I recently came across a journal article titled, “New developments in the diagnosis of fibromyalgia syndrome: Say goodbye to tender points?” Since there has been some debate over the past few years as to whether or not it was time to update the method by which fibromyalgia is diagnosed, I was excited, thinking that a new diagnostic tool had been developed. However, by the time I finished reading the article and researching its origins, I was not only disappointed – I was angry.
History of FM Diagnosis
In 1990, the American College of Rheumatology published classification criteria which identified 18 specific points on the body. Since then, people are diagnosed with fibromyalgia if they meet two criteria: 1) a history of widespread pain in all four quadrants of the body for a minimum duration of three months, and 2) pain in at least 11 of the 18 tender points when four kilograms of pressure is applied.
What is interesting, though, is that these criteria were originally developed as a research tool to ensure that all FM research studies used the same defined group of criteria so that results from different studies could be accurately compared. However, since this tool was able to distinguish fibromyalgia from other conditions with a sensitivity of 88.4% and a specificity of 81.1%, clinicians began using it in their practices to diagnose patients.
The ACR criteria put FM on the map and made it possible for FM research to make great strides in learning more about the illness and developing medications to treat it. But critics have argued that the criteria only addresses the pain of FM and fails to take into account two other symptoms that are almost always present – fatigue and sleep disorders. Figuring there is always room for improvement, I thought perhaps a new tool had been developed that would be able to diagnose FM with an even greater degree of accuracy. I was soon to be disappointed.
Symptom Intensity Scale
The new tool being promoted in this article by William S. Wilke, MD is the Symptom Intensity Scale. He claims that it can be used to establish the diagnosis of fibromyalgia and measure its severity. That sounded reasonable. But he further claims that it can also serve as a surrogate measure of depression, anxiety, personality disorders, previous or ongoing abuse and even possible obstructive sleep apnea. At that point, I was starting to feel a bit skeptical. That was a lot to expect from one simple scale. And the emphasis on mental/emotional problems concerned me.
Imagine my surprise a few pages later when I saw the actual Symptom Intensity Scale. There were two parts to it. The first part was a list of 19 areas of the body. The patient is instructed to indicate in which areas they had experineced pain in the past seven days. The second part was a line 10-centimeters long with “No fatigue” written on the left end and “Very fatigued” written on the right end of the line. The patient is told to mark a spot on the line indicating their level of fatigue. That's it – that's the entire scale. Apparently fibromyalgia is indicated if the patient marks eight or more pain areas and their fatigue mark is at least 6 centimeters from the left end.
Admittedly I'm not a scientist, but this scale seems far too simplistic to be an accurate diagnostic tool. Using this scale, someone who has had the flu for a week could be diagnosed with FM. Another big deficit is the lack of any way to screen for patients who may be hypochondriacal or who may, for whatever reason, want to receive a diagnoisis of fibromyalgia. In a properly performed tender point exam, the physician presses on spots other than just the 18 tender points so it is difficult for a patient to “fake it.” With the Symptom Intensity Scale, all a patient has to do is mark eight or more painful areas and place their mark about ¾ of the way across the fatigue line to be diagnosed with FM.
Something Smells Fishy
As I continued reading the journal article, the arguments put forth in favor of the Symptom Intensity Scale seemed weak at best. So I began doing some digging to find out more about this new tool. Lo and behold, what I found was that Dr. Frederick Wolfe was one of the developers of the Symptom Intensity Scale. For those of you who may not be familiar with Dr. Wolfe, he was among the group of rheumatologists who first established the 1990 ACR criteria for diagnosing FM. However, a short time later he changed his mind and seems to have made it one of his main goals in life to prove that fibromyalgia doesn't exist, or at least relegate it to a psychological problem.
In 2006 Dr. Wolfe did a study with the objective of using the Symptom Intensity Scale to characterize a scale for the measurement of “fibromyalgia-like” symptoms and to investigate whether FM is a discreet disorder. Not surprisingly, among the conclusions he stated, “We identified a clinical marker for general symptom intensification that applies in all patients and is independent of a diagnosis of FM. We found no clinical basis by which FM may be identified as a separate entity.” Maybe I'm crazy, but it seems to me that when you use such a generalized scale, you can't expect to identify a specific disease with any degree of accuracy.
Should the SIS Replace the ACR Criteria?
In my opinion, the Symptom Intensity Scale is simply an attempt to water down the significance of an FM diagnosis by making it less of a distinct entity. The scale may have some use in doing just what the name of it implies – rating the intensity of FM symptoms, but I don't think it has any value as a diagnostic tool. At the present time, the original ACR criteria is still the most accurate measure we have for diagnosing fibromyalgia.
Source: Wilke, William S. (2009, June). New developments in the diagnosis of fibromyalgia syndrome: Say goodbye to tender points?. Cleveland Clinic Journal of Medicine, Vol. 76, No. 6,
Published On: July 30, 2009