Mortality and rehospitalization rates among patients with severe mental illness (SMI) at different levels of hospital spending

Abstract

Background Evidence has shown that the relationships between hospital spending and treatment outcomes for physical conditions have been inconclusive. So to investigate the association between hospital spending and both risk-adjusted mortality and rehospitalization rates among patients with severe mental illness (SMI). Method This was a retrospective cohort study that used the Taiwan National Health Research Institute Database (NHRID) from 1999 to 2010. Hospital end-of-life (EOL) spending was used to quantify hospital spending and was determined by the total medical costs of the last year of life of patients with at least one previous psychiatric hospitalization. Patients with schizophrenia (n=13,229), bipolar disorder (n=4,476) and major depressive disorder (n=5,177) were followed for mortality and rehospitalization to psychiatric wards from 2009 to 2010 after they had been discharged from the study hospitals. Results Patients with schizophrenia had lower rehospitalization and mortality rates when treated at higher-spending hospitals than when treated at the lowest-spending hospitals. However, these associations became weak, even nonsignificant, when adjusted for patient-level variables. There were no significant findings for patients with bipolar disorder and major depressive disorder when patient-level variables were adjusted for. Patient-level variables showed more determinant roles than hospital-level variables in the relationships between hospital spending and treatment outcomes. Conclusion Hospitals that spend more at the EOL had lower mortality and rehospitalization rates for patients with schizophrenia but higher rates for bipolar disorder and major depressive disorder. Most of these associations could be explained by patients’ characteristics more than hospitals’ characteristics.