High inpatient utilization among Veterans Health Administration patients with substance-use disorders and co-occurring mental health conditions

Abstract

ABSTRACTBackground. Substance-use disorders (SUDs) are common and costly conditions. Understanding high inpatient utilization (HIU) among patients with SUD can inform the development of treatment approaches designed to reduce healthcare expenditures and improve service quality. Objectives. To examine the prevalence, type, and predictors of HIU among patients with SUD and co-occurring mental health conditions. Methods. Service utilization and demographic and clinical variables were extracted from a national sample of Veterans Health Administration (VA) patients with SUD-only [n = 148,960 (98.3% male)], SUD plus serious mental illness ([i.e. schizophrenia- and/or bipolar-spectrum disorders; SUD/SMI; n = 75,913 (91.6% male)], and SUD plus other mental illness [SUD/MI; n = 245,675 (94.6% male)]. Regression models were used to examine HIU during a follow-up year. Results. Prevalence of HIU among the SUD-only group was 6.2% (95% confidence interval (CI): 6.1%–6.3%) compared with 22.7% (95% CI: 22.4%–23.0%) and 9.7% (95% CI: 9.6%–9.8%) among the SUD/SMI and SUD/MI groups, respectively. Patients with SUD/MI represented nearly half of the HIU sample. Primary type of inpatient service use varied by comorbidity: SUD-only = medicine; SUD/SMI = psychiatric; SUD/MI similar use of psychiatric, SUD-related, and medicine. Predictors of HIU were generally similar across groups: older age, unmarried, homelessness, suicide risk, pain diagnosis, alcohol/opioid/sedative-use disorders, and prior-year emergency department/inpatient utilization. Conclusions. Substantial reductions in HIU among an SUD population will likely require treatment approaches that target patients with less-severe mental health conditions in addition to SMI. Cross-service collaborations (e.g., integration of medical providers in SUD care) and interventions designed to target issues and/or conditions that lead to HIU (e.g., homeless care services) may be critical to reducing HIU in this population.