Table 2.

Summary of risk of bias assessments.

Risk of bias item	n (of 8) included studies with
	High risk	Low risk	Unclear risk
Sequence generation	–	–	8
Baseline Characteristics	–	–	8
Random outcome assessment	–	–	8
Blinding of outcome assessment	–	–	8
Incomplete outcome data	–	–	8
Other	–	–	8
Meta-analyst’s extraction bias	6	2	–