Randomized controlled trial of a mobile phone intervention for improving adherence to naltrexone for alcohol use disorders

Abstract

Background: Naltrexone is a front-line treatment for alcohol use disorders, but its efficacy is limited by poor medication adherence. This randomized controlled trial evaluated whether a mobile health intervention could improve naltrexone adherence.

Methods: Treatment-seeking participants with an alcohol use disorder (N = 76) were randomized to intervention and control conditions. All participants received naltrexone (50 mg/day) with a medication event monitoring system (MEMS) and a prepaid smartphone, and received a daily text message querying medication side effects, alcohol use, and craving. Those in the intervention arm received additional medication reminders and adherence assessment via text message.

Results: The primary outcome, proportion of participants with adequate adherence (defined as ≥80% of prescribed doses taken through Week 8), did not differ between groups in intent-to-treat analyses (p = .34). Mean adherence at study midpoint (Week 4) was 83% in the intervention condition and 77% in the control condition (p = .35). Survival analysis found that the intervention group sustained adequate adherence significantly longer (M = 19 days [95% CI = 0.0-44.0]) than those in the control group (M = 3 days [95% CI = 0.0-8.1]) during the first month of treatment (p = .04). Medication adherence did not predict drinking outcomes.

Conclusions: These results suggest that in the context of daily monitoring and assessment via cell phone, additional text message reminders do not further improve medication adherence. Although this initial trial does not provide support for the efficacy of text messaging to improve adherence to pharmacotherapy for alcohol use disorders, additional trials with larger samples and alternate designs are warranted.

Trial registration: ClinicalTrials.gov: NCT01349985.

Conflict of interest statement

Competing Interests: All authors report no conflicts of interest and no financial relationships with commercial interests. The development and evaluation of the mHealth intervention described in this manuscript were wholly funded by a Small Business Innovation Research Phase II contract from the National Institute on Alcohol Abuse and Alcoholism to Talaria, Inc., a small business in Seattle, WA (Principal Investigator: Dr. Susan Stoner). Talaria, Inc., did not provide any of its own funds for the study described in this manuscript. Neither the funders nor the owners of Talaria, Inc., had any role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Talaria, Inc., went out of business in June 2014 and donated its products and web-based content authorship platform to the Alcohol and Drug Abuse Institute at the University of Washington, with which Dr. Stoner is now affiliated. This does not alter our adherence to all PLOS ONE policies on sharing data and materials.

Figures

Fig 1. Study CONSORT diagram.

Fig 2. Study outcomes.

Time to first drop below 80% cumulative adherence among all randomized participants, time to first drink among participants with a goal of abstinence completing the Week 4 Timeline Followback assessment, and time to first heavy drinking episode among all participants completing the Week 4 Timeline Followback assessment.

Fig 3. Changes in Self-Reported Drinking and Craving.

95% confidence intervals around the mean numbers of self-reported drinks per drinking day (line graph) and ratings of alcohol craving intensity (column graph), assessed via smartphone, among heavy drinkers randomly assigned to the intervention or control condition. The number of participants making at least one report for each time frame is the number shown in the columns.