Skip to main content
. 2017 Jan 5;15:3. doi: 10.1186/s12916-016-0764-6

Table 2.

Knowledge synthesis method characteristics

Method characteristics (n = 438)a Count (%)
A priori protocol and review design A priori protocol Use of a protocol mentioned 66 (15.1)
Published 40 (9.1)
Registered 25 (5.7)
Available upon request 6 (1.4)
Not reported 301 (68.7)
Research question Clearly reported 437 (99.8)
Unclear/inferred 1 (0.2)
Eligibility criteria Clearly reported 430 (98.2)
Unclear/inferred 1 (0.2)
Not reported 7 (1.6)
Identifying relevant studies Databases searched Searched more than one database 407 (92.9)
Searched only one database 29 (6.6)
Not reported 2 (0.5)
Search string Complete literature search 207 (47.3)
MeSH terms only 173 (39.5)
Not reported 58 (13.2)
Additional search strategy Scanned references 309 (70.5)
Grey literature searched 270 (61.6)
Consulted topic experts 80 (18.3)
Consulted librarian 67 (15.3)
Performed updated search 62 (14.2)
Manually searched selected journals 37 (8.4)
Limits applied Limited by study design 291 (66.4)
Limited by language 147 (33.6)
Limited by date 135 (30.8)
Other limits (e.g., age, humans) 129 (29.5)
Study selection Title & abstract screening Two or more independent reviewers 285 (65.1)
One reviewer and one verifier 9 (2.1)
One reviewer only 16 (3.7)
Done but unclear number of reviewers 92 (21.0)
Not reported 36 (8.2)
Full-text screening Two or more independent reviewers 282 (64.4)
One reviewer and one verifier 11 (2.5)
One reviewer only 7 (1.6)
Done but unclear number of reviewers 105 (24.0)
Not reported 33 (7.5)
Study flow Completely in PRISMA-like flow diagram 374 (85.4)
Completely in text/table only 20 (4.6)
Partially reported 15 (3.4)
Not reported 29 (6.6)
Data abstraction & quality assessment Data abstraction Two or more independent reviewers 238 (54.3)
One reviewer and one verifier 94 (21.5)
One reviewer only 8 (1.8)
Done but unclear number of reviewers 75 (17.1)
Not reported 23 (5.3)
Quality appraisal Two or more independent reviewers 181 (41.3)
One reviewer and one verifier 21 (4.8)
One reviewer only 9 (2.1)
Done but unclear number of reviewers 133 (30.4)
Not reported 94 (21.5)

a18 out of 456 NMAs did not provide details of their knowledge synthesis method