Patterns of Health Care Use 5 Years After an Intervention Linking Patients in Addiction Treatment With a Primary Care Practitioner

IMPORTANCE: Substance use disorders are associated with high rates of emergency department (ED) use and challenges engaging with primary care services. OBJECTIVE: To examine 5-year health care engagement and utilization outcomes for participants in the LINKAGE trial, given previously reported associations of LINKAGE with improved care engagement in the short term. DESIGN, SETTING, AND PARTICIPANTS: In this post hoc analysis of a nonrandomized controlled trial, participants were assigned to the LINKAGE or usual care (UC) groups using a nonrandomized 3-month alternating off and on strategy over 30 months. Baseline through 5-year follow-up data were collected from April 2011 to October 2018. The trial was conducted at an urban outpatient addiction treatment clinic within a large health system among patients newly enrolled in addiction treatment. Data analysis was conducted from April 2021 to February 2022. INTERVENTION: The LINKAGE intervention included 6 group-based sessions emphasizing patient agency, skill, and motivation in navigating health care services as well as a facilitated telephone or email connection with a primary care practitioner. The UC group received medical education. MAIN OUTCOMES AND MEASURES: Substance use problem discussions with primary care practitioners (by patient self-report at 1-, 2-, and 5-year follow-up interview) and annual use of the electronic patient portal, primary care, and ED based on electronic health records. RESULTS: A total of 503 participants, with a mean (SD) age of 42 (12) years, 346 (69%) male participants and 37 (7%) African American, 34 (7%) Asian, and 101 (20%) Hispanic participants, were assigned to LINKAGE (252 participants) or UC (251 participants). Compared with UC participants, LINKAGE participants were significantly more likely to discuss substance use problems with a primary care practitioner at 1-year follow-up (risk ratio [RR], 1.30; 95% CI, 1.03-1.65; P = .03) and use the electronic patient portal at 1- and 2-year follow-up (eg, messaging clinicians at 2 years: RR, 1.24; 95% CI, 1.04-1.47; P = .02). The LINKAGE group had small, statistically significant 5-year annual increases in primary care use (RR, 1.03; 95% CI, 1.003-1.07; P = .03) and significant annual decreases in substance-related ED use (RR, 0.79; 95% CI, 0.64-0.97; P = .03), relative to UC. The LINKAGE group did not significantly differ from the UC group on other types of ED utilization. CONCLUSIONS AND RELEVANCE: In this study, a patient activation intervention embedded in outpatient addiction treatment was associated with sustained improvements in health care engagement beyond previously reported 6-month outcomes and with long-term improvements in health care use patterns. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01621711