TABLE 2.
Multivariate analyses of overall survival in patients with stage IV non‐small‐cell lung cancer aged <75 and ≥75 years
| Factors | <75 years old (n = 62 037) | ≥75 years old (n = 24 136) | ||
|---|---|---|---|---|
| Univariate | Multivariable | Univariate | Multivariable | |
| HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | |
| p value | p value | p value | p value | |
| Sex | ||||
| Male | 1.27 (1.24–1.29) | 1.22 (1.20–1.24) | 1.17 (1.14–1.21) | 1.19 (1.16–1.23) |
| Female | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
| Race | ||||
| Whites | 1.13 (1.11–1.16) | 1.14 (1.11–1.17) | 1.16 (1.11–1.21) | 1.16 (1.11–1.21) |
| Others | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
| Insurance status | ||||
| Uninsured | 1.12 (1.07–1.18) | 1.06 (1.01–1.12) | 1.01 (0.80–1.25) | 1.16 (0.94–1.46) |
| Insured | <0.0001 | 0.0118 | 0.9307 | 0.1906 |
| Institution | ||||
| Others | 1.20 (1.17–1.22) | 1.19 (1.16–1.21) | 1.18 (1.14–1.21) | 1.14 (1.11–1.18) |
| Academic | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
| Charlson–Deyo score | ||||
| ≥2 | 1.37 (1.33–1.40) | 1.26 (1.23–1.30) | 1.33 (1.28–1.38) | 1.22 (1.18–1.27) |
| ≤1 | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
| Year of diagnosis | ||||
| 2014 | 1.05 (1.03–1.07) | 1.05 (1.02–1.07) | 1.04 (1.01–1.07) | 0.91 (0.88–0.94) |
| 2015 | <0.0001 | <0.0001 | 0.0088 | <0.0001 |
| Histology | ||||
| Others | 1.23 (1.21–1.25) | 1.13 (1.11–1.15) | 1.14 (1.11–1.17) | 1.05 (1.02–1.08) |
| Adenocarcinoma not otherwise specified | <0.0001 | <0.0001 | <0.0001 | 0.0014 |
| Nodal status | ||||
| ≥N1 | 1.22 (1.19–1.24) | 1.33 (1.30–1.36) | 1.17 (1.14–1.21) | 1.31 (1.27–1.35) |
| N0 | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
| Brain metastasis | ||||
| Yes | 1.09 (1.06–1.12) | 1.02 (0.99–1.05) | 1.24 (1.18–1.31) | 1.25 (1.18–1.32) |
| No | <0.0001 | 0.2439 | <0.0001 | <0.0001 |
| Bone metastasis | ||||
| Yes | 1.24 (1.21–1.27) | 1.13 (1.11–1.15) | 1.17 (1.13–1.22) | 1.20 (1.15–1.25) |
| No | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
| Liver metastasis | ||||
| Yes | 1.45 (1.40–1.50) | 1.32 (1.27–1.36) | 1.32 (1.25–1.39) | 1.26 (1.19–1.33) |
| No | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
| Surgery for primary lesion | ||||
| No | 2.02 (1.90–2.14) | 2.04 (1.92–2.16) | 1.85 (1.66–2.08) | 1.83 (1.64–2.06) |
| Yes | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
| Radiation | ||||
| Yes | 1.10 (1.08–1.12) | 1.12 (1.10–1.14) | 1.06 (1.03–1.09) | 1.00 (0.98–1.04) |
| No | <0.0001 | <0.0001 | <0.0001 | 0.7468 |
| Chemotherapy | ||||
| No | 2.19 (2.15–2.23) | 2.30 (2.25–2.34) | 2.11 (2.05–2.17) | 2.18 (2.12–2.24) |
| Yes | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
| Immune checkpoint inhibitor | ||||
| No | 1.50 (1.46–1.54) | 1.47 (1.43–1.51) | 1.65 (1.57–1.73) | 1.63 (1.55–1.71) |
| Yes | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
Abbreviations: CI, confidence interval; HR, hazard ratio; NOS, not otherwise specified.