Table 3

Factors associated with reporting funding sources of included RCTs

Proportion that reported some or all declared funding sources from included RCTsUnadjusted OR (95% CI)Adjusted OR
(95% CI)
FCOI of meta-analysis (including meta-analysis funding)
Reference=no FCOI67/151 (44%)
Any disclosed FCOI35/51 (69%)2.74 (1.42 to 5.49)1.29 (0.53 to 3.19)
Not reported9/48 (19%)0.29 (0.12 to 0.62)1.18 (0.40 to 3.44)
 Impact factor and journal type
Reference=Cochrane90/107 (84%)
Specialty impact factor ≤3*4/65 (6%)0.01 (<0.01 to 0.03)0.01 (<0.01 to 0.04)
General (n=31) or multidisciplinary (n=10) impact factor ≤34/41 (10%)0.02 (<0.01 to 0.06)0.02 (<0.01 to 0.06)
Specialty impact factor 3.1–6.7†10/27 (37%)0.11 (0.04 to 0.28)0.11 (0.04 to 0.28)
Specialty (n=8) or general (n=2) impact factor >6.83/10 (30%)0.08 (0.02 to 0.32)0.08 (0.02 to 0.32)
  • *Two meta-analyses were from journals that did not have an impact factor, and these were coded as having an impact factor of 0.5 for our analyses.

  • †There were no multidisciplinary or general medicine journals with an impact factor of 3.1–6.7.

  • ‡Not reported included meta-analyses for which the presence of FCOI could not be determined because either meta-anlaysis funding, meta-analysis author FCOI or both were not reported.

  • .FCOI, financial conflicts of interest; RCT, randomised controlled trial.