Local Area Variation in Morbidity Among Low-Income, Older Adults in the United States: A Cross-sectional Study.

Background: Recent studies have reported that low-income adults living in more affluent areas of the United States have longer life expectancies. Less is known about the relationship between the affluence of a geographic area and morbidity of the low-income population. Objective: To evaluate the association between the prevalence of chronic conditions among low-income, older adults and the economic affluence of a local area. Design: Cross-sectional association study. Setting: Medicare in 2015. Participants: 6 363 097 Medicare beneficiaries aged 66 to 100 years with a history of low-income support under Medicare Part D. Measurements: Adjusted prevalence of 48 chronic conditions was computed for 736 commuting zones (CZs). Factor analysis was used to assess spatial covariation of condition prevalence and to construct a composite condition prevalence index for each CZ. The association between morbidity and area affluence was measured by comparing the average of condition prevalence index across deciles of median CZ house values. Results: The mean age of study participants was 77.7 years (SD, 8.2); 67% were women, and 61% were white. The crude prevalence of 48 chronic conditions ranged from 72.5 per 100 for hypertension to 0.6 per 100 for posttraumatic stress disorder. The prevalence of these 48 chronic conditions was highly spatially correlated. Composite condition prevalence was on average substantially lower in more affluent CZs. Limitation: Low-income status measured on the basis of receipt of Medicare Part D low-income subsidies and not capturing persons not enrolled in Medicare Part D. Conclusion: Low-income, older adults living in more affluent areas of the country are healthier, and areas with poor health in the low-income, older adult population tend to have a high prevalence of most chronic conditions. Primary Funding Source: National Institute on Aging.