Relationship between conflicts of interest and research results


CONTEXT: To date, research regarding the influence of conflicts of interest on the presentation of findings by researchers has been limited.

OBJECTIVE: To evaluate the sources of funding for published manuscripts, and association between reported findings and conflicts of interest.

METHODS: Data from both print and electronic issues of The New England Journal of Medicine (NEJM) and The Journal of the American Medical Association (JAMA) were analyzed for sources of funding, areas of investigation, conflict of interest (COI), and presentation of results. We reviewed all original manuscripts published during the year 2001 within NEJM (N=193) and JAMA (N=205). We use 3 definitions for COI in this paper: a broadly defined criterion, the criterion used by The International Council of Medical Journal Editors (ICMJE), and a criterion defined by the authors.

RESULTS: Depending on the COI criteria used, 16.6% to 32.6% of manuscripts had 1 or more author with COI. Based on ICMJE criterion, 38.7% of studies investigating drug treatments had authors with COI. We observed a strong association between those studies whose authors had COI and reported positive findings (P < .001). When controlling for sample size. study design, and country of primary authors, we observed a strong association between positive results and COI (ICMJE definition) among all treatment studies (adjusted odds ratio [OR], 2.35; 95% confidence interval [CI], 1.08 to 5.09) and drug studies alone (OR, 2.64; 95% CI, 1.09 to 6.39).

CONCLUSION: COI is widespread among the authors of published manuscripts and these authors are more likely to present positive findings.

This is a preview of subscription content, log in to check access.


  1. 1.

    Rochon PA, Gurwitz JH, Simms RW, et al. A study of manufacturer-supported trials of nonsteroidal anti-inflammatory drugs in the treatment of arthritis. Arch Intern Med. 1994;154:157–63.

    PubMed  Article  CAS  Google Scholar 

  2. 2.

    Davidson RA. Source of funding and outcome of clinical trials. J Gen Intern Med. 1986;1:155–8.

    PubMed  Article  CAS  Google Scholar 

  3. 3.

    Yaphe J, Edman R, Knishkowy B, Herman J. The association between funding by commercial interests and study outcome in randomized controlled drug trials. Fam Pract. 2001;18:565–8.

    PubMed  Article  CAS  Google Scholar 

  4. 4.

    Friedberg M, Saffran B, Stinson TJ, Nelson W, Bennet CL. Evaluation of conflict of interest in economic analyses of new drugs in oncology. JAMA. 1999;282:1453–7.

    PubMed  Article  CAS  Google Scholar 

  5. 5.

    Clifford TJ, Barrowman NJ, Moher D. Funding source, trial outcome and reporting quality: are they related? Results of a pilot study. BMC Health Serv Res. 2002;2:18.

    PubMed  Article  Google Scholar 

  6. 6.

    ISI Journal Citation Report 2000. Available at: Accessed February 5, 2002.

  7. 7.

    N Engl J Med. 2001:344–345: 1–1978 and 1–1882.

  8. 8.

    J Am Med Assoc. 2001;285–286:1–3129 and 1–3119.

  9. 9.

    Abramson JH. Survey Methods in Community Medicine, 4th edn. Churchill Livingstone;1990:ch. 2.

  10. 10.

    International Committee of Medical Journal Editors. Uniform requirements for manuscripts submitted to biomedical journals. Updated October 2001.

  11. 11.

    Drug Monitor, IMS Health Global Services. 2002. Available at: Accessed July 17, 2002.

  12. 12.

    Holden C. NEJM admits breaking its own tough rules. Science. 2000;287:1573.

    PubMed  Article  CAS  Google Scholar 

  13. 13.

    Thompson DF. Understanding financial conflicts of interest. NEJM. 1993;329:573–6.

    PubMed  Article  CAS  Google Scholar 

  14. 14.

    Stelfox HT, Chua G, O’Rourke K, Detsky A. Conflict of interest in the debate over calcium-channel antagonists. NEJM. 1998;338:101–6.

    PubMed  Article  CAS  Google Scholar 

  15. 15.

    Kahn JO, Cherng DW, Mayer K, Murray H, Lagakos S. Evaluation of HIV-1 Immunogen, an immunologic modifier, administered to patients infected with HIV having 300–549, X106/L CD4 counts: a randomized controlled trial. JAMA 2000;284:2193–202.

    PubMed  Article  CAS  Google Scholar 

  16. 16.

    Dickersin K, Min Y, Meinert CL. Factors influencing publication of research results. JAMA. 1992;267:374–8.

    PubMed  Article  CAS  Google Scholar 

  17. 17.

    Schulman K, Sulmasy DP, Roney D. Ethics, economics and the publication policies of major medical journals. JAMA. 1994;272:154–6.

    PubMed  Article  CAS  Google Scholar 

  18. 18.

    Task Force on Financial Conflicts of Interest in Clinical Research. Protecting Subjects, Preserving Trust, Promoting Progress—Policy and Guidelines for the Oversight of Individual Financial Interests in Human Subjects Research. Association of American Medical Colleges; 2001.

  19. 19.

    Boyd EA, Bero LA. Assessing faculty financial relationships with industry. JAMA. 2000;284:2209–14.

    PubMed  Article  CAS  Google Scholar 

  20. 20.

    Korn D. Conflicts of interest in biomedical research. JAMA. 2000;285:2234–6.

    Article  Google Scholar 

  21. 21.

    Temptation to fudge scientific findings. The Virginian-Pilot and The Ledger-Star, Norfolk, Va. November 12, 2000.

  22. 22.

    Deangelis CD. Conflict of interest and the public trust. JAMA. 2000;284:2237–8.

    PubMed  Article  CAS  Google Scholar 

  23. 23.

    Friedman Ross L. Correspondence to editor in reply to “Is Academic Medicine for Sale?” NEJM. 2000;342:508.

    Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Dr. Lee S. Friedman BA.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Friedman, L.S., Richter, E.D. Relationship between conflicts of interest and research results. J GEN INTERN MED 19, 51–56 (2004).

Download citation

Key words

  • conflict of interest
  • publication bias
  • biomedical ethics
  • funding
  • research