The conclusion of "alteration of effort preference" driving PEM from an underpowered study that blatantly misuses CPET in the face of all relevant research and clinical guidance for ME/CFS is what we get after years of developing the protocol and waiting for these results?
The sample size makes this study a glorified case series. In a heterogeneous condition like ME/CFS, there is no way 17 participants out of 217 screened is representative. But get this: not all the participants got all the endpoint measures. How can the authors infer causation?
For sure the CPET results are underpowered but there are some clear differences between groups. The authors interpret these differences as deconditioning, which is easy to do on the basis of a single CPET. That's why you need the second one completed in the post-exertional state.
One revealing thing from CPET was the fact the authors included obviously trained individuals in their analysis. Half of them performed at or above their age-predicted maximum heart rate. If you want to conclude PEM is deconditioning and altered effort preference, at least...
...make this comparison with sedentary people who are likely to be deconditioned instead of relatively fit individuals.
PEM is tricky because simply trying to measure it can induce it. The authors didn't grasp this important concept. The effort preference task is a lengthy complex choice reaction time task. This just sounds like the perfect way to induce cognitive PEM during a measurement.
So, there will be a lot more said about this study in the weeks and months to come, and most of it will be about how this study wasn't worth the resources, time, and waiting. For now I'll just contribute that Nature editorial staff were asleep at the wheel, ...
... there were plenty of people who had to do with this work who had reason to know better than what they put out both from basic scientific and content area perspectives, and this work is so poorly interpreted and so poorly reported that it should be retracted immediately.
This article reinforces every negative stereotype about PEM simply being a choice. It's so inconsistent with the findings of their own -omics analysis, to let alone the extant literature. And in light of that inconsistency, it's inhumane. People with ME deserve better than this.
There may be some useful details of this work stuck between the couch cushions, but they won't make the global headlines. What will make those headlines are people with ME are either lazy or crazy. Again.
What an utter and total waste of resources and good faith. I just can't.
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@twoShaws Some interesting notes while waiting for a flight: 🧵
The exercise cohort was not pre-screened for PEM because they did not fill out the DSQ-PEM. It's no secret that I'm not a huge fan of how investigators use this questionnaire, but they did not use the most common survey.
@twoShaws Instead, they used a visual analog scale survey and focused on a symptom cluster they found to be prevalent after CPET in a prior study. Maybe this is fine but using a different survey tool may compare apples with oranges. Seems odd to not screen for PEM using a common approach.
@twoShaws Seems even odder they wouldn't use the DSQ-PEM in people with suspected PEM because *mounts soap box and loudly inhales* IT IS IN SET OF COMMON DATA ELEMENTS CREATED BY A *checks notes and loudly inhales again* AN NIH WORKING GROUP. SO WHY WOULDN'T THEY USE THEIR OWN GUIDELINES?
I totally acknowledge the role of poor mental health in people with ME and ME-like/ME-subtypes of conditions. But to say there’s a reciprocal relationship between mental and physical health, and to leave it there, only tells part of the story and leaves out the *important* part.
Let me explain. If you stop at saying there’s a bidirectional relationship between mental and physical health, you might be tempted to assume, as a clinician, that you can intervene on both ends and those interventions should have exactly the same effect. After all, why bother…
…with figuring out what comes first—chickens and eggs—when you can have omelets *and* chicken tenders. That logic is so tempting. But here’s the fatal flaw. If someone is depressed, I’m going to encourage them to engage in pleasurable activities. Like going to take a nice walk.
Yet another trial that doesn't appear to track PEM properly through using the DSQ as designed and validated. They say DSQ Short Form but it appears from the supplemental tables they mean DSQ-PEM. DSQ was only assessed in a subset of participants at follow-up and not at baseline.
It is so unhelpful how investigators use validated measurements however they want because vibes. The prevalence of PEM in this study sample may be overestimated. The incomplete follow-up prevents our ability to determine the influence of PEM on the primary and secondary outcomes.
But, the same people will use these data and their standard messaging to carry on about how PEM isn't a big deal and people who talk about it are reinforcing negative illness perceptions that impair recovery, as though that explains the evidence for a broken aerobic metabolism.
Did you know that according to @NIH Common Data Elements Work Group on #MECFS, assessment for #PEM is a two-stage process involving the use of a questionnaire followed by a confirmation process? Most studies on PEM only use the symptom screening portion, but this is not specific.
Did you know few exercise studies in Long Covid purporting to use the DSQ-PEM use both stages of the PEM scoring or the (unmodified) questionnaire as originally validated? Incomplete use and bootleg versions seriously compromise inferences about the effect exercise has on PEM.
Did you know even using the full scoring of the unmodified version of DSQ-PEM, it only has about a 61% positive predictive value, meaning that 61% of people with positive survey results will turn out to have a diagnosis of ME/CFS vs. multiple sclerosis and post-polio syndrome?
A 🧵. Back in early 2022, the editorial staff of the @CPTJournal approved a Special Issue on Long Covid. Against all better judgement, I was selected to be its Guest Editor. The Special Issue published today.
Here are the contents.
@CPTJournal Leading off is a lived experience essay by Samantha Laswell PTA (USA). It appropriately centers this volume of work on the patient’s voice. We clinicians and researchers benefit from leadership from people living with Long Covid in all we do. journals.lww.com/cptj/fulltext/…
Malachy Clancy PhD OTR/L BCPR and Robert Dekerlegand PT MPT PhD CCS (USA) share data from a nationwide multidisciplinary survey of rehabilitation clinicians on awareness of #LongCovid and related clinical practice guidelines. journals.lww.com/cptj/fulltext/…
E. Coli is endemic, i.e. never going way. Given this, under what conditions will you advocate ever stopping washing your hands after using the restroom or coming into contact with contaminated material?
Sexually transmitted infections are endemic, i.e. never going away. Given this, under what conditions will you advocate ever stopping the use of evidence based mitigation methods like condoms, vaccination, behavioral counseling, and prophylaxis?
Influenza is endemic, i.e. never going away. Given this, under what conditions will you advocate ever stopping cough and hand hygiene, vaccination, ventilation, masking, and staying home when you’re sick?