Reference equations for DL,CO,NO,5s and DL,CO,10s.

The GAMLSS model was used with a gamma distribution for all outcomes except DL,NO/DL,CO,5s which had a normal distribution, and DL,CO,5s,hb-corr that had a Box-Cox-Cole-Green distribution (BCCG). H = height in cm, A = age in years, S = sex (male = 1, female = 0),*DLNO = diffusing capacity for NO,†VA = alveolar volume,‡KNO = DLNO/VA,§DLCO = diffusing capacity for CO, ll KCO = DL,CO/VA,**Vc = capillary volume,††Dm = diffusing capacity of the alveolar membrane.The notation (10s) and (5s) indicates if the outcomes were found using the DL,CO,10s method or the DL,CO,NO,5s method. “hb-corr” = values corrected for hemoglobin concentration.Reference equations for DL,CO,NO,5s and DL,CO,10s.