Table 3– Prospective cohort: 3-yr survival, univariate analysis of variables at the time of diagnosis
VariableHazard ratio (95% CI)p-value
Age yrs1.02 (0.98–1.07)ns
Smoking pack-yrs0.99 (0.97–1.02)ns
Time to diagnosis months1.01 (0.99–1.03)ns
BMI m·kg−20.89 (0.80–0.98)0.0155
MRC dyspnoea score2.52 (1.76–3.62)<0.0001
6MWD m1.00 (1.00–1.00)ns
6MWD % pred0.98 (0.96–0.99)0.0007
Desaturation at 6MWT#0.54 (0.32–0.84)0.0052
PA-a,O2 mmHg1.03 (1.01–1.05)0.0063
FVC % pred0.97 (0.95–0.99)0.0039
DL,CO % pred0.94 (0.92–0.97)<0.0001
CPI1.06 (1.03–1.10)<0.0001
HRCT fibrosis score % of total lung volume1.03 (1.00–1.07)0.0497
BAL total cell count cells·mL−11.00 (1.00–1.00)0.0009
Concomitant emphysema1.82 (0.90–3.66)0.096
  • BMI: body mass index; MRC: Medical Research Council; 6MWD: 6-min walking distance; % pred: % predicted; 6MWT: 6-min walking test; PA–a,O2: alveolar–arterial oxygen tension difference; FVC: forced vital capacity; DL,CO: diffusing capacity of the lung for carbon monoxide; CPI: composite physiologic index; HRCT: high-resolution computed tomography; BAL: bronchoalveolar lavage; ns: not significant. #: no desaturation (arterial oxygen saturation ≤88%) during the 6MWT.