Effectiveness and costs of the recruitment strategies used in the MetA-Bone trial, a randomized clinical trial to test the effects of soluble corn fiber supplementation for 1 year in children

Background: Pediatric recruitment into clinical trials is very challenging. A recruitment plan was designed to recruit healthy children (9–14 years) in a trial testing the 1-year effect of corn soluble fiber supplementation on bone mass. We evaluated the effectiveness and costs of the recruitment strategies used in this trial. Methods: The recruitment plan included “Traditional” (mailings, flyers, posters, visits, snowball, etc.) or “Online” (email campaigns, social media, website, etc.) strategies. All strategies led to the pre-screening online form, which asked how they learned about the study. This analysis includes the number of pre-screenings and enrollment (consents signed), ineligibility, socio-demographics, and costs per strategy. Differences were analyzed using ANOVA or chi-square. Results: 649 individuals completed the pre-screening; 37.1 % came from “Traditional”, 46.7 % from “Online”, 2.6 % from “Other”, and 13.6 % from “Unknown” strategies. The most successful strategies were related to Florida International University (posting flyers around campus and email campaigns). The main reasons for ineligibility were obesity (38.9 %) or outside the age range (22.7 %). A total of 48.4 % of the children enrolled came from “Traditional”, 50.2 % from “Online”, and 1.4 % from “Other” strategies. The cost per screened participant was $1112 for “Traditional” and $512 for “Online” strategies, and the cost per enrolled participant was $2704 for “Traditional” and $1454 for “Online” strategies. The highest costs were staff salary. Conclusion: “Online” strategies were more effective and had a lower implementation cost than “Traditional” strategies, although these were also important in achieving the recruitment goal. Future pediatric trials should consider some of these strategies and their costs. ClinicalTrials.gov registry number: NCT02916862