Table 1.
Characteristics of the included systematic reviews (n = 301).
| Variables | n (%) |
|---|---|
| Year of publication | |
| 2018 | 60 (20.0) |
| 2019 | 87 (28.9) |
| 2020 | 119 (39.5) |
| 2021 | 35 (11.6) |
| Number of authors (Median, IQR) | 5 (4–6) |
| Country of the first author | |
| United States of America | 56 (18.6) |
| United Kingdom | 35 (11.6) |
| Australia | 30 (10.0) |
| China | 30 (10.0) |
| Iran | 14 (4.7) |
| Canada | 13 (4.3) |
| Spain | 13 (4.3) |
| Germany | 12 (4.0) |
| Ethiopia | 9 (3.0) |
| Italy | 9 (3.0) |
| Korea | 9 (3.0) |
| Netherlands | 8 (2.6) |
| Brazil | 6 (2.0) |
| Switzerland | 6 (2.0) |
| Japan | 5 (1.7) |
| Othersa | 46 (15.2) |
| Protocol registration | |
| PROSPERO | 92 (30.6) |
| Open Science Framework | 2 (0.6) |
| None | 207 (68.8) |
| Reporting statements cited b | |
| PRISMA and its extensions | 204 (67.8) |
| MOOSE | 10 (3.3) |
| ENTREQ | 2 (0.7) |
| Othersc | 3 (1.0) |
| No | 90 (30.0) |
| Funding for the systematic review reported | |
| Yes | 146 (48.5) |
| No | 155 (51.5) |
| Methodological quality of the primary studies assessed | |
| Yes | 221 (73.4) |
| No | 80 (26.6) |
| Quality of the body of evidence assessed | |
| Yes | 20 (6.6) |
| Etiology | 81 (27.0) |
| Distribution | 69 (23.0) |
| Therapeutic | 46 (15.3) |
| Prevention | 40 (13.3) |
| Screening | 8 (2.6) |
| Diagnosis/Prognosis | 4 (1.3) |
| Other | 53 (17.5) |
| Systematic reviews of interventions | |
| Yes | 86 (28.6) |
| No | 215 (71.4) |
| Number of the included primary studies (Median, IQR) | 19 (12–35) |
Others included France (n = 4), Greece (n = 4), Portugal (n = 4), Singapore (n = 3), Thailand (n = 3), Belgium (n = 2), Cameroon (n = 2), Finland (n = 2), Norway (n =2), South Africa (n = 2), United Arab Emirates (n = 2), Austria (n = 1), Bangladesh (n = 1), Chile (n = 1), Colombia (n = 1), Denmark (n = 1), Ireland (n = 1), Lebanon (n = 1), Malaysia (n = 1), New Zealand (n = 1), Nigeria (n = 1), Pakistan (n = 1), Philippines (n = 1), Serbia (n = 1), Slovenia (n = 1), Sweden (n = 1), Tanzania (n = 1).
Some studies reported following two or more reporting statements.
Others included the Center for Reviews and Dissemination, Method for the thematic synthesis of qualitative research in systematic reviews, ROSES (RepOrting Standards for Systematic Evidence Syntheses).
ENTREQ, Enhancing transparency in reporting the synthesis of qualitative research; IQR, interquartile range; MOOSE, Meta-analysis Of Observational Studies in Epidemiology; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses.