Obstructive lung disease and low lung function in adults in the United States: data from the National Health and Nutrition Examination Survey, 1988-1994.
BACKGROUND
Obstructive lung disease (OLD) is an important cause of morbidity and mortality in the US adult population. Potentially treatable mild cases of OLD often go undetected. This analysis determines the national estimates of reported OLD and low lung function in the US adult population.


METHODS
We examined data from the Third National Health and Nutrition Examination Survey (NHANES III), a multistage probability representative sample of the US population. A total of 20,050 US adults participated in NHANES III from 1988 to 1994. Our main outcome measures were low lung function (a condition determined to be present if the forced expiratory volume in 1 second-forced vital capacity ratio was less than 0.7 and the forced expiratory volume in 1 second was less than 80% of the predicted value), a physician diagnosis of OLD (chronic bronchitis, asthma, or emphysema), and respiratory symptoms.


RESULTS
Overall a mean (SE) of 6.8% (0.3%) of the population had low lung function, and 8.5% (0.3%) of the population reported OLD. Obstructive lung disease (age-adjusted to study population) was currently reported among 12.5% (0.7%) of current smokers, 9.4% (0.6%) of former smokers, 3.1% (1.1%) of pipe or cigar smokers, and 5.8% (0.4%) of never smokers. Surprisingly, 63.3% (0.2%) of the subjects with documented low lung function had no prior or current reported diagnosis of any OLD.


CONCLUSIONS
This study demonstrates that OLD is present in a substantive number of US adults. In addition, many US adults have low lung function but no reported OLD diagnosis, which may indicate the presence of undiagnosed lung disease.
Mannino
D M
DM
Division of Environmental Hazards and Health Effects, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341-3724, USA. dmm6@cdc.gov
Gagnon
R C
RC
Petty
T L
TL
Lydick
E
E
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D044383:Black People; D005260:Female; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008173:Lung Diseases, Obstructive / Q000453:epidemiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D015995:Prevalence; D012129:Respiratory Function Tests / Q000706:statistics & numerical data; D017678:Sex Distribution; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D044465:White People; D001741:Black or African American