RESUMEN
INTRODUCTION: Mindfulness-based relapse prevention has shown promise as a treatment for substance use disorder but its efficacy according to racial/ethnic minority status and group composition is unknown. METHOD: This is a secondary analysis of existing data (Bowen et al., 2014) testing individual race/ethnicity and racial/ethnic group composition as moderators of mindfulness-based relapse prevention (MBRP). Participants (Nâ¯=â¯191; 29% female; 47% racial/ethnic minority; mean ageâ¯=â¯39) with substance use disorder were randomized to MBRP or relapse prevention (RP). Outcomes were heavy drinking days (HDD) and drug use days (DUD) 12â¯months after treatment completion. Negative binominal regression models were conducted. RESULTS: Analyses accounted for drug of choice. Individual race/ethnicity was a significant moderator of substance use outcomes. White participants had lower HDD in MBRP than RP (IRRâ¯=â¯0, 95% CI: 0,0), whereas for minority participants, there was no treatment difference in HDD. Conversely, minorities had lower DUD in MBRP than RP (IRRâ¯=â¯0.03, 95% CI: 0.01, 0.10), whereas for whites there was no treatment difference in DUD. Group racial/ethnic composition was a significant moderator. Participants in groups with more than half whites had lower HDD in MBRP than RP (IRRâ¯=â¯0.01, 95% CI: 0, 0.09), whereas for participants in groups with more than half minorities there was no treatment difference in HDD. Exploratory analyses suggested MBRP resulted in better outcomes than RP when individual race/ethnic status was reflected in the group race/ethnicity (i.e., whites in groups with more than half whites or minorities in groups with more than half minorities). CONCLUSIONS: Among whites, MBRP appears to be more effective than RP in preventing heavy drinking relapse. However, among racial/ethnic minorities, MBRP appears to more effective than RP in preventing drug use relapse. This suggests that the interaction between individual race/ethnicity and group composition may influence primary outcomes.