Quality assessment
The quality of the included RCTs
was assessed with the Cochrane Risk of Bias Tool26.
It contained six domains:
randomization process, intervention deviation, missing outcome data,
outcome measurement, selective outcome reporting.
The retrospective studies were
assessed by the Newcastle-Ottawa Scale (NOS) in the following 3 aspects:
cohort selection, cohort comparability, assessment of
outcome27. Details of NOS were available in Appendix
1.