3.1. Agreement and Reliability. Substantial agreements (>80% or nearly 80%) were observed in majority of the individual items (item 1, 2, 3, 4, 6, 7, 8, 10, 11) on AMSTAR, with a mean percentage of 84% (95% CI: 71.1%-91.9%); agreements on item 5 and item 9 were mild at a percentage of less than 60%. Kappa ranged widely from −0.03 to 1.00 with a mean of 0.50 (95% CI: 0.26, 0.73); five items (item 2, 3, 4, 10, 11) scored a kappa of >0.70 (0.70 to 1.00); the highly agreements in four items (item 1, item 6, item 7, item 8) ranged from 80% to 95% and inversely low kappa (−0.034, 0.40, 0.36, 0.36) may be explained by a skewed distribution of responses, that is, approximately 80% (in item 6) to 90% (in item 1, 7, 8) of reviews in which the assessors agreed on the score "yes." However, items 5 (list of included and excluded studies) and 9 (appropriate method to combine studies) scored relative low either in agreement percentage or in kappa parameter (Table 1) . Agreements on individual items of OQAQ were inferior to AMSTAR, with a mean percentage of 79% (95% CI: 64%, 89.5%), and the mean of kappa was relatively low too, with a mean of 0.35 (95% CI: 0.08, 0.62).