Journal of Obesity / 2018 / Article / Tab 2 / Review Article
Trial Characteristics and Appropriateness of Statistical Methods Applied for Design and Analysis of Randomized School-Based Studies Addressing Weight-Related Issues: A Literature Review Table 2 Study characteristics by study years: median (Q1, Q3), N (%).
Study characteristics All years ( ) 1995–2012 ( ) 2013–2017 ( ) valueNumber of schools 13 (7, 28) 14 (8, 31) 12 (6, 20) 0.434 Analytic sample size 620 (340, 1182) 670 (407, 1295) 610 (310, 1083) 0.269 Follow-up length in months 12 (6, 24) 12 (6, 24) 12 (5, 20) 0.078 Number of repeated measurements 2 (2, 3) 2 (2, 3) 2 (2, 3) 0.098 Randomization at a cluster level 108 (89.3%) 57 (90.5%) 51 (87.9%) 0.772 Follow-up ≥1 year 68 (56.2%) 38 (60.3%) 30 (51.7%) 0.365 Two measurements including baseline 70 (57.9%) 32 (50.8%) 38 (65.5%) 0.140 Trials conducted outside the US 69 (57.0%) 32 (50.8%) 37 (63.8%) 0.198 School type 0.038 Preschool 11 (9.1%) 3 (4.8%) 8 (13.8%) Primary/elementary school 83 (68.6%) 50 (79.4%) 33 (56.9%) Middle school 20 (16.5%) 7 (11.1%) 13 (22.4%) High school 5 (4.1%) 3 (4.8%) 2 (3.5%) College 2 (1.7%) 0 (0.0%) 2 (3.5%)