14 research outputs found

    Profiling medical sites based on adverse events data for multi-center clinical trials

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    Profiling medical sites is an important activity in both clinical research and practice. Many organizations provide public report cards comparing outcomes across hospitals. An analogous concept applied in multicenter clinical trials, such “report cards” guide sponsors to choose sites while designing a study, help identify areas of improvement for sites, and motivate sites to perform better. Sponsors include comparative performance of sites, a concept to perform risk-based monitoring and central statistical monitoring. In clinical research, report cards are powerful tools for relating site performance to treatment benefits. This study evaluates approaches to estimating the proportion of adverse events at the site-level in a multicenter clinical trial setting and also methods in detecting outlying sites. We address three topics. First we assess the performance of different models for obtaining estimates of adverse events rates utilizing Bayesian beta-binomial and binomial logit-normal models with MCMC estimation and fixed effects maximum likelihood estimation (MLE) methods. We - vary sample sizes, number of medical sites, overall adverse event rates, and intraclass correlation within sites. Second, we compare the performance of these methods in identifying outlier sites, contrasting MLE and Bayesian approaches. A fixed threshold method detects sites as outliers under a Bayesian approach, while in the fixed effects assumption, a 95% interval-based approach is applied. Third, we extend this approach in estimating multiple outcomes at the site level and detecting outlier sites. A standard bivariate normal MLE method is compared to a Bayesian bivariate binomial logit-normal MCMC. These are examined using simulation studies. Results show for single outcomes, Bayesian beta-binomial MCMC method perform well under certain parametric conditions for estimation and detecting outlier sites. For multiple outcomes with higher adverse event rate and larger difference between outliers and non-outliers, for detecting outlier sites, both methods – Bayesian MCMC and MLE work well, irrespective of the correlation between outcomes.2020-02-14T00:00:00

    Teaching adolescents about changing bodies: Randomized controlled trial of an Internet puberty education and body dissatisfaction prevention program

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    This study tested the efficacy of an Internet-based prevention program, Trouble on the Tightrope: In Search of Skateboard Sam, on pubertal knowledge, body esteem, and self-esteem. One hundred ninety participants (mean age 11.6 years) were randomized to either an intervention or attention placebo control condition and were assessed at baseline, after 3 Internet-based sessions, and at 3-month follow-up. Although the primary hypotheses were not supported, exploratory moderator analyses indicated that the intervention was beneficial for select students. Specifically, pubertal status moderated the effects on weight-related body esteem and several domains of self-esteem, resulting in positive effects for participants in the intervention group who had begun puberty. Gender differences were found on self-esteem subscales, indicating more robust effects for girls than boys. Tailored Internet programs based on personal characteristics such as gender and pubertal status may be a fruitful area for future research with adolescents

    Deficiency of 25-Hydroxyvitamin D and Dyslipidemia in Indian Subjects

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    Background. Vitamin D deficiency is widespread throughout the world. Several reports have incriminated vitamin D deficiency as the cause of rickets, osteomalacia, and other chronic diseases. Recent studies have suggested a possible link between deficiency of 25-hydroxyvitamin D and dyslipidemia. Aim. To investigate the association between 25-hydroxyvitamin D deficiency and dyslipidemia in Indian subjects. Methodology. We recruited 150 asymptomatic consecutive subjects from patients' attendees at the Departments of Neurology and Medicine in Yashoda Hospital, Hyderabad, India. Study period was from October 2011 to March 2012. All subjects underwent 25-hydroxyvitamin D assay by chemiluminescent microparticle immunoassay, fasting blood sugar and lipid profile, calcium, phosphorus, alkaline phosphatase, and C-reactive protein (CRP). Results. Out of 150 subjects, men were 82 (54.6%), and mean age was 49.4 (±15.6) years. Among risk factors, hypertension was noted in 63/150 (42%), 25-hydroxyvitamin D deficiency in 59/150 (39.3%), diabetes in 45/150 (30%), dyslipidemia in 60 (40%), smoking in 35/150 (23.3%), and alcoholism in 27/150 (18%). Deficiency of 25-hydroxyvitamin D was significantly associated with dyslipidemia ( = 0.0001), mean serum glucose ( = 0.0002) mean CRP ( = 0.04), and mean alkaline phosphatase ( = 0.01). Multivariate analysis showed that 25-hydroxyvitamin D deficiency was independently associated with dyslipidemia (odds ratio: 1.9; 95% CI : 1.1-3.5). Conclusions. We found that deficiency of 25-hydroxyvitamin D was independently associated with dyslipidemia in Indian subjects

    Deficiency of 25-Hydroxyvitamin D and Dyslipidemia in Indian Subjects

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    Background. Vitamin D deficiency is widespread throughout the world. Several reports have incriminated vitamin D deficiency as the cause of rickets, osteomalacia, and other chronic diseases. Recent studies have suggested a possible link between deficiency of 25-hydroxyvitamin D and dyslipidemia. Aim. To investigate the association between 25-hydroxyvitamin D deficiency and dyslipidemia in Indian subjects. Methodology. We recruited 150 asymptomatic consecutive subjects from patients’ attendees at the Departments of Neurology and Medicine in Yashoda Hospital, Hyderabad, India. Study period was from October 2011 to March 2012. All subjects underwent 25-hydroxyvitamin D assay by chemiluminescent microparticle immunoassay, fasting blood sugar and lipid profile, calcium, phosphorus, alkaline phosphatase, and C-reactive protein (CRP). Results. Out of 150 subjects, men were 82 (54.6%), and mean age was 49.4 (±15.6) years. Among risk factors, hypertension was noted in 63/150 (42%), 25-hydroxyvitamin D deficiency in 59/150 (39.3%), diabetes in 45/150 (30%), dyslipidemia in 60 (40%), smoking in 35/150 (23.3%), and alcoholism in 27/150 (18%). Deficiency of 25-hydroxyvitamin D was significantly associated with dyslipidemia (P=0.0001), mean serum glucose (P=0.0002) mean CRP (P=0.04), and mean alkaline phosphatase (P=0.01). Multivariate analysis showed that 25-hydroxyvitamin D deficiency was independently associated with dyslipidemia (odds ratio: 1.9; 95% CI : 1.1–3.5). Conclusions. We found that deficiency of 25-hydroxyvitamin D was independently associated with dyslipidemia in Indian subjects
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