Cost analysis and efficacy of recruitment strategies used in a large pragmatic community-based clinical trial targeting low-income seniors: a comparative descriptive analysis

OBJECTIVE: One of the most challenging parts of running clinical trials is recruiting enough participants. Our objective was to determine which recruitment strategies were effective in reaching specific subgroups. STUDY DESIGN AND SETTING: We assessed the efficacy and costs of the recruitment strategies used in the Assessing Outcomes of Enhanced Chronic Disease Care Through Patient Education and a Value-based Formulary Study (ACCESS) in Alberta, Canada. RESULTS: Twenty percent of the study budget ($354,330 CAD) was spent on recruiting 4013 participants, giving an average cost per enrolled of $88 CAD. Pharmacies recruited the most participants (n = 1217), at a cost of $128/enrolled. ”Paid media” had the highest cost ($806/enrolled), whereas ”word of mouth” and ”unpaid media” had the lowest (~$3/enrolled). Participants enrolled from ”seniors outreach” had the lowest baseline quality of life and income, while participants from ”word of mouth” had the lowest educational attainment. CONCLUSION: The ”health care providers” strategies were especially successful — at a moderate cost per enrolled. The "media" strategies were less effective, short lasting, and more costly. No strategy was singularly effective in recruiting our targeted groups, emphasizing the importance of utilizing a variety of strategies to reach recruitment goals. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02579655. Registered on 19 October 2015. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13063-019-3652-5) contains supplementary material, which is available to authorized users.