LAUSR

Objective To compare the efficacy of opt‐in versus opt‐out recruitment methods in pediatric weight management clinical trials. Methods Recruitment of preschoolers and school‐age children across two obesity randomized controlled trials (RCTs) were compared using the same opt‐in recruitment approach (parents contact researchers in response to mailings). Opt‐in and opt‐out strategies (parents send decline postcard in response to mailings if they do not want to participate) were then compared across two preschool obesity RCTs. Results Opt‐in strategies yielded a significantly lower overall recruitment rate among preschoolers compared with school‐age children. Among preschoolers, an opt‐out strategy demonstrated a significantly higher overall recruitment rate compared with an opt‐in strategy with the main advantage in the number of families initially contacted. Conclusions Opt‐out recruitment strategies may be more effective in overcoming the barriers of recruitment in the preschool age‐group because it does not rely on parent recognition of obesity.