Conflict of Interest

Conflict of interest within the medical context occurs when a doctor’s ability to act in the best interest of the patient is influenced by an outside relationship with a person, group, or business. The conflict may be expressed at the individual or institutional level. The most common conflicts of interest arise when the potential for financial gain exists for the physician, which is often due to relationships with industry sponsors, or with personal ownership of testing facilities. The conflict may ultimately compromise the patient’s standard of care or bias research studies. Conflicts of interest should always be disclosed and attempts made to minimize bias.

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Conflict of interest within the medical context describes situations in which a doctor’s ability to act in the best interest of the patient is influenced by an outside relationship with a person, group, or business.

Underlying ethical principles

  • Trust: The physician, investigator, and/or institution is entrusted with a patient’s well-being; a conflict of interest violates trust by placing another party’s interests above the patient’s interests. 
  • Fidelity to the patient: the faithfulness of 1 person to another

How conflicts of interest arise

A conflict of interest most commonly arises in medicine when a physician has the potential for financial gain. The conflict can happen when the physician:

  • Has a relationship (either personally or professionally) with drug or medical-device companies:
    • Physicians may develop or invent new drugs or medical devices.
    • Physicians may invest in drug or biotechnology companies, or specific treatment facilities.
  • Owns the testing or treatment facility
  • Is involved in industry-sponsored research:
    • Research requires funding: The funding source can lead to bias within the study.
    • Research activities may impact a physician’s compensation either from their employer or from the industry sponsor.
    • Physicians may be compensated for enrolling patients into clinical trials, which may impact a patient’s willingness to enroll.

Examples of external influence

Many outside influences may constitute a conflict of interest, including the potential for:

  • Financial gain (most prevalent):
    • 43% of researchers have received gifts, discretionary funding, and/or consulting fees.
    • Almost 33% of researchers have personal financial ties with industry sponsors.
  • Professional recognition and promotion
  • Successful acquisition of research funding: 23%–28% of academic investigators have received funding from the industry.
  • Quest for knowledge (may occur at the expense of the patient)
  • Political implications (e.g., personal values, affiliation, political agenda)

Positions at risk of developing conflicts of interest

  • Physicians/individual researchers, especially with:
    • Long-standing relationships with pharmaceutical companies
    • Significant financial relationships with involved parties
  • People involved in clinical research
  • Journal editors and reviewers
  • University faculty members, trustees, and department chairs

Consequences of Conflicts of Interest

The consequences of conflicts of interest can have a significant impact on both patient care and research outcomes.

Medical care and medical education

  • Prescription of newer and/or more expensive drugs, equipment, or procedures with no clear advantage when compared to older/generic alternatives:
    • May be unintentional on the part of the physician and the result of a highly effective marketing/influencing activity on a subconscious level
  • Referral to specific testing or treatment centers owned by the physician (may not be the best option for the patient):
    • Studies show more tests are ordered when the physician or practice owns the lab or imaging equipment.
  • Biased training of medical students and residents


Conflicts of interest may result in:

  • Biased study results in favor of the sponsor’s product
  • Study designs favoring positive conclusions
  • Publication delays
  • Raw-data and interpretation manipulation:
    • Data deletion, withholding, and/or tweaking
    • Compromises in internal validity (e.g., unaccounted-for confounding factors, inadequate control of other variables)

Solutions, Disclosures, Limitations, and Funding

  • Limitations: The physician/investigator should limit ties to industry as much as possible:
    • Limits subconscious bias in prescribing/referring patterns
    • Researchers may associate with impartial institutions (e.g., universities or governmental agencies).
    • Preference can be given to funding from university or government grants over unrestricted industry donations.
  • Disclosures: The physician/investigator is obligated to report sponsors and/or financial ties:
    • Includes any presentations, courses, and/or manuscripts submitted for publication
    • Different journals have distinct policies regarding external ties (some reject work by authors with potentially conflicting interests).
    • Sources of funding must be disclosed prior to publication.
  • Importance: 
    • Gives readers/learners a lens to view the information and assess potential biases
    • All potential biases should be adequately addressed
    • All readers should ask if the information is presented by a paid spokesperson (more like an advertisement)


  1. Muth, C.C. (2017). Conflict of interest in medicine. JAMA. 2017;317(17):1812. Retrieved June 10, 2021, from
  2. Shmerling, R.H. (2018). Conflict of interest in medicine. Harvard Health Publishing. Retrieved June 10, 2021, from 
  3. MacKenzie, C. R., & Cronstein, B. N. (2006). Conflict of interest. HSS journal: the musculoskeletal journal of Hospital for Special Surgery, 2(2), 198–201.
  4. Celentano, D., Szklo, M. & Gordis, L. (2019). Gordis epidemiology. Philadelphia, PA: Elsevier.

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