Table 1.
Characteristics of systematic review and meta-analyses included in the review.
| Variable | Category | Frequency (%) |
|---|---|---|
| Publication year | 2008–2013 | 5 (21.7) |
| 2014–2018 | 7 (30.4) | |
| 2019–2023 | 11 (47.8) | |
| Number of authors | Mean ± SD (range) | 5.6 ± 2.7 (1–9) |
| Two authors | 4 (17.4) | |
| Multiple authors (>2 authors) | 19 (82.6) | |
| Number of studies included | Total (median) | 413 (13) |
| Mean ± SD (range) | 18.0 ± 13.5 (1–62) | |
| Summary findings | Systematic review only | 7 (30.4) |
| Meta-analysis only | 8 (34.8) | |
| Combination of both (systematic review and meta-analysis) | 6 (26.1) | |
| Meta-analysis and qualitative review | 1 (4.3) | |
| Network meta-analysis | 1 (4.3) | |
| Number of databases included in search | Mean ± SD (range) | 8.0 ± 3.1 (1–12) |
| 3–4 | 2 (8.7) | |
| 5–7 | 11 (47.8) | |
| 8–10 | 6 (26.1) | |
| >10 | 4 (17.4) | |
| Other search strategies used (not mutually exclusive) | Not reported (No other strategies were used) | 8 (34.8) |
| Search reference list of included studies | 8 (34.8) | |
| Other additional searches done (online/through reviews/personal database) | 3 (13.0) | |
| Combination of both | 4 (17.4) | |
| Search start date | Setting up a database | 13 (56.5) |
| 1950–1979 | 2 (8.7) | |
| 1980–2009 | 2 (8.7) | |
| 2010–2023 | 2 (8.7) | |
| Not reported | 4 (17.4) | |
| Search end date | Before 2010 | 3 (13.0) |
| 2010–2014 | 3 (13.0) | |
| 2015–2019 | 10 (43.5) | |
| 2020–2022 | 7 (30.4) | |
| Participant inclusion criteria: Age | No limit | 12 (52.3) |
| Not reported/stated | 11 (47.8) | |
| Participant inclusion criteria: Sex | No limit | 11 (47.8) |
| Not reported/stated | 12 (52.3) | |
| Study design inclusion criteria (not mutually exclusive) | Randomized controlled trials | 20 (87.0) |
| Randomized controlled design | 2 (8.7) | |
| Randomized controlled trials and Semi-randomized controlled clinical trial and Controlled clinical trials with the word randomized but without a specific description of the randomized method | 1 (4.3) | |
| Language inclusion criteria | Two languages | 7 (30.4) |
| Multiple languages | 9 (39.1) | |
| Not reported | 7 (30.4) | |
| Reporting guidelines | Yes | 6 (26.1) |
| No | 17 (73.9) | |
| Registered in PROSPERO | Yes | 3 (13.0) |
| No | 20 (87.0) | |
| Quality assessment of the studies included in the systematic reviews and meta-analyses | Reported but no categorization possible | 8 (34.8) |
| Reported with categorization | 14 (60.9) | |
| Not reported | 1 (4.3) | |
| Quality of the primary studies (n = 242) included in the systematic reviews and meta-analyses where quality was reported with categorization (n = 14) | High | 45 (18.6) |
| Moderate | 44 (18.2) | |
| Low | 106 (43.8) | |
| Undetermined (unclear) | 47 (19.4) | |
| Quality assessment tools used in the systematic reviews and meta-analyses | Not reported (or not applicable) | 2 (8.7) |
| Adapted/modified from previous study or tool | 3 (13.0) | |
| Cochrane Collaboration's Tool for Assessing Risk of Bias | 15 (65.2) | |
| Others | 3 (13.0) |