CDC: Rates of COPD Are Similar by Geographical Location Regardless of Smoking Status

Patterns of chronic obstructive pulmonary disease (COPD) prevalence among current, former, and never smokers were similar by geographical location and may indicate that exposure to secondhand smoke influences development of the progressive lung disease, according to a study appearing June 21, 2019, in CDC’s Morbidity and Mortality Weekly Report.

“Although smoking tobacco is the main contributor to COPD in the United States, other factors might play a role in the development of COPD among nonsmokers, including secondhand smoke exposure, occupational and environmental exposures, and chronic asthma,” researchers said. “Secondhand smoke exposure, in either childhood or as an adult, has been associated with an increased risk for COPD-associated mortality.”

Researchers analyzed data from 418,378 respondents to the 2017 Behavioral Risk Factor Surveillance System (BRFSS) survey. The prevalence of COPD was defined as an affirmative response to the question, “Has a doctor, nurse, or other health professional ever told you that you had chronic obstructive pulmonary disease or COPD, emphysema, or chronic bronchitis?”

Respondents were considered to be never smokers if they reported either smoking less than 100 cigarettes during their lifetime or never smoking at all. Former smokers reported having smoked at least 100 cigarettes but were not current smokers. Respondents who’d smoked at least 100 cigarettes and reported smoking regularly or every day were considered current smokers.

The age-adjusted prevalence of COPD:

• among adults 18 or more years old throughout the United States was 6.2% overall and ranged from 3.4% in Hawaii to 13.8% in West Virginia
• among current smokers was 15.2% overall and ranged from 7.8% in Hawaii to 25.9% in West Virginia
• among former smokers was 7.6% overall and ranged from 4.7% in Hawaii to 15.1% in West Virginia
• among never smokers was 2.8% overall and ranged from 1.6% in Minnesota to 6.0% in West Virginia

COPD prevalence among current smokers was highest in states located in the Southeast and the Midwest. Among never smokers, COPD prevalence was highest in states located in the Southeast.

Researchers found the overall age-adjusted prevalence of COPD was higher among women, older adults, American Indians, and Alaska Natives. COPD prevalence was also higher among individuals who were obese or underweight, reported no leisure-time physical activity in the past 30 days, had a history of asthma, were less educated, resided in rural areas, and had other chronic conditions. Prevalence patterns were similar regardless of smoking status.

Researchers also found state-level COPD prevalence among current and former smokers was strongly correlated with state-level current smoking prevalence, which, they mentioned, was an expected finding. However, they also found state-level COPD prevalence among never smokers was also strongly correlated with state-level current smoking prevalence, leading researchers to believe that secondhand smoke exposure may influence development of COPD.

“Population-based strategies for smoking prevention and control have the potential to decrease the prevalence of COPD in the United States. Such strategies include tobacco product price increases, mass media antismoking campaigns, comprehensive smoke-free laws, and barrier-free access to evidence-based cessation interventions,” researchers said. “Comprehensive smoke-free laws not only help protect nonsmokers from secondhand smoke exposure, but they can also promote adoption of voluntary smoke-free rules in private settings and reduce smoking prevalence through increased cessation and decreased initiation.”

Researchers suggested that continued promotion of smoke-free environments may reduce COPD prevalence among both smokers and nonsmokers. They also recommended that clinicians should offer smoking cessation support to patients and test symptomatic patients for COPD using spirometry, regardless of their smoking history.

Reference

Wheaton AG, Liu Y, Croft JB, et al. Chronic obstructive pulmonary disease and smoking status - United States, 2017. MMWR Morb Mortal Wkly Rep. 2019;68(24):533-538. doi: 10.15585/mmwr.mm6824a1.