Increased risk of avoidable hospitalization among patients with schizophrenia

Some studies suggest that hospitalizations for certain conditions, called ambulatory care sensitive conditions (ACSCs), are potentially avoidable. However, almost no study has addressed the risk of ACSC hospitalizations specifically for patients with severe mental illness. Our study examines the risk of ACSC hospitalizations among patients with schizophrenia in Taiwan, using a 5-year, nationwide, population-based database.

Our study included 2503 patients with schizophrenia and 20 024 matched patients without schizophrenia. Poisson regression analysis was then performed in which the number of ACSC hospitalizations from 2002 to 2006 (including ruptured appendix, asthma, cellulitis, congestive heart failure, diabetes, gangrene, hypokalemia, immunizable conditions, malignant hypertension, pneumonia, pyelonephritis, and perforated or bleeding ulcer) was regressed against the independent variable of whether or not a patient had a schizophrenia diagnosis in 2001.

Results show that 9.83% of patients with schizophrenia and 4.71% of patients in the comparison group experienced ACSC hospitalizations from 2002 to 2006. After adjusting for each patient's sex, age, level of urbanization, geographic location of residence within a community, and monthly income, patients with schizophrenia had a 3.26-fold higher (95% CI 3.00 to 3.54, P < 0.001) risk of experiencing ACSC hospitalizations than the comparison participants. After excluding the conditions of diabetes, hypertension, and asthma, patients with schizophrenia independently had a 2.46-fold higher risk of ACSC hospitalizations (95% CI 2.12 to 2.86, P < 0.001), compared with participants in the comparison group.

We conclude that schizophrenia patients are at a higher risk for hospitalizations owing to ACSCs, despite a national health insurance system providing universal coverage to citizens.