A comparison of diabetic complications and health care utilization in diabetic patients with and without comorbid depression

Background: Depression has been found to interfere with patient selfmanagement of diabetes and adherence to a medication regimen. Data on health care utilization indicate that depression is at least as prevalent as diabetes, and that both of these conditions represent substantial costs to the health care system. In this analysis, we used Canadian data from outpatient visits, hospital discharges, extended health care claims,andlong-termdisabilityclaims to compare the rate of diabetic complications for subjects with diabetes alone and those with diabetes and depression. We then determined whether there is a higher rate of utilization of health care services by diabetic patients with depression. Methods: In this cross-sectional study, 1427 diabetic patients were identified in a group of acute care hospital workers employed in British Columbia in 1998. Diabetic complications and depression were identified based on ICD-9 diagnostic codes. Rates of diabetes-related complications and use of health care services were then considered for diabetic patients with and without comorbid depression. Results: Overall, the rate of utilization of health care services was found to be greater in diabetic patients with comorbid depression than those with diabetes alone. The rates of ischemic heart disease, peripheral vascular disease, and altered consciousness experienced by thegroupofdiabeticindividualswith depression were found to be significantly higher than those with diabetes alone.