Table 1.
The characteristics of the included umbrella reviews’ protocols and publications.
| Characteristics | Protocols (n=31) | Publications (n=35) | |
| Journal impact factora, median (IQR) | 3.007 (0.000-3.136) | 3.312 (2.329-5.926) | |
| Journal impact factor, n (%) | |||
|
|
0.0 to 3.0 | 1 (3) | 6 (17) |
|
|
>3.0 to 6.0 | 20 (65) | 14 (40) |
|
|
>6.0 | 0 (0) | 8 (23) |
|
|
Non-SCIb | 9 (29) | 6 (17) |
|
|
Preprint | 1 (3) | 1 (3) |
| Number of authors, median (IQR) | 6 (4-8) | 6 (5-9) | |
| Number of authors, n (%) | |||
|
|
2-5 | 13 (42) | 13 (37) |
|
|
6-10 | 15 (48) | 17 (49) |
|
|
>10 | 3 (10) | 5 (14) |
| Registration, n (%) | |||
|
|
PROSPERO | 21 (68) | 23 (66) |
|
|
Open Science Framework | 1 (3) | 1 (3) |
|
|
Not registered | 9 (29) | 11 (31) |
| Funding, n (%) | |||
|
|
Yes | 18 (58) | 26 (74) |
|
|
No | 5 (16) | 4 (11) |
|
|
Not reported | 8 (26) | 5 (14) |
| Conflicts of interest, n (%) | |||
|
|
Yes | 2 (6) | 4 (11) |
|
|
No | 29 (94) | 31 (89) |
aThe journal impact factor was determined using the 2021 Journal Citation Report.
bSCI: Science Citation Index.