Fig. 1
Flow chart showing inclusion and exclusion of patients in the study. A total of 1262 IPF patients were analysed in this study, excluding 501 with other interstitial lung disease and 423 who had not undergone pulmonary function testing that had included DLCO. Note: Groups with a total GAP score of 0 and 7 were excluded because they contained too few patients and because the baseline characteristics of patients with GAP score 0 were significantly different (all women, never smokers). No patients with a GAP score of 8 were included, because the “unable to perform” category in DLCO was not checked in this study. Definition of abbreviations: IIP, idiopathic interstitial pneumonia; ILD, interstitial lung disease; AIP, acute interstitial pneumonia; BOOP, bronchiolitis obliterans organizing pneumonia; DIP, desquamative interstitial pneumonia; LIP, lymphocytic interstitial pneumonia; NSIP, non-specific interstitial pneumonia; RB-ILD, respiratory bronchiolitis-associated interstitial lung disease