Recruitment and Retention for a Weight Loss Maintenance Trial Involving Weight Loss Prior to Randomization

Abstract

Objective: A weight loss maintenance trial involving weight loss prior to randomization is challenging to implement due to the potential for dropout and insufficient weight loss. We examined rates and correlates of non-initiation, dropout, and insufficient weight loss during a weight loss maintenance trial.

Methods: The MAINTAIN trial involved a 16-week weight loss program followed by randomization among participants losing at least 4 kg. Psychosocial measures were administered during a screening visit. Weight was obtained at the first group session and 16 weeks later to determine eligibility for randomization.

Results: Of 573 patients who screened as eligible, 69 failed to initiate the weight loss program. In adjusted analyses, failure to initiate was associated with lower age, lack of a support person, and less encouragement for making dietary changes. Among participants who initiated, 200 dropped out, 82 lost insufficient weight, and 222 lost sufficient weight for randomization. Compared to losing sufficient weight, dropping out was associated with younger age and tobacco use, whereas losing insufficient weight was associated with non-White race and controlled motivation for physical activity.

Conclusions: Studies should be conducted to evaluate strategies to maximize recruitment and retention of subgroups that are less likely to initiate and be retained in weight loss maintenance trials.

Keywords: clinical trials; recruitment; retention; weight loss maintenance.

Figure 1

CONSORT Flow Diagram for Phase I of MAINTAIN Trial. Note: ^aN = 10,807 were mailed letters; n = 38 were mailed letters as well as being self‐referred; n = 239 were self‐referred with no letter sent ^bN = 2 of the n = 267 ineligibles at phone screen (1 due to BMI < 30 kg/m², and 1 due to age) are included in both the “Scheduled for in‐person consent and screening” and “In‐person consent and screening” boxes. One was ineligible at phone screen due to BMI < 30 kg/m², but then was erroneously re‐screened in‐person and excluded at that point for the same reason. The second was listed as excluded due to age > 75 at both phone and in‐person screen. Both exclusions were erroneous as the patient was 75 at both time points; however, the patient was not included in study after the in‐person screen.