Conflicts of Interest are Prevalent Among Writers, Reviewers of Cardiovascular Clinical Practice Guidelines

An analysis of recent clinical practice guidelines for cardiology finds that of nearly 500 individuals involved in the development of these guidelines, more than half reported a conflict of interest, according to a report in the March 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.1

“Clinical practice guidelines (CPGs) have become a fixture in clinical medicine. Though individual clinical trials have meaningful impacts on patient care, CPGs are often adopted as the standard of care and taught as such in training programs at all levels. CPGs also play a prominent role in quality improvement initiatives,” according to background information in the article. “Although conflicts of interest (COIs) are found in all spheres of medicine, their role in the formation of CPGs may be especially significant. Improper bias in the CPG production process can have a potentially more widespread adverse effect on patient care than individual practitioners’ COIs.” The extent of COIs in cardiology guideline production has not been well studied.

Todd B. Mendelson, M.D., M.B.E., of the University of Pennsylvania, Philadelphia, and colleagues examined the 17 most recent American College of Cardiology/American Heart Association guidelines through 2008. Using disclosure lists, the researchers cataloged COIs for each participant as receiving a research grant, being on a speaker's bureau and/or receiving honoraria, owning stock, or being a consultant or member of an advisory board. The researchers also cataloged the companies and institutions reported in each disclosure. "Episode" describes one instance of participation in one guideline by one person. "Individual" describes one person who may be involved in multiple episodes. "Company" describes a commercial or industry affiliation reported by an individual in a single episode.

In the 17 guidelines, the researchers found 651 episodes of participation by 498 individuals. On average, each individual participated in 1.31 episodes. A total of 277 of the 498 individuals (56 percent) reported a COI. Over half of the episodes (365 of 651 [56 percent]) involved a COI. The most common form of COI was consultant/advisory board, followed by research grant, honoraria/speakers' bureau, and stock/other ownership. The percentage of episodes involving a COI ranged widely across guidelines, from 13 percent (2 of 15 episodes) to 87 percent (13 of 15 episodes).

“Role as guideline committee member (vs. peer reviewer) was associated with COI (63 percent vs. 51 percent), as was role as chair/co-chair/first author (81 percent vs. 55 percent). Only 105 of the 498 individuals (21 percent) were involved in two or more guidelines. The percentage of individuals reporting a COI was higher among individuals with more episodes of participation, and the number of episodes of participation was associated with both presence of COIs and number of COIs,” the authors write.

There were 510 commercial companies involved in the 17 guidelines, with a wide range in the number of companies reported to be involved in different guidelines (average, 38 companies; range, 2-242 companies). In contrast, there were only 18 noncommercial organizations reported to be involved in COIs. The researchers identified the commercial company involved in the greatest number of COIs in each guideline. One specific company was reported by more individuals than any other company in seven of the 17 guidelines.

“Our finding that most episodes of guidelines participation involve COIs, and that most individuals involved in producing guidelines report COIs, is a cause for concern. These findings are a particular cause for concern given the fact that many of the newest ACC/AHA guideline recommendations are based more on expert opinion than on clinical trial data. However, our findings of the average number of companies (38) and the range of numbers of companies (2-242) reported per guideline are perhaps less salient than the finding that a few companies were most reported in multiple different guidelines, and that one company was most reported in seven of 17 guidelines,” the authors write.

“In conclusion, CPGs play an increasingly influential role in the practice of medicine. COIs are prevalent but vary widely in recent ACC/AHA guidelines. Individuals with greater involvement in CPGs reported more COIs. Although restricting participation may prevent some qualified individuals from serving in the guidelines production process, we found that a large percentage of individuals with guidelines experience reported no disclosures, suggesting there is a substantial pool of potential guideline writers and reviewers without COIs.”

In an accompanying invited commentary, Steven E. Nissen, M.D., of The Cleveland Clinic Foundation, writes that the findings of this study “raise disturbing questions about the independence and reliability of CPGs in cardiovascular medicine.”2

“Why have professional societies allowed such extraordinary levels of commercial influence to infiltrate CPG committees? Professional societies and their leadership are often plagued by the same commercial relationships as the CPG-writing committees. Pharmaceutical and medical device companies provide large amounts of the financial support for the education and advocacy efforts of professional societies. Such relationships have created a dependency that is difficult to terminate because the leadership of professional societies is reluctant to antagonize their financial benefactors. The extent to which such financial ties bias the selection of CPG chairs and writers is unknown, but it certainly raises appropriate concerns. The revelations reported in the current article highlight troubling concerns that must be urgently addressed. If we fail as a profession to police our CPG process, the credibility of evidence-based medicine will suffer irreparable harm.”


1. Arch Intern Med. 2011;171[6]:577-584.

(Arch Intern Med. 2011;171[6]:584-585.