Ecosocial environments and chronic lower respiratory disease mortality: a nationwide ecological study

Chronic lower respiratory disease (CLRD) is a leading cause of death in the United States and imposes a substantial economic burden. Ecosocial environments are closely linked to population health, yet nationwide evidence on their associations with CLRD mortality remains limited. This ecological study analyzed a longitudinal county-year panel of U.S. counties from 2014–2020. The primary outcome was the annual number of CLRD deaths among adults aged 55 years and older, obtained from the CDC Underlying Cause of Death database. Annual measures of four county-level ecosocial environments (food environment index, access to exercise opportunities, preventable hospital stays, and primary care physician density) were obtained from the County Health Rankings & Roadmaps program. Associations were estimated using quasi-Poisson models with a population offset, year fixed effects, and county-level cluster-robust standard errors. Models were progressively adjusted for demographic, socioeconomic, and environmental and behavioral covariates, and exposures were examined both continuously and by quartiles. Robustness was assessed through stratified analyses, within-between decomposition, state fixed-effects models, spatially lagged X models, and time-lagged models. In fully adjusted models, a more favorable food environment index (RR = 0.96 [0.94–0.98] per 1 SD) and greater access to exercise opportunities (RR = 0.98 [0.96–0.99]) were associated with lower county-level CLRD mortality, whereas elevated preventable hospital stays were associated with higher mortality (RR = 1.05 [1.03–1.06]). These associations varied by sex and urbanization and were accounted for predominantly by between-county differences. They remained consistent in spatially lagged and time-lagged analyses, although the association for access to exercise opportunities was no longer significant after inclusion of state fixed effects. More favorable county-level food and exercise environments, as well as lower rates of preventable hospital stays, were associated with lower county-level CLRD mortality among middle-aged and older adults.