Table 2. Subgroup analyses for PD-L1 ≥1% Cutoff and PD-L1 ≥50% Cutoff.

Subgroups	Combined relative risk (95% CI), No. of studies
	PD-L1 ≥1% Cutoff	PD-L1 ≥50% Cutoff
PD-L1 IHC assays	0.78 (0.71–0.86), 10	0.70 (0.58–0.84),10
SP263	0.98 (0.83–1.15), 2	0.79 (0.56–1.10), 3
22C3	0.93 (0.80–1.07), 5	0.79 (0.59–1.06), 4
SP142	0.48 (0.39–0.59), 3	0.53 (0.38–0.75), 3
Type of biopsy specimens	0.83 (0.76–0.91), 12	0.69 (0.58–0.83), 11
Histological specimens	0.75 (0.67–0.84), 7	0.64 (0.51–0.80), 6
Tissue microarrays	0.92 (0.73–1.15), 2	0.78 (0.50–1.23), 2
Cytologic specimens	1.02 (0.85–1.23), 3	0.79 (0.56–1.12), 3

PD-L1, programmed cell death ligand-1.