Study selection
The software EndNote X9 was used to import all the references and remove duplicates. Titles and abstracts of the retrieved articles were evaluated independently by two reviewers (X.L.L and H.Q.L). Abstracts that did not provide sufficient information regarding the eligibility criteria were retained for full-text evaluation. Two reviewers (X.L.L and H.Q.L) independently evaluated full texts and determined study eligibility based on the inclusion and exclusion criteria. Any discrepancies were resolved by the third reviewer (R.H.X).