A brief, comprehensive measure of post-exertional malaise, 2025, Jason and Chee

Trish

Trish

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A brief, comprehensive measure of post-exertional malaise, Jason and Chee
https://www.explorationpub.com/Journals/ent/Article/1004116

Abstract

Aim: Post-exertional malaise (PEM) has been a challenging construct to measure, particularly with self-report instruments, which have the benefits of being less expensive and less invasive than cardiopulmonary exercise tests. Existing PEM questionnaires have often been used for diagnostic purposes and less frequently as outcome measures. Few self-report PEM measures address comprehensive PEM domains, including types of triggers, duration of symptoms, delayed symptom onset, number of symptoms, frequency and severity of symptoms, as well as whether pacing or other strategies reduce or eliminate PEM. Without characterizing these features, salient aspects of PEM would be overlooked. However, efforts to assess all these domains can be time-consuming and potentially burdensome.

Methods: The current study offers investigators a brief but comprehensive instrument of critical PEM domains, called the DePaul Symptom Questionnaire (DSQ)-PEM-2, to assess PEM. Validation data were derived from a large sample of individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Results: The DSQ-PEM-2 was developed using an existing dataset of individuals with ME, CFS, or both ME and CFS, allowing comprehensive coverage of key PEM domains.

Conclusions: The DSQ-PEM-2 can be used either for diagnostic purposes or as an outcome measure. The instrument’s time frames for symptom manifestation can be adapted to suit a variety of research or clinical contexts. Future validation studies need to include a healthy control group.

Link | PDF Open access
 
Table 6. PEM frequency and severity.

Next day soreness or fatigue after non-strenuous, everyday activities.
Mentally tired after the slightest effort.
Physically drained or sick after mild activity.
Dead, heavy feeling after starting to exercise.
Minimum exercise makes you physically tired.		Frequency
None of the time
A little of the time2.1 (20)
About half the time10.2 (96)
Most of the time33.5 (314)
All of the time54.1 (508)
Severity
Symptom not present
Mild1.8 (17)
Moderate15.3 (143)
Severe44.3 (413)
Very severe38.4 (358)


The last 5 items from question 6

Post-exertional malaise

% (n)

[/th]
 
The above table shows the frequency and severity percentages for the 5 items Jason calls definitions of PEM.
Note that over half of the participants report experiencing them all the time, and adding in those who report them most of the time, brings the figure up to about 90%.

Surely that should demonstrate clearly to Leonard Jason that these are not descriptors of PEM, but of fatigability that many of us experience all day every day with every activity.
 
Table 1. Triggers of PEM.

Minimal amounts of physical and/or cognitive exertion97.3 (1,492)
Emotional stress93.2 (1,429)
Noise85.3 (1,308)
Sensory overload83.6 (1,282)
Visual overload79.7 (1,223)
Basic activities of daily living78.2 (1,199)
Heat74.4 (1,141)
Light68.8 (1,055)
Cold66.3 (1,017)
Positional changes64.5 (990)
Foods61.0 (935)
Chemicals58.0 (889)
Watching movement52.5 (806)
Mold39.4 (605)

I find this list very unbalanced. There are far more items about non exertion triggers, sensory and environmental. All the exertion triggers are lumped together as physical/cognitive exertion, activities of daily living and positional changes. So if there's a scoring system for triggers, that would give a higher score to someone with sensory and environmental sensitivities than someone with post exertional malaise.
Why lump cognitive exertion in the same category as physical exertion, so it's almost an afterthought, yet, for example, have separate categories for heat and cold? It makes no sense to me.
 
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Table 2. Duration of PEM.

No prolonged recovery time5.6 (86)
< 24 hours0.5 (8)
24 hours–1 week33.0 (506)
1 week–1 month22.6 (347)
1 month–6 months17.5 (269)
6 months–12 months5.1 (78)
12 months–24 months3.3 (51)
> 24 months12.3 (189)

Quoting from the text under the table:

Note. Question 3ʼs data is presented in Table 2, which displays options provided in the original questionnaire. At the time of data collection, participants were allowed to select all duration options that applied to their experience of PEM. This approach accounts for the detailed breakdowns beyond one month and the higher proportion of respondents reporting symptoms lasting over a month. Within the DSQ-PEM-2, this has been revised to require participants to select only one response to improve clarity and consistency. Although some individuals do have PEM for more than a month and even beyond 2 years, our revised questionnaire only stipulates the time of ‘greater than one month’ because in most cases PEM occurs for less than one month.

End quote.
 
Trish said:
Table 2. Duration of PEM.

No prolonged recovery time5.6 (86)
< 24 hours0.5 (8)
24 hours–1 week33.0 (506)
1 week–1 month22.6 (347)
1 month–6 months17.5 (269)
6 months–12 months5.1 (78)
12 months–24 months3.3 (51)
> 24 months12.3 (189)

Quoting from the text under the table:

Note. Question 3ʼs data is presented in Table 2, which displays options provided in the original questionnaire. At the time of data collection, participants were allowed to select all duration options that applied to their experience of PEM. This approach accounts for the detailed breakdowns beyond one month and the higher proportion of respondents reporting symptoms lasting over a month. Within the DSQ-PEM-2, this has been revised to require participants to select only one response to improve clarity and consistency. Although some individuals do have PEM for more than a month and even beyond 2 years, our revised questionnaire only stipulates the time of ‘greater than one month’ because in most cases PEM occurs for less than one month.

End quote.
Click to expand...
I disagree with their decision to 'simplify' the questionnaire to only allow participants to choose one option. In my experience PEM duration depends very much on how much I've exceeded my PEM threshold and can vary from a day or two to over a month. I would have no idea which to select from the list if only allowed one. Also lumping together all the 'over one month' categories gives a false picture of the range.
 
Quote from the discussion:
Using the DSQ instruments, Wold et al. [38] categorized patients into three groups: those experiencing fatigue, those with PEM, and those with multi-dimensional PEM (who experience malaise after exceeding thresholds in physical, mental, or social activities, requiring extended recovery periods). This type of subtyping is useful and our instrument provides other options as well.
Click to expand...


So they seem to be calling daily experience of ME/CFS PEM, and what I call PEM they call multi-dimensional PEM. What a mess.

I can't help wondering what they think our daily lives are like when not in PEM. Do they imagine we only suffer symptoms and have effects from exertion when we have PEM, and have symptom free and fatigablity free days in between?
 
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Trish said:
Quote from the discussion:
Using the DSQ instruments, Wold et al. [38] categorized patients into three groups: those experiencing fatigue, those with PEM, and those with multi-dimensional PEM (who experience malaise after exceeding thresholds in physical, mental, or social activities, requiring extended recovery periods). This type of subtyping is useful and our instrument provides other options as well.
End of quote.

So they seem to be calling daily experience of ME/CFS PEM, and what I call PEM they call multi-dimensional PEM. What a mess.

I can't help wondering what they think our daily lives are like when not in PEM. Do they imagine we only suffer symptoms and have effects from exertion when we have PEM, and have symptom free and fatigablity free days in between?
Click to expand...
That's what I don't understand about this and the other questionnaire. I think you explained it very well in the other thread about the DePaul questionnaire @Trish. In order to measure PEM, you'd need to compare overall ME/CFS symptoms with symptoms when having PEM, and ideally you'd ask patients to track and document those for a year or so. That's how you could see that 'general' (as in 'usually present') symptoms and PEM vary but are clearly different.
 
I appreciate the effort to include key factors of delay and duration of PEM as well as PEM symptoms and severity in the questionnaire, but until they understand that lumping together all effects of exertion and sensory and environmental inputs every day, with the specific phenomenon of episodic PEM, they are contributing to the muddle.

Also I think the need to take another look at the relative weighting of the triggers list giiving much higher weighting to sensory and environmental stimuli, and barely mentioning cognitive exertion and OI, they are skewing the scoring.
And similarly for symptoms, they inexplicably cut off at 50% prevalence the symptoms they include on their list, leaving off, for example, nausea, inability to eat, OI, headaches, and more which at least for me are a major factor that distinguish my daily ME/CFS symptoms from PEM.
 
How can people who've been in the field so long get it so utterly wrong? I find it really worrying. For one thing, this would be so misleading for recently ill people that it could impair their ability to understand and manage their symptoms.

[Minor edits for sense]
 
Trish said:
So they seem to be calling daily experience of ME/CFS PEM, and what I call PEM they call multi-dimensional PEM. What a mess.
Click to expand...
It seems like there are three categories: fatigue that does not change with activity, symptoms directly triggered by activity (during or right after), and delayed malaise triggered by activity level above a threshold.

For me, only the third is PEM.

Physically drained or sick after mild activity.
Dead, heavy feeling after starting to exercise.
Minimum exercise makes you physically tired.
Click to expand...
The problem with these three is that there's no criterion for delay. "after mild activity" can mean 1 minute after. "after starting to exercise" implies symptoms that occur while exercising. "minimum exercise makes you physically tired" is not meaningful because it's too subjective. Many people have this who do not suffer from ME/CFS. I suspect just being out of shape allows people to score positive on this question.

These three questions are probably positive for many different problems that could be described as poor tolerance of exercise. Someone with poor orthostatic tolerance will also not feel good during exercise
 
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It looks to me to be an okay study of somehing. I just don’t think that something is necessarily PEM. It may be PEM if you can be sure what everyone is describing is PEM. But by the nature of the design we do not know that it is.

Given people also use these surveys to distinguish PEM and therefore ME/CFS from other conditions that is a concern.
 
Our revised and briefer instrument, called the DSQ-PEM-2, can be used as a diagnostic measure for ME/CFS case definitions as well as to measure the amount and intensity of PEM symptoms, triggers, severity, frequency, and effects of pacing.
Click to expand...
Says who?

This is entirely circular. It says that this questionnaire measures PEM because it measures what we say that PEM is.
 
Question 1 was a screen for PEM, and it was important to be able to identify all those who might have PEM. In our dataset of 1,534 patients with ME/CFS with complete data, 97.3% (n = 1,492) responded affirmatively to having “an abnormal response to minimal amounts of physical and/or cognitive exertion”, and 97.4% (n = 1,494) responded affirmatively to the question: “A severity and duration of symptoms out of proportion to the initial trigger”. This combined question has high sensitivity and can identify almost all those with PEM in an ME/CFS sample. This question could be used as a screen, and only those responding positively would need to be asked the remaining questions on the DSQ-PEM-2.
Click to expand...
If this is supposed to function as a screening question, you need to assess its ability to avoid false positives.

If you answer no to this question you clearly do not have PEM, but there is nothing here that differentiates between PEM, DOMS, rapid fatiguability, deconditioning etc. For any previously healthy person, DOMS and rapid fatiguability will be experienced as «out of proportion to the initial trigger». Even just struggling with OI will possibly lead to a yes on this question. Edit: even people just having the flu will say that what the experience when they try to exercise is out of proportion to the trigger.»

To go on to suggest using this as a «diagnostic measure for ME/CFS» is completely inappropriate. That’s like using chronic coughing alone as a diagnostic measure for COPD. Sure, it will flag everyone with COPD, but it will also flag anyone with lung cancer, respiratory infections, etc.
 
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The questionnaire does have too many different factors mushed together to provide useful information. For the five items in the first table, I'd give different individual ratings, and I'd rate some of those symptoms as occurring without exertion being the cause.

I still think it's the equivalent of an inkblot (random data) which a researcher can use to support any made-up theory. Useless.
 
Aside from the strange trigger event groupings it's a shame they didn't build on the PEM work done by Work well. Ifirc that identified 3 different types including rolling pem. I suspect categorising those and correlating them with symptoms on the one hand and severity on the other might have started to see a pattern instead of noise.

This is tricky and noisy because people do not seem yet to understand that pem is something of a moving target and especially if surveying a broad range of the patient population, symptoms change with severity.
 
Kiristar said:
This is tricky and noisy because people do not seem yet to understand that pem is something of a moving target and especially if surveying a broad range of the patient population, symptoms change with severity.
Click to expand...

Yup. I'm still a bit vague on what these instruments are supposed to be for.

They're not needed for diagnosis, and when it comes to management, PEM has different features and patterns in nearly everyone. Once newly ill people have understood the concept, they need to learn about their own pattern of symptoms and activity limits.

That takes time and experience, there aren't really any shortcuts, and because people learn differently they won't all find the same tools and strategies useful.
 
I think most look at PEM as ME/CFS underscored. It's ME/CFS on steroids. The relation reduces to degrees.

It may be more appropriate to come at it as an overarching reaction that, although it involves usual ME/CFS symptoms, transcends all the "normal" sequelae in terms of time-to-onset, intensity, and duration.

If this were an SAT question, maybe it would go like PEM is to ME/CFS like tsunami is to ocean. There's more than simply degrees involved.

Also, Lenny was always too enamored with the whole fatigue schtick. I recall debating this with his staff many many years ago.
 
Kitty said:
Yup. I'm still a bit vague on what these instruments are supposed to be for.

They're not needed for diagnosis, and I when it comes to management, PEM has different features and patterns in nearly everyone. Once newly ill people have understood the concept, they need to learn about their own pattern of symptoms and activity limits.

That takes time and experience, there aren't really any shortcuts, and because people learn differently they won't all find the same tools and strategies useful.
Click to expand...
I guess it might help reduce misdiagnosis if a good way could be found to isolate fatiguability from PEM?

I also wonder if there might be help with management of newer patients if some main PEM phenotypes could be found, even if that was just initially merely by basic staging, trigger or comorbidity patterns.

When I documented the evolution of my own PEM lived experience through my disease course to date for a workshop, I found my colleagues did say a surprising amount resonated with their own experiences.

But from this study there's still a lot of work to do to build researcher understanding of the phenomenon, particularly perhaps about how it is different in the more severely affected who generally find it harder to participate in PPI programmes.
 
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