The NIH/CDC are deciding on the “common data elements“, CDE, that must be collected in all studies they fund. And they’ve asked for patient comments on the draft proposals by 31 January. Perhaps the most important of the CDEs covers PEM, as the cardinal symptom of the illness. The PEM subgroup has proposed a questionnaire that will play a key role in defining PEM and I have concerns about its suitability. I’d like to hear what other patients think. I should say that its choice - the PEM subscale from Lenny Jason’s DePaul Symptom questionnaire, DSQ, - seems to be the only credible option right now. And the subgroup recognises many of the DSQ’s limitations. However, I feel we need a clear plan to urgently develop a better option. The questionnaire will help define who has PEM and who does not (in some cases it will be the only measure used). If it’s inaccurate, it risks including patients who don’t have the illness, weakening research, and excluding patients who should be, making recruitment harder and leading to smaller studies, again weakening research. The DSQ assesses post-exertional malaise by asking patients to rate severity and frequency of five symptoms over the last six months: Dead, heavy feeling after starting to exercise. Next day soreness or fatigue after non-strenuous, everyday activities. Mentally tired after the slightest effort. Minimum exercise makes you physically tired. Physically drained or sick after mild activity. My feeling is that these question circle around PEM rather than really capturing its essence. How do others feel about this? A 2017 study by Murdock found that the PEM subscale did differentiate patients from healthy controls, but only when the volume was turned up quite high (score >20/40). A really good PEM measure should do that more easily – PEM is not a normal, healthy experience. Interestingly, the subgroup itself has adopted the Institute of Medicine’s definition of PEM (now the National Academy of medicine, NAM). As it put it: Post-exertional malaise is defined as an abnormal response to minimal amounts of physical or cognitive exertion that is characterised by (my summary, full text in a later post): A flare of some or all of an individual’s symptoms, with an immediate or delayed onset and with prolonged recovery. Severity and duration of symptoms are out of proportion to the initial trigger. There is a loss of functional capacity and/or stamina. Which to me looks like a good description of PEM and substantially different from the DSQ. So, on the one hand, the subgroup have adopted the NAM definition, while on the other they have selected the DSQ to measure it, and that doesn’t seem to stack up. Of course, what’s actually needed is a short, validated questionnaire that can be used in studies. We don’t have that yet for anything but the DSQ. For now, it’s the right call to use the DSQ, but I believe we need a clear plan to urgently develop a replacement that starts with patient input. Only patients experience PEM, so their input is crucial. I’ve started this thread to hear if other people share my concerns. I’d appreciate any answers to (any of) the following three questions: Does the proposed five items questionnaire fall short of properly capturing post-exertional malaise? If so, should we be asking for a timetabled plan to urgently develop a better alternative? I also have concerns that the way symptoms are scored could give misleading results - see next post. Again, is this an issue for anyone else? IMPORTANT. This is not intended as a criticism of Professor Leonard Jason, who has been a lonely pioneer of case definitions and post-exertional malaise in particular. Without the research of him and his team there would be nothing to use now. Likewise, it’s not a criticism of the working group (co-chaired by Lily Chu and patient advocate Mary Dimmock). This has produced many good recommendations (including using the DSQ for PEM at first) and has highlighted many of the weaknesses of the DSQ. This, though, is about how PEM will be defined in every N I H and CDC study, every biomedical study, so it needs to be as good as it can be, as soon as possible, to produce the best possible research. Can anyone help with more info e.g. more on the DSQ, especially the PEM questions, which I believe were discussed on PR in the past? I’ve read the research myself years back but am too ill now to revisit. Just doing this has been a huge effort. @Woolie is a questionnaire expert, @Adrian and @Graham know a lot too.