Background: The study evaluated the change in the prevalence of airflow obstruction in the U.S. population 40-79 years of age from years 1988-1994 to 2007-2010.
Methods: Spirometry data from two representative samples of the U.S. population, the National Health and Nutrition Examination Surveys (NHANES) conducted in 1988-1994 and 2007-2010, were used. The American Thoracic Society/European Respiratory Society (ATS/ERS) criteria were used to define airflow obstruction.
Results: Based on ATS/ERS criteria, the overall age-adjusted prevalence of airflow obstruction among adults aged 40-79 years decreased from 16.6% to 14.5% (p < 0.05). Significant decreases were observed for the older age category 60-69 years (20.2% vs. 15.4%; p < 0.01), for males (19.0% vs. 15.4%; p < 0.01), and for Mexican American adults (12.7% vs. 8.4%; p < 0.001). The prevalence of moderate and more severe airflow obstruction decreased also (6.4% vs. 4.4%; p < 0.01). Based on ATS/ERS criteria, during 2007-2010, an estimated 18.3 million U.S. adults 40-79 years had airflow obstruction, 5.6 million had moderate or severe airflow obstruction and 1.4 million had severe airflow obstruction.
Conclusions: The overall age-adjusted prevalence of airflow obstruction among U.S. adults aged 40-79 years decreased from 1988-1994 to 2007-2010, especially among older adults, Mexican Americans, and males.
Keywords: NHANES; airflow obstruction; chronic obstructive pulmonary disease; spirometry.