In both the black and white subgroups, 30-day abstinence rates were highest for participants who utilized formal substance use treatment versus those who did not (Figure 1). Formal treatment utilization was significantly associated with 30-day abstinence over time. After adjusting for potential confounders, participants who went to treatment had higher odds of abstinence compared to participants who did not go to treatment (OR: 1.66, 95% CI: 1.3–2.1). Race was not significantly associated with 30-day abstinence in the adjusted model. There was no significant interaction between formal treatment utilization and race on 30-day abstinence over seven years (z-statistic on interaction term: −0.94, p-value = 0.349).
