Table 1– Participant characteristics in the derivation cohort
Participants nTOR L·min−1
Participants n10442202814
Age yrs10462±1262±662±764±4
Males %10479707993
Body mass index kg·m−210428±530±628±430±5
Ever-smokers %10471706164
FVC % pred10465±2145±1744±1650±16
Total lung capacity % pred10367±1848±1149±953±10
DL,CO % pred10145±1337±833±1127±10
Resting supplemental oxygen prescription
 L·min−11040 (0–0)2 (0–2.5)3 (2–4)3.5 (0–4)
 Room air#10479401843
pa mmHg8319±422±423±727±11
PVR Wood units762.3±0.72.5±0.73.2±1.33.0±1.4
6MWD m104456±134372±133335±101357±119
End-walk Sp,O2 %10489±784±783±792±6
  • Data are presented as mean±sd or median (interquartile range), unless otherwise stated. End-walk arterial oxygen saturation measured by pulse oximetry (Sp,O2) represents oxyhaemoglobin saturation at the end of 6-min walk testing. TOR: titrated oxygen requirement; FVC: forced vital capacity; % pred: % predicted; DL,CO: diffusing capacity of the lung for carbon monoxide; pa: mean pulmonary artery pressure; PVR: pulmonary vascular resistance; 6MWD: 6-min walk distance. #: 0 L·min−1; : missing for 14 participants in the 0 L·min−1 group, three in the 1–2 L·min−1 group, two in the 3–6 L·min−1 group and two in the 8–15 L·min−1 group.