Limitations
This study has some limitations, including the exclusion of people with symptomatic alcohol dependence or substance use. Additionally, few or no Alaska Native, American Indian, Asian, Hispanic or Latinx, multiracial, or Pacific Islander people enrolled, limiting generalizability to these populations. Additionally, study participants were given free medications and modest compensation for study visits, which are both elements that reduce generalizability. Another limitation emerged from the fact that that the study was stopped early due to COVID-19, resulting in a sample size of 188 instead of 300, with our lower sample size resulting in the relatively wide 95% CI for our main outcome. The relatively high percentage (27%) of participants lost to follow up might be explained by modest compensation and high comorbidity. Participants with missing abstinence data were counted as nonabstinent, which adds to the uncertainty of study outcomes. An additional limitation is that the study was designed to compare adaptive treatment as a whole with standard treatment as a whole and was not designed to assess individual components of adaptive treatment (effects of extended precessation treatment, effects of adding a second medication for nonresponders). Overall, these limitations were seen as decreasing the strength of but not negating our conclusions.