Strategies to increase attendance in substance use disorder group treatment: results from a randomized controlled...

Attendance in substance-use-disorder group-treatment is challenging with only 32% of patients attending at least one session (Substance Abuse and Mental Health Services Administration and Center for Behavioral Health Statistics and Quality. Treatment Episode Data Set (TEDS): 2023 admissions to and discharges from substance use treatment services reported by single state agencies, Bethesda, 2025). The present study tested a set of strategies to increase group session attendance in Community Wise, an innovative evidence-based group-intervention delivered in harm-reduction-community-based agencies and designed to reduce alcohol and substance use among people with substance-use-disorders living in predominantly Black and disinvested communities. We examined: (1) if strategies to increase attendance stratified by surveillance status (participation in mandatory programs that use urine screens regularly) would result in a clinically and statistically significant increase in intervention session attendance, with a goal of at least 50% of participants attending at least half of sessions; (2) the effects of group session attendance and strategies to increase attendance on alcohol and substance use frequency in the past 30 days at three-months-follow-up.

We conducted a 2² stratified full factorial experiment with 164 adults with substance-use-disorder in East St. Louis, IL. Participants were randomized to combinations of two strategies to increase attendance: Financial incentives (receiving $20 to attend group sessions) and group type (open versus closed groups). Surveillance status was treated as a fixed factor in the analytical model. Logistic and multiple regression models, using effect coding, tested main and interaction effects on number of sessions attended and alcohol and substance use. Analyses followed an intent-to-treat approach, adjusting for demographic covariates, using SAS 9.4.

Of 164 participants, 29% attended ≥ 50% of Community Wise sessions. Paying participants increased odds of attending at least 50% of sessions (OR = 1.97, p = 0.004), while being under surveillance reduced odds by 39% (OR = 0.61, p = 0.036). No main effects were found for group type. Yet, a significant interaction showed financial incentives were more effective in closed versus open groups (OR = 0.58, p = 0.021). Higher attendance predicted reduced percent alcohol and substance use at follow-up (p = 0.011).

Financial incentives effectively improved intervention attendance, while being under surveillance reduced participation. Higher attendance was associated with decreased alcohol and substance use. The Community Wise intervention should be further tested for effectiveness in harm reduction community-based-organizations among people who are disengaged from treatment and experiencing vulnerabilities such as poverty and houselessness.

Clinical Trials: NCT05934591.