Table 1.
Characteristics of included meta-analyses
| Cochrane meta-analyses (n=107) |
Non-Cochrane meta-analyses (n=143) |
|
| Year of publication, N (%) | ||
| 2016 | 0 | 4 (3) |
| 2017 | 22 (21) | 31 (22) |
| 2018 | 85 (79) | 108 (76) |
| Number of Included RCTs, mean±SD | 21.4±24.4 | 19.6±46.4 |
| Registered in PROSPERO or published protocol, N (%) | 107 (100) | 25 (17)* |
| Impact factor, mean±SD | 6.8±0 | 3.6±5.4 |
| ≤3 | 0 | 106 (74%) |
| 3.1–6.7 | 0 | 27 (19%) |
| 6.8 | 107 (100%) | 0 |
| >6.8 | 0 | 10 (7.0%) |
| Meta-analysis funding sources, N (%) | ||
| Not reported | 4 (4)† | 39 (27) |
| Industry | 0 | 3 (2) |
| Non-industry | 93 (87) | 55 (38) |
| No funding | 10 (9) | 46 (32) |
| Meta-analysis author financial ties to industry (including employment), N (%)‡ | ||
| Not reported | 1 (1) | 11 (8) |
| No authors with reported financial ties | 70 (65) | 117 (81) |
| ≥1 author with reported financial ties | 36 (34) | 15 (10) |
| Proportion of authors with financial ties, mean±SD§ | 11%±17% | 4%±15% |
| Journal category, N (%) | ||
| Cochrane review | 107 (100) | 0 |
| Specialty medicine | 0 | 100 (70) |
| General medicine (non-Cochrane)¶ | 0 | 33 (23) |
| Multidisciplinary** | 0 | 10 (7) |
*One meta-analysis reported that they registered in PROSPERO but did not provide a registration number and one could not be found. We contacted the authors, and they did not provide us with further information; thus, this was coded as not registered.
†Only three included meta-analyses reported author–industry employment, and these were grouped with author–industry financial ties for this table.
‡Cochrane reviews typically have a ‘Sources of Support’ section with funding information. These reviews did not include that section.
§Proportion of authors with financial ties or employment of those that reported.
¶Of the 33 included general medicine journals, 28 were published in the journal ‘Medicine’.
**Of the 10 journals classified as multidisciplinary, nine were published in the journal ‘PLOS One’.
††Classifications for specialty medicine journals (note that some journals had more than one classification): anaesthesiology: n=3; biochemistry and molecular biology: n=1; biotechnology and applied microbiology: n=2; cardiac and cardiovascular systems: n=7; cell biology: n=1; chemistry, medicinal: n=4; chemistry, multidisciplinary: n=2; clinical neurology: n=6; critical care medicine: n=2; dermatology: n=3; emergency medicine: n=2; endocrinology and metabolism: n=2; gastroenterology and hepatology: n=6; genetics and heredity: n=1; haematology: n=2; immunology: n=6; infectious diseases: n=3; integrative and complementary medicine: n=1; medicine, research and experimental: n=3; microbiology: n=2; neurosciences: n=3; no classification: n=2; obstetrics and gynaecology: n=4; oncology: n=11; ophthalmology: n=3; orthopaedics: n=6; parasitology: n=1; peripheral vascular disease: n=5; pharmacology and pharmacy: n=13; physiology: n=1; psychiatry: n=4; psychology: n=1; reproductive biology: n=1; respiratory system: n=6; rheumatology: n=3; sport sciences: n=1; surgery: n=11; toxicology: n=2; tropical medicine: n=1; urology and nephrology: n=1.