Baseline characteristics at the time of diagnosis of patients with a short (<1 year) or long (>1 year) diagnostic delay
| Diagnostic delay<1 year (N=78) | Diagnostic delay>1 year (N=186) | Total (N=264) | P value | |
| Age (years), mean (SD) | 73.38 (7.64) | 73.20 (7.66) | 73.26 (7.64) | 0.80 |
| Male sex | 59 (75.6%) | 140 (75.3%) | 199 (75.4%) | 0.95 |
| Smoking status | 0.77 | |||
| Never | 19 (24.4%) | 46 (24.7%) | 65 (24.6%) | |
| Active | 6 (7.7%) | 10 (5.4%) | 16 (6.1%) | |
| Former | 53 (67.9%) | 130 (69.9%) | 183 (69.3%) | |
| Pack years, mean (SD) | 28.61 (21.58) | 27.80 (21.50) | 28.04 (21.47) | 0.81 |
| BMI, mean (SD) | 27.74 (4.95) | 27.82 (4.53) | 27.79 (4.64) | 0.90 |
| College degree or higher | 35 (46.1%) | 83 (45.9%) | 118 (45.9%) | 0.98 |
| Home oxygen therapy at baseline | 4 (5.1%) | 9 (4.9%) | 13 (5.0%) | 0.94 |
| FVC (% predicted), mean (SD) | 91.12 (21.82) | 88.78 (18.21) | 89.46 (19.32) | 0.38 |
| DLCO (% predicted), mean (SD) | 51.77 (13.73) | 52.31 (13.29) | 52.15 (13.40) | 0.77 |
| GAP index | 0.72 | |||
| 1 | 35 (47.3%) | 91 (51.4%) | 126 (50.2%) | |
| 2 | 38 (51.4%) | 82 (46.3%) | 120 (47.8%) | |
| 3 | 1 (1.4%) | 4 (2.3%) | 5 (2.0%) | |
| Emphysema on baseline HRCT | 11 (14.1%) | 14 (7.5%) | 25 (9.5%) | 0.10 |
P values based on univariate analysis.
BMI, body mass index; DLCO, diffusing capacity for carbon monoxide; FVC, forced vital capacity; HRCT, high-resolution CT; GAP index, gender–age–physiology index.