Prevalence and costs of major depression among elderly claimants with diabetes.

Objective: To compare the odds of major depression among Medicare claimants with and without diabetes and to test whether annual medical payments are greater for those with both diabetes and major depression than for those with diabetes alone.

Research Design And Methods: This retrospective analysis relies on claims data from the 1997 Medicare 5% Standard Analytic Files. Using these data, we statistically determined whether the odds of major depression are greater among elderly claimants with diabetes after controlling for age, race/ethnicity, and sex. We then used regression analysis on a sample of over 220,000 elderly claimants with diabetes to test whether payments for non-mental health-related services are greater for those with both diabetes and major depression (n = 4,203) than for those with diabetes alone.

Results: Our findings indicate that the odds of major depression are significantly greater among elderly Medicare claimants with diabetes than among those without diabetes (OR 1.58 +/- 0.05). We also found that elderly claimants with both diabetes and major depression seek treatment for more services and spend more time in inpatient facilities, and as a result incur higher medical costs than claimants with diabetes but without major depression. These results hold even after excluding services related to mental health treatment.

Conclusions: This analysis suggests that treatment for major depression among claimants with diabetes may reduce total medical costs if treatment results in a decrease in utilization for general medical services in the future.