Research Paper Title

Impact of financial reimbursement on retention rates in military clinical trial research: A natural experiment within a multi-site randomised effectiveness trial with active duty service members.

Background

Achieving adequate retention rates in clinical trials is essential to ensuring meaningful results. Although financial reimbursement is an effective strategy to increase participant retention, current policies restrict the use of federal funds to reimburse US active duty Service members for research participation. It is unknown whether permitting financial reimbursement among this population would improve trial retention rates. A recent randomised effectiveness trial received approval to provide reimbursement to Service member participants several months after recruitment began, creating a natural experiment to study the effects of financial reimbursement on retention.

Methods

Active duty Service members recruited from six US military treatment facilities (N = 666) were enrolled in a collaborative care study and completed assessments at baseline, three-, six-, and 12-months. Data on study assessment completion rates at three- and six-months were analysed using the mixed-effects binary logit model to determine the probabilities of completing assessments based on reimbursement status.

Results

Participants who received reimbursement were significantly more likely to complete study assessments at both time-points than participants who did not receive reimbursement (p < 0.01). Survey completion was 5% and 4% greater among participants offered reimbursement at three- and six-month time-points, respectively.

Conclusions

Results suggest that providing Service members with reimbursement for research participation is associated with modest increases in retention rates in clinical trials. Findings provide useful insight for researchers, funding agencies, and policy-makers in considering retention strategies to maximise the value and impact of military research.

Reference

Novak, L.A., Belsher, B.E., Freed, M.C., McCutchan, P.K., Liu, X., Evatt, D.P., Tanielian, T., Bray, R.M. & Engel, C.C. (2019) Impact of financial reimbursement on retention rates in military clinical trial research: A natural experiment within a multi-site randomized effectiveness trial with active duty service members. Contemporary Clinical Trials Communications. 15:100353. doi: 10.1016/j.conctc.2019.100353. eCollection 2019 Sep.