A Mysterious Illness

Blog entry posted by anciendaze, Jan 31, 2016.

The following is from a letter written to explain this illness to someone well-intentioned but misinformed. I've tried to avoid the heavy use of bibliographic references and other academic practices to concentrate on a limited number of objective measures intelligible to almost anyone. It turns out that PACE was a good source for such data, if you avoid their interpretations.

This is a draft rather than a finished document. Anyone who finds factual errors, or wishes to suggest improvements can send me a PM or email as anciendaze at gmail dot com.

ME/CFS is a peculiar illness that doesn't get much respect. (It is hard to spell myalgic encephalomyelitis, making "chronic fatigue syndrome" the most common term. Everyone thinks they know what fatigue means, even if their experience is quite different from anyone else's. Systemic Exertion Intolerance Disease (SEID) has failed to catch on, and there are already competing definitions of exercise intolerance in professional use.) Patients regularly end up diagnosed as subject to a mental illness, and I can testify that suffering years of effects and watching your life tank while being told there is nothing physically wrong can get you down. Secondary depression is common in many chronic illnesses, like MS or lupus, and quite different from the unknown cause of this condition.

Standard advice, not just from laymen, but from medical professionals, is that all you need is a positive attitude and exercise to recover. The problem with this is that an unusual physiological response to exercise is a hallmark of the disease. We now have replicated research showing that effects of a serious exercise challenge last more than a day, often several days. During this time capacity for aerobic exercise is reduced. This is simply not normal fatigue. I'm going to put this laboratory evidence to one side, however, and concentrate on research by those most strongly advocating the standard advice.

It happens that a large study with the name PACE in the U.K. set out to show this could be cured by the above suggestions, but demonstrated something quite different. Unfortunately, the authors of that study have yet to admit the results completely confounded their expectations.

(My own physical performance is better than the patients in this study, if you overlook problems with orthostatic intolerance or dysautonomia. This would likely have caused me to be excluded from the study. I'm not sure what medical category I would end up in, but would expect it to be a waste basket for unpromising cases. Been there. Ineffective treatment has lasted long enough to blame some current problems on old age. Much earlier, persistent aches were described as "growing pains". There are answers suitable for dismissing any symptom not connected with clinical signs.)

To dispense with the idea that the illness is trivial, or similar to what most people experience as fatigue, I will concentrate on one of two objective measures of physical performance published in that study. This simple test could be performed by almost anyone, it asks how far you can walk in 6 minutes.

Most people use a rule of thumb that healthy people can walk about 4 miles in an hour. This is roughly 6 km. Dividing 6,000 meters by 60 minutes yields 100 meters per minute. So, a healthy person, even at age 70, walking for 6 minutes should be capable of covering close to 600 meters. Those in this trial averaged between 320 and 380 meters, even the control group reached some 340 meters.

(Note: "control" in this case refers to CFS patients receiving only "specialist medical care", not healthy people. We still have no idea if "specialist medical care" has any value compared to no care at all. Gains by the control group could well have resulted entirely from test/retest familiarity.)

What other medical conditions reduce performance this much? Two I can name are congestive heart failure and chronic obstructive pulmonary disease. Nobody discounts either of these as trivial. In fact, if distance walked is less than 300 meters there is a strong increase in predicted mortality. Patients in the PACE study were just above this level of performance, and far below any reasonable value for health. If anyone tells you the people in this study were "only one standard deviation below the mean" you need to take a good look at how they got that number, since the same thing applies to patients with the two known serious conditions mentioned above.

(I'm well aware that even heart patients should be tested by something better than walking for 6-minutes to evaluate performance. Studies of VO2max show where aerobic metabolism departs from energy output, which would take us back to the laboratory measurements mentioned above. Such tests were not part of PACE, and other objective measures were simply dropped. I'm working with what the authors published.)

The hypothesis behind the suggested treatment was that these patients were merely deconditioned following a possible real illness, and held "false illness beliefs" which hindered exercise and recovery. One prescription for this was Cognitive-Behavioral Therapy (CBT).

Patients in one arm of the study received a year of CBT, and subjective measures based on questionnaires indicated their attitudes did change significantly. What effect did this have on physical performance? There was no significant difference between the CBT group and control group. One might think that this would dispose of the idea that "false illness beliefs" were the only thing holding patients back.

A second prescription was Graded Exercise Therapy (GET). Again, patients in one arm of the study received a year of GET. At the end of this time they walked a little farther. Those in the control group also walked farther, but this was not considered significant. How much did patients in the GET group improve? After a year they were still covering significantly less than 400 meters in 6 minutes. A separate "step-test" failed to show any difference in physical performance between arms of the study.

Patients with stage II congestive heart failure are said to cover at least more than 402 meters in 6 minutes, but those in the preferred GET group fell well below that threshold, still placing them with stage III congestive heart failure patients -- after therapy. This should not be counted as recovery by anyone's standards.

Long-term follow-up at three years showed no significant difference between patients in any arm of the study. You would never guess this based on the study's press releases.

There were real problems with some data said to show objective improvement as a result of therapy, 1/3 of those patients did not take the walk test both before and after therapy. If you assume including them would not reduce the group mean you are in effect assuming one conclusion of the study, which was to show that no one was worse as a result of therapy. Scientific research is much easier if you assume the conclusion you want.

There were other measures which appear -- on paper -- to show that patients could enter the study with an activity score of 65, drop to a score of 60, then be counted as recovered. Detailed data which would allow outsiders to see what actually happened has not been released, despite repeated requests by professionals. We don't know what those scores mean in relation to "recovery", but this is a side issue.

None of this detailed criticism is necessary to decide that the preferred therapies were not sufficiently effective to return patients to employment or reduce need for medical insurance outlays, whether by government or private insurers. The bottom line appears to be that patients with this diagnosis can be as seriously disabled as those with devastating chronic conditions, and will remain so for at least several years despite the recommended therapies. Please note that this study necessarily excluded all patients who were bedbound or housebound, and unable to participate. Such patients really do exist.

No opponent of these authors or patient advocate could have produced such convincing data on the complete ineffectiveness of those chosen therapies. Either CBT had no effect on "false illness beliefs", or correcting those beliefs had no effect on physical performance. That hypothesis was definitely falsified.

In the case of GET we might well assume that patients who declined to take the 6-minute walk test believed they had some reason to do so. This would automatically introduce a subjective bias into an objective performance measure which excluded those patients. In fact later analysis of the results by PACE authors themselves now attributes the marginal gain in performance to subjective effects. You still need considerable belief in GET to interpret a questionable gain of a few meters as clinically significant. In this respect this study resembles reports of Uri Geller mentally bending spoons, believers see something different from critics.

It is also possible to argue that results were negative because no patients in the study received both CBT and GET. This puts such a proponent in the peculiar position of basing recommendations for future treatment entirely on negative results from the study. Anyone who makes such assertions should at least be suspected of having a bias caused by material interest in the ineffective therapies, not patients' welfare.
anciendaze

About the Author

As the name suggests, I am old and dazed. The avatar illustrates my rule of thumb: "Hang on! This ride isn't over."
  1. anciendaze
  2. Marco
    All I would suggest is that you make it clear early on that the pathetic 6MWT results were recorded after 'rehabiltative' therapy and that the control group is not healthy controls but 'business as usual' patients.