Table 3 AMSTAR rating for included systematic reviews

AMSTAR criteria

Use of an ’a priori’ design

Duplicate study selection and data extraction

Comprehensive searching of the literature

Use of publication status as an exclusion criterion

Provision of (included and excluded) studies

Provision of characteristics of included studies

Assessment of methodological quality of included studies

Appropriate use of quality of included studies in formulating conclusions

Appropriate methods for combining results of studies

Assessment of publication bias

Conflict of interest (both review and included studies) stated