In addition, we compared the total scores obtained by applying AMSTAR on Cochrane reviews (n = 6, 8.42 ± 1.02) with that of non-Cochrane reviews (n = 35, 5.66 ± 1.31), and the former had higher quality score than the latter (mean difference = 2.76, P < 0.001, 95% CI: 1.62, 3.90).