Methodological quality of systematic reviews based on AMSTAR2 criteria
| First author (year) | Q1 | Q2 | Q3 | Q4 | Q5 | Q6 | Q7 | Q8 | Q9 | Q10 | Q11 | Q12 | Q13 | Q14 | Q15 | Q16 | Overall quality |
| Kumar (2020)21 | Y | N | Y | PY | Y | N | N | PY | N | N | Y | N | N | Y | N | Y | Critically low quality |
| Dougherty (2020)25 | Y | N | Y | PY | Y | N | N | Y | N | N | X | X | N | N | X | Y | Critically low quality |
| Xing (2020)23 | Y | N | Y | PY | Y | Y | N | PY | Y | N | Y | N | N | Y | Y | Y | Low quality |
| Mantovani (2020)39 | Y | N | Y | PY | Y | Y | Y | PY | PY | N | X | X | Y | Y | X | Y | Moderate quality |
| Pan and Stanley (2020)24 | Y | N | Y | N | N | N | N | PY | N | N | X | X | N | N | X | Y | Critically low quality |
| Raj (2019)40 | Y | Y | Y | PY | Y | N | N | PY | Y | Y | X | X | N | N | X | Y | Low quality |
| Tang (2016)22 | Y | N | Y | PY | N | Y | N | PY | PY | N | X | X | N | Y | Y | Y | Low quality |
Q1: Were patient/problem, intervention, comparsion and outcome (PICO) components taken into consideration when drawing up the research questions and inclusion criteria? Q2: Does the review report explicitly state that the methods of the review were decided before commencing the review, and if these methods were changed does the report justify the change? Q3: Have the authors provided an explanation for their choice of the study designs they include in the review? Q4: Was the authors’ strategy for literature search sufficiently comprehensive? Q5: Were any duplicates of studies selected? Q6: Were any duplicate data extracted? Q7: Were excluded studies listed and a justification given for the exclusion? Q8: Is the detail with which the authors describe the studies adequate to the task? Q9: Has the risk of bias in individual studies been addressed satisfactorily through an appropriate technique? Q10: Are the individual studies’ funding sources reported in the review? Q11: Have the authors of the review employed appropriate methods to statistically combine the results of any meta-analysis conducted? Q12: Have the review authors assessed what impact risk of bias in individual studies might have on the results of their meta-analyses or on other evidence formation? Q13: Is risk of bias in the individual studies adequately addressed by the authors in the discussion and interpretation of their review’s results? Q14: Where heterogeneity was observed in the review results, have the authors attempted a satisfactory discussion and explanation thereof? Q15: If quantitative synthesis was performed, have the authors adequately addressed the issue of publication bias (small study bias) and offered a discussion of how it might be likely to impact the review results? Q16: Have the review authors reported on any conflicts of interest, including through funding of their review, which might arise?
AMSTAR2, Assessment of Multiple Systematic Reviews 2; N, no: negative response or response not available; PY, partial yes: incomplete adherence to the criteria; X, no meta-analyses performed; Y, yes: positive response.