Grandparental caregiving, income inequality, and respiratory infections in US seniors

Abstract

Background: Pneumonia and influenza (P&I) is a major cause of morbidity and mortality in the US, particularly in seniors. Recent research indicates that P&I may be linked to socioeconomic conditions associated with interactions of children to vulnerable seniors that may proliferate the spread of disease. This study assessed the associations between four sociodemographic characteristics-median county income, Gini Index, youth dependency ratio, and proportion of coresidential caregiver grandparent-and P&I on the county level overall and by age group.

Methods: All hospitalizations due to P&I from 1991 to 2004 were abstracted from the Centers for Medicare and Medicaid Services database and categorized by influenza season, and age category. Using generalized estimating equations, associations between P&I rates and four sociodemographic variables were assessed and models were stratified by income to assess income as a potential effect modifier.

Results: P&I rates were higher in counties with lower median income. In low income counties, high levels of live-in grandparental caregivers were associated with consistently higher levels of pneumonia and influenza rates. Gini Index was positively associated with disease rates, particularly in the younger age groups.

Discussion: These results suggest complex relationships between sociodemographic characteristics and P&I outcomes for seniors, particularly those related to children. The strength of the relationship between the proportion of grandparental caregivers and disease rates decreases with age, which may caregiving patterns, or may serve as a proxy for related sociodemographic characteristics. These findings merit further research to better understand how area-level factors affect P&I patterns in seniors.