RESUMO
OBJECTIVES: For child health randomized controlled trials (RCTs) published in 2012, we aimed to describe design and reporting characteristics and evaluate changes since 2007; assess the association between trial design and registration and risk of bias (RoB); and assess the association between RoB and effect size. STUDY DESIGN: For 300 RCTs, we extracted design and reporting characteristics and assessed RoB. We assessed 5-year changes in design and reporting (based on 300 RCTs we had previously analyzed) using the Fisher exact test. We tested for associations between design and reporting characteristics and overall RoB and registration using the Fisher exact, Cochran-Armitage, Kruskal-Wallis, and Jonckheere-Terpstra tests. We pooled effect sizes and tested for differences by RoB using the χ2 test for subgroups in meta-analysis. RESULTS: The 2012 and 2007 RCTs differed with respect to many design and reporting characteristics. From 2007 to 2012, RoB did not change for random sequence generation and improved for allocation concealment (P < .001). Fewer 2012 RCTs were rated high overall RoB and more were rated unclear (P = .03). Only 7.3% of 2012 RCTs were rated low overall RoB. Trial registration doubled from 2007 to 2012 (23% to 46%) (P < .001) and was associated with lower RoB (P = .009). Effect size did not differ by RoB (P = .43) CONCLUSIONS: Random sequence generation and allocation concealment were not often reported, and selective reporting was prevalent. Measures to increase trialists' awareness and application of existing reporting guidance, and the prospective registration of RCTs is needed to improve the trustworthiness of findings from this field.