<p>The forest plot for all included studies pooled together using a random-effects model. <sup>a</sup> em, mean decline in experimental group; es, standard deviation in experimental group; en, number of subjects in experimental group; cm, mean decline in control group; cs, standard deviation in control group; cn, number of subjects in control group, MD, mean difference; I2, variability due to heterogeneity; Q, chi-square test; K, number of included studies.</p
