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Disclosure of financial competing interests in randomised controlled trials: cross sectional review

BMJ 2003; 326 doi: (Published 08 March 2003) Cite this as: BMJ 2003;326:526
  1. Cary P Gross, assistant professor (cary.gross{at},
  2. Anu R Gupta, clinical scholarb,
  3. Harlan M Krumholz, associate professor of medicinec
  1. a Section of General Internal Medicine, Department of Medicine,Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
  2. b Robert Wood Johnson Clinical Scholars Program, Yale University School of Medicine
  3. c Section of Cardiovascular Medicine, Department of Medicine, Yale University School of Medicine
  1. Correspondence to: C P Gross
  • Accepted 14 December 2002

Financial relationships among industry, investigators, and academic institutions are growing increasingly complex, raising concerns about sponsors' considerable and perhaps inappropriate involvement in the conduct and reporting of biomedical research. 1 2 Medical journals use disclosure as a primary mechanism for managing these conflicts, and many have adopted the 1997 uniform requirements for manuscripts submitted to biomedical journals to guide this process.3

According to the 1997 uniform requirements, authors are asked to “acknowledge in the manuscript all financial support for their work.”3 For industry support for specific projects, authors are asked to describe the sponsor's role in the design, analysis, and reporting of the study data.3 If there has been no such involvement, the manuscript is expected to explicitly state this fact.3

Previous work has shown that many published papers do not contain statements of financial competing interests.4 However, little is known about journals' adherence to other parts of the disclosure guidelines or about the nature of the interests that are being disclosed. We performed a cross sectional explicit review of published randomised controlled trials in five high impact medical journals to assess adherence to all the 1997 disclosure requirements and to document the specific nature of the disclosed interests.

Methods and results

All randomised controlled trials published in each issue of the Annals of Internal Medicine, the BMJ, JAMA, the Lancet, and the New England Journal of Medicine from 1 April 1999 to 31 March 2000 were identified. We focused on randomised controlled trials as they often have great impact on clinical medicine. Trials were excluded if they were follow up analyses of a previously published study. An abstractor used an explicit abstraction to record source(s) of study support, author-sponsor relationships, and the role of study sponsor. Disclosed author-sponsor relationships were coded as follows: advisory board, consultant/honoraria, educational activities/speakers bureau, employment, grants, patent/licences, and stock. Study authors who had an industry address were categorised as employees.

We identified 268 trials: 16 (6%) in the Annals of Internal Medicine, 47 (18%) in the BMJ, 46 (17%) in JAMA, 93 (35%) in the Lancet, and 66 (25%) in the New England Journal of Medicine. Of these, 238 (89%) disclosed the source of study support (table).

Compliance with requirement for disclosure of financial competing interests in randomised trials published April 1999 to March 2000

View this table:

The nature of the relationship between the authors and the study sponsor was included in 69 of the 100 industry sponsored studies (table). In the manuscripts that provided this information, the most commonly cited relationships were: employment (30/69, 43%); consultant/honorarium (22, 32%); grants (18, 26%); and stock ownership and participation in a speaker's bureau (7, 10% each). The 30 manuscripts that were coauthored by employees of the industry sponsor represented 30% of published industry-sponsored studies and 11% of all randomised controlled trials in our sample.

Only eight of the 100 industry sponsored studies reported the role of the study sponsor in the methods section, as recommended by the uniform requirements. Of these studies, two manuscripts explicitly stated that the sponsor had no role in the study and six described the sponsor's role. Further analysis of these six studies found that the degree of sponsor involvement was highly variable and was usually described with vague wording. For instance, the sponsor's role in data analysis was described in terms ranging from “preliminary evaluation” to “coordinating data collection and statistical analysis.”


Although industry involvement in published randomised controlled trials was substantial, the true extent and nature of financial relationships between investigators and industry is difficult to assess because of variable adherence to the disclosure guidelines. Recently, editors of prominent medical journals have moved beyond disclosure as a mechanism for managing competing interests. Editors will ask authors to document that they had access to the data and were able to make publication decisions independently.5 Poor adherence to the existing uniform requirements raises the question of the degree to which journals adhere to these more stringent requirements.


Contributors: CPG was principal investigator and is guarantor. He designed the study along with ARG and HMK. Study data were abstracted by CPG and ARG. All authors collaborated on interpretation of the data and writing the manuscript.


  • Funding No external funding.

  • Competing interests None declared.


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