Background: Emergency department (ED)-initiated buprenorphine/naloxone with continuation in primary care was found to increase engagement in addiction treatment and reduce illicit opioid use at 30 days compared to referral only or a brief intervention with referral.
Objective: To evaluate the long-term outcomes at 2, 6 and 12 months following ED interventions.
Design: Evaluation of treatment engagement, drug use, and HIV risk among a cohort of patients from a randomized trial who completed at least one long-term follow-up assessment.
Participants: A total of 290/329 patients (88% of the randomized sample) were included. The followed cohort did not differ significantly from the randomized sample.
Interventions: ED-initiated buprenorphine with 10-week continuation in primary care, referral, or brief intervention were provided in the ED at study entry.
Main measures: Self-reported engagement in formal addiction treatment, days of illicit opioid use, and HIV risk (2, 6, 12 months); urine toxicology (2, 6 months).
Key results: A greater number of patients in the buprenorphine group were engaged in addiction treatment at 2 months [68/92 (74%), 95% CI 65-83] compared with referral [42/79 (53%), 95% CI 42-64] and brief intervention [39/83 (47%), 95% CI 37-58; p < 0.001]. The differences were not significant at 6 months [51/92 (55%), 95% CI 45-65; 46/70 (66%) 95% CI 54-76; 43/76 (57%) 95% CI 45-67; p = 0.37] or 12 months [42/86 (49%) 95% CI 39-59; 37/73 (51%) 95% CI 39-62; 49/78 (63%) 95% CI 52-73; p = 0.16]. At 2 months, the buprenorphine group reported fewer days of illicit opioid use [1.1 (95% CI 0.6-1.6)] versus referral [1.8 (95% CI 1.2-2.3)] and brief intervention [2.0 (95% CI 1.5-2.6), p = 0.04]. No significant differences in illicit opioid use were observed at 6 or 12 months. There were no significant differences in HIV risk or rates of opioid-negative urine results at any time.
Conclusions: ED-initiated buprenorphine was associated with increased engagement in addiction treatment and reduced illicit opioid use during the 2-month interval when buprenorphine was continued in primary care. Outcomes at 6 and 12 months were comparable across all groups.
Keywords: emergency medicine; opioid use disorder; primary care; substance use disorder.