Single-breath carbon monoxide diffusing capacity prediction equations from a Mediterranean population.

TLDR: Standardized DLCO measurements were carried out in a selected sample of 361 healthy nonsmoking volunteers living in the Barcelona metropolitan area (Spain) and showed that the assumptions of the multiple regression analysis (independence, homoscedasticity and Gaussian distribution of residuals) were fulfilled using simple linear equations.

Abstract: Because of unanswered questions about prediction equations for the single-breath carbon monoxide diffusing capacity (DlCO) and as part of a larger collaborative project, standardized DlCO measurements were carried out in a selected sample of 361 healthy nonsmoking volunteers (194 men and 167 women) living in the Barcelona metropolitan area (Spain). Except for the test FiO2 (0.18), the study essentially followed the American Thoracic Society (ATS) and European Community for Coal and Steel (ECCS) recommendations for standardizing the methodology of measuring DlCO. Prediction equations for ages 20 through 70 were calculated separately for both sexes. Simple linear equations using age, height, and body weight as independent variables predicted the DlCO indices (DlCO, Va, and Dl/Va) as well as more complex equations. In addition, a complete analysis of the residuals (predicted measured values) showed that the assumptions of the multiple regression analysis (independence, homoscedasticity and Gaussian distribut...