What would a good questionnaire for diagnosing PEM look like?

The most popular questionnaire for PEM is the De-Paul Symptom Questionnaire, which, to be frank, is not the best, as it mostly focuses on fatigue after exertion and seems to flag an unlikely proportion of people with other illnesses having PEM.

It seems there isn’t much competition. The FUNCAP Scale is excellent for measuring disability in people with PEM, but is ill suited to diagnose PEM itself. Davenport’s team made a similar questionnaire that might serve as an outcome measure for functional capacity related to PEM but is not exactly suited to measure if a person has PEM.

Obviously, in an ideal world, PEM would be flagged based on clinical observations, but we’re operating in an environment in which 99% of clinicians would not recognise PEM if the most classical description was provided to them, nor do I trust researchers to discern PEM. So I’m creating this thread so we can discuss how we would make a scale for determining if an individual has PEM or not.

 

For reference here is the depaul questionnaire:

 

I'll start it off with a question suggestion:

Does mental or physical activity cause fatigue or other symptoms (maybe reference some examples) to be exacerbated far worse than would be expected in a healthy individual, and does this exacerbation normally last at least three days?

I still am not sure if non-delayed PEM is a thing, so not sure if anything about delay should be required.

Edit: Also I like question 10 of DePaul:

 

Isn't that just a questionnaire with one question?

 

Is there a definition already written anywhere that you think would be a good option for this?

 

To illustrate the issues with the DSQ PEM scale: in RECOVER-Adult, more of the "likely Long COVID" patients apparently had PEM than those that had fatigue or soreness after exercise. In the Nerli study an unusually high number of a heterogeneous post-COVID population were reported as having PEM and a physical rehabilitation programme was said to improve PEM. And in the Barz study, in a heterogeneous post-COVID fatigued cohort, almost all the participants were said to have PEM.

This is the 10-item version of DSQ-PEM with the scoring instructions; a score of only 2 on 2 out of the first 5 items in both frequency and severity represents PEM caseness:



One of the principal reasons exercise studies were downGRADEd by NICE was due to population indirectness (lacking applicability to a population now defined using modern diagnostic criteria with PEM as a mandatory feature). Yet the only metric of PEM in common use is inexact, lacking in specificity, and is producing results like those given above. The questions seem to be assessing exertional intolerance as opposed to the crashes that we understand.

Developing something better would, I think, be a very worthwhile effort.

 

I guess all the stuff about frequency of PEM symptoms can be deleted. More severely affected people may rarely be free of PEM, while mildly affected people who pace well might be able to avoid it some of the time. Frequency doesn't really tell us much.

Nor does how many hours it lasts, because (apart from the delay in onset) it's the wrong measurement. Even in the mild/moderate group PEM is often measured in days, and it can be weeks and months.

As for symptoms, it isn't helpful to have people picking from a list of pre-defined terms that could be understood in several different ways. All the same, it's hard to come up with something better! The term that best describes PEM is probably something like "feeling really ill".

Maybe Trish is right. What this really needs is people trained to recognise the clinical picture when they see it. Who ask questions based not on a list, but on what they don't yet know about that individual.

 

Why not just measure the time spent lying down? That would be less subjective than questionnaires that ask about feelings. If you don't have a tracker, a $5 dollar timer from Amazon actually does a decent job. You have to manually punch the button whenever you lie down or get up, but it's not bad if you affix it on your arm or chest. I keep the hours every day on my activity log.

 

DecodeME used these two questions.

Symptoms after effort or activity

12.
In the last 6 months, what happens to your symptoms after you do more physical or mental activity than usual (exceed your energy limit)?
If you pace your energy, we want you to think about what would have happened if you didn't. Please only choose ONE answer.

• My symptoms (such as pain, fatigue or feeling out-of-sorts) get worse, or I get new symptoms, and this reduces how much I can do
• My symptoms either stay the same or improve (Skip to Question 14)

13.
In the last 6 months, after you have done more physical or mental activity than usual (exceeded your energy limit), how long does the change in your symptoms usually last?
If you pace your energy, we want you to think about what would have happened if you didn't. Please only choose ONE answer.

• The change in my symptoms lasts a long time, which can be more than 24 hours
• I bounce back straight away or my symptoms don’t last very long given the effort I just made

 

I would ask the patient to describe all aspects of their problems in their own words first and then clarify how they are using words with tailored questions. I would not mention PEM until I had come to an analysis. When faced with doctors people are very easily led into saying what they don't mean based on expectation bias (the same old problem). Questionnaires amplify the problem by asking questions people think there is a right or wrong answer to.

 

I’m just gonna reput this part from the original question here. Because I agree with Trish and Jonathan in theory, but in practice in the current environment I don’t know how feasible it is to leave it up to doctors the vast majority of which think ME = CFS = [psychiatric] Chronic Fatigue

 

Lying down's not a universal indicator of PEM, though. I lived with it for decades, but I couldn't lie down when I felt at my worst because I was at work. People only stop because they're forced to, and some of those who're not severely ill keep going for a surprisingly long time (longer than is good for them).

I've been retired seven years, but I'm now at an age where lying down isn't comfortable. I tried it last week when I had Covid and PEM, but it was a choice between sitting up and feeling ill, or lying down and feeling ill with my back going into spasm every couple of minutes.

Lying down wouldn't help diagnose PEM anyway, as people could be doing it for any number of reasons. Diagnosis needs attention to the whole pattern.

 

I had a lot of difficulty describing delayed PEM on Leonard Jason's questionnaires. Every question asked to describe 'fatigue' 10 different ways.

 

Good questions!

How did DecodeME use this to determine whether a patient has PEM? Did they require a positive response to both of the first answer options?


The PEM-questions of Decode2 are great as well, I think:

Symptoms after effort or activity
8. Do you experience post-exertional malaise (PEM)? (
PEM is described as a worsening of your ME/CFS symptoms, or development of new symptoms, after you do more physical or mental activity than usual (exceed your energy limit).
If you pace your energy, we want you to think about what would have happened if you didn't.
 Yes
 Sometimes
 No (Skip to Question 14)

9. How likely are the following types of exertion to trigger your PEM?

10. Whilst experiencing PEM, how likely is it for the following symptoms to become worse or develop?

11. On average, how long does it take for your symptoms to worsen, or develop, after exertion?
 Less than 6 hours
 Between 6 and 12 hours
 Between 12 and 24 hours
 Between 24 and 48 hours
 More than 48 hours

12. On average, how long from the onset of PEM does it take to return to your baseline level of symptoms?
 Less than 24 hours
 1-3 days
 3-7 days
 7-28 days
 Over 28 days

13. Does your level of functioning worsen whilst experiencing PEM?

 

Yes, the participant needed to agree with the first options on both questions 12 and 13.

 

Same.