health plans, including Medicare, use evidence summarized in compendia as a basis for payment and coverage decisions.)
The committee also found a few assessments of the adequacy of disclosures in studies that have applied the standardized evaluation tool AGREE (Appraisal of Guidelines Research and Evaluation), which is further described below. One of the evaluation criteria (Item 23) is whether a guideline document includes information about participant conflicts of interest. Another criterion (Item 22) is whether the guideline is editorially independent from the funding source. Studies have found shortcomings in reporting on conflicts of interest by participants and editorial independence in a wide array of clinical practice guidelines, including guidelines on stroke rehabilitation (Hurdowar et al., 2007), occupational medicine (Cates et al., 2006), pediatrics (Boluyt et al., 2005), lung cancer (Harpole et al., 2003), low back pain (Arnau et al., 2006), and nonsteroidal anti-inflammatory drug and acetaminophen treatment of osteoarthritis of the hip or knee (Wegman et al., 2004). It is not clear whether a lack of disclosure was related to the policies of the group developing the guidelines (e.g., no policy on disclosure or disclosures were not revealed) or the policies of particular journals (e.g., no request for disclosure). A study of 191 guidelines published in six leading journals in 1979, 1984, 1989, 1994, and 1999 found reporting of conflicts of interest only in the most recent year (1999) and then for only 7 of the 40 guidelines and 18 authors for that year (Papanikolaou et al., 2001). Although all the disclosures were in journals that had disclosure policies, only 4 percent of the articles in those journals included disclosures.
The committee found no systematic studies that investigated the association between the funding source and the development process or the content of the clinical practice guidelines. As illustrated in Box 7-2, it did find cases that raised concerns about the influence of industry funding.
The committee also found no systematic studies of the relationship between participant financial relationships and the content of the guidelines.8 As described above, a study by Choudhry and colleagues (2002) found that
In a possibly relevant study of a different kind of panel, Lurie and colleagues (2006) examined the financial relationships and decisions reached in 221 meetings of 16 advisory committees of the Food and Drug Administration. They reported that in nearly three-quarters (73 percent) of the meetings at least one committee member had a financial link to the maker of a drug being considered by the committee or had a link to a competitor company. Overall, approximately one-quarter (28 percent) of the members reported conflicts. They concluded, “A weak relationship between certain types of conflicts and voting behaviors was detected, but excluding advisory committee members and voting consultants with conflicts would not have altered the overall vote outcome at any meeting studied” (p. 1921).