Barriers to Recruitment in Pediatric Obesity Trials: Comparing Opt-in and Opt-out Recruitment Approaches.

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.