| Characteristics | Adverse Events (%) | OR | 95% Confidence Interval | p Value |
| Tobacco smoking Never smoker Smoker Former smoker |
80.0 42.9 28.6 |
Ref 0.188 0.100 |
0.018 - 1.977 0.010 - 1.038 |
0.164 0.054 |
| Brain local treatment Surgery or radiosurgery Whole brain radiation therapy None |
50.0 41.5 14.3 |
Ref 0.708 0.167 |
0.127 - 3.943 0.012 - 2.368 |
0.694 0.186 |
| Immunotherapy type Anti-CTLA-4 Anti-PD-1 Anti-PD-L1 |
33.3 37.0 60.0 |
Ref 1.172 3.000 |
0.099 - 13.916 0.150 - 59.890 |
0.900 0.472 |
| ECOG PS 0 - 1 ≥2 |
36.4 50.0 |
Ref 1.750 |
0.439 - 6.980 |
0.428 |
| Pathology Non-squamous Squamous |
42.2 22.2 |
Ref 0.391 |
0.073 - 2.096 |
0.273 |
| Mutation status No molecular alteration Molecular alteration |
40.0 50.0 |
Ref 1.500 |
0.423 - 5.315 |
0.530 |
| Brain metastases Synchronous Metachronous |
42.3 35.7 |
1.320 Ref |
0.441 - 3.953 |
0.620 |
| Number of brain metastases at diagnosis 0 1 to 5 >5 |
35.7 52.6 14.3 |
Ref 2.000 0.300 |
0.610 - 6.553 0.032 - 2.857 |
0.252 0.295 |