Table 1 Frequency distribution of items/recommended practices by domains for the total number of systematic reviews with meta-analysis (SRMAs)
SRMAs (n = 103) | |
|---|---|
Domain: transparency | |
Registration | |
No | 46 (44.7%) |
Yes | 57 (55.3%) |
Protocol | |
No | 98 (95.1%) |
Yes | 5 (4.9%) |
Available searches | |
No | 20 (19.4%) |
Yes | 83 (80.6%) |
Data statement | |
No | 66 (64.1%) |
Yes | 37 (35.9%) |
Domain: completeness | |
Title as SRMA | |
No | 3 (2.9%) |
Yes | 100 (97.1%) |
Data sources (ab) | |
No | 33 (32.0%) |
Yes | 70 (68.0%) |
Key eligibility criteria (ab) | |
No | 26 (25.2%) |
Yes | 77 (74.8%) |
Number of included studies (ab) | |
No | 5 (4.9%) |
Yes | 98 (95.1%) |
Research question | |
No | 29 (28.2%) |
Yes | 74 (71.8%) |
PICOS explanation | |
No | 32 (31.1%) |
Yes | 71 (68.9%) |
Number of references | |
No | 6 (5.8%) |
Yes | 97 (94.2%) |
Description of sample sizes | |
No | 5 (4.9%) |
Yes | 98 (95.1%) |
Duration of included studies | |
Does not apply | 16 (15.5%) |
No | 7 (6.8%) |
Yes | 80 (77.7%) |
Sources of funding | |
No | 7 (6.8%) |
Yes | 96 (93.2%) |
Potential conflicts of interest | |
No | 7 (6.8%) |
Yes | 96 (93.2%) |
Domain: participants | |
Description of participants (ab) | |
No | 22 (21.4%) |
Yes | 81 (78.6%) |
Detailed studies’ characteristics | |
No | 15 (14.6%) |
Yes | 88 (85.4%) |
Domain: intervention/exposure | |
Description of interventions/exposures (ab) | |
No | 7 (6.8%) |
Yes | 96 (93.2%) |
Detailed studies’ characteristics | |
No | 15 (14.6%) |
Yes | 88 (85.4%) |
Domain: outcome | |
Main outcome of interest (ab) | |
No | 5 (4.9%) |
Yes | 98 (95.1%) |
Statistical methods | |
No | 18 (17.5%) |
Yes | 85 (82.5%) |
Statistical heterogeneity | |
No | 12 (11.7%) |
Yes | 91 (88.3%) |
Meta-analytic summary estimates | |
No | 31 (30.1%) |
Yes | 72 (69.9%) |
Statistics per study | |
No | 46 (44.7%) |
Yes | 57 (55.3%) |
Domain: methodological rigor | |
Searches in gray literature | |
No | 49 (47.6%) |
Yes | 54 (52.4%) |
Searches from inception or with justification | |
No | 8 (7.8%) |
Yes | 95 (92.2%) |
Number of languages | |
1 | 62 (60.2%) |
2 | 11 (10.7%) |
3 | 7 (6.8%) |
4 | 1 (1.0%) |
No restriction | 19 (18.4%) |
No statement | 3 (2.9%) |
Study selection in duplicate | |
No | 26 (25.2%) |
Partial yes (e.g., a sample of 50% of studies were checked by two independent researchers) | 3 (2.9%) |
Yes | 74 (71.8%) |
Data extraction in duplicate | |
No | 47 (45.6%) |
Partial yes (e.g., a sample of 50% of studies were checked by two independent researchers) | 1 (1.0%) |
Yes | 55 (53.4%) |
Description of RoB assessment | |
No | 5 (4.9%) |
Yes | 98 (95.1%) |
RoB assessment in duplicate | |
No | 35 (34.0%) |
Yes | 68 (66.0%) |
Domain: critical appraisal | |
RoB results within studies | |
No | 14 (13.6%) |
Partial yes (there are individual results without specification of specific criteria/domains) | 17 (16.5%) |
Yes | 72 (69.9%) |
Description of protocol deviations | |
No | 18 (17.5%) |
Unclear | 43 (41.7%) |
Yes | 16 (15.5%) |
Does not apply | 26 (25.2%) |
Presence of spin bias | |
No | 82 (79.6%) |
Yes | 21 (20.4%) |
Discussion addressing RoB | |
No | 70 (68.0%) |
Yes | 33 (32.0%) |
Limitations thoroughly addressed | |
No | 6 (5.8%) |
Yes, BOTH for study and review levels | 74 (71.9%) |
Yes, ONLY for the review level (limitation within or across studies not mentioned) | 2 (1.9%) |
Yes, ONLY for the study and/or outcome level (review processes not mentioned) | 21 (20.4%) |