Fig. 5

Survival curves for patients with idiopathic pulmonary fibrosis (IPF) (yellow) and chronic hypersensitivity pneumonitis (CHP) (green and blue). CHP cases with end stage disease (denoted by a PaO2 < 7 · 5kPa) were excluded. IPF cases without a measured PaO2 or with end stage disease (denoted by a PaO2 < 7 · 5kPa) were excluded. IPF patients (n = 185) were compared to CHP cases at pulmonary vessel volume (PVV) thresholds above (green) and below (blue) 5%, 5 · 5%, 6 · 5% and 7% (a–d). The IPF and poor-outcome CHP curves were most comparable at a CHP PVV threshold of 6 · 5% where the mean survival in the IPF population (38 · 4 ± 2 · 2 months; n = 185) was found to be similar to the poor-outcome CHP population (35 · 3 ± 6 · 1 months; n = 20) and distinct from the good-outcome CHP population (71 · 3 ± 2 · 8 months; n = 96). The PVV > 6% threshold contained only two patients more than the PVV > 6 · 5% threshold which did not significantly alter the results and accordingly was not been formally plotted