Background: Hospitalizations among patients with opioid use disorder (OUD) have skyrocketed in the past 10 years (1). These patients represent an ever-growing portion of the typical hospital medicine census and often have readmission rates greater than expected for their age and other health status. Discharge against medical advice (AMA) is common in this population, and independently associated with readmission to the hospital within 30 days (2). Factors associated with fewer readmissions in this population include buprenorphine use at the time of admission, using heroin (as compared to prescription opioids) at the time of admission, and shorter length of hospital stay) (3), but it is not known whether readmissions are common throughout this population or are concentrated in a small group of high utilizers.

Methods: Vizient database and electronic health record data was obtained for all patients discharged from an urban tertiary care center between January 1, 2019 to July 31, 2019 who had an OUD-related ICD-10 code billed during the admission. Descriptive statistics were calculated using SPSS. We aimed to describe the pattern of readmissions among this population and determine the influence of multiply-readmitted patients on the overall readmission rate as compared to patients with one readmission.

Results: 684 patients had a total of 901 admissions during the study period. 141 (15.6%) admissions resulted in readmission within 30 days. Mean patient age of all admissions was 40.5 years (SD 13.4), with a mean age of 39.5 years among those readmitted (SD 12.3). 492 (54.6%) admissions were for female patients and 409 (45.4%) male. 627 (69.6%) were for white patients, and 165 (18.3%) were for Black patients, with 1 (0.1%) Asian patient and 108 (12.0%) for patients where race was other or unavailable.684 (75.9%) admissions were a first-time admission within the study period. Admissions which were a first, second, or third admission for an individual accounted for 95.7% of admissions. Five individuals (0.8%) had greater than five admissions, while the most admissions for any individual was fourteen. 58.9% (n=83) of hospitalizations that resulted in readmission were first-time admissions and 19.1% (n=27) were second-time admissions. Percent of admissions with an “extreme” or “major” severity of illness rating trended toward increasing (p=0.088) with each successive admission (first admission: 61.1%, second admission: 57.5%, third admission: 70.5%, four or more admissions: 82.1%).127 admissions (14.1%) ended in AMA discharge. AMA rate was 12.1% among first admissions, 17.2% among second admissions, 20.5% among third admissions, and 30.8% among four or more admissions (p<0.01); only 14 patients had 4 admissions or greater. 33.1% of AMA discharges resulted in readmission, as opposed to 12.8% of non-AMA discharges.

Conclusions: The challenge of frequent readmissions among patients with OUD is not driven by a small group of “super utilizers.” Most readmitted patients are readmitted only a few times. Successful interventions to decrease readmissions among patients with OUD will improve transitions and outpatient care for this population in general, as well improving hospital care to reduce AMA discharge. Interventions targeting only patients with extremely high numbers of readmissions will likely have a negligible impact on rates overall.