Table 4.

Multivariable Cox regression analysis of the hazard of disease progression

Characteristics	Hazard ratio (95% CI)	P‐value
Age (≧75 years vs. <75 years)	0.89 (0.42–1.79)	0.758
Brinkman index (≧400 vs. <400)	0.96 (0.32–3.27)	0.940
Sex (male vs. female)	1.16 (0.32–4.67)	0.827
Histology (squamous vs. nonsquamous)	0.65 (0.31–1.30)	0.225
ECOG PS (0/1 vs. 2/3)	0.77 (0.28–2.38)	0.631
Reason for ICI discontinuation (irAEs vs. non‐irAEs)	0.41 (0.18–0.85)	0.016

CI, confidence intervals; ECOG, Eastern Cooperative Oncology Group; ICI, immune checkpoint inhibitor; irAEs, immune‐related adverse events; PS, performance status.