Science for ME are pleased to announce that we have today submitted another critique to the NIH/CDC review (following our earlier submission on the Chalder Fatigue Scale). All credit for this submission should go to the authors, and we are very grateful for all their hard work. The post below, written by the authors, summarises their submission. The full paper and a PDF containing the results of their related poll, are attached. -------------------------------------------------------------------------------- Submission to the public review on Common Data Elements for ME/CFS: Concerns with the proposed measure of post-exertional malaise A Science for ME working group of research-oriented patients, including Simon McGrath, Carly Maryhew, Graham McPhee and Sean Kirby, have submitted a paper (see attached) to the NIH/CDC’s consultation on its plans for common data elements (CDEs). The summary is as follows: Summary: Post-exertional malaise (PEM) is the cardinal symptom of ME/CFS. The accurate identification of PEM therefore underpins good ME/CFS research, especially that which is aimed at discovering the biology behind the disease. The NIH/CDC PEM Subgroup has recommended using the PEM subscale of the DePaul Symptom Questionnaire (DSQ) as the primary basis of a core common data element (CDE) to identify PEM in all of the studies that they fund from now on. This subscale has many desirable qualities, but we have concerns about its selection as it was not developed as a standalone, PEM-specific scale. In particular, there is a mismatch between the DSQ PEM subscale and the Subgroup’s own definition of PEM. Also, there are questions about what the DSQ PEM subscale actually measures, both from research evidence and our poll, which found that two thirds of more than 750 patients said that the DSQ subscale description of PEM did not broadly reflect their own experience. We believe that the Subgroup’s primary recommendation should be that the NIH/CDC fund the urgent development of a new, validated scale designed specifically to ascertain PEM, developed in partnership with patients. We discuss a potential interim strategy while such a scale is being created. Our additional recommendations were: (1) to determine whether a patient has PEM on the basis of their propensity for it, not just on how intensely and how often they experience it (which can be affected by pacing); (2) to develop the new PEM scale in true partnership with patients, starting with open-ended interviews about PEM, and then allowing patients to submit their own potential questionnaire items and to give their opinions on any proposed items, and to keep consulting until patients consider that the resulting questionnaire truly reflects PEM; (3) while waiting for a validated questionnaire to be developed, to use the DePaul PEM scale with a structured researcher/clinician interview based on a description of PEM (based on one from the Institute of Medicine report) that our poll showed was well received by most patients. Despite our concerns with the NIH/CDC’s proposed use of the core PEM items from the DePaul scale, we intend no criticism of Professor Leonard Jason. The DePaul PEM scale was not designed for the purpose for which the NIH/CDC are considering it. Rather, the full DePaul Symptom Questionnaire of approximately 100 items, including PEM ones, was designed as a screen for ME and to be supplemented by a medical examination. To determine whether a patient has PEM in the NIH/CDC research context, we need a specific PEM scale that has been validated against known cases of PEM. The best “gold standard” for this is likely to be the patient or clinician's opinion of whether the patient has PEM. Professor Jason’s research covers the whole area of ME case definitions and diagnosis. We, in contrast, have focused almost exclusively on PEM, and entirely in the context of the NIH/CDC attempt to come up with common data elements for PEM for their future research. So Professor Jason is correct when he points out in his commentary on our poll that we have omitted mention of details of his wider work. For example, we do not mention other items from the DePaul questionnaire that may relate to PEM (or perhaps, in some cases, other symptomology) beyond the five symptoms that he considers the ‘core’ PEM items and that are the same ones being considered for use by the NIH/CDC. These ‘core’ items were the five items picked out by factor analysis in his work as representing a ‘PEM’ factor. Another study from his group, looking at a range of possible PEM descriptions from several different sources, including the International Consensus Criteria as well his own scale, only included these five core factors. The DePaul Symptom Questionnaire as a whole has many valuable properties and has been shown to be effective in discriminating between patients and both healthy and sick comparison groups. Professor Jason’s work with the scale, and on ME case ascertainment in general, has much advanced the field. Patients owe him a great debt of gratitude for that work. Our only concern is with the NIH/CDC’s proposed use of the PEM subscale for a purpose for which it was never intended. And, concerning the NIH/CDC, it’s critical that any scale of post-exertional malaise really does capture what patients experience, and is validated as doing so.