We conducted a final post-hoc analysis to assess whether our findings might be explained by greater utilization of formal substance use treatment by blacks (versus whites) who did not attend AA. Among non-AA users, whites were more likely than blacks to have attended formal substance use treatment at each time point, with the difference in proportions attending formal treatment ranging from two to 26 percentage points over the seven years. At the 7-year follow-up, 34% of the whites who did not attend AA went to formal treatment, as compared to 8% of their black counterparts. These findings counter the hypothesis that part of the noted effect for black non-AA goers was due to formal substance use treatment attendance.
