The American Thoracic Society recommends race-specific spirometric reference values
from the National Health and Nutrition Survey (NHANES) III for clinical evaluation
of pulmonary function in whites, African-Americans, and Mexican-Americans in the United
States and a correction factor of 0.94 for Asian-Americans. We aimed to validate the
NHANES III reference equations and the correction factor for Asian-Americans in an
independent, multiethnic sample of US adults.
The Multi-Ethnic Study of Atherosclerosis (MESA) recruited self-identified non-Hispanic
white, African-American, Hispanic, and Asian-American participants aged 45 to 84 years
at six US sites. The MESA-Lung Study assessed prebronchodilator spirometry among 3,893
MESA participants who performed acceptable tests, of whom 1,068 were asymptomatic
healthy nonsmokers who performed acceptable spirometry.
The 1,068 participants were mean age 65 +/- 10 years, 60% female, 25% white, 20% African-American,
23% Hispanic, and 32% Asian-American. Observed values of FEV(1), FEV(6), and FVC among
whites, African-Americans, and Hispanics of Mexican origin in MESA-Lung were slightly
lower than predicted values based on NHANES III. Observed values among Hispanics of
non-Mexican origin were consistently lower. Agreement in classification of participants
with airflow obstruction based on lower limit of normal criteria was good (overall
kappa = 0.88). For Asian-Americans, a correction factor of 0.88 was more accurate
than 0.94.
The NHANES III reference equations are valid for use among older adults who are white,
African-American, or Hispanic of Mexican origin. Comparison of white and Asian-American
participants suggests that a correction factor of 0.88, applied to the predicted and
lower limits of normal values, is more appropriate than the currently recommended
value of 0.94.