Should physicians adhere to ACC/AHA guidelines? In response to a February report in JAMA by Pierluigi Tricoci, Robert Califf, and Sidney Smith (which we wrote about here) discussing an explosion in ACC/AHA guideline recommendations despite the lack of a solid evidence base, letter writers in JAMA have continued the debate over the value of ACC/AHA guidelines. A major target of the letter writers is an editorial by Terrence Shaneyfelt and Robert Centor that accompanied the report and argued that “clinicians and policy makers must reject calls for adherence to guidelines. Physicians would be better off making clinical decisions based on valid primary data.”
Elliott Antman and Raymond Gibbons, past chairs of the ACC/AHA Task Force on Practice Guidelines, are especially critical of the editorial. They note that “although an average of 50% of recommendations in ACC/AHA guidelines are based on evidence level C (expert consensus), the conclusion by Shaneyfelt and Centor that all of these recommendations reflect subjective bias was not justified. Many recommendations are based on sound clinical judgment that will never be tested in a clinical trial (eg, obtaining a 12-lead electrocardiogram in a patient presenting to the emergency department with chest pain).”
Antman and Gibbons point out that “the final recommendations reflect the input from extensive peer review and are not simply the opinion of the writing committee members.” They go on to say that “relationships with industry are submitted by every writing committee member and reviewer and are published with each document. It is current policy that the chair of a writing committee must be free of any relevant relationships with industry. Members are recused from voting on any recommendation for which they have a relationship with industry.” Along with several other letter writers, they argue that “when clinicians practice in accordance with guidelines, patient outcomes can be improved.”
Along similar lines, Mark D. Huffman and Robert Bonow write that the CRUSADE and OPTIMIZE registries “have demonstrated that increased adherence to clinical practice guidelines is associated with improved in-hospital and follow-up morbidity and mortality.”
Responding to the letters, Tricoci, Califf, and Smith take a middle line, writing that “it is our conclusion that the need for recommendations is increasing at a rate much greater than the available evidence base.” They write that they agree with Antman and Gibbons that “the results of our analysis should not lead to a call for rejecting guidelines, but rather to expanding the evidence based foundation from which guidelines are derived.”
They write: “we hope that such critiques of the guidelines process will not detract from our main finding: the ability of the clinical research system to generate critical evidence is seriously inadequate. When adequate evidence is not available, there is no guideline process that can make up for the missing knowledge.”
Defending their editorial, Shaneyfelt and Centor write that they “object to calling recommendations guidelines unless they meet rigorous standards. Expert opinions are important but should be labeled expert opinions rather than guidelines. The presence of fewer guidelines might actually have a greater effect on health care than the current explosion of guidelines.”
Responding to Antman and Gibbons, they note that “what is considered sound clinical judgment changes over time. Not long ago experts recommended against using beta-blockers in patients with heart failure and recommended suppressing premature ventricular contractions after myocardial infarction. Expert opinion should not be labeled as a guideline because of the implied importance that term carries; it should be called a consensus statement.”
Here is the JAMA press release:
Guidelines For Treating Patients With Cardiovascular Disease Often Based on Weaker Evidence
CHICAGO—An examination of clinical practice guidelines for treating cardiovascular disease finds that current recommendations are largely based on lower levels of evidence or expert opinion, according to a study in the February 25 issue of JAMA.
Clinical practice guidelines are developed to assist practitioners with decisions about appropriate health care for specific patients’ circumstances, and are often assumed to be the standard of evidence-based medicine, according to background information in the article.
For more than 20 years, the American College of Cardiology (ACC) and the American Heart Association (AHA) have released clinical practice guidelines to provide recommendations on care of patients with cardiovascular disease. The ACC/AHA guidelines currently use a grading scheme based on level of evidence and class of recommendation. The level of evidence classification combines an objective description of the existence and the types of studies supporting the recommendation and expert consensus, and are categorized as A (higher level of evidence), B, or C [lower level of evidence).
The class of recommendation designation indicates the strength of a recommendation and requires guideline writers not only to make a judgment about the relative strengths and weaknesses of the study data but also to make a value judgment about the relative importance of the risks and benefits identified by the evidence. Classes include I (evidence that a treatment or procedure is effective), II, IIa, IIb and III (evidence that a treatment or procedure is not effective).
Whether the increase in publication of studies concerning cardiovascular disease has resulted in guideline recommendations with more certainty and supporting evidence is not known. Pierluigi Tricoci, M.D., M.H.S., Ph.D., of Duke University, Durham, N.C., and colleagues examined the changes in recommendations in ACC/AHA cardiovascular guidelines and evaluated the adequacy of evidence behind current guideline recommendations. The analysis included data from ACC/AHA practice guidelines issued from 1984 to September 2008. Fifty-three guidelines on 22 topics, including a total of 7,196 recommendations, were examined.
Considering only the current guidelines with at least 1 revision, the total number of recommendations has increased from 1,330 to 1,973 (48 percent increase) from the first guideline to the current version. Overall, the guidelines shifted to more class II recommendations and fewer class III recommendations, while the use of class I recommendations remained fairly constant over time. The 16 current guidelines reporting levels of evidence, comprising a total of 2,711 recommendations, classify 314 recommendations as level of evidence A (median [midpoint], 11 percent), and 1,246 with level of evidence C (median, 48 percent).
Among all 1,305 class I recommendations of guidelines reporting level of evidence, only 245 have level of evidence A (median, 19 percent), with 481 (median, 36 percent) having a level of evidence C. Level of evidence significantly varies across categories of guidelines (disease, intervention, or diagnostic) and across individual guidelines.
“Our finding that a large proportion of recommendations in ACC/AHA guidelines are based on lower levels of evidence or expert opinion highlights deficiencies in the sources of definitive data available for the generation of cardiovascular guidelines. To remedy this problem, the medical research community needs to streamline clinical trials, focus on areas of deficient evidence, and expand funding for clinical research. In addition, the process of developing guidelines needs to be improved with information about the impact that recommendations based on lower levels of evidence has on clinical practice. Finally, clinicians need to exercise caution when considering recommendations not supported by solid evidence,” the authors conclude.
(JAMA. 2009;301[8]:831-841.
Filed under: Uncategorized
===========================================================
Don’t lose touch with CardioBrief. Click here to sign up for a daily email newsletter.
===========================================================
Filed under: Uncategorized
