A study published in the January issue of Mayo Clinic Proceedings shows that most clinical practice guidelines for interventional procedures (e.g., bronchoscopy, angioplasty) are based on lower-quality medical evidence and fail to disclose authors' conflicts of interest.

"Guidelines are meant to create a succinct roadmap for the diagnosis and treatment of medical conditions by analyzing and summarizing the increasingly abundant medical research," write Joseph Feuerstein, M.D., and colleagues from Beth Israel Deaconess Medical Center. "Guidelines are used as a means to establish a standard of care ... However, a guideline's validity is rooted in its development process."

In an accompanying editorial, Jayant Talwalkar, M.D., associate medical director of the Value Analysis Program in the Mayo Clinic Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, says that the study further illustrates that existing guidelines are highly variable with respect to evidence quality and transparency.

"Most of the current practice guidelines in circulation do not meet criteria that represent trustworthiness as defined by the Institute of Medicine," Dr. Talwalkar says.

Dr. Talwalkar also points out that more attention needs to be paid to potential conflicts of interest among guideline authors and guideline development panels.

"There is a growing body of literature documenting the existence of one or more potential conflicts of interest reported for authors or members of guideline development panels," he says. "As a result, the influence of external activities such as consulting or speaking fees, research grant funding and stock ownership has the potential to create significant bias and uncertainty for issued recommendations."

Dr. Talwalkar notes that up to 80 percent of recommendations from most guidelines are supported by evidence from non-randomized studies or expert consensus opinion, making conflict of interest disclosure crucial.

Dr. Talwalkar says that, in the future, the guideline-writing process must evolve to include more concise and up-to-date recommendations as well as more transparency about the management of potential conflicts of interest.