The prevalence of major depression or dysthymia among aged Medicare Fee-for-Service beneficiaries

Abstract

Research objective: Estimates of the prevalence of major depression vary widely. Current estimates range from 2 to 14 % depending upon the definition and procedure for diagnosis. Further, most estimates are for special populations, either living in selected geographic areas or receiving specific types of medical care. A national survey of Medicare Fee-for-Service (FFS) beneficiaries provides an opportunity to assess the current level of major depression or dysthymia among a diverse population of older Americans.

Study design: The Health Outcomes Survey (HOS) was administered to a national random sample of 1,000 Medicare FFS beneficiaries. We used the Mental Component Summary (MCS) measure of the SF-36 to estimate the prevalence of major depression or dysthymia. Logistic regression was used to examine associated factors.

Results: The response rate was 61.7%. Using an MCS score of 42 or lower, prevalence of major depression or dysthymia was estimated to be 25% for respondents age 65 years and older. Logistic regression analysis revealed that the likelihood of major depression or dysthymia was associated with years of education (Odds Ratio (OR) = 0.87), difficulties performing activities of daily living (OR = 1.72), and Medicaid enrollment (OR = 2.67).

Conclusions: The results revealed that one-quarter of the respondents reported mental health problems consistent with major depression or dysthymia. This is higher than previously reported. Like previous studies, years of education, physical impairment, and poverty are strong predictors of major depression or dysthymia. The high rate of major depression or dysthymia implies there may be considerable unmet need among elderly Medicare FFS beneficiaries for diagnosing and treating mental illness.