Table 4.

Level of evidence of systematic reviews with meta-analysis included according to the AMSTAR 2 tool.

Level	Description	Aghaloo, 2019 [36]	Chappuis, 2018 [37]	Fiorillo, 2022 [38]	Luo, 2018 [39]	Monje, 2017 [40]	Papadakis, 2023 [41]	Stavropoulos, 2018 [42]	Werny, 2022 [43]
High	No or one non-critical weakness: the systematic review provides an accurate and comprehensive summary of the results of the available studies that address the question of interest.
Moderate	More than one non-critical weakness: The systematic review has more than one weakness but no critical flaws. It may provide an accurate summary of the results of the available studies that were included in the review.		✓					✓
Low	One critical flaw with or without non-critical weaknesses: the review has a critical flaw and may not provide an accurate and comprehensive summary of the available studies that address the question of interest.	✓		✓	✓		✓		✓
Critically low	More than one critical flaw with or without non-critical weaknesses: the review has more than one critical flaw and should not be relied on to provide an accurate and comprehensive summary of the available studies.					✓