Poor, rural areas in the United States have almost double the occurrence of chronic obstructive pulmonary disease (COPD) compared with the general public, according to a study published in the American Journal of Respiratory and Critical Care Medicine.
Researchers analyzed public datasets from the National Health Interview Survey, the US Census’s American Community Survey, and the National Center for Health Statistics Urban-Rural Classification Scheme to depict prevalence of COPD based on community population, poverty level, individual socioeconomic status, dwelling heating sources, and risk factors in smokers and nonsmokers. Communities were divided into population-based categories of large metro, central; large metro, fringe; medium metro, small metro, micropolitan, and non-core. Demographic data, health information, COPD classification, and potential risk factors were based on answers from self-reported surveys.
Of the 90,334 individuals included in this study, 14.9% lived in rural areas, 15.7% lived in poor communities, and 43.9% had a history of smoking or were current smokers. Overall, 8.4% of individuals had COPD, and 23.2% of the subset with COPD had never smoked. The prevalence of COPD was highest in rural, poor communities at 15.7% (14.0%-17.7%) and lowest in non-poor, urban communities at 6.1% (5.7%-6.6%).
After adjusting for confounding variables, living in a rural community was a predictor for COPD prevalence (odds ratio [OR], 1.34; P <.001), whether the individual had a history of smoking or was a current smoker (OR, 1.19; P =.031), or whether the individual had never smoked (OR, 1.34; P <.001). The poverty level of the community was an independent variable associated with the prevalence of COPD with an OR of 1.12 (P =.012), and a 1-unit decrease in household income below the poverty level increased the risk for COPD by 8% (P <.001).
Prevalence of COPD increased for individuals who lived in the South (OR, 1.20; P =.003) or Midwest (OR, 1.27; P <.001). The use of coal as the heat source in nonsmokers’ neighborhood increased the risk for COPD (OR, 1.09, P <.001) but was not significant in individuals with a history of smoking or current smokers.
Limitations to this study include the nature of self-reported diagnosis, in that COPD has been largely underreported by those who may be affected by the condition, especially if they are not educated on the effect of secondhand smoke and other household air pollutants. Researchers were also unable to calculate other risk factors such as time living in rural tracts, geographic mobility, and childhood infections.
Future research should evaluate the effect environmental factors and secondhand smoke has on the prevalence of COPD, analyze risk factors at the individual level rather than at the census level, utilize measurement data to diagnosis COPD, and include a history of the individuals’ residences.
The researchers concluded that “[l]iving in a rural area, community poverty, and indicators of household wealth were significant risk factors associated with higher COPD prevalence.” These insights can help develop policies to reduce the risk for COPD in this underserved population.
Raju S, Keet CA, Paulin LM, et al. Rural residence and poverty are independent risk factors for COPD in the United States [published online November 2, 2018]. Am J Respir Crit Care Med. doi:10.1164/rccm.201807-1374OC