2.3 Data extraction
Inclusion and exclusion criteria were defined to determine the selection
of clinical studies. References of all included articles were manually
examined and added to our electronic citation manager to ensure that all
pertinent published works had been identified. With no prior knowledge
of the authors or results of the selected publications, 2 reviewers (Cao
Z and Ling Y) rated the clinical and methodological quality of each
study using a standardized scoring system independently after acquiring
full texts of the studies. Studies that did not rate above a quality
score threshold were excluded from data extraction.