| Characteristics | Patients n (%) | Overall survival time months | Univariate analysis | Multivariate analysis | ||
| HR (95% CI) | p-value | HR (95% CI) | p-value | |||
| Age years | ||||||
| ≥75 | 259 (34) | 10.9 | 1.51 (1.27–1.80) | <0.001 | 1.08 (0.90–1.30) | 0.412 |
| <75 | 512 (66) | 18.1 | Reference | Reference | ||
| Sex | ||||||
| Male | 520 (67) | 11.1 | 1.35 (1.13–1.62) | <0.001 | 1.22 (0.98–1.53) | 0.080 |
| Female | 251 (33) | 20.9 | Reference | Reference | ||
| Smoking status | ||||||
| Never | 218 (28) | 21.4 | 0.73 (0.60–0.87) | <0.001 | 1.04 (0.81–1.32) | 0.774 |
| Current or former smoker | 553 (72) | 12.9 | Reference | Reference | ||
| ECOG PS just prior to opting for chemotherapy | ||||||
| 0 or 1 | 516 (67) | 20.5 | 0.30 (0.25–0.36) | <0.001 | 0.36 (0.29–0.44) | <0.001 |
| 2–4 | 255 (33) | 5.3 | Reference | Reference | ||
| EGFR mutations | ||||||
| Yes | 128 (17) | 30.7 | 0.48 (0.37–0.59) | <0.001 | 0.49 (0.38–0.63) | <0.001 |
| No or not investigated | 643 (83) | 12.7 | Reference | Reference | ||
| Stage | ||||||
| IIIB | 158 (20) | 17.7 | 0.72 (0.57–0.88) | 0.001 | 0.64 (0.51–0.80) | <0.001 |
| IV | 613 (80) | 15.0 | Reference | Reference | ||
| Histology | ||||||
| Adenocarcinoma | 533 (69) | 17.8 | 0.72 (0.60–0.86) | <0.001 | 0.81 (0.67–0.99) | 0.044 |
| Non-adenocarcinoma | 238 (31) | 12.6 | Reference | Reference | ||
| Chemotherapy# | ||||||
| Yes | 651 (84) | 18.2 | 0.20 (0.16–0.25) | <0.001 | 0.40 (0.31–0.52) | <0.001 |
| No | 120 (16) | 2.9 | Reference | Reference | ||
| DFEA | ||||||
| Yes | 103 (13) | 6.4 | 1.76 (1.36–2.23) | <0.001 | 1.16 (0.89–1.49) | 0.267 |
| No | 668 (87) | 16.6 | Reference | Reference | ||
HR: hazard ratio; ECOG: Eastern Cooperative Oncology Group; PS: performance status; EGFR: epidermal growth factor receptor gene; DFEA: diagnosed following an emergency admission. #: Chemotherapy, including definitive chemoradiotherapy.