Geriatric depression, antidepressant treatment, and healthcare utilization in a health maintenance organization

To assess the separate effects of depressive symptoms and antidepressant treatment on healthcare utilization and cost.

Social Health Maintenance Organization (HMO) at HealthPartners in Minnesota.

Geriatric Social HMO enrollees were screened for depressive symptoms using the 30-item Geriatric Depression Scale. A stratified sample was created, composed of geriatric enrollees with depressive symptoms, with antidepressant prescriptions, or with neither (n = 516).

Regression analyses were conducted with separate equations for utilization and charge outcome variables, both outpatient and inpatient (log-transformed). The Charlson Comorbidity Index, age, and gender served as covariates.

Depressive symptoms were identified through the Diagnostic Interview Schedule. Antidepressant treatment was determined from the HMO pharmacy database.

Having depressive symptoms was associated with a 19 increase in the number of outpatient encounters and a 30 increase in total outpatient charges. Antidepressant treatment was associated with a 32 increase in total outpatient charges but was not significantly associated with number of outpatient encounters. Depressive symptoms and antidepressant therapy were not significantly associated with inpatient utilization or charges.

This study found that patients with depressive symptoms generated more outpatient health care and higher charges but not necessarily more inpatient care. Our findings suggest that programs targeted to geriatric patients whose depression is comorbid with other chronic medical conditions might be cost-effective and particularly appropriate for geriatric care.