Substantial hospital level variation in all-cause readmission rates among medicare beneficiaries with serious mental illness

Abstract

Background: Patients with serious mental illness (i.e., SMI; bipolar disorder, major depressive disorder, and schizophrenia) are at increased risk of readmission, yet little is known about the extent to which readmission rates among these patients vary across hospitals. The purpose of this study was to examine the variation across hospitals in readmissions for patients with SMI and differences in the characteristics of hospitals with the highest and lowest adjusted readmission rates.

Methods: We conducted a cross-sectional analysis of pooled inpatient claims from 2013-2016. Mixed logit models with hospital random effects were used to estimate the hospital-level variance. The sample included patients with SMI from a 5% sample of fee-for-service Medicare beneficiaries.

Results: We identified 2066 hospitals with at least 30 index admissions for Medicare beneficiaries with SMI. In multivariate analyses, factors most strongly associated with increased risk of readmission included substance use disorder (OR 2.311; p < 0.001) and end stage renal disease (OR 2.024; p < 0.001). Unadjusted readmission for hospitals at the 5th and 95th percentiles of performance were 7.05% and 15.24%, respectively, constituting an 8.2% difference. Adjusting for patient and community characteristics reduced the spread in readmission rates between the 5th and 95th percentiles of hospitals by 1.0% (i.e. to 7.2%). Hospitals in the lowest vs. highest quintiles of adjusted readmission rates were more likely to be teaching hospitals (11.1% vs. 16.7%; p < 0.05) and located in the South (37.7% vs. 40.4%) or Midwest (19.8% vs. 30.0%; p < 0.001 for region differences).

Conclusions: There is substantial hospital-level variation in readmission rates among patients with serious mental illness, even after adjusting for patient and community characteristics. This has implications for policy guiding investment in hospital-based services and community resources, to improve transitions of care for patients with SMI.

Keywords: General medical readmissions; Hospital variation; Psychiatric comorbidity.