Multimorbidity Profiles and Cause-Specific Mortality Among Older Adults with Schizophrenia

To characterize multimorbidity patterns among mid- to late-life adults with schizophrenia and evaluate the relationship between multimorbidity patterns and cause-specific mortality. This study utilized a national, longitudinal, cohort of U.S. veterans aged 50 years and older with schizophrenia who were followed 2012-2020 (n = 91,680). Latent class analysis was used to identify multimorbidity profiles of medical and neuropsychiatric diagnoses. Demographic variables and diagnoses were extracted from the Veterans Affairs (VA) National Patient Care Database and Centers for Medicare & Medicaid Services data. Information on cause-specific mortality was drawn from the VA Mortality Data Repository. Fine-Gray models were used to examine associations between multimorbidity classes and incident mortality over the study period, including death due to natural causes, unintentional injury, and suicide. Four multimorbidity classes were identified: Minimal Multimorbidity (52%), high anxiety/post-traumatic stress disorder (PTSD) (19%), psychiatric and substance use disorder (SUD) (19%), and high Medical-Psychiatric (11%). The high Medical-Psychiatric class had the highest risk of overall mortality during the study period (HR 2.03, 95% CI 1.97-2.09 versus Minimal Multimorbidity), with the most common causes of death due to heart disease, cancer, and chronic lower respiratory disease. The psychiatry and SUD class had the highest risk of death due to unintentional injury (HR 2.24, 95% CI 2.00-2.51). The High Anxiety/PTSD group had the highest risk of suicide death (HR 1.37, 95% CI 1.06-1.77). Older veterans with schizophrenia are a heterogeneous group with distinct multimorbidity patterns and associated causes of mortality. Tailored interventions should address the specific clinical and psychosocial needs of these subgroups.