There is an increasing push for physicians to practice “Evidence Based Medicine”. However, the “evidence” is getting harder and harder to come by. The creation of “Guidelines” by expert bodies may be of little help. There are simply too many of them.
Alvin Feinstein, MD (1925-2001) and David Sackett, MD (1934-2015) began to consider how evidence might be applied to clinical decision-making (Clinical Judgment) in the late 1960’s and early 1980’s, respectively. One of Sackett’s students introduced the term EBM to the medical profession in the 1990’s. Sackett graduated from the University of Illinois Medical School and practiced of Internal Medicine and Clinical Epidemiology at McMaster University in Hamilton, Ontario.
In the 1970’s, the randomized clinical trial (RCT) came into favor as the preferred way to determine the efficacy of treatments. Since then the types of papers published have changed markedly. No longer do we have many case reports, small studies or “reviews of the literature”. Most medical publications are now replete with RCTs of various size and complexity. The number of papers published in biomedicine has increased by 5-6 times from the approximately 50,000 a year in 1970. Keeping this published information straight has become harder and harder, some might say almost impossible. Sometimes a series of RCTs or observational studies are combined into a “Meta Analysis”. One might say that a MA is simply a more structured “review of the literature”, with a somewhat stronger mathematical bent.
Until the 1970’s, guidelines rarely existed. Some documents proposed schemes to help with diagnosis. These were initially the work of a single expert clinician[i]. Today guidelines are frequently produced to help clinicians in the care of chronic diseases[ii] or for the use in imaging and diagnostic testing[iii].
One of the very first sets of standards for provision of one form of patient care was the “Standards for cardiopulmonary resuscitation (CPR) and emergency cardiac care (ECC)”, published in 1974[iv]. In the next edition[v] the guidelines were specifically designated NOT be a legal document and were NOT to be construed as evidence in legal proceedings.[vi]
Dr. Sackett always regarded the evidence base as one of several components of patient care. He once said that EBM had “… three arms: very good evidence, seen by a very good clinician and integrated with patients’ expectations.”[vii]
A review of data at the National Guideline Clearing House (NGCH), a service of the Agency for Health Care Research and Quality, revealed over 2,400 unique guidelines sets (GS). There are 111 unique agencies that participated in the development of more than 5 GS each. There is frequently significant overlap with several organizations collaborating on several sets of guidelines. The table shows that there are MANY sets of guidelines for 7 chronic cardiac conditions. It also illustrates how rapidly the guideline numbers are being changed:
Table: Some Cardiac Conditions with Guidelines at NGCH
Number of Guidelines
September ‘15 October ‘15 November ‘15
Hypertension 442 468 486
Heart Failure 369 515 517
Myocardial Infarction 201 230 230
Peripheral vascular disease 151 151 188
Atrial Fibrillation 108 108 129
Angina 78 78 86
Aortic Aneurysm 53 53 59
It may strain one’s sense of credibility to imagine that any single physician would be able to evaluate 442 sets of guidelines for the evaluation and management of hypertension, or for any heart failure clinic to have evaluated and combined the recommendations of 369 sets of guidelines for heart failure.
Looking at Heart Failure alone, I found 486 sets of guidelines that relate to heart failure. Of those 113 have been published or revised since 2000. Of those 113, 30 are primarily related to diagnosis or treatment of Heart Failure or CHF. The remainder has statements regarding the place that the presence of heart failure may modify the recommendations in that set of guidelines.
The American College of Radiology leads the list of GS, having collaborated in creation of 239 sets. The National Institute for Health and Care Excellence (NICE) in Great Britain was the next most prolific organization publishing 211 sets. One hospital has developed 112 GS, which they called “best evidence statement” or BEST.
In an effort to be thorough, medical organizations and societies may have actually complicated the job of the clinician in his/her quest to remain up to date on what is “the most appropriate” strategy for diagnosis and treatment.
This leads to the question, “Why is this guideline group promulgating this set of guidelines?” It would appear that at least some groups are trying to give a “distinctive voice” to a unique subset of stakeholders in any specific clinical condition.
What are we to do with this “Tower of Babel” of guidelines?
The clinical system or clinician, who might want to use summaries of available evidence to help with clinical judgment, would be well served to ask if each source of available guidelines is relatively unbiased, and associated with a nationally recognized leader in the field[viii]. Governmental sources are frequently relatively unbiased[ix]. National Medical Associations[x] are generally considered reputable organizations with minimal biases. Recommendations published in the journals sponsored by them should be well rounded.. Finally, another filter to help find reliable guidelines would be where they are published. Guidelines published in well-recognized journals with as good a rigorous peer review process as possible are more likely to be reliable. Whether a provider group should accept a published series of guidelines or try to synthesize an analysis of others may be up to the group. However, in spite of the best intentions of the guideline writing groups, payers, lawyers and quality review organizations most often refer to a published set of guidelines. This makes trying to create an individual set of guidelines often counterproductive.
[i] The Jones’ Criteria for Diagnosis of Rheumatic Fever published in 1944 is one example – the problem with these often is that there was no “gold standard”
[ii] Hypertension, Heart Failure, Diabetes, Asthma are some conditions for which guidelines may be necessary.
[iii] ACC – Appropriate Use Criteria – the first set of AUCs appeared in 2005
[iv] JAMA, 1974, 227 Suppl: 833-868
[v] JAMA,1980, 244, 453-509
[vi] ibid p 505.
[vii] J of Undergraduate Life sciences; 2010, 45, 66-67
[viii] In cardiovascular disease some relatively unbiased sources might include the American College of Cardiology, American Heart Association, and the European Society of Cardiology
[ix] United States Public Health Service (USPHS), the National Institute for Health and Care Excellence (NICE) in the United Kingdom are examples
[x] British Medical Association, American Medical Association, Massachusetts Medical Society among others