Healthcare Utilization and Expenditures for Persons with Diabetes Comorbid with Mental Illnesses

The aim of this study was to investigate healthcare utilization and expenditure for patients with diabetes comorbid with and without mental illnesses in Taiwan. People with diabetes comorbid with and without mental illnesses in 2000 were identified and followed up to 2004 to explore the healthcare utilization and expenditure. Healthcare utilization included outpatient visits and use of hospital inpatient services, and expenditure included outpatient, inpatient and total medical expenditure. General estimation equation models were used to explore the factors associated with outpatient visits and expenditure. To identify the factors associated with hospitalization, multiple logistic regressions were applied. The average number of annual outpatient visits of the patients with mental illnesses ranged from 37.01 to 41.91, and 28.83 to 31.79 times for the patients without mental illnesses from 2000 to 2004. The average annual total expenditure for patients with mental illnesses during this period ranged from NT$77,123-NT$90,790, and NT$60,793- NT$84,984 for those without mental illnesses. After controlling for covariates, the results indicated that gender, age, mental illness and time factor were associated with outpatient visits. Gender, age, and time factor were associated with total expenditure. Age and mental illness were associated with hospitalization in logistic regression. The healthcare utilization and expenditure for patients with mental illnesses was significantly higher than for patients without mental illnesses. The factors associated with healthcare utilization and expenditure included gender, age, mental illness and time trends.