Table 2.

Individual studies’ outcomes risk of bias.

Study	Selection Bias: Random Sequence Generation	Selection Bias: Allocation Concealment	Performance Bias: Blinding of Participants and Personnel	Detection Bias: Blinding of Outcome Assessment	Attrition Bias: Incomplete Outcome Data	Reporting Bias: Selective Reporting	Other Bias
MCS 1 A	low	high	high	high	low	low	low
MCS 1 B	low	high	high	high	high	low	low
MCS 1 C	high	high	high	high	low	low	low
MCS 1 D	low	high	high	high	high	low	low
MCS 1 E	low	high	high	high	high	low	low
MCS 2 A	low	unknown	high	low	low	low	low
MCS 2 B	low	unknown	high	low	low	low	low
MCS 2 C	low	unknown	high	low	low	low	low
MCS 2 D	low	unknown	high	low	low	low	low
MCS 2 E	low	unknown	high	low	low	low	low
MCS 2 F	low	unknown	high	low	high	low	low
SCS 1	unknown	unknown	high	high	low	low	low
SCS 2	low	unknown	high	high	high	low	low

MCS, multicenter study; A–F, study sites; SCS, single center study.