Hospital readmissions and emergency department encounters among patients who initiate medications for opioid use disorder during hospitalization: Comparison of patients with and without co-occurring methamphetamine use.

BACKGROUND

Many hospitals initiate medications for opioid use disorder (MOUD), which are associated with reduced opioid use and fewer readmissions. Among people who use opioids, co-occurring methamphetamine use is increasingly prevalent and is associated with worse health and treatment outcomes. This study evaluated the frequency of hospital readmissions and emergency department (ED) encounters over a 6-month period after MOUD was initiated in a hospital setting. It was hypothesized that methamphetamine use within the 30 days prior to hospital admission would be associated with increased risk for hospital readmissions and ED encounters.

METHODS

The sample included patients aged 18-64 with Title XIX Medicaid coverage who were admitted to a large, urban, public, university-affiliated hospital and initiated on MOUD by an addiction consult service between May 2019 and December 2021. Hospital readmissions and ED encounters were identified over 6 months after the index hospitalization using Medicaid claims. Patients self-reported past 30-day methamphetamine use during structured interviews. Cox proportional hazards models tested whether time to first readmission or first ED encounter differed for patients with and without recent methamphetamine use, adjusting for demographics and clinical covariates.

RESULTS

Of 690 hospitalized patients initiating MOUD, 404 met study inclusion criteria (41 % unhoused, 56 % with methamphetamine use). Within 6 months after the index hospitalization, 35 % of patients had at least one hospital readmission and 54 % had at least one ED encounter. Hospitalization and ED incidence risks and event rates did not significantly differ for patients with and without methamphetamine use. In survival analyses, methamphetamine use was not associated with earlier hospital readmission (aHR = 0.98, 95 % CI: 0.70-1.35) or ED encounter (aHR = 0.90, 95 % CI: 0.67-1.20). Among patients with methamphetamine use, receiving buprenorphine (vs. methadone) was associated with earlier time to first ED encounter (aHR = 1.64, 95 % CI: 1.13-2.40, p = 0.01).

CONCLUSIONS

This study did not observe a significant association between methamphetamine use and risk of hospital readmission or ED encounters up to 6 months after initiation of MOUD in the hospital. Frequent hospital readmissions and ED encounters after discharge highlight the need for research on drivers of acute care utilization and interventions that better serve patients who initiate MOUD in hospital settings.