Spirometry reference values for Black adults in Brazil

OBJECTIVE: To derive reference equations for spirometry in healthy Black adult never smokers in Brazil, comparing them with those published in 2007 for White adults in the country. METHODS: The examinations followed the standards recommended by the Brazilian Thoracic Association, and the spirometers employed met the technical requirements set forth in the guidelines of the American Thoracic Society/European Respiratory Society. The lower limits were defined as the 5th percentile of the residuals. RESULTS: Reference equations and limits were derived from a sample of 120 men and 124 women, inhabitants of eight Brazilian cities, all of whom were evaluated with a flow spirometer. The predicted values for FVC, FEV(1), FEV(1)/FVC ratio, and PEF were better described by linear equations, whereas the flows were better described by logarithmic equations. The FEV(1) and FVC reference values derived for Black adults were significantly lower than were those previously derived for White adults, regardless of gender. CONCLUSIONS: The fact that the predicted spirometry values derived for the population of Black adults in Brazil were lower than those previously derived for White adults in the country justifies the use of an equation specific to the former population.