Copyright © 2016 Elsevier Inc. All rights reserved.

Nurse-delivered counselling intervention for parental HIV disclosure: results from a pilot randomized controlled trial in China.

PubMed

Simoni, Jane M; Yang, Joyce P; Shiu, Cheng-Shi; Chen, Wei-Ti; Udell, Wadiya; Bao, Meijuan; Zhang, Lin; Lu, Hongzhou

2015-06-01

The objective of this study was to design and conduct a preliminary evaluation of an intervention to assist parents in decision-making about disclosure of their HIV diagnosis to their children. This was a pilot randomized controlled trial (RCT) with blinded assessment. Participants were randomized to intervention or treatment-as-usual (TAU) arms. The study occurred at an outpatient HIV primary care centre in Shanghai, China. Participants were 20 HIV-positive outpatients with at least one child (13-25 years old) who was unaware of the parent's HIV diagnosis. The nurse-delivered intervention involved three, hour-long, individual sessions over 4 weeks. Intervention content comprised family assessment, discussion of advantages and disadvantages of disclosure, psycho-education about cognitive, social and emotional abilities of children at different developmental stages, and disclosure planning and practicing via role-plays. Primary study outcomes for intervention versus TAU arms were self-reported disclosure distress, self-efficacy, and behaviours along a continuum from no disclosure to full disclosure and open communication about HIV. In all cross-sectional (Wald tests) and longitudinal (general estimating equations) analyses, at both postintervention (4 weeks) and follow-up (13 weeks), effects were in the hypothesized directions. Despite the small sample size, most of these between-arm comparisons were statistically significant, with at least one result for each outcome indicating a 'large' effect size. Our results suggest that nurses are able to deliver a counselling intervention in a clinic setting with the potential to alleviate parental distress around HIV disclosure to their children. Findings warrant future trials powered for efficacy.

Does physical activity protect against drug abuse vulnerability?

PubMed

Bardo, Michael T; Compton, Wilson M

2015-08-01

The current review examined recent literature to determine our state of knowledge about the potential ability of physical activity serve as a protectant against drug abuse vulnerability. Both preclinical and clinical studies were examined using either associational or random assignment study designs. In addition to examining drug use as an outcome variable, the potential neural mediators linking physical activity and drug abuse vulnerability were examined. Several important conclusions may be drawn. First, the preclinical evidence is solid in showing that physical activity in various forms is able to serve as both a preventive and treatment intervention that reduces drug use, although voluntary alcohol drinking appears to be an exception to this conclusion. Second, the clinical evidence provides some evidence, albeit mixed, to suggest a beneficial effect of physical activity on tobacco dependent individuals. In contrast, there exists only circumstantial evidence that physical activity may reduce use of drugs other than nicotine, and there is essentially no solid information from random control studies to know if physical activity may prevent initiation of problem use. Finally, both preclinical and clinical evidence shows that various brain systems are altered by physical activity, with the medial prefrontal cortex (mPFC) serving as one potential node that may mediate the putative link between physical activity and drug abuse vulnerability. It is concluded that novel neurobehavioral approaches taking advantage of novel techniques for assessing the physiological impact of physical activity are needed and can be used to inform the longitudinal random control studies that will answer definitively the question posed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Longitudinal Stability and Control Characteristics of a B-29 Airplane with a Booster Incorporated in the Elevator Control System to Provide Various Stick-Force and Control-Rate Characteristics

NASA Technical Reports Server (NTRS)

Mathews, Charles W.; Talmage, Donald B.; Whitten, James B.

1948-01-01

The longitudinal stability and control characteristics of a B-29 airplane have been measured with a booster incorporated in the elevator control system. Tests were made to determine the effects on the handling qualities of the test airplane of variations in pilots control-force gradients as well as the effects of variations in the maximum rate of control motion supplied by the booster system.

Coaching to Augment Mentoring to Achieve Faculty Diversity: A Randomized Controlled Trial.

PubMed

Williams, Simon N; Thakore, Bhoomi K; McGee, Richard

2016-08-01

The Academy for Future Science Faculty (the Academy) is a novel coaching intervention for biomedical PhD students designed to address limitations in previous efforts to promote faculty diversity. Unlike traditional research mentoring, the Academy includes both group and individual coaching, coaches have no research or evaluation roles with the students, and it is based on social science theories. The authors present a qualitative case study of one of the coaching groups and provide statistical analyses indicating whether one year in the Academy effects students' perceptions of the achievability and desirability of an academic career. The authors tested (July 2012-July 2013), with Northwestern University ethical approval, the Academy via a longitudinal randomized controlled trial. Participants were 121 latter-stage biomedical PhD students. The authors collected data via questionnaires, interviews, and meeting recordings. The case study shows how group career coaching can effectively supplement traditional one-to-one research mentoring; provide new role models for underrepresented minority students; and provide theory-based lenses through which to engage in open conversations about race, gender, and science careers. Repeated-measures analysis of variance showed that perceived achievability increased in the Academy group from baseline to one-year follow-up (mean, 5.75 versus 6.39) but decreased in the control group (6.58 versus 5.81). Perceived desirability decreased significantly less (P < .05) in the Academy group (7.00 versus 6.36) than in the control group (7.83 versus 5.97). Early results suggest that an academic career coaching model can effectively supplement traditional research mentoring and promote persistence toward academic careers.

The effect of a couples intervention to increase breast cancer screening among korean americans.

PubMed

Lee, Eunice; Menon, Usha; Nandy, Karabi; Szalacha, Laura; Kviz, Frederick; Cho, Young; Miller, Arlene; Park, Hanjong

2014-05-01

To assess the efficacy of Korean Immigrants and Mammography-Culture-Specific Health Intervention (KIM-CHI), an educational program for Korean American (KA) couples designed to improve mammography uptake among KA women. A two-group cluster randomized, longitudinal, controlled design. 50 KA religious organizations in the Chicago area. 428 married KA women 40 years of age or older who had not had a mammogram in the past year. The women and their husbands were recruited from 50 KA religious organizations. Couples were randomly assigned to intervention or attention control groups. Those in the KIM-CHI program (n = 211 couples) were compared to an attention control group (n = 217 couples) at baseline, as well as at 6 and 15 months postintervention on mammogram uptake. Sociodemographic variables and mammography uptake were measured. Level of acculturation was measured using the Suinn-Lew Asian Self-Identity Acculturation Scale. Researchers asked questions about healthcare resources and use, health insurance status, usual source of care, physical examinations in the past two years, family history of breast cancer, and history of mammography. The KIM-CHI group showed statistically significant increases in mammography uptake compared to the attention control group at 6 months and 15 months postintervention. The culturally targeted KIM-CHI program was effective in increasing mammogram uptake among nonadherent KA women. Nurses and healthcare providers should consider specific health beliefs as well as inclusion of husbands or significant others. They also should target education to be culturally relevant for KA women to effectively improve frequency of breast cancer screening.

Nurse care coordination and technology effects on health status of frail older adults via enhanced self-management of medication: randomized clinical trial to test efficacy.

PubMed

Marek, Karen Dorman; Stetzer, Frank; Ryan, Polly A; Bub, Linda Denison; Adams, Scott J; Schlidt, Andrea; Lancaster, Rachelle; O'Brien, Anne-Marie

2013-01-01

Self-management of complex medication regimens for chronic illness is challenging for many older adults. The purpose of this study was to evaluate health status outcomes of frail older adults receiving a home-based support program that emphasized self-management of medications using both care coordination and technology. This study used a randomized controlled trial with three arms and longitudinal outcome measurement. Older adults having difficulty in self-managing medications (n = 414) were recruited at discharge from three Medicare-certified home healthcare agencies in a Midwestern urban area. All participants received baseline pharmacy screens. The control group received no further intervention. A team of advanced practice nurses and registered nurses coordinated care for 12 months to two intervention groups who also received either an MD.2 medication-dispensing machine or a medplanner. Health status outcomes (the Geriatric Depression Scale, Mini Mental Status Examination, Physical Performance Test, and SF-36 Physical Component Summary and Mental Component Summary) were measured at baseline and at 3, 6, 9, and 12 months. After covariate and baseline health status adjustment, time × group interactions for the MD.2 and medplanner groups on health status outcomes were not significant. Time × group interactions were significant for the medplanner and control group comparisons. Participants with care coordination had significantly better health status outcomes over time than those in the control group, but addition of the MD.2 machine to nurse care coordination did not result in better health status outcomes.

Hand washing with soap and WASH educational intervention reduces under-five childhood diarrhoea incidence in Jigjiga District, Eastern Ethiopia: A community-based cluster randomized controlled trial.

PubMed

Hashi, Abdiwahab; Kumie, Abera; Gasana, Janvier

2017-06-01

Despite the tremendous achievement in reducing child mortality and morbidity in the last two decades, diarrhoea is still a major cause of morbidity and mortality among children in many developing countries, including Ethiopia. Hand washing with soap promotion, water quality improvements and improvements in excreta disposal significantly reduces diarrhoeal diseases. The objective of this study was to evaluate the effect of hand washing with soap and water, sanitation and hygiene (WASH) educational Intervention on the incidence of under-five children diarrhoea. A community-based cluster randomized controlled trial was conducted in 24 clusters (sub-Kebelles) in Jigjiga district, Somali region, Eastern Ethiopia from February 1 to July 30, 2015. The trial compared incidence of diarrhoea among under-five children whose primary caretakers receive hand washing with soap and water, sanitation, hygiene educational messages with control households. Generalized estimating equation with a log link function Poisson distribution family was used to compute adjusted incidence rate ratio and the corresponding 95% confidence interval. The results of this study show that the longitudinal adjusted incidence rate ratio (IRR) of diarrhoeal diseases comparing interventional and control households was 0.65 (95% CI 0.57, 0.73) suggesting an overall diarrhoeal diseases reduction of 35%. The results are similar to other trials of WASH educational interventions and hand washing with soap. In conclusion, hand washing with soap practice during critical times and WASH educational messages reduces childhood diarrhoea in the rural pastoralist area.

Developmental Outcomes at 24 Months of Age in Toddlers Supplemented with Arachidonic Acid and Docosahexaenoic Acid: Results of a Double Blind Randomized, Controlled Trial

PubMed Central

Devlin, Angela M.; Chau, Cecil M. Y.; Matheson, Julie; McCarthy, Deanna; Yurko-Mauro, Karin; Innis, Sheila M.; Grunau, Ruth E.

2017-01-01

Little is known about arachidonic acid (ARA) and docosahexaenoic acid (DHA) requirements in toddlers. A longitudinal, double blind, controlled trial in toddlers (n = 133) age 13.4 ± 0.9 months (mean ± standard deviation), randomized to receive a DHA (200 mg/day) and ARA (200 mg/day) supplement (supplement) or a corn oil supplement (control) until age 24 months determined effects on neurodevelopment. We found no effect of the supplement on the Bayley Scales of Infant and Toddler Development 3rd Edition (Bayley-III) cognitive and language composites and Beery–Buktenica Developmental Test of Visual–Motor Integration (Beery VMI) at age 24 months. Supplemented toddlers had higher RBC phosphatidylcholine (PC), phosphatidylethanolamine (PE), and plasma DHA and ARA compared to placebo toddlers at age 24 months. A positive relationship between RBC PE ARA and Bayley III Cognitive composite (4.55 (0.21–9.00), B (95% CI), p = 0.045) in supplemented boys, but not in control boys, was observed in models adjusted for baseline fatty acid, maternal non-verbal intelligence, and BMI z-score at age 24 months. A similar positive relationship between RBC PE ARA and Bayley III Language composite was observed for supplemented boys (11.52 (5.10–17.94), p < 0.001) and girls (11.19 (4.69–17.68), p = 0.001). These findings suggest that increasing the ARA status in toddlers is associated with better neurodevelopment at age 24 months. PMID:28878181

Symptoms of internalizing and externalizing problems: modeling recovery curves after the death of a parent.

PubMed

Schmiege, Sarah J; Khoo, Siek Toon; Sandler, Irwin N; Ayers, Tim S; Wolchik, Sharlene A

2006-12-01

The death of a parent is a major family disruption that can place children at risk for later depression and other mental health problems. Theoretically based randomized controlled trial for parentally bereaved children. Two-hundred and forty-four children and adolescents and their caregivers from 156 families were randomly assigned to the Family Bereavement Program (FBP) intervention condition (90 families; 135 children) or to a control condition (66 families; 109 children). Data collection occurred from 1996 to 1998. Children and caregivers in the intervention condition met separately for 12 two-hour weekly sessions. Skills targeted by the program for children included positive coping, stress appraisals, control beliefs, and self-esteem. The caregiver program targeted caregiver mental health, life stressors, and improved discipline in the home. Both child and caregiver programs focused on improved quality of the caregiver-child relationship. Child and caregiver reports of internalizing and externalizing symptoms. Longitudinal growth curve modeling was performed to model symptoms over time from the point of parental death. The rate of recovery for girls in the program condition was significantly different from that of girls in the control condition across all outcomes. Boys in both conditions showed reduced symptoms over time. The methodology offers a conceptually unique way of assessing recovery in terms of reduced mental health problems over time after an event and has contributed to further understanding of FBP intervention effects. The intervention program facilitated recovery among girls, who did not show reduction in behavior problems without the program, while boys demonstrated decreased symptoms even without intervention.

Buffering Syndemic Effects in a Sexual Risk-Reduction Intervention for Male Clients of Female Sex Workers: Results From a Randomized Controlled Trial

PubMed Central

Strathdee, Steffanie A.; Semple, Shirley J.; Chavarin, Claudia V.; Magis-Rodriguez, Carlos; Patterson, Thomas L.

2015-01-01

Objectives. We sought to test the efficacy of a sexual risk intervention for male clients of female sex workers (FSWs) and examine whether efficacy was moderated by syndemic risk. Methods. From 2010 to 2014, we conducted a 2-arm randomized controlled trial (60-minute, theory-based, safer sex intervention versus a didactic time-equivalent attention control) that included 400 male clients of FSWs on the US–Mexico border with follow-up at 4, 8, and 12 months. We measured 5 syndemic risk factors, including substance use and depression. Primary outcomes were sexually transmitted infections incidence and total unprotected sex with FSWs. Results. Although participants in both groups became safer, there was no significant difference in behavior change between groups. However, baseline syndemic risk moderated intervention efficacy. At baseline, there was a positive association between syndemic risk and unprotected sex. Then at 12 months, longitudinal analyses showed the association depended on intervention participation (B = −0.71; 95% confidence interval [CI] = –1.22, –0.20; P = .007). Among control participants there still existed this modest association (B = 0.36; 95% CI = –0.49, 1.22; P = .09); among intervention participants there was a significant negative association (B = −0.35; 95% CI = –0.63, –0.06; P = .02). Conclusion. A brief intervention might attenuate syndemic risks among clients of FSWs. Other populations experiencing syndemic problems may also benefit from such programs. PMID:25713953

Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73).

PubMed

Ramsden, Christopher E; Zamora, Daisy; Majchrzak-Hong, Sharon; Faurot, Keturah R; Broste, Steven K; Frantz, Robert P; Davis, John M; Ringel, Amit; Suchindran, Chirayath M; Hibbeln, Joseph R

2016-04-12

To examine the traditional diet-heart hypothesis through recovery and analysis of previously unpublished data from the Minnesota Coronary Experiment (MCE) and to put findings in the context of existing diet-heart randomized controlled trials through a systematic review and meta-analysis. The MCE (1968-73) is a double blind randomized controlled trial designed to test whether replacement of saturated fat with vegetable oil rich in linoleic acid reduces coronary heart disease and death by lowering serum cholesterol. Recovered MCE unpublished documents and raw data were analyzed according to hypotheses prespecified by original investigators. Further, a systematic review and meta-analyses of randomized controlled trials that lowered serum cholesterol by providing vegetable oil rich in linoleic acid in place of saturated fat without confounding by concomitant interventions was conducted. One nursing home and six state mental hospitals in Minnesota, United States. Unpublished documents with completed analyses for the randomized cohort of 9423 women and men aged 20-97; longitudinal data on serum cholesterol for the 2355 participants exposed to the study diets for a year or more; 149 completed autopsy files. Serum cholesterol lowering diet that replaced saturated fat with linoleic acid (from corn oil and corn oil polyunsaturated margarine). Control diet was high in saturated fat from animal fats, common margarines, and shortenings. Death from all causes; association between changes in serum cholesterol and death; and coronary atherosclerosis and myocardial infarcts detected at autopsy. The intervention group had significant reduction in serum cholesterol compared with controls (mean change from baseline -13.8%v-1.0%; P<0.001). Kaplan Meier graphs showed no mortality benefit for the intervention group in the full randomized cohort or for any prespecified subgroup. There was a 22% higher risk of death for each 30 mg/dL (0.78 mmol/L) reduction in serum cholesterol in covariate adjusted Cox regression models (hazard ratio 1.22, 95% confidence interval 1.14 to 1.32; P<0.001). There was no evidence of benefit in the intervention group for coronary atherosclerosis or myocardial infarcts. Systematic review identified five randomized controlled trials for inclusion (n=10,808). In meta-analyses, these cholesterol lowering interventions showed no evidence of benefit on mortality from coronary heart disease (1.13, 0.83 to 1.54) or all cause mortality (1.07, 0.90 to 1.27). Available evidence from randomized controlled trials shows that replacement of saturated fat in the diet with linoleic acid effectively lowers serum cholesterol but does not support the hypothesis that this translates to a lower risk of death from coronary heart disease or all causes. Findings from the Minnesota Coronary Experiment add to growing evidence that incomplete publication has contributed to overestimation of the benefits of replacing saturated fat with vegetable oils rich in linoleic acid. 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.

Effects of Early Relationships on Children's Perceived Control: A Longitudinal Study

ERIC Educational Resources Information Center

Dan, Orrie; Sagi-Schwartz, Abraham; Bar-haim, Yair; Eshel, Yohanan

2011-01-01

People's response to stress depends to a large extent on their sense of perceived control over the situations they encounter. This longitudinal study of 136 children (70 girls) examined associations between attachment patterns and maternal sensitivity at 12 months of age, and perceived primary and secondary control at 11 years of age. Compared…

A comparison of multiple imputation methods for handling missing values in longitudinal data in the presence of a time-varying covariate with a non-linear association with time: a simulation study.

PubMed

De Silva, Anurika Priyanjali; Moreno-Betancur, Margarita; De Livera, Alysha Madhu; Lee, Katherine Jane; Simpson, Julie Anne

2017-07-25

Missing data is a common problem in epidemiological studies, and is particularly prominent in longitudinal data, which involve multiple waves of data collection. Traditional multiple imputation (MI) methods (fully conditional specification (FCS) and multivariate normal imputation (MVNI)) treat repeated measurements of the same time-dependent variable as just another 'distinct' variable for imputation and therefore do not make the most of the longitudinal structure of the data. Only a few studies have explored extensions to the standard approaches to account for the temporal structure of longitudinal data. One suggestion is the two-fold fully conditional specification (two-fold FCS) algorithm, which restricts the imputation of a time-dependent variable to time blocks where the imputation model includes measurements taken at the specified and adjacent times. To date, no study has investigated the performance of two-fold FCS and standard MI methods for handling missing data in a time-varying covariate with a non-linear trajectory over time - a commonly encountered scenario in epidemiological studies. We simulated 1000 datasets of 5000 individuals based on the Longitudinal Study of Australian Children (LSAC). Three missing data mechanisms: missing completely at random (MCAR), and a weak and a strong missing at random (MAR) scenarios were used to impose missingness on body mass index (BMI) for age z-scores; a continuous time-varying exposure variable with a non-linear trajectory over time. We evaluated the performance of FCS, MVNI, and two-fold FCS for handling up to 50% of missing data when assessing the association between childhood obesity and sleep problems. The standard two-fold FCS produced slightly more biased and less precise estimates than FCS and MVNI. We observed slight improvements in bias and precision when using a time window width of two for the two-fold FCS algorithm compared to the standard width of one. We recommend the use of FCS or MVNI in a similar longitudinal setting, and when encountering convergence issues due to a large number of time points or variables with missing values, the two-fold FCS with exploration of a suitable time window.

A longitudinal and experimental study of the impact of knowledge on the bases of institutional trust

PubMed Central

Kimbrough, Christopher D.; Shockley, Ellie; Neal, Tess M. S.; Herian, Mitchel N.; Hamm, Joseph A.; Bornstein, Brian H.; Tomkins, Alan J.

2017-01-01

This study examined a knowledge-centered theory of institutional trust development. In the context of trust in water regulatory institutions, the moderating impact of knowledge was tested to determine if there were longitudinal changes in the bases of institutional trust as a function of increases in knowledge about a target institution. We hypothesized that as people learn about an institution with which they were previously unfamiliar, they begin to form more nuanced perceptions, distinguishing the new institution from other institutions and relying less upon their generalized trust to estimate their trust in that institution. Prior to having specific, differential information about a new institution, we expected institutional trust to be a function of generalized trust variables such as dispositional trust and trust in government. The longitudinal experiment involved 185 college students randomly assigned to one of three information conditions. Every 3 months for 15 months, participants read information about water regulatory institutions or a control institution. At each time point, participants reported their trust in and perceptions of the trust- and distrust-worthiness of the water regulatory institutions. Participants also completed measures of knowledge of water regulatory institutions, dispositional trust, and governmental trust. Our manipulation check indicated that, as expected, those in the experimental group increased in subjective knowledge of water regulatory institutions to a greater extent than those in the control condition. Consistent with our hypotheses, there was some evidence that, compared to the control group, the experimental group relied less on their general trust in government as a basis for their trust in water regulatory institutions. However, contrary to our hypotheses, there was no evidence the experimental group relied less on dispositional trust as a basis for institutional trust. There also was some evidence the experimental group’s trust in water regulatory institutions was less affected by fluctuations of trustworthiness (but not distrustworthiness) perceptions over time. This suggests that knowledge results in the development of more stable institutional trust attitudes, but that trustworthiness and distrustworthiness perceptions may operate somewhat differently when impacting trust in specific institutions. PMID:28414808

A longitudinal and experimental study of the impact of knowledge on the bases of institutional trust.

PubMed

PytlikZillig, Lisa M; Kimbrough, Christopher D; Shockley, Ellie; Neal, Tess M S; Herian, Mitchel N; Hamm, Joseph A; Bornstein, Brian H; Tomkins, Alan J

2017-01-01

This study examined a knowledge-centered theory of institutional trust development. In the context of trust in water regulatory institutions, the moderating impact of knowledge was tested to determine if there were longitudinal changes in the bases of institutional trust as a function of increases in knowledge about a target institution. We hypothesized that as people learn about an institution with which they were previously unfamiliar, they begin to form more nuanced perceptions, distinguishing the new institution from other institutions and relying less upon their generalized trust to estimate their trust in that institution. Prior to having specific, differential information about a new institution, we expected institutional trust to be a function of generalized trust variables such as dispositional trust and trust in government. The longitudinal experiment involved 185 college students randomly assigned to one of three information conditions. Every 3 months for 15 months, participants read information about water regulatory institutions or a control institution. At each time point, participants reported their trust in and perceptions of the trust- and distrust-worthiness of the water regulatory institutions. Participants also completed measures of knowledge of water regulatory institutions, dispositional trust, and governmental trust. Our manipulation check indicated that, as expected, those in the experimental group increased in subjective knowledge of water regulatory institutions to a greater extent than those in the control condition. Consistent with our hypotheses, there was some evidence that, compared to the control group, the experimental group relied less on their general trust in government as a basis for their trust in water regulatory institutions. However, contrary to our hypotheses, there was no evidence the experimental group relied less on dispositional trust as a basis for institutional trust. There also was some evidence the experimental group's trust in water regulatory institutions was less affected by fluctuations of trustworthiness (but not distrustworthiness) perceptions over time. This suggests that knowledge results in the development of more stable institutional trust attitudes, but that trustworthiness and distrustworthiness perceptions may operate somewhat differently when impacting trust in specific institutions.

Effects of a Flexibility/Support Intervention on Work Performance: Evidence From the Work, Family, and Health Network.

PubMed

Bray, Jeremy W; Hinde, Jesse M; Kaiser, David J; Mills, Michael J; Karuntzos, Georgia T; Genadek, Katie R; Kelly, Erin L; Kossek, Ellen E; Hurtado, David A

2018-05-01

To estimate the effects of a workplace initiative to reduce work-family conflict on employee performance. A group-randomized multisite controlled experimental study with longitudinal follow-up. An information technology firm. Employees randomized to the intervention (n = 348) and control condition (n = 345). An intervention, "Start. Transform. Achieve. Results." to enhance employees' control over their work time, to increase supervisors' support for this change, and to increase employees' and supervisors' focus on results. We estimated the effect of the intervention on 9 self-reported employee performance measures using a difference-in-differences approach with generalized linear mixed models. Performance measures included actual and expected hours worked, absenteeism, and presenteeism. This study found little evidence that an intervention targeting work-family conflict affected employee performance. The only significant effect of the intervention was an approximately 1-hour reduction in expected work hours. After Bonferroni correction, the intervention effect is marginally insignificant at 6 months and marginally significant at 12 and 18 months. The intervention reduced expected working time by 1 hour per week; effects on most other employee self-reported performance measures were statistically insignificant. When coupled with the other positive wellness and firm outcomes, this intervention may be useful for improving employee perceptions of increased access to personal time or personal wellness without sacrificing performance. The null effects on performance provide countervailing evidence to recent negative press on work-family and flex work initiatives.

The Marriage Checkup: A Randomized Controlled Trial of Annual Relationship Health Checkups

PubMed Central

Cordova, James V.; Fleming, C.J. Eubanks; Morrill, Melinda Ippolito; Hawrilenko, Matt; Sollenberger, Julia W.; Harp, Amanda G.; Gray, Tatiana D.; Darling, Ellen V.; Blair, Jonathan M.; Meade, Amy E.; Wachs, Karen

2014-01-01

Objective This study assessed the efficacy of the Marriage Checkup for improving relationship health and intimacy. Method Cohabiting married couples (N=215, Mage women=44.5 years, men=47 years, 93.1% Caucasian) recruited from a northeastern U.S. metropolitan area through print and electronic media were randomly assigned to MC treatment or wait-list control. Treatment but not control couples participated in assessment and feedback visits, at the beginning of the study and again one year later. All couples completed nine sets of questionnaires over two years. Outcome measures included the Quality of Marriage Index, the Global Distress subscale of the Marital Satisfaction Inventory-Revised, the Intimate Safety Questionnaire, and the Relational Acceptance Questionnaire. Results A latent growth curve model indicated significant between group differences in intimacy at every measurement point after baseline (d ranged from .20 to .55, Md = .37), significant between group differences in women’s felt acceptance for every measurement point after baseline (d ranged from .17 to .47, Md = .34), significant between group differences in men’s felt acceptance through the 1-year-2 week follow-up (d across follow-up ranged from .11 to .40, Md = .25), and significant between group differences in relationship distress through 1-year 6-month follow-up (d across follow-up ranged from .11 to .39, Md = .23). Conclusions Longitudinal analysis of the MC supports the hypothesis that the MC significantly improves intimacy, acceptance, and satisfaction. Implications for dissemination are discussed. PMID:24932565

PlanYourLifeSpan.org - an intervention to help seniors make choices for their fourth quarter of life: Results from the randomized clinical trial.

PubMed

Lindquist, Lee A; Ramirez-Zohfeld, Vanessa; Sunkara, Priya D; Forcucci, Chris; Campbell, Dianne S; Mitzen, Phyllis; Ciolino, Jody D; Gregory, Dyanna; Kricke, Gayle; Cameron, Kenzie A

2017-11-01

Few older adults contemplate their home support and health needs that may be required for aging-in-place. We sought to assess the efficacy of PlanYourLifespan.org (PYL), in influencing seniors' planning behaviors, perception of the importance of planning, and confidence accessing services. Randomized controlled trial, of adults, age ≥65 years in urban, suburban, rural areas of Texas, Illinois, Indiana. Among 385 participants, mean age was 71.9 years, 79.5% female. Between baseline and one-month follow-up, average planning behavior score increased 0.22 points in the PYL arm when compared to the attention control (AC) arm. After controlling for baseline, mean one-month planning behavior score was significantly higher in the PYL arm than in the AC arm (1.25 points, CI 0.37-2.12, p=0.005). Secondary analyses via longitudinal linear mixed modelling suggested a study arm-by-time interaction effect for both planning behavior (p=0.047 and perception of importance (p=0.05). Significant baseline covariates included self-efficacy, education, perceived social support, power of attorney, and history of stroke. PlanYourLifespan.org demonstrated efficacy in helping seniors plan for and communicate their health support needs. This free, nationally available tool may help individuals understand, plan, and communicate their options for their future support needs. Copyright © 2017 Elsevier B.V. All rights reserved.

Classification of childhood asthma phenotypes and long-term clinical responses to inhaled anti-inflammatory medications.

PubMed

Howrylak, Judie A; Fuhlbrigge, Anne L; Strunk, Robert C; Zeiger, Robert S; Weiss, Scott T; Raby, Benjamin A

2014-05-01

Although recent studies have identified the presence of phenotypic clusters in asthmatic patients, the clinical significance and temporal stability of these clusters have not been explored. Our aim was to examine the clinical relevance and temporal stability of phenotypic clusters in children with asthma. We applied spectral clustering to clinical data from 1041 children with asthma participating in the Childhood Asthma Management Program. Posttreatment randomization follow-up data collected over 48 months were used to determine the effect of these clusters on pulmonary function and treatment response to inhaled anti-inflammatory medication. We found 5 reproducible patient clusters that could be differentiated on the basis of 3 groups of features: atopic burden, degree of airway obstruction, and history of exacerbation. Cluster grouping predicted long-term asthma control, as measured by the need for oral prednisone (P < .0001) or additional controller medications (P = .001), as well as longitudinal differences in pulmonary function (P < .0001). We also found that the 2 clusters with the highest rates of exacerbation had different responses to inhaled corticosteroids when compared with the other clusters. One cluster demonstrated a positive response to both budesonide (P = .02) and nedocromil (P = .01) compared with placebo, whereas the other cluster demonstrated minimal responses to both budesonide (P = .12) and nedocromil (P = .56) compared with placebo. Phenotypic clustering can be used to identify longitudinally consistent and clinically relevant patient subgroups, with implications for targeted therapeutic strategies and clinical trials design.

A Longitudinal Examination of Positive Parenting Following an Acceptance-Based Couple Intervention

PubMed Central

Morrill, Melinda Ippolito; Hawrilenko, Matt; Córdova, James V.

2015-01-01

Positive parenting practices have been shown to be essential for healthy child development, and yet have also been found to be particularly challenging for parents to enact and maintain. This paper explores an innovative approach for increasing positive parenting by targeting specific positive emotional processes within marital relationships. Couple emotional acceptance is a powerful mechanism that has repeatedly been found to improve romantic relationships, but whether these effects extend to the larger family environment is less well understood. The current longitudinal study examined the role of improved levels of acceptance in mother’s and father’s positive parenting after a couple intervention. Participants included 244 parents (122 couples) in the Marriage Checkup (MC) study, a randomized, controlled, acceptance-based, intervention study. Data indicated that both women and men experienced significantly greater felt acceptance two-weeks after the MC intervention, treatment women demonstrated greater positive parenting two weeks after the intervention, and all treatment participants’ positive parenting was better maintained than control couple’s six months later. Importantly, although mothers’ positive parenting was not influenced by different levels of felt acceptance, changes in father’s positive parenting were positively associated with changes in felt acceptance. As men felt more accepted by their wives, their levels of positive parenting changed in kind, and this effect on positive parenting was found to be mediated by felt acceptance two weeks after the MC. Overall, findings supported the potential benefits of targeting couple acceptance to generate positive cascades throughout the larger family system. PMID:26551659

Ambivalence toward palatable food and emotional eating predict weight fluctuations. Results of a longitudinal study with four waves.

PubMed

Keller, Carmen; Siegrist, Michael

2015-02-01

Weight fluctuations pose serious challenges to people's health. Research suggests that the interplay between cognitive dietary restraint and counter-regulative overeating impairs weight control. In a random sample from the general population (N = 2733, 49% male), a longitudinal survey was conducted over 4 consecutive years (2010-2013). Self-reported weight was used to calculate the variance of three weight changes from one wave to the next. Separate regression analyses for women and men were conducted. The dependent variable was weight fluctuation, and the independent variables were eating styles (emotional, external, and restrained) and ambivalence toward palatable food. Age and weight changes between the fourth and first years were controlled. A significant positive effect of emotional eating for men and women, and a significant positive effect of ambivalence for women, were found. Participants who demonstrated high levels of emotional eating, and women who had high levels of ambivalence in the beginning of the study, had more extreme relative weight fluctuations in the consecutive years than did persons with low levels of emotional eating or women with low levels of ambivalence. Restrained and external eating had no effect. The results suggest that emotional eating and ambivalence toward palatable food need to be addressed to prevent health-damaging weight fluctuations. Furthermore, ambivalence toward palatable food was revealed as an additional overeating tendency beyond emotional eating that must be considered to understand the interplay between dietary restraint and overeating. Copyright © 2014 Elsevier Ltd. All rights reserved.

Occurrence of Multiple Sclerosis After Drug Exposure: Insights From Evidence Mapping.

PubMed

Antonazzo, Ippazio Cosimo; Raschi, Emanuel; Vignatelli, Luca; Baldin, Elisa; Riise, Trond; D'Alessandro, Roberto; De Ponti, Fabrizio; Poluzzi, Elisabetta

2017-09-01

The role of drugs in the occurrence of multiple sclerosis (MS) is perceived to be insufficiently investigated. The aim of this study was to map and assess the evidence on MS occurrence after drug exposure, in order to identify possible signals of causal association. A search strategy was performed in MEDLINE and Embase as of July 2016; references consistent with the aim of the study were analysed to extract relevant measures of causal association between drugs and MS. The Newcastle-Ottawa Scale and appropriate guidelines from the International Society for Pharmacoepidemiology (ISPE) and the International Society of Pharmacovigilance (ISoP) were used to assess the quality of included studies. After screening 832 articles, 58 were selected (of which 14 were found by checking the reference lists of reviews): 30 case reports and case series, 24 longitudinal studies and four randomized controlled trials. Seven longitudinal studies had good (at least 7 out of 9) quality scores, whereas case reports/case series presented several limitations. Half of included articles focused on immunomodulatory drugs (etanercept, infliximab and adalimumab), especially in case reports/series, suggesting an association with MS occurrence. Contraceptives and antibacterials were investigated in some population-based studies, without definite results. A heterogeneous pharmacological profile of identified classes emerged. Low strength of evidence and conflicting results highlighted the difficulties in addressing the possible contribution of drugs in MS occurrence. Methodological advances are needed, especially to control the confounding role of underlying disease for specific drug classes.

Social relationships and cognitive decline: a systematic review and meta-analysis of longitudinal cohort studies.

PubMed

Kuiper, Jisca S; Zuidersma, Marij; Zuidema, Sytse U; Burgerhof, Johannes Gm; Stolk, Ronald P; Oude Voshaar, Richard C; Smidt, Nynke

2016-08-01

Although poor social relationships are assumed to contribute to cognitive decline, meta-analytic approaches have not been applied. Individual study results are mixed and difficult to interpret due to heterogeneity in measures of social relationships. We conducted a systematic review and meta-analysis to investigate the relation between poor social relationships and cognitive decline. MEDLINE, Embase and PsycINFO were searched for longitudinal cohort studies examining various aspects of social relationships and cognitive decline in the general population. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using random effects meta-analysis. Sources of heterogeneity were explored and likelihood of publication bias was assessed. We stratified analyses according to three aspects of social relationships: structural, functional and a combination of these. We identified 43 articles. Poor social relationships predicted cognitive decline; for structural (19 studies): pooled OR: 1.08 (95% CI: 1.05-1.11); functional (8 studies): pooled OR: 1.15 (95% CI: 1.00-1.32); and combined measures (7 studies): pooled OR: 1.12 (95% CI: 1.01-1.24). Meta-regression and subgroup analyses showed that the heterogeneity could be explained by the type of social relationship measurement and methodological quality of included studies. Despite heterogeneity in study design and measures, our meta-analyses show that multiple aspects of social relationships are associated with cognitive decline. As evidence for publication bias was found, the association might be overestimated and should therefore be interpreted with caution. Future studies are needed to better define the mechanisms underlying these associations. Potential causality of this prognostic association should be examined in future randomized controlled studies. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

Are Clinical Diagnoses of Alzheimer’s Disease and Other Dementias Affected by Education and Self-Reported Race?

PubMed Central

Teresi, Jeanne A.; Grober, Ellen; Eimicke, Joseph P.; Ehrlich, Amy R.

2012-01-01

A randomized controlled trial examined whether the diagnostic process for Alzheimer’s disease and other dementias may be influenced by knowledge of the patient’s education and/or self-reported race. Four conditions were implemented: diagnostic team knows (a) race and education, (b) education only, (c) race only, or (d) neither. Diagnosis and clinical staging was established at baseline, at Wave 2, and for a random sample of Wave 3 respondents by a consensus panel. At study end, a longitudinal, “gold standard” diagnosis was made for patients with follow-up data (71%). Group differences in Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) diagnosis were estimated using logistic regression and generalized estimating equations. Sensitivity and specificity were examined for baseline diagnosis in relation to the gold standard, longitudinal diagnosis. Despite equivalent status on all measured variables across waves, members of the “knows race only” group were less likely than those of other groups to receive a diagnosis of dementia. At final diagnosis, 19% of the “knows race only” group was diagnosed with dementia versus 38% to 40% in the other 3 conditions (p = .038). Examination of sensitivities and specificities of baseline diagnosis in relation to the gold standard diagnosis showed a nonsignificant trend for lower sensitivities in the knowing race conditions (0.3846), as contrasted with knowing education only (0.480) or neither (0.600). The finding that knowledge of race may influence the diagnostic process in some unknown way is timely, given the recent State-of-the-Science conference on Alzheimer’s disease prevention, the authors of which called for information about and standardization of the diagnostic process. PMID:22309001

Patterns and Correlates of PrEP Drug Detection among MSM and Transgender Women in the Global iPrEx Study

PubMed Central

Liu, Albert; Glidden, David V.; Anderson, Peter L.; Amico, K.R.; McMahan, Vanessa; Mehrotra, Megha; Lama, Javier R.; MacRae, John; Hinojosa, Juan Carlos; Montoya, Orlando; Veloso, Valdilea G.; Schechter, Mauro; Kallas, Esper G.; Chariyalerstak, Suwat; Bekker, Linda-Gail; Mayer, Kenneth; Buchbinder, Susan; Grant, Robert

2014-01-01

Background Adherence to pre-exposure prophylaxis (PrEP) is critical for efficacy. Antiretroviral concentrations are an objective measure of PrEP use and correlate with efficacy. Understanding patterns and correlates of drug detection can identify populations at risk for non-adherence and inform design of PrEP adherence interventions. Methods Blood antiretroviral concentrations were assessed among active-arm participants in iPrEx, a randomized, placebo-controlled trial of emtricitabine/tenofovir in men who have sex with men (MSM) and transgender women in 6 countries. We evaluated rates and correlates of drug detection among a random sample of 470 participants at week 8 and a longitudinal cohort of 303 participants through 72 weeks of follow-up. Results Overall, 55% (95% CI 49–60%) of participants tested at week 8 had drug detected. Drug detection was associated with older age and varied by study site. In longitudinal analysis, 31% never had drug detected, 30% always had drug detected, and 39% had an inconsistent pattern. Overall detection rates declined over time. Drug detection at some or all visits was associated with older age; indices of sexual risk, including condomless receptive anal sex; and responding "don't know" to a question about belief of PrEP efficacy (0–10 scale). Conclusions Distinct patterns of study-product use were identified, with a significant proportion demonstrating no drug detection at any visit. Research literacy may explain greater drug detection among populations having greater research experience, such as older MSM in the US. Greater drug detection among those reporting highest-risk sexual practices is expected to increase the impact and cost-effectiveness of PrEP. PMID:25230290

Are clinical diagnoses of Alzheimer's disease and other dementias affected by education and self-reported race?

PubMed

Teresi, Jeanne A; Grober, Ellen; Eimicke, Joseph P; Ehrlich, Amy R

2012-09-01

A randomized controlled trial examined whether the diagnostic process for Alzheimer's disease and other dementias may be influenced by knowledge of the patient's education and/or self-reported race. Four conditions were implemented: diagnostic team knows (a) race and education, (b) education only, (c) race only, or (d) neither. Diagnosis and clinical staging was established at baseline, at Wave 2, and for a random sample of Wave 3 respondents by a consensus panel. At study end, a longitudinal, "gold standard" diagnosis was made for patients with follow-up data (71%). Group differences in Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) diagnosis were estimated using logistic regression and generalized estimating equations. Sensitivity and specificity were examined for baseline diagnosis in relation to the gold standard, longitudinal diagnosis. Despite equivalent status on all measured variables across waves, members of the "knows race only" group were less likely than those of other groups to receive a diagnosis of dementia. At final diagnosis, 19% of the "knows race only" group was diagnosed with dementia versus 38% to 40% in the other 3 conditions (p = .038). Examination of sensitivities and specificities of baseline diagnosis in relation to the gold standard diagnosis showed a nonsignificant trend for lower sensitivities in the knowing race conditions (0.3846), as contrasted with knowing education only (0.480) or neither (0.600). The finding that knowledge of race may influence the diagnostic process in some unknown way is timely, given the recent State-of-the-Science conference on Alzheimer's disease prevention, the authors of which called for information about and standardization of the diagnostic process. PsycINFO Database Record (c) 2012 APA, all rights reserved.

The first clinical experience on efficacy of topical flutamide on melasma compared with topical hydroquinone: a randomized clinical trial.

PubMed

Adalatkhah, Hassan; Sadeghi-Bazargani, Homayoun

2015-01-01

Treatment of melasma is unsatisfactory most of the times. Hormonal role is shown to exist in pathogenesis of the melasma, and sex-hormone related drugs may have an effect on melasma. To investigate efficacy of 1% flutamide cream versus 4% hydroquinone cream on melasma. In a parallel randomized clinical trial, 74 women with melasma were allocated to receive a sunscreen along with 4% hydroquinone cream or 1% flutamide cream. Melasma Area and Severity Index (MASI), mexameter melanin assay, and patient satisfaction were investigated. Mean age of the participants was 33.8 years. Mean length of time suffering from Melasma was 96.3 months. The subjects reported in average 1.1 hours per day of exposure to sunlight. Mean standardized total patient satisfaction score was 28.8 (standard deviation [SD] 17.2) in flutamide group patients versus 18 (SD 15.5) in control group (P<0.01). Regardless of treatment group, the skin darkness assessed upon MASI scales was reduced over the treatment course (P<0.001). Using mixed effects, longitudinal modeling showed better treatment efficacy based on MASI scale for flutamide group compared to the hydroquinone group (P<0.05). However, longitudinal analysis of mexameter scores did not reveal any significant difference in melanin measurements between flutamide and hydroquinone. Topical flutamide appeared as effective as topical hydroquinone in treating melasma using mexameter assessment but with a better MASI improvement trend and higher patient satisfaction in flutamide treatment versus topical hydroquinone. As the present study is possibly the first clinical experience on efficacy of topical flutamide on melasma, it would be quite unreasonable to recommend clinical use of it before future studies replicate the results on its efficacy and safety.

The first clinical experience on efficacy of topical flutamide on melasma compared with topical hydroquinone: a randomized clinical trial

PubMed Central

Adalatkhah, Hassan; Sadeghi-Bazargani, Homayoun

2015-01-01

Background Treatment of melasma is unsatisfactory most of the times. Hormonal role is shown to exist in pathogenesis of the melasma, and sex-hormone related drugs may have an effect on melasma. Aim To investigate efficacy of 1% flutamide cream versus 4% hydroquinone cream on melasma. Methods In a parallel randomized clinical trial, 74 women with melasma were allocated to receive a sunscreen along with 4% hydroquinone cream or 1% flutamide cream. Melasma Area and Severity Index (MASI), mexameter melanin assay, and patient satisfaction were investigated. Results Mean age of the participants was 33.8 years. Mean length of time suffering from Melasma was 96.3 months. The subjects reported in average 1.1 hours per day of exposure to sunlight. Mean standardized total patient satisfaction score was 28.8 (standard deviation [SD] 17.2) in flutamide group patients versus 18 (SD 15.5) in control group (P<0.01). Regardless of treatment group, the skin darkness assessed upon MASI scales was reduced over the treatment course (P<0.001). Using mixed effects, longitudinal modeling showed better treatment efficacy based on MASI scale for flutamide group compared to the hydroquinone group (P<0.05). However, longitudinal analysis of mexameter scores did not reveal any significant difference in melanin measurements between flutamide and hydroquinone. Conclusion Topical flutamide appeared as effective as topical hydroquinone in treating melasma using mexameter assessment but with a better MASI improvement trend and higher patient satisfaction in flutamide treatment versus topical hydroquinone. As the present study is possibly the first clinical experience on efficacy of topical flutamide on melasma, it would be quite unreasonable to recommend clinical use of it before future studies replicate the results on its efficacy and safety. PMID:26345129

Critical review of immediate implant loading.

PubMed

Gapski, Ricardo; Wang, Hom-Lay; Mascarenhas, Paulo; Lang, Niklaus P

2003-10-01

Implant dentistry has become successful with the discovery of the biological properties of titanium. In the original protocol, studies have advocated a 2-stage surgical protocol for load-free and submerged healing to ensure predictable osseointegration. However, the discomfort, inconvenience, and anxiety associated with waiting period remains a challenge to both patients and clinicians. Hence, loading implant right after placement was attempted and has gained popularity among clinicians. Issues/questions related to this approach remain unanswered. Therefore, it is the purpose of this review article to (1). review and analyze critically the current available literature in the field of immediate implant loading and (2). discuss, based on scientific evidence, factors that may influence this treatment modality. Literature published over the past 20 years was selected and reviewed. Findings from these studies were discussed and summarized in the tables. The advantages and disadvantages associated with immediate implant loading were analyzed. Factors that may influence the success of immediate implant loading, including patient selection, type of bone quality, required implant length, micro- and macrostructure of the implant, surgical skill, need for achieving primary stability/control of occlusal force, and prosthesis guidelines, were thoroughly reviewed and discussed. Various studies have demonstrated the feasibility and predictability of this technique. However, most of these articles are based on retrospective data or uncontrolled cases. Randomized, prospective, parallel-armed longitudinal human trials are primarily based on short-term results and long-term follow-ups are still scarce in this field. Nonetheless, from available literature, it may be concluded that anatomic locations, implant designs, and restricted prosthetic guidelines are key to ensure successful outcomes. Future studies, preferably randomized, prospective longitudinal studies, are certainly needed before this approach can be widely used.

A Systematic Review and Meta-Analysis of The Effect of Low Vitamin D on Cognition.

PubMed

Goodwill, Alicia M; Szoeke, Cassandra

2017-10-01

With an aging population and no cure for dementia on the horizon, risk factor modification prior to disease onset is an urgent health priority. Therefore, this review examined the effect of low vitamin D status or vitamin D supplementation on cognition in midlife and older adults without a diagnosis of dementia. Systematic review and random effect meta-analysis. Observational (cross-sectional and longitudinal cohort) studies comparing low and high vitamin D status and interventions comparing vitamin D supplementation with a control group were included in the review and meta-analysis. Studies including adults and older adults without a dementia diagnosis were included. Medline (PubMed), AMED, Psych INFO, and Cochrane Central databases were searched for articles until August 2016. The Newcastle-Ottawa Scale and Physiotherapy Evidence Database assessed methodological quality of all studies. Twenty-six observational and three intervention studies (n = 19-9,556) were included in the meta-analysis. Low vitamin D was associated with worse cognitive performance (OR = 1.24, CI = 1.14-1.35) and cognitive decline (OR = 1.26, CI = 1.09-1.23); with cross-sectional yielding a stronger effect compared to longitudinal studies. Vitamin D supplementation showed no significant benefit on cognition compared with control (SMD = 0.21, CI = -0.05 to 0.46). Observational evidence demonstrates low vitamin D is related to poorer cognition; however, interventional studies are yet to show a clear benefit from vitamin D supplementation. From the evidence to date, there is likely a therapeutic age window relevant to the development of disease and therefore vitamin D therapy. Longitudinal lifespan studies are necessary to depict the optimal timing and duration in which repletion of vitamin D may protect against cognitive decline and dementia in aging, to better inform trials and practice towards a successful therapy. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

Randomized Controlled Trial on the Effect of Channa striatus Extract on Measurement of the Uterus, Pulsatility Index, Resistive Index of Uterine Artery and Superficial Skin Wound Artery in Post Lower Segment Caesarean Section Women.

PubMed

Abu Bakar, Mohd Rizal; Abdul Kadir, Azidah; Abdul Wahab, Siti Zubaidah; Abdul Karim, Ahmad Helmy; Nik Hussain, Nik Hazlina; Mohd Noor, Norhayati; Omar, Julia; Bin Bai Bae, Saringat; Wan Mahmood, Wan Haslindawani; Abdul Razak, Asrenee; Yunus, Rohaizan

2015-01-01

To compare the mean of anteroposterior (AP) measurements of the uterus in longitudinal and oblique transverse planes, and the pulsatility index (PI) and resistive index (RI) of the uterine artery and superficial skin wound artery between patients taking Channa striatus and placebo. Channa striatus, also known as haruan, is a fresh water snakehead fish consumed in many parts of Southeast Asia. Channa striatus is also normally consumed by women postpartum to promote wound healing as well as to reduce post-operative pain. This study is a randomised, double blind, placebo-controlled study conducted in women after Lower Segment Caesarean Section (LSCS). Subjects were randomised to either a Channa striatus or a placebo group and were given a daily dosage of 500 mg of Channa striatus extract or 500 mg maltodextrin, respectively, for six weeks post LSCS. The anteroposterior measurements of the uterus in the longitudinal and oblique transverse planes, and the pulsatility index (PI) and resistive index (RI) of the uterine and superficial skin wound arteries were assessed using pelvic Gray-scale ultrasound and Doppler ultrasound at baseline (Day 3) and at two weeks, four weeks and six weeks post-operatively. Sixty-six subjects were randomised into the study with 33 in the Channa striatus group and 33 in the placebo group. No significant differences were detected in terms of the pulsatility index (PI) and the resistive index (RI) of the uterine and superficial skin wound arteries between the Channa striatus and placebo groups. However, in the Channa striatus group, the AP measurements of the uterus on the longitudinal and oblique transverse planes were significantly lower compared to the placebo group (p<0.05 and p<0.001, respectively). Daily intake of Channa striatus extract results in marked differences compared to placebo in terms of uterine involution and recovery in women post LSCS. www.isrctn.com 11960786.

A Model of Manual Control with Perspective Scene Viewing

NASA Technical Reports Server (NTRS)

Sweet, Barbara Townsend

2013-01-01

A model of manual control during perspective scene viewing is presented, which combines the Crossover Model with a simpli ed model of perspective-scene viewing and visual- cue selection. The model is developed for a particular example task: an idealized constant- altitude task in which the operator controls longitudinal position in the presence of both longitudinal and pitch disturbances. An experiment is performed to develop and vali- date the model. The model corresponds closely with the experimental measurements, and identi ed model parameters are highly consistent with the visual cues available in the perspective scene. The modeling results indicate that operators used one visual cue for position control, and another visual cue for velocity control (lead generation). Additionally, operators responded more quickly to rotation (pitch) than translation (longitudinal).

The response of an airplane to random atmospheric disturbances

NASA Technical Reports Server (NTRS)

Diederich, Franklin W

1957-01-01

The statistical approach to the gust-load problem which consists in considering flight through turbulent air to be a stationary random process is extended by including the effect of lateral variation of the instantaneous gust intensity on the aerodynamic forces. The forces obtained in this manner are used in dynamic analyses of rigid and flexible airplanes free to move vertically, in pitch, and in roll. The effect of the interaction of longitudinal, vertical, and lateral gusts on the wing stresses is also considered.