Table 2. The comparison of patients’ characteristics between training set and validation set. There was no significant difference of patients’ characteristics between training set and validation set, including gender, age, smoking history, pathological stage, EGFR status and sample type.
| Characteristic | Training set (n=810) | Validation set (n=200) | Statistical method and P value |
|---|---|---|---|
| Gender, n (%) | Pearson χ2 test, P=0.813 | ||
| Male | 442 (54.6) | 111 (55.5) | |
| Female | 368 (45.4) | 89 (44.5) | |
| Age (years) | Independent-samples t-test, P=0.108 | ||
| Median age | 61 | 62 | |
| Range | 25–88 | 39–85 | |
| Smoking history, n (%) | Pearson χ2 test, P=0.954 | ||
| Smoking | 209 (25.8) | 53 (26.5) | |
| No smoking | 601 (74.2) | 147 (73.5) | |
| Pathological stage, n (%) | Mann-Whitney test, P=0.149 | ||
| I | 253 (31.2) | 54 (27.0) | |
| II | 40 (4.9) | 9 (4.5) | |
| III | 304 (37.5) | 76 (38.0) | |
| IV | 213 (26.3) | 61 (30.5) | |
| Genetic status, n (%) | Pearson χ2 test, P=0.364 | ||
| Wild type | 407 (50.2) | 93 (46.5) | |
| Exon 19 mutation | 192 (23.7) | 57 (28.5) | |
| Exon 21 mutation | 211 (26.0) | 50 (25.0) | |
| Sample type, n (%) | Pearson χ2 test, P=0.81 | ||
| Biopsy | 308 (38.0) | 78 (39.0) | |
| Surgery | 502 (62.0) | 122 (61.0) |
EGFR, epithelial growth factor receptor.