Table 3.

Subgroup of PFS.

Subgroup	Heterogeneity
	No of studies	I2	P values	Pooled HR (95% CI)	P values
Study type
Clinical trail	8	0%	0.48	1.60 [1.40, 1.84]	<0.01
Cohort study	6	45%	0.11	1.62 [1.41, 1.85]	<0.01
Race
Easterner	4	45%	0.14	1.44 [0.84, 2.45]	<0.01
Westerner	10	9%	0.36	1.62 [1.41, 1.85]	<0.01
Immunotherapy drug
anti-PD-1	9	0%	0.58	1.61 [1.36, 1.90]	<0.01
anti-PD-1/PD-L1	1	NA	NA	0.32 [0.07, 1.42]	0.13
anti-CTLA-4	1	NA	NA	1.40 [1.05, 1.89]	0.02
anti-PD-1+anti-CTLA-4	3	0%	0.4	1.99 [1.46, 2.72]	<0.01
sample size
≤30	5	12%	0.37	2.04 [1.05, 3.99]	<0.01
>30	9	19%	0.28	1.58 [1.39, 1.81]	<0.01