Follow-up after ED visits for opioid use disorder: Do they reduce future overdoses?

Introduction: Follow-up visits within 7 days of an emergency department (ED) visit related to opioid use disorder (OUD) is a key measure of treatment quality, but we know little about its protective effect on future opioid-related overdoses. The objective this paper is to examine the rate of 7-day follow-up after an OUD-related ED visit and the association with future overdoses. Methods: Retrospective analysis of Medicaid enrollees in 11 states that had an OUD-related ED visit from 2016 through 2018. Each state used Cox proportional hazard models to estimate the association between having a follow-up visit within 7 days of an OUD-related ED visit, and an overdose within 6 months of the ED visit. State analyses were pooled to generate global estimates using random effects meta-analysis. Results: Among 114,945 Medicaid enrollees with an OUD-related ED visit, 15.7% had a follow-up visit within 7 days. State-specific rates varied from 7.2% to 22.4% across the 11 states. Compared to those with no follow-up visit, enrollees with a follow-up visit were more likely to be female, non-Hispanic White, less likely to have had an overdose or other substance use disorder at the time of the ED visit, and much more likely to have been receiving MOUD treatment prior to the ED visit. Global estimates based on multivariate analysis showed that having a 7-day follow-up visit was associated with a lower likelihood of overdose within 6 months of the index ED visit (HR = 0.91, CI = 0.84, 0.99). However, states had considerable heterogeneity in this association, with only two states having statistically significant results. Conclusions: Among Medicaid enrollees with OUD, having a follow-up visit 7 days after an ED visit is protective against fatal or nonfatal overdose within 6 months, although the association varies considerably across states. Although the association with future overdoses was relatively modest, both practitioners and policymakers should seek to increase the number of Medicaid enrollees with OUD who receive follow-up care within 7 days after an ED visit.