Table 2.
Comparison of model’s coefficients.
| Characteristics | Complete case | P value | Imputation (full model) | P value | Reduced modela | P value | Final Modelb |
|---|---|---|---|---|---|---|---|
| Age | 0.008 | 0.137 | -0.001 | 0.834 | – | – | – |
| Female | -0.123 | 0.346 | -0.155 | 0.122 | -0.17 | 0.086 | -0.16 |
| KPS score > 70% | -0.242 | 0.089 | -0.341 | 0.002 | -0.334 | 0.002 | -0.317 |
| Histology | |||||||
| - Adenocarcinoma | – | – | – | – | – | – | – |
| - Nonadenocarcinoma | -0.029 | 0.852 | -0.013 | 0.913 | |||
| EGFR/ALK mutation | |||||||
| - Negative | – | – | – | – | – | – | – |
| - Positive | -0.623 | 0.025 | -0.155 | 0.474 | |||
| - Unknown | 0.072 | 0.725 | 0.054 | 0.733 | |||
| Neurological symptoms | |||||||
| - None | – | – | – | – | – | – | – |
| - Mild | 0.054 | 0.814 | 0.158 | 0.386 | 0.17 | 0.346 | 0.16 |
| - Major | 0.321 | 0.135 | 0.311 | 0.073 | 0.324 | 0.052 | 0.305 |
| Measurable lesions | |||||||
| - Absence | – | – | – | – | – | – | – |
| - Presence | -0.071 | 0.681 | -0.016 | 0.928 | |||
| Extracranial disease | |||||||
| - Controlled lung and no ECM | – | – | – | – | – | – | – |
| - Controlled lung & ECM | 0.934 | 0.001 | 0.599 | 0.011 | 0.601 | 0.009 | 0.565 |
| - Uncontrolled lung or ECM | 1.064 | < 0.001 | 0.857 | < 0.001 | 0.868 | < 0.001 | 0.816 |
| - First Dx lung with any ECM | 1.387 | < 0.001 | 1.028 | < 0.001 | 1.038 | < 0.001 | 0.977 |
| Previous systemic treatment | 0.374 | 0.051 | 0.294 | 0.079 | 0.283 | 0.078 | 0.271 |
| Received further systemic treatment | -0.926 | < 0.001 | -0.973 | < 0.001 | -1.022 | < 0.001 | -0.961 |
| WBRT | -0.693 | < 0.001 | -0.529 | < 0.001 | -0.514 | < 0.001 | -0.483 |
ECM, extra-cranial metastasis; N/A, not applicable; WBRT, whole brain radiotherapy a Reduced model from imputation set before optimism correction; b Final model after optimism correction using slope of 0.94.