Data analysis
The meta-analysis was performed using RevMan version 5.3
software[25]. For continuous variables, data were synthesized using
the mean difference (MD) with a 95% confidence interval (CI) or
standardized mean difference (SMD). An odds ratio (OR) or risk ratio
(RR) was used to analyze discontinuous variables. The Chi-squared test
and I -squared (I2 ) tests were used to
assess for statistical heterogeneity. High heterogeneity in the results
was identified if the tests were statistically significant (p
< 0.05) and the I 2 >
50%, in which case a random-effects model was selected. Otherwise, a
fixed-effects model was used. Sensitivity analysis was conducted by
removing individual studies or eliminating studies with a high risk of
bias. If necessary, a subgroup analysis was conducted according to the
different intervention conditions (dose, duration, and
population)[26].