Data Extraction
Two investigators extracted the following information: basic information
of included studies, baseline characteristics of study subjects, details
of the intervention, length of follow-up, key elements of risk of bias
assessment, and outcomes of interest. Disagreements were resolved
through consensus and, if necessary, consultation with a third
investigator (Y.Z.M.).
Quality
Assessment
Two investigators independently
assessed the risk of bias according to the Cochrane Collaboration risk
of bias tool, including the following domains: sequence generation,
allocation concealment, blinding of participants or personnel, blinding
of outcome assessors, incomplete outcome data, selective outcome
reporting, and other sources of bias. 14 We rated each
criterion as ’low’ risk of bias, ’high’ risk of bias, or ’unclear’ risk
of bias.