From the International Academy of Hypothyroidism
A question often raised by patients is: Why doesnt my physician know about the inaccuracies and limitations of standard thyroid tests? The reason is that the overwhelming majority of physicians (endocrinologists, internists, family practitioners, rheumatologists, etc.) do not read medical journals. When asked, most doctors will claim that they routinely read medical journals, but this has been shown not to be the case. Many reasons exist, but it comes down to the fact that doctors do not have the time they are too busy running their practices. The overwhelming majority of physicians rely on what they have learned in medical school and on consensus statements by medical societies, such as the Endocrine Society, the American Association of Clinical Endocrinologists or the American Thyroid Association, to direct treatment decisions. Historically, relying on a consensus statement to treat or not to treat a particular patient has been shown to result in poor care and, as such, society consensus statements and practice guidelines are considered to be worst level of evidence in support of a particular therapy or treatment. A number of organizations, including the World Health Organization and others, have ranked the strength and accuracy of various types of evidence used in the medical decision process. In all scoring systems, the highest strength of evidence is randomized control trials and meta-analyses, with lower scores for other types of evidence. All grading systems place consensus statements and expert opinion by respected authorities (societies) as the poorest level of evidence, because historically they have failed to adopt new concepts and treatments based on new knowledge or new-found understanding demonstrated in the medical literature (1-6).
For instance, a recent study published in the 2009 Journal of American Medical Association studied the evidence supporting the practice guidelines and consensus statements published by the American College of Cardiology and the American Heart Association. It was found that only 11% of the recommendations, practice guidelines and consensus statements were based on quality evidence and over half were based on poor quality evidence that was little more than the panels opinion. The review also found that even the strongest (Class 1) recommendations, which are considered medical dogma, cited as a legal standards and often go unquestioned as medical fact, were only supported by high quality evidence 19% of the time and not revised based on new evidence (6).
Similarly, the Endocrine Society, the American Association of Clinical Endocrinologists and the American Thyroid Association also have a long history of guidelines and recommendations that are not supported by the medical literature and fail to adjust or abandon recommendations when new understanding and knowledge contradicts their recommendations. A case in point is the recommendation by these societies that a normal TSH adequately rules out thyroid dysfunction, despite massive amounts of literature that demonstrate this not to be the case (see Diagnosis of Hypothyroidism) or that T4 only replacement is adequate for most patients. A doctor who simply follows outdated society treatment guidelines that relies on a simple laboratory test and ignores the clinical aspects of a patient is not practicing evidence-based medicine. (1-7). Such doctors may be adequate as lab technicians, but as doctors and clinicians they fall short (1-7). This method of practice is consistently rebuked as improper and poor medicine, but has become the standard used by a large percentage of endocrinologists and physicians who feel medicine can be related to simply reading normal or abnormal in a laboratory column.
Discussing the lack of scientific basis of most medical societys consensus statements and treatment guidelines in Internal Medicine News, Dr. Diana Petritti, states, Expert opinion and consensus statements can be quite misleading when used as the basis for a practice. Expert opinions imply that there is something that the experts know that clinician doesnt know. I dont think its always appreciated that its only opinion. There is a tendency to make guidelines and recommendations seem authoritative. I believe that physicians think that there is a great deal more behind authoritative recommendations than there might be when you lift the lid of the box and see whats underneath(8).