Commitment strength, alcohol dependence and HealthCall participation: effects on drinking reduction in HIV patients

The role of three factors in drinking outcome after brief intervention among heavily drinking HIV patients were investigated: strength of commitment to change drinking, alcohol dependence, and treatment type: brief Motivational Interview (MI) only, or MI plus HealthCall, a technological extension of brief intervention.

HIV primary care patients (N=139) who drank ≥4 drinks at least once in the 30 days before study entry participated in MI-only or MI+HealthCall in a randomized trial to reduce drinking. Patients were 95.0% minority; 23.0% female; 46.8% alcohol dependent; mean age 46.3. Outcome at end of treatment (60 days) was drinks per drinking day (Timeline Follow-Back). Commitment strength (CS) was rated from MI session recordings.

Overall, stronger CS predicted end-of-treatment drinking (p<.001). After finding an interaction of treatment, CS and alcohol dependence (p=.01), we examined treatment×CS interactions in alcohol dependent and non-dependent patients. In alcohol dependent patients, the treatment×commitment strength interaction was significant (p=.006); patients with low commitment strength had better outcomes in MI+HealthCall than in MI-only (lower mean drinks per drinking day; 3.5 and 4.6 drinks, respectively). In non-dependent patients, neither treatment nor CS predicted outcome.

Among alcohol dependent HIV patients, HealthCall was most beneficial in drinking reduction when MI ended with low commitment strength. HealthCall may not merely extend MI effects, but add effects of its own that compensate for low commitment strength. Thus, HealthCall may also be effective when paired with briefer interventions requiring less skill, training and supervision than MI. Replication is warranted.