Author

Aspect of Bias

Answer

Explanation

Waters DL, et al. [22]

Random sequence generation (selection bias)

Yes

Central randomization by computer

Allocation concealment (selection bias)

Yes

Sequence generation was made on eligible individual stratified by site and blocked to ensure balance numbers

Blinding of participants and personnel (performance bias)

Yes

Assessors and participants were blinded

Blinding of outcome assessments (detection bias)

Yes

Strong blinding system

Incomplete outcome data (attrition bias)

Yes

No missing data

Selective reporting (reporting bias) 

Unclear

Protocol unclear

Other sources of bias

Yes

Study appears to be free of other sources of risk