Prevalence and geographic distribution of depression among Medicare beneficiaries in the District of Columbia

Depression is the second leading cause of disability worldwide. As the US population continues to age, treating depression among the aging population will consume more resources and increase healthcare costs. Data from the Centers for Medicaid & Medicare Services 100% beneficiary file were used to estimate the prevalence of depression among Medicare fee-for-service beneficiaries by zip code in the District of Columbia. Standardized prevalence ratios (SPR) and 95% confidence intervals were produced and mapped to illustrate the geographic distribution of depression. Persons aged 65 years and older with both Medicare Part A and B for at least 10 months in 2000 that resided in the District of Columbia were included in the study (n = 41,805). The prevalence of depression among Medicare beneficiaries in the District of Columbia was 5.6% (compared with 7.6% nationwide), and varied significantly by zip code, from 4.1% to 9.6%. SPRs indicated that depression prevalence was significantly lower in zip codes that were predominately black, while zip codes with significantly higher SPRs were predominately white. The prevalence of depression in Medicare beneficiaries was also higher among females, whites, and increased with age. These findings define the burden of depression in the District of Columbia and should inform clinicians and policy makers in planning for mental health care needs for the elderly.