Comparison 6. Cell salvage ‐ blood transfused (language and methodological quality).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Language of Publication (All Studies)	66		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
1.1 English	60	5711	Risk Ratio (M‐H, Random, 95% CI)	0.61 [0.54, 0.70]
1.2 Non‐English	6	274	Risk Ratio (M‐H, Random, 95% CI)	0.63 [0.50, 0.79]
2 Methodological Quality ‐ Allocation concealment (All Studies)	67		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
2.1 Allocation concealment ‐ Yes	1	47	Risk Ratio (M‐H, Random, 95% CI)	0.35 [0.04, 3.11]
2.2 Allocation concealment ‐ Unclear	42	3812	Risk Ratio (M‐H, Random, 95% CI)	0.62 [0.53, 0.72]
2.3 Allocation concealment ‐ No	24	2166	Risk Ratio (M‐H, Random, 95% CI)	0.62 [0.51, 0.75]