Recruiting participants to an Internet-based eating disorder prevention trial: Impact of the recruitment strategy on symptom severity and program utilization

Objective: Using data from a randomized controlled trial, we examined two different strategies to recruit participants for an indicated preventive intervention (StudentBodies-AN) for women at risk for anorexia nervosa and compared symptom severity and program utilization in participants recruited through each strategy.

Method: We recruited participants by announcing the study (a) in lectures at universities and handing out screening questionnaires (face-to-face recruitment) and (b) through different media channels, and the participants completed the screening questionnaire on our study website (media-based recruitment). We compared symptom severity and program utilization between the two groups.

Results: A total of 4,646 women (face-to-face: 3,741, media-based: 905) were screened and 168 women (face-to-face: 114, media-based: 54) were randomized to the intervention. We found a statistically and clinically significant association between recruitment strategy and symptom severity: Participants who were recruited through media were more likely to fulfill the inclusion criteria (40.6% vs. 13.3%; p < .001) and endorsed significantly more frequently core behaviors and attitudes of disordered eating (EDE global score: 2.72 vs. 2.17, p < .05; Weight Concerns Scale [WCS] score: 66.05 vs. 56.40, p < .05) at baseline than participants recruited face-to-face. Also, participants recruited through media were more likely to log onto the program (χ² = 5.06; p = .029) and accessed more of the intervention.

Discussion: Recruitment through media seems both more feasible and suitable to reach individuals in need of indicative prevention, and should be part of a multimodal recruitment package. Future studies should be explicitly designed to investigate the impact of recruitment modality on reach and effectiveness including cost-effectiveness analyses.