Increased medical costs of a population-based sample of depressed elderly patients.

BACKGROUND: We examined whether older adults with depressive symptoms below the diagnostic threshold and those with DSM-IV major depression and/or dysthymia have higher medical costs than those without depression.
METHODS: We mailed the PRIME-MD 2-item depression screen to the patients of 2 large primary care clinics of a staff-model health maintenance organization in Seattle, Wash. All 11 679 patients 60 years and older with primary care providers at the participating clinics were included, and 8894 (76.2%) were successfully enrolled. An additional 107 patients were referred to the study by their primary care physician. Nonrespondents were slightly younger and had higher inpatient medical costs in the previous 6 months. Patients with positive findings on at least 1 item or referred by their family physician were offered an interview with the Structured Clinical Interview for DSM-IV. The total cost of medical services for the 6 months before the study was obtained from the cost accounting system of the health maintenance organization.
RESULTS: Total ambulatory costs were 43% to 52% higher and total ambulatory and inpatient costs were 47% to 51% higher in depressed compared with nondepressed elderly patients after adjustment for chronic medical illness. This increase was seen in every component of health care costs, with only a small percentage due to mental health treatment. In mean costs, depressed elderly patients averaged an increase of 763 US dollars to 979 US dollars in ambulatory costs and 1045 US dollars to 1700 US dollars in ambulatory and inpatient costs. No differences in costs were noted between patients with subthreshold depressive syndromes and those with DSM-IV depressive disorders.
CONCLUSION: Depressive symptoms and DSM-IV depressive disorders in elderly patients are associated with significantly higher health care costs, even after adjustment for chronic medical illness.