Table 2– Bivariate clinical and radiological predictors of mortality and disease progression in unclassifiable interstitial lung disease
VariablePatients n (%)MortalityDisease progression#
HR (95% CI)p-valueOR (95% CI)p-value
Age years1.24 (0.92–1.68)0.161.03 (0.67–1.58)0.91
Sex male %1.52 (0.76–3.08)0.211.09 (0.40–2.98)0.87
Smoking history
 Ever smoked %1.10 (0.98–1.24)0.111.35 (0.48–3.81)0.57
 Pack-years+1.15 (1.01–1.32)0.041.10 (0.92–1.30)0.31
Measures of disease severity
 Long-term oxygen therapy %2.81 (1.35–5.86)0.0062.19 (0.64–7.46)0.21
 Pulmonary function129 (98)
  FVC % pred0.85 (0.72–1.00)0.0470.77 (0.59–1.00)0.05
  DLCO % pred0.55 (0.42–0.73)<0.00050.66 (0.48–0.91)0.01
  Composite physiologic index1.07 (1.03–1.10)<0.00051.06 (1.01–1.10)0.01
 HRCT findings109 (83)
  Fibrosis score¶,§1.82 (1.30–2.55)<0.00052.16 (1.32–3.56)0.002
  UIP pattern
  Inconsistent with UIP36 (33)ReferenceReference
  Possible UIP54 (50)2.60 (0.93–7.27)0.074.88 (1.36–17.47)0.02
  UIP19 (17)2.92 (0.89–9.61)0.084.33 (0.80–23.49)0.09
  UIP or possible UIP90 (83)2.69 (1.00–7.21)0.0494.73 (1.42–15.73)0.01
  Honeycombing %54 (50)2.81 (1.21–6.55)0.026.57 (1.98–21.78)0.002
  • Hazard ratios (HR) and odds ratios (OR) are shown for the bivariate (unadjusted) relationship of each variable with the stated outcome. FVC: forced vital capacity; DLCO: diffusing capacity of the lung for carbon monoxide; HRCT: high-resolution computed tomography; UIP, usual interstitial pneumonia. #: Disease progression was defined as any of the following within 12 months of the initial visit to the University of California San Francisco ILD Clinic: 10% decline in FVC, 15% decline in DLCO, lung transplantation, or death due to any cause (this was only assessable in a subgroup of patients with complete follow-up data: n = 61); :HR and OR reported for 10-unit change. +: HR and OR ratios are reported for the square root of pack-years; §: mean 20.3.