Study population by initial chest X-ray group
| Variable | Initial CXR code 1 | Initial CXR code 2 | Initial CXR code 3 | Initial CXR code 4 | ‘Positive’ (code 1 or 2) | ‘Negative’ (code 3 or 4) | Total |
|---|---|---|---|---|---|---|---|
| n (%)a | 1383 (65.0) | 370 (17.4) | 230 (10.8) | 146 (6.9) | 1753 (82.3) | 376 (17.6) | 2129 |
| Age, years, mean | 71 | 72 | 75 | 70 | 71 | 73 | 72 |
| Sex, male, n (%) | 753 (54.4) | 189 (51.1) | 121 (52.6) | 72 (49.3) | 942 (53.7) | 193 (51.3) | 1135 (53.3) |
| CXR to diagnosis, median days (IQR) | 36 (23–63) | 93 (55–154) | 211 (181–296) | 193 (87–279) | 43 (27–78) | 204 (105–287) | 51 (29–107) |
| Survival from CXR, median days (IQR) | 313 (126–877) | 400 (163–964) | 408 (238–958) | 420 (214–1117) | 328 (135–899) | 412 (225–1011) | 345 (148–920) |
| Stage | |||||||
| I/II, n (%), (95% CI) | 397 (28.7), (26.4 to 31.2) | 111 (30.0), (25.4 to 35.0) | 83 (36.1), (30.0 to 42.7) | 43 (29.5), (22.4 to 37.7) | 508 (29.0), (26.9 to 31.2) | 126 (33.5), (28.8 to 38.6) | 634 (29.8), (27.9 to 31.8) |
| III/IV, n (%), (95% CI) | 981 (70.9), (68.4 to 73.3) | 259 (70.0), (65.0 to 74.5) | 147 (63.9), (57.3 to 70.1) | 103 (70.5), (62.4 to 77.7) | 1240 (70.7), (68.5 to 72.9) | 250 (66.5), (61.4 to 71.2) | 1490 (70.0), (68.0 to 71.9) |
| Unknown, n (%) | 5 (0.4) | 0 | 0 | 0 | 5 (0.3) | 0 | 5 (0.2) |
| Histology, n (%) | |||||||
| Small-cell | 170 (12.3) | 39 (10.5) | 30 (13.0) | 25 (17.1) | 209 (11.9) | 55 (14.6) | 264 (12.4) |
| Non-small-cell | 961 (69.5) | 257 (69.5) | 123 (53.5) | 87 (60.0) | 1218 (69.5) | 210 (55.9) | 1428 (67.1) |
| Other histologiesb | — | — | — | — | 12 (0.7) | 5 (1.3) | 17 (0.8) |
| Unknown | 244 (17.6) | 70 (18.9) | 76 (33.0) | 30 (20.5) | 314 (17.9) | 106 (28.2) | 420 (19.3) |