Newswise — Nov. 2, 2018─Whether they are smokers or not, people living in poor, rural areas of the United States are more likely to have COPD, or chronic obstructive pulmonary disease, according to research published online in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.
In “Rural Residence and Poverty are Independent Risk Factors for COPD in the United States,” Meredith C. McCormack, MD, MHS, and colleagues report that the prevalence of COPD in poor, rural areas was nearly twice that of the overall population—15.4 percent versus 8.4 percent.
The researchers also found that neighborhood use of coal for heating increased the risk of COPD among never-smokers (fewer than 100 cigarettes in their lifetime) by 9 percent.
“Living in a rural area has been associated with increases in prevalence of chronic diseases and poses challenges that can include access to health care, poverty and unique environmental exposures,” said senior study author Dr. McCormack, an associate professor of medicine and a pulmonologist and critical care physician at Johns Hopkins University. “Measuring the burden of COPD, which is the third leading cause of death in the U.S., and identifying those most affected is critical to defining strategies to prevent COPD and manage existing disease.”
According to the authors, this is the first study to report on individual, community and geographic risk factors for COPD in the U.S. The study linked data at a census-tract level from the National Health Interview Survey from 2012-1015 to the Census Bureau’s 2015 American Community Survey on more than 90,000 adults over the age of 40.
As part of their analysis, the researchers adjusted for a range of factors that might have biased results, including age, sex, race/ethnicity, smoking duration, occupation, markers of access to care and socioeconomic status.
The study found that, compared to the population as a whole, COPD was:
- 23 percent more prevalent in rural areas
- 12 percent more prevalent in neighborhoods with 20 percent or more of households living below the poverty line
- 34 percent more prevalent in rural areas among never smokers.
Dr. McCormack said that factors contributing to study findings may include early life infections, nutrition and indoor and outdoor air pollution. The study found that these and other factors are influenced by individual and community-level poverty and vary by whether one lives in a major city or a rural community.
Dr. McCormack added that the never smokers finding suggests that indoor air pollution may be an important risk factor for COPD in rural communities and merits further investigation.
The study did not find that COPD prevalence was linked to occupations that are more common in rural areas, such as mining, despite the fact that previous studies have found a link between mining and COPD.
“Although we did not find that occupations assessed at the community level were associated with COPD, we lacked individual occupational data and our assessment was further limited by the fact that occupations, such as agriculture, mining and forestry, were grouped together, said lead study author Sarath Raju, MD, MPH, a post-doctoral fellow in pulmonary and critical care medicine at Johns Hopkins. “Occupational exposures in rural communities and the link to COPD warrants further study.”
Study limitations include the fact that COPD was self-reported rather than based on a medical record or made by having all participants undergo spirometry, a breathing test essential for diagnosing COPD. Studies indicate that about half of those with COPD are unaware they have the disease. The authors write that this under-reporting of the disease may underestimate the disparities in COPD prevalence their study found.
”Strategies to reduce COPD in rural communities should include defining and reducing unique exposures in these communities,” Dr. McCormack said. “There is also a need to overcome barriers to disease management. For example, pulmonary rehabilitation and supplemental oxygen are
key aspects of COPD management that are more challenging to implement in rural regions.”
She added that success in providing comprehensive COPD management for all Americans, will require “collaborative partnerships and innovative strategies to increase awareness of the disease, reduce its risk factors and provide the best care to those with COPD.”
This study was funded by the National Institute of Minority Health and Health Disparities, the National Institute of Environmental Health Sciences, the Environmental Protection Agency and the National Heart, Lung, and Blood Institute.