Factors Associated with Long-Term Retention in Buprenorphine-Based Addiction Treatment Programs: a Systematic Review

Background: The average length of buprenorphine treatment for opioid use disorder is less than 6 months. Objective: We conducted a systematic review to determine what factors were associated with longer retention in buprenorphine treatment. Design: We searched Medline, Embase, and Cochrane Database of Systematic Reviews in February 2018. Articles were restricted to randomized controlled trials on human subjects, written in English, which contained ≥ 24 weeks of objective data on retention in buprenorphine treatment. Main Measures: We assessed whether dose of buprenorphine, treatment setting, or co-administration of behavioral therapy was associated with retention rates. Key Results: Over 14,000 articles were identified. Thirteen articles (describing 9 studies) met inclusion criteria. Measures of retention varied widely. Three studies compared doses of buprenorphine between 1 and 8 mg and showed significantly higher rates of retention with higher doses (p values < 0.01). All other studies utilized buprenorphine doses between 8 and 24 mg daily, without comparison. No study found a significant difference in retention between buprenorphine alone and buprenorphine plus behavioral therapy (p values > 0.05). Initiating buprenorphine while hospitalized or within criminal justice settings prior to outpatient treatment programs was significantly associated with retention in buprenorphine treatment (p values < 0.01 respectively). Conclusions: Setting of treatment initiation and a higher buprenorphine dose are associated with improved long-term treatment retention. More objective data on buprenorphine treatment programs are needed, including a standardized approach to defining retention in buprenorphine treatment programs. Registration: This review was registered with PROSPERO (#CRD42019120336) in March 2019.