Table 5.

The Cochrane risk-of-bias tool for assessing risk of bias of RCTs.

Study	Random sequence generation	Allocation concealment	Blinding of participants and personal	Blinding of outcome assessment	Incomplete outcome data	Selection reporting	Other sources of bias
Moayyedi et al[21]	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Rossen et al[22]	Low risk	Low risk	Low risk	Unclear	Unclear	Low risk	Low risk
Paramsothy et al[8]	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Costello et al[23]	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk