Assessment of risk of biasĀ 
We assessed the risk of bias in the RCTs with the Cochrane Risk of Bias Tool for Randomized Controlled Trials (ROB 2.0). The bias was classified into five domains, including (1) Bias arising from the randomization process; (2) Bias due to deviations from intended interventions; (3) Bias due to missing outcome data; (4) Bias in measurement of the outcome; (5) Bias in selection of the reported result. Two authors (YHL, LHH) independently evaluated bias in each RCT; a third author (THL) would be consulted if no consensus was reached.
Data extraction and assessment
After independently reviewing all the abstracts, two authors (YHL, LHH) agreed on their potential relevance. If any discrepancies could not be resolved, a third author (THL) was present to settle them. One author performed the data extraction (YYH), and a second author (HJC) verified it. Study characteristics were extracted, together with the results that were of interest.