Depression treatment among the U.S. elderly and the role of prescription drug coverage quality

Research Objectives: Depression among the elderly has historically been considered underdiagnosed and undertreated, but diagnosis and treatment rates have increased rapidly in the past 15 years. Nevertheless, socioeconomic disparities in treatment rates persist. Of particular interest is the effect both of the presence and of the quality of prescription drug coverage. We examine the association of demographic, clinical, and coverage factors with depression treatment in a large, nationally representative sample of U.S. elderly.

Study Design: Data are from the 1992-1998 and 1999-2004 Medicare Current Beneficiary Survey (MCBS), enhanced with diagnostic and utilization information from Medicare claims. Analyses focused on community dwelling elderly, enrolled in full-year fee-for-service Medicare, with diagnoses of depression from a health care provider (n=3190). Prescription drug coverage quality was measured by ratio of out-of-pocket to total prescription drug expenditures (<30% = “comprehensive” coverage). Other explanatory variables included gender, age, race/ethnicity, education, income, perceived access to care, functional impairment, disease severity, self rated health and comorbidities.

Principal Findings: In 1999-2004, African Americans continued to have lower odds of receiving antidepressant treatment (OR=.51, CI .36-.74) as did individuals with income under 150% of poverty. There was no evidence of improvement in the gap for African Americans from the 1992-98 period, when the odds ratio for treatment was .56 (CI .34-.91). Women were more likely than men to be treated (OR=1.57, CR 1.19-2.07). History of stroke or of cancer was associated with increased odds of depression treatment, as was diagnosis with major depressive disorder vs. other depression. Compared to beneficiaries without pharmacy coverage, the OR for limited coverage was 1.38 (CI 1.01-1.89) and the OR for comprehensive coverage was 2.46 (CI 1.77-3.41). Other self-reported access barriers, such as general difficulty getting needed health care due to cost or difficulty with transportation to healthcare sites, did not predict treatment. Results of models for use of any treatment (antidepressant or psychotherapy) were similar to those for antidepressant use.

Conclusion: Disparities in depression treatment persist for African American elderly diagnosed with depression. Lack of comprehensive prescription drug coverage may be a barrier to access to treatment for depression among the elderly.