Prevention of eating disorders-Efficacy and cost-benefit of a school-based program ("MaiStep") in a randomized controlled trial (RCT).

Objective: Given the severity of eating disorders, effective and easily implementable prevention programs which reduce incidence rates and in addition have health-economic benefits are essential. The majority of research on prevention programs focuses on questionnaire-based efficacy or the reduction of eating disorder symptoms while neglecting the health-economic perspective. By contrast, the present study focuses on both an efficacy analysis considering diagnostic criteria (DSM-5) and on evaluating the cost-benefit of a universal prevention program for eating disorders ("MaiStep").

Method: A three-arm randomized controlled trial with baseline, posttreatment and 12-month follow-up was conducted with 1,654 adolescents (M = 13.35, SD = 0.76), comprising two intervention groups (MaiStep delivered by psychologists or teachers, IG-T) and an active control group (ACG). The primary outcome was DSM-5 eating disorder diagnosis measured with the SIAB-S. Furthermore, the costs of the prevention program and the savings in health care costs were calculated.

Results: A significant difference in eating disorder diagnosis was found between the IG-T and the ACG for posttreatment (χ (1= 7.352, p = .007), Relative Risk (RR) = .53 and 12-month follow-up (χ (1= 5.203, p = .023), RR = .61. MaiStep proved to be cost-effective (t  = 6.75), saving about 560,000 € (standardized per 1,000 students = 601,388.19 €).

Discussion: Universal prevention can both reduce incidence rates of eating disorders and be cost-beneficial for health care systems. Future research should analyze prevention programs regarding efficacy and cost-benefit to enable comparability and derive guidelines for political decision-makers.

Trial Registration Number: MaiStep is registered at the German Clinical Trials Register (DRKS00005050).