The overall aim of the Child and Adolescent Trial for Cardiovascular Health (CATCH) is to formally evaluate the effectiveness of school and family- based interventions in reducing the risk of cardiovascular disease. Specific primary and secondary goals clearly differentiated by level of the student (and that of the school) have been identified. The primary student goal is to demonstrate an average reduction in total cholesterol of 5 mg/dl after three school years among students in intervention schools compared to students in control schools. The primary school level goals are to: (a) maintain recommended levels of essential nutrients and student participation in school lunches in intervention schools while reducing total fat content and sodium intake; and (b) engage students in moderate to vigorous physical activity (MVPA) for at least 40% of the class period in intervention schools. To accomplish these and a range of secondary goals, the proposed Phase II trial is a balanced randomized block design with replication. Three treatment arms are proposed: Control (C), involving no intervention beyond current school curricula and policies; School Intervention (S) only, including food service intervention, PE and a policy of no tobacco use as well as specific health curricula in grades 3-5; and a combined School and Family (SF) program which adds a Family Program component to the above School Intervention, for students in grades 3-5. Ninety-six schools will be selected to represent the population of elementary school in the U.S. Twenty-four schools will be selected by each of the Field Centers from school districts that are being approached during Phase I. Interventions will be staggered, with school level interventions and grade 3 curricula introduced in School Year 1, grades 3 and 4 curricula in School Year 2 and grades 3,4 and 5 in School Year 3. The evaluation design includes a pre-randomized baseline measurement at the beginning of School Year 1 and two post-test measurement points for students at the end of Years 2 and 3. Additional measurements at the school level will be made at the end of School Year 1 and at the beginning of Years 2 and 3. Student measurements will be completed at each time point on random samples of at most 100 students (grades 3-5) in each school or on random sub-samples. Two cohorts of grade 3 students (at most 30 each) will be measured twice (pre-test and one post-test). Sampling will be designed so that no student provides more that two blood samples. Analysis will focus on school level measurements as means, using school as the unit of analysis and a fixed effects model.
| Keever-Taylor, C A; Wagner, J E; Kernan, N A et al. (2010) Comparison of immune recovery in recipients of unmanipulated vs T-cell-depleted grafts from unrelated donors in a multicenter randomized phase II-III trial (T-cell depletion trial). Bone Marrow Transplant 45:587-9 |
| Feldman, H A; McKinlay, S M (1994) Cohort versus cross-sectional design in large field trials: precision, sample size, and a unifying model. Stat Med 13:61-78 |
| McKinlay, S M (1994) Cost-efficient designs of cluster unit trials. Prev Med 23:606-11 |
