Table 2. Assessment of methodological quality of systematic using the Assessment of Multiple Systematic Reviews items.

^*1: Was an ‘a priori’ design provided?

^†2: Was there duplicate study selection and data extraction?

^‡3: Was a comprehensive literature search performed?

^§4: Was the status of publication (e.g., grey literature) used as an inclusion criterion?

^‖5: Was a list of studies (included and excluded) provided?

^¶6: Were the characteristics of the included studies provided?

^**7: Was the scientific quality of the included studies assessed and documented?

^††8: Was the scientific quality of the included studies used appropriately in formulating conclusions?

^‡‡9: Were the methods used to combine the findings of the studies appropriate?

^§§10: Was the likelihood of publication bias assessed?

^‖‖11: Was the conflict of interest stated?

AMSTAR: Assessment of Multiple Systematic Reviews