Table 1.
Demographic and baseline characteristics of training and validation data sets
| Characteristic | Training | Validation |
|---|---|---|
| Patients, n | 335 | 202 |
| Sex, female, n (%) | 142 (42) | 88 (44) |
| Mean age at primary diagnosis, years (95% range) | 61 (38–79) | 64 (42–83) |
| Smoking history, n (%) | ||
| Never smoked | 84 (25) | 27 (13) |
| Current smoker | 23 (7) | 21 (11) |
| Former smoker | 228 (68) | 154 (76) |
| Stage at primary diagnosis, n (%) | ||
| Stage I | 7 (2) | 0 (0) |
| Stage II | 3 (1) | 1 (0) |
| Stage III | 54 (16) | 17 (9) |
| Stage IV | 271 (81) | 184 (91) |
| ECOG performance status, n (%) | ||
| ECOG 0 | 122 (36) | 48 (24) |
| ECOG 1 | 213 (64) | 154 (76) |
| EGFR mutation status, n (%) | ||
| Positive | 67 (20) | 15 (7) |
| Negative | 268 (80) | 187 (93) |
| PD‐L1 expression, n (%) | ||
| <25% | 97 (29) | 83 (41) |
| ≥25% | 222 (66) | 105 (52) |
| Unknown | 15 (5) | 14 (7) |
| Mean baseline SLD, mm (95% range) | 86.1 (16.1–209.3) | 74.6 (15.2–191.0) |
| Mean baseline NEU, ×109 (95% range) | 6.2 (2.3–13.8) | 6.5 (2.7–15.4) |
| Mean baseline NLR (95% range) | 5.6 (1.2–20.7) | 7.0 (1.3–21.6) |