Effectiveness of a Motivational Interviewing-Based Intervention in Decreasing Risky Alcohol Use in Primary Care Patients in Spain: A Controlled Clinical Trial

Abstract

Objective: Our study aimed to evaluate the effectiveness of an intervention based on Motivational Interviewing (MI) performed by healthcare professionals in Primary Care (PC) patients with risky alcohol use through a multicenter, two-arm parallel, cluster-randomized, open-label controlled clinical trial.

Methods: PC professionals were randomized into two groups: an Experimental Group (EG) and a Control Group (CG). The study was carried out in PC centers of the Andalusian Health Service, located in Cordoba, Spain. An MI-based approach was implemented with patients recruited in the EG, while health advice was provided to those included in the CG. The follow-up period was 12 months, with five visits scheduled. The consumption of standard drinking units per week was quantified, and risky alcohol use was estimated using the Alcohol Use Disorders Identification Test (AUDIT). An intention-to-treat statistical analysis was performed. Relative risk (RR), absolute risk reduction (ARR) and the number of subjects needed to treat (NNT) were used to estimate the intervention effect size.

Results: A total of 268 patients were included, 148 in the EG and 120 in the CG. Considering the quantification of risky alcohol use, the ARR at 12 months after baseline visit was 16.46% (95% CI: 5.37-27.99), with an NNT of 6 (95% CI: 4-19). According to the AUDIT, the ARR at 12 months was 13.15% (95% CI: 2.73-24.24%), and the NNT was 8 (95% CI: 4-37).

Conclusions: We concluded that MI is more effective than the usual health advice in decreasing risky alcohol use in patients treated in PC.

Keywords: clinical trial; motivational interviewing; primary care; risky alcohol use.

Figure 1

Flow diagram of the study.

Figure 2

Percentages of participating patients in each of the stages of change according to the Prochaska and DiClemente model, based on the allocation group at 6 months after the intervention.

Figure 3

Alcohol use (SDU/week) throughout the study period based on group (95% CI: 95% confidence interval).

Figure 4

Risky alcohol use based on SDU/week at each follow-up visit in each group (%).

Figure 5

Mean scores obtained in each group with the AUDIT questionnaire at the baseline, at 6 months and at 12 months (95% CI: 95% confidence interval).