Participant retention in a fully remote trial of digital psychotherapy: Comparison of incentive types

Abstract

Numerous studies have found that long term retention is very low in remote clinical studies (>4 weeks) and to date there is limited information on the best methods to ensure retention. The ability to retain participants in the completion of key assessments periods is critical to all clinical research, and to date little is known as to what methods are best to encourage participant retention. To study incentive-based retention methods we randomized 215 US adults (18+ years) who agreed to participate in a sequential, multiple assignment randomized trial to either high monetary incentive (HMI, $125 USD) and combined low monetary incentive ($75 USD) plus alternative incentive (LMAI). Participants were asked to complete daily and weekly surveys for a total of 12 weeks, which included a tailoring assessment around week 5 to determine who should be stepped up and rerandomized to one of two augmentation conditions. Key assessment points were weeks 5 and 12. There was no difference in participant retention at week 5 (tailoring event), with approximately 75% of the sample completing the week-5 survey. By week 10, the HMI condition retained approximately 70% of the sample, compared to 60% of the LMAI group. By week 12, all differences were attenuated. Differences in completed measures were not significant between groups. At the end of the study, participants were asked the impressions of the incentive condition they were assigned and asked for suggestions for improving engagement. There were no significant differences between conditions on ratings of the fairness of compensation, study satisfaction, or study burden, but study burden, intrinsic motivation and incentive fairness did influence participation. Men were also more likely to drop out of the study than women. Qualitative analysis from both groups found the following engagement suggestions: desire for feedback on survey responses and an interest in automated sharing of individual survey responses with study therapists to assist in treatment. Participants in the LMAI arm indicated that the alternative incentives were engaging and motivating. In sum, while we were able to increase engagement above what is typical for such study, more research is needed to truly improve long term retention in remote trials.

Barriers and facilitators for recruiting and retaining male participants into longitudinal health research: a systematic review

“…Of the included studies, 20 had male and female participants [ 37 – 40 , 42 – 49 , 51 – 58 ], with a number of these studies having a predominantly male sample [ 42 , 52 , 53 , 58 ]. Four studies recruited only male participants [ 36 , 41 , 50 , 61 ] (Table 2 ).…”

“…Overall, all studies provided information on recruitment rates and 19 provided information on retention rates [ 36 , 38 – 41 , 43 – 47 , 49 – 52 , 55 – 58 , 61 ] (Table 2 ). A variety of methods for male participant recruitment included advertising [ 36 , 43 , 54 , 57 ], letters of invitation [ 39 – 43 , 47 , 52 , 56 – 58 , 61 ], selection of participants from larger cohorts [ 42 , 43 , 50 , 53 ], or recruitment from hospitals or registers [ 37 , 44 , 48 , 51 , 54 , 57 ] (Table 3 ).…”

“…Study attrition for both male and female participants by the 1 year follow up was 79.8% Griffith Fillipo et al . 2022 [ 49 ] 1,652 were assessed for eligibility via the Mental Health America online platform. No details are given about how eligible participants were invited.…”

“…While other barriers included time commitment [ 40 , 58 ], reluctance for medical testing [ 58 ], or the belief that the study is an invasion of privacy [ 58 ]. A large number of studies reported that men did not attend study visits [ 40 , 58 ], were not interested in the study or could not be bothered to participate [ 36 , 40 , 41 , 44 , 48 , 49 , 51 , 58 , 61 ], and study staff received no response to invitations [ 40 , 41 , 61 ].…”

“…A large number of studies reported that men did not attend study visits [ 40 , 58 ], were not interested in the study or could not be bothered to participate [ 36 , 40 , 41 , 44 , 48 , 49 , 51 , 58 , 61 ], and study staff received no response to invitations [ 40 , 41 , 61 ].…”