Trends in the prevalence of obstructive and restrictive lung function among adults in the United States: findings from the National Health and Nutrition Examination surveys from 1988-1994 to 2007-2010.

BACKGROUND

National spirometric surveillance data in the United States were last collected during 1988-1994. The objective of this study was to provide current estimates for obstructive and restrictive impairment of lung function and to examine changes since 1988-1994.

METHODS

We used data from 14,360 participants aged 20 to 79 years from the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and 9,024 participants from NHANES 2007-2010. Spirometry was conducted using the same spirometers and generally similar protocols.

RESULTS

During 2007-2010, 13.5% (SE, 0.6) of participants had evidence of airway obstruction (FEV1/FVC < 0.70): 79.9% of adults had normal lung function, 6.5% had a restrictive impairment, 7.5% had mild obstruction, 5.4% had moderate obstruction, and 0.7% had severe obstruction. Although the overall age-adjusted prevalence of any obstruction did not change significantly from 1988-1994 (14.6%) to 2007-2010 (13.5%) (P = .178), significant decreases were noted for participants aged 60 to 79 years and for Mexican Americans. The prevalence of current smoking remained high among participants with moderate (48.4%) and severe (37.9%) obstructive impairments. A significant decline in current smoking occurred only among those with normal lung function (P < .05).

CONCLUSION

Spirometry revealed little change in the prevalence of any obstructive and restrictive impairment in lung function during 2007-2010, compared with 1988-1994.