Table 3.

Subgroup analysis of blood transfusion rate

Outcome of subgroup	Studies	Effect estimate
		χ 2	I2 (%)	RD	95% CI	P value
TKA	3	13.34	88	− 0.22	[− 0.42, − 0.02]	0.03
THA	3	3.20	38	− 0.17	[− 0.21, − 0.13]	0.00001
Transfusion trigger	3	4.47	57	− 0.23	[− 0.35, − 0.12]	0.0001
Continuous application	4	4.88	39	− 0.20	[− 0.26, − 0.14]	0.00001

TKA total knee arthroplasty, THA total hip arthroplasty, CI confidence interval, MD mean difference