Table 3. Meta-analysis of PD-L1 expression and clinicopathological features in BTC patients.

Tumor type	Clinicopathological feature	Studies, n	Effects model	OR (95%CI)	P value	Heterogeneity
						I2(%)	p value
eCCA	Sex (male vs female)	6	Fixed	1.09(0.69-1.72)	0.710	0	0.826
	T stage (T3-T4 vs T1-T2)	4	Fixed	0.80(0.43-1.50)	0.492	0	0.515
	N stage (N1 vs N0)	6	Fixed	1.48(0.97-2.27)	0.070	42.3	0.123
	Grading (G3 vs G1+G2)	3	Fixed	1.85(0.84-4.07)	0.126	22.2	0.277
iCCA	Sex (male vs female)	4	Fixed	1.11(0.71-1.73)	0.651	0	0.931
	Tumor size (≥5cm vs <5cm)	2	Random	0.73(0.18-2.98)	0.661	80.3	0.024
	N stage (N1 vs N0)	4	Random	1.22(0.15-9.91)	0.852	92.8	<0.001
	Vascular invasion (yes vs no)	4	Random	3.24(0.75-14.00)	0.116	82.4	0.001
	Perineural invasion (yes vs no)	3	Fixed	0.77(0.36-1.72)	0.529	0	0.706
iCCA+eCCA	Sex (male vs female)	2	Fixed	1.36(0.77-2.42)	0.290	9.3	0.294
	T stage (T3-T4 vs T1-T2)	2	Fixed	1.10(0.63-1.91)	0.741	41.9	0.190
	N stage (N1 vs N0)	3	Fixed	1.46(0.85-2.52)	0.174	0	0.586