Confidence in cumulative evidence

The assessment of the confidence in cumulative evidence will be carried out by two independent reviewers so that eventual disagreements are resolved through a consensus meeting or with the help of an expert. The Quality Index (Downs and Black, 1998) which has been adopted in recent systematic reviews (Bujalance-Moreno et al., 2019; Praça et al., 2022) will be used to assess methodological quality of the eligible studies. The scale is composed of 25 items, as follows: 1: Is the hypothesis/aim/objective of the study clearly described?; 2: Are the main outcomes to be measured clearly described in the Introduction or Methods section?; 3: Are the characteristics of the participants included in the study clearly described ?; 4: Are the interventions of interest clearly described?; 5: Are the distributions of principal confounders in each group of subjects to be compared clearly described?; 6: Are the main findings of the study clearly described?; 7: Does the study provide estimates of the random variability in the data for the main outcomes?; 8: Have all important adverse events that may be a consequence of the intervention been reported?; 9: Have the characteristics of patients lost to follow-up been described?; 10: Have current probability values have been reported (e.g. 0.035 rather than <0.05) for the main outcomes except where the probability value was less than 0.001?; 12: Were those subjects who were prepared to participate representative of the entire population from which were they recruited?; 13: Were the staff, places, and facilities where the patients were treated, representative of the treatment the majority of patients receive?; 14: Was an attempt made to blind study subjects to the intervention they have received?; 15: Was an attempt made to blind those measuring the main outcomes of the intervention?; 16: If any of the results of the study were based on “data dredging”, was this made clear?; 17: In trials and cohort studies, do the analyses adjust for different lengths of follow-up of patients, or in case-control studies, is the time period between the intervention and outcome the same for cases and controls?; 18: Were the statistical tests used to assess the main appropriate outcomes?; 19: Was compliance with the intervention/s reliable?; 20: Were the main outcome measures used accurate (valid and reliable)?; 21: Were the patients in different intervention groups (trials and cohort studies) or were the cases and controls (case-control studies) recruited from the same population? 22: Were study subjects in different intervention groups (trials and cohort studies) or were the cases and controls (case-control studies) recruited over the same period?; 23: Were Study subjects randomized to intervention groups?; 24: Was the randomized intervention assignment concealed from both patients and health care staff until recruitment was complete and irrevocable?; 25: Was there an adequate adjustment for confounding in the analyzes from which the main findings were drawn