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Full-Text Articles in Analytical, Diagnostic and Therapeutic Techniques and Equipment

Assessing Intervention Effects In A School-Based Nutrition Intervention Trial: Which Analytic Model Is Most Powerful?, Jessica B. Janega, David M. Murray, Sherri P. Varnell, Jonathan L. Blitstein, Amanda Birnbaum, Leslie A. Lytle Dec 2004

Assessing Intervention Effects In A School-Based Nutrition Intervention Trial: Which Analytic Model Is Most Powerful?, Jessica B. Janega, David M. Murray, Sherri P. Varnell, Jonathan L. Blitstein, Amanda Birnbaum, Leslie A. Lytle

Department of Public Health Scholarship and Creative Works

This article compares four mixed-model analyses valid for group-randomized trials (GRTs) involving a nested cohort design with a single pretest and posttest. This study makes estimates of intraclass correlations (ICCs) available to investigators planning GRTs addressing dietary outcomes. It also provides formulae demonstrating the potential benefits to the standard error of the intervention effect (σΔ) from adjustments for both fixed and time-varying covariates and correlations over time. These estimates will allow other researchers to use these variables to plan their studies by estimating a priori detectable differences and sample size requirements for any of the four analytic options. These methods …


Qtc Is Associated With Obesity And Physical Activity Level For African American Females, C. Jayne Brahler Apr 2004

Qtc Is Associated With Obesity And Physical Activity Level For African American Females, C. Jayne Brahler

Health and Sport Science Faculty Publications

Long QT syndrome (LQTS) is an independent risk factor for cardiovascular or ischemic disease mortality. Obesity as a cause for acquired LQTS in otherwise healthy individuals is rapidly gaining the attention of the scientific community. African American people have a higher incidence of obesity compared to Caucasians, yet race-specific information is not available for their prevalence of LQTS. Chronic physical activity can help reduce the incidence of obesity, yet little is known about the effects of chronic physical activity on acquired LQTS. Subjects in this study were a volunteer sample of African American mothers (21-53 yr, n = 44) and …