Cochrane: industry-sponsored studies reach favourable results more often, and the usual bias checks do not explain it
Across 75 papers, "Industry sponsored studies more often had favorable efficacy results, RR: 1.27 (95% CI: 1.17 to 1.37)" and conclusions, RR 1.34: "an industry bias that cannot be explained by standard 'Risk of bias' assessments".
Reasonable evidence with real limitations. how we score evidence
Caveat on this rating: Quality of evidence is graded moderate for efficacy results and low for conclusions by the review itself; the harms comparison rests on four papers and is very low quality. A methodological review of comparisons, not of any single drug.
The most cited answer to "does it matter who paid for the study" is a Cochrane review of the studies that measured exactly that.
Significant findings
Lundh and colleagues (Cochrane Database of Systematic Reviews, 2017) updated their review of empirical studies comparing industry-sponsored drug and device research with research sponsored by others: "Twenty-seven new papers were included in this update and in total the review contains 75 included papers."
"Industry sponsored studies more often had favorable efficacy results, RR: 1.27 (95% CI: 1.17 to 1.37) (25 papers) (moderate quality evidence), similar harms results RR: 1.37 (95% CI: 0.64 to 2.93) (four papers) (very low quality evidence) and more often favorable conclusions RR: 1.34 (95% CI: 1.19 to 1.51) (29 papers) (low quality evidence) compared with non-industry sponsored studies."
The part that surprises people: "Comparing industry and non-industry sponsored studies, we did not find a difference in risk of bias from sequence generation, allocation concealment, follow-up and selective outcome reporting. However, industry sponsored studies more often had low risk of bias from blinding, RR: 1.25 (95% CI: 1.05 to 1.50) (13 papers)". And: "In industry sponsored studies, there was less agreement between the results and the conclusions than in non-industry sponsored studies, RR: 0.83 (95% CI: 0.70 to 0.98) (six papers)."
The conclusion: "Sponsorship of drug and device studies by the manufacturing company leads to more favorable efficacy results and conclusions than sponsorship by other sources. Our analyses suggest the existence of an industry bias that cannot be explained by standard 'Risk of bias' assessments."
Worth asking
Industry trials are not sloppier; on blinding they are better. The bias shows up in what gets asked, compared against and concluded, which is why a funding line matters even when a trial's methods look clean. That is the reason every study record in this library carries a funding entry, and why it says unknown when the statement could not be read. The review's own authors disclose that some of them wrote the earlier reviews it includes.
Source
Industry sponsorship and research outcome — Lundh A, Lexchin J, Mintzes B, Schroll JB, Bero L (2017)
Top-tier peer-reviewed journal
Read the source: https://doi.org/10.1002/14651858.MR000033.pub3
DOI: 10.1002/14651858.MR000033.pub3
How this was scored
- Study design
- Systematic review of observational studies
- Funding
- Funding not disclosed
- Published in
- Top-tier peer-reviewed journal
- Sample size
- not recorded
- Preregistered
- not recorded
- Conflicts disclosed
- Yes
- Independent of proponent
- not recorded
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published September 21, 2026.
Questions
How strong is the evidence behind this?
veisund rates this source "moderate evidence". Reasonable evidence with real limitations. It scores 59 out of 100 on our published rubric. One caveat travels with that badge: Quality of evidence is graded moderate for efficacy results and low for conclusions by the review itself; the harms comparison rests on four papers and is very low quality. A methodological review of comparisons, not of any single drug. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Industry sponsorship and research outcome — Lundh A, Lexchin J, Mintzes B, Schroll JB, Bero L (2017). Published in: Top-tier peer-reviewed journal. DOI: 10.1002/14651858.MR000033.pub3. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Systematic review of observational studies. Funding: Funding not disclosed. Independence from the proponent is not recorded. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.