Brief Motivational Interviewing Interventions in Primary Care Do Not Reduce Drug Use in Adults
EBM Focus - Volume 9, Issue 33
Substance abuse is an important issue in primary care. In patients with alcohol use disorder, a high-quality trial of 774 adults previously showed that a brief primary care physician intervention (2 physician visits and 2 nurse follow-up phone calls) can decrease alcohol use, problem drinking, and hospitalization rates vs. usual care (Alcohol Clin Exp Res 2002 Jan;26(1):36). However, data supporting similar brief interventions in primary care for reducing drug use are limited. Two recent randomized trials evaluated the efficacy of brief motivational interviewing interventions for reducing drug use in adults attending primary care.
In the first trial, 868 adults with illegal drug or nonprescribed medication use were randomized to a brief intervention (motivational interview plus handout and list of substance abuse resources) vs. enhanced usual care (handout and list of substance abuse resources) and were followed for up to 1 year. At baseline, the mean use of the most common problem drug in the previous month was 13.8 days. At 3 months post-intervention, the mean use of the most common problem drug in the previous month was 11.9 days with the brief intervention vs. 9.8 days with enhanced usual care (not significant).
In the second trial, 528 adults with drug use were randomized to brief negotiated interview (10-15 minute structured interview conducted by health educators) vs. adapted motivational interview (30-45 minute session followed by 20-30 minute booster session conducted by counselors) vs. no intervention (control) and followed for 6 months. At baseline, the mean use of the main drug in the previous month was 14.4 days. At 6 months post-intervention, the mean use of the main drug in the previous month was 11.2 days with the brief negotiated interview, 12.1 days with the adapted motivational interview, and 11.5 days with control. There were no significant differences between either intervention vs. control in an unadjusted analysis, or after adjusting for baseline differences.
Based on the findings from these 2 new trials, brief interventions for adults with drug abuse problems do not appear effective in the primary care setting. An important limitation of both trials is the wide variation in the specific substance being used, and it is possible that these interventions had some benefit for specific substances of abuse but did not demonstrate benefit since trials were not adequately powered for subgroup analyses. However, this is not supported by current evidence. Given that substance abuse is a chronic disease, it seems likely that interventions that include ongoing treatment and monitoring are warranted.
For more information see the Substance use disorders topic in DynaMed.
Special thanks to Greg Haman and Hoi See Tsao of Harvard Medical School and Dr. Soo Choi of Seoul National University for their contributions to this week’s article.