Open DSQ PEM survey - DePaul University, open October 2025

[TheDePaulGroup]

Hello all,

I am part of the team that created and deployed this survey (DSQ-PEM 2). I have been reviewing all the feedback across forums, comments online, and comments left on the survey. I would like to pass on a message from Dr. Leonard Jason:

I would like to thank the patient community for their participation in our recent surveys—one focused on criteria for measuring illness severity and burden, and the other on post-exertional malaise (PEM). More than 4,000 individuals responded to the first survey, and over 600 to the second. My team and I are deeply appreciative of this remarkable response and the thoughtful comments we received. Several participants asked how we have collaborated with patient groups on these and other efforts. Below, I provide a brief overview of this broader participatory process, followed by the rationale for doing our two most recent studies.

For more than 35 years, our group has been privileged to work closely with the patient community on a wide range of initiatives. Beginning in 1990, patients alerted us to the harm caused by the CDC’s inaccurate prevalence estimates and the stigmatizing media portrayal of ME/CFS as “Yuppie Flu.” With financial support and encouragement from the largest patient organization at that time—the CFIDS Association—we conducted a pilot study that challenged the CDC’s estimate of only 20,000 affected individuals. With these pilot data, we were able to successfully obtain NIH funding, and we carried out our community-based epidemiologic research demonstrating that ME/CFS prevalence was far higher than originally reported. The effort took our group a decade. This major shift in understanding the prevalence of ME/CFS would not have been possible without the sustained engagement and guidance of the patient community. When patients raised concerns about the stigmatizing effects of the term “chronic fatigue syndrome,” we conducted research showing that labeling indeed influenced public perceptions—validating patient experiences and supporting the use of “ME” as the preferred term. These two foundational projects were both patient-driven. More details on this early collaborative work can be found in: Jason, L.A. (2015). Ethical and diversity challenges in ecologically sensitive systems-oriented interventions. American Psychologist, 70, 762–775. PMCID: PMC4863698.

In part due to these efforts, I was later appointed Chairperson of the U.S. Research Committee of the CFS Advisory Committee, which advised the Secretary of Health and Human Services. At those meetings, patients repeatedly voiced concerns about the limitations of the Fukuda criteria used in research and clinical trials. Guided by these concerns, our team spent the next decade evaluating the adequacy of these criteria. We found that many studies using Fukuda’s definition recruited participants who did not experience PEM or cognitive impairment—core symptoms of ME/CFS. Moreover, the criteria relied on symptom “occurrence” rather than precise frequency and severity measures. Our research demonstrated that such measures failed to distinguish ME/CFS from major depressive disorder, while frequency/severity metrics could make that distinction.

Addressing our work on measuring post-exertional malaise (PEM): The original DSQ was not designed as a comprehensive PEM measure, though it included ten relevant PEM items. Rather, it was a measure of the multiple symptoms that occur among patients. Just before the pandemic, we published what we call the DSQ-PEM, a short PEM tool derived from the DSQ survey. But this brief scale did not cover key issues such as the delay of onset of symptoms and triggers for symptoms. Recognizing the need for a more complete instrument, we sought patient input through social media, inviting suggestions for additional questions and refining the measure iteratively based on feedback. Once a patient-led effort had developed the PEM questionnaire, we then posted it on my Facebook account, and 1,534 patients completed the resulting comprehensive PEM questionnaire. Details on this patient-generated measure are available in:
Holtzman, C.S., Bhatia, S., Cotler, J., & Jason, L.A. (2019). Assessment of post-exertional malaise (PEM) in patients with Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS): A patient-driven survey. Diagnostics, 9(1), 26. However, it is a lengthy questionnaire of 8 pages.

When the pandemic began, few validated PEM measures were available, but as we know, PEM is a key symptom of Long COVID. As there were very few PEM-validated measures at the time, Long COVID researchers worldwide adopted our brief 5-item PEM scale and the 10-item DSQ-PEM, both of which have since been translated into 28 languages. These instruments that been used in dozens of articles over the last few years. However, our comprehensive 8-page PEM questionnaire proved too lengthy and was not used by researchers. This led our group to explore whether a balanced, intermediate solution could be developed—a more current and comprehensive measure than the DSQ-PEM, yet briefer and more practical than the full 8-page version. Using data that we had already collected on the 8-page version, we just examined core PEM domains, so we were able to keep it to 2 pages. We finished this study in the summer, and it has been accepted for publication in a journal. We are now working on the page proofs, but it will be released shortly.

After finalizing this briefer version, which we now call the DSQ-PEM2, we wanted to collect new data with this briefer PEM instrument. That is the instrument that I circulated last week on my Facebook page, and the items originally had been recommended by patients when we created the more comprehensive 8-page instrument, but of course, it was briefer at just two pages, with the hope that this briefer instrument might be used by investigators, and it certainly is more comprehensive than the DSQ-PEM that has been so widely used.

I also want to acknowledge the thoughtful feedback we have received regarding this new PEM instrument, and all comments are being carefully reviewed. Some participants mentioned they would have preferred to be able to skip items, and several respondents requested more details clarifying items. Several mentioned it was difficult to differentiate a PEM occurrence from the overall ME experience, and this certainly is a difficult task to differentiate in a self-report questionnaire. While we did include a question about whether pacing was effective in reducing PEM, we did not ask for each question what it would be like if a patient were not pacing, but to do so would have doubled the number of questions on our brief 2-page questionnaire. These suggestions reflect fundamental measurement issues and reinforce that operationalizing PEM in a way that matches lived experience remains a challenging process for these types of surveys. However, self-report questionnaires do have the advantage of being less expensive than many other methods, such as two-day cardiopulmonary exercise tests.

We are immensely grateful to the more than 600 participants who completed the survey. Although this version (the DSQ-PEM-2) is less detailed than the 8-page comprehensive measure, we hope it will serve as a practical and scientifically valuable tool for future research on PEM. Fortunately, there are more PEM instruments today than when we began working on the creation of DSQ in 2009.

Warm regards,

Lenny Jason

 

[Hoopoe]

I also wanted to add my special perspective as person who used to be much more sicker and can now do physical activities but who still considers himself disabled.

My feeling is that questionnaires are failing to capture the limitations that I still have because they ask questions such as "can you do x?" or "if you do x do you suffer PEM?" or "how limited in doing x are you". These questionaires go through a list of important activities and ask these questions for each activity.

I think these kinds of questions are not capturing the essence of what PEM is.

It does not matter that much what activity x is.

What appears to matter is how sensitive someone to PEM is, and the cumulative effect of activities that each contribute to triggering PEM. Each of these activities might be tolerated on its own.

We should be asking people whether they are FORCED to maintain an overall activity level (after explaining what is meant) that is lower than they would like, because of PEM (after describing the phenomenon). If they answer positively, we should ask them whether they can recognize this as something that happens again and again, and how long this has continued to happen.

By activity level I mean how much a person does over the course of the day. Have they shifted from more demanding activities and more hours per day dedicated to these and other activities to less demanding ones and more hours per day to rest or restful activities?

 

[Kitty]

I can't really see anything that looks useful or meaningful after the first four questions (and as @Trish says, the first question does need some clarification).

Before answering any further questions I'd like to know what it is they're actually trying to find out and why. Without knowing that it's really hard to assess the suitability of a questionnaire. At face value this one mainly appears to be asking whether people get PEM, which is a Yes/No answer. It's fair enough to add two or three supplementaries to probe whether what the respondent means by PEM is roughly the same as the investigator, but beyond that I start to get lost.

I'd also decline to give information about my racial background or education history on a form like this. Unless there's a clear explanation of why it's necessary, I'd assume it falls into the category of unnecessary and intrusive information that European data protection regulations strongly dissuade organisations from collecting.

 

[Utsikt]

@TheDePaulGroup

While I appreciate the response, there is nothing in the post that addresses some of the serious issues raised by e.g. Trish and other members in this thread.

There seems to be a profound confusion about what PEM is, and maybe more importantly what it is not. I personally do not at all feel confident that the PEM2 questionnaire is able to sufficiently weed out false positives.

Surely the purpose of such a questionnaire is to try to sus out of the person actually has experienced PEM, not just ask them a yes or no? How does that help anyone determine anything? The patient might have a completely wrong belief about what PEM is, and this will do nothing to identify the discrepancies.

The key thing about PEM is that it is not delayed onset muscle soreness, rapid fatiguability or anything of the sort. PEM is what you’re left with when you rule out all of the normal responses to exertion, delayed or not.

Why does this matter? Because we’ve had enough of researchers using DSQ-PEM to say that these patients had PEM when some of them very clearly did not. This will just ensure that the trend continues.

 

[Trish]

Hello, @TheDePaulGroup, Lenny Jason, thank you for joining us.

As you will have seen, I copied the questions from your questionnaire on this thread as I was filling it in, so members could discuss them.

You will also have seen that I am totally confused by the whole premise of the questionnaire, which seems to conflate the daily grind of living with ME/CFS and the episodes of PEM, the frequency and severity of which is affected by activity in the preceding days.

Your first set of questions is about symptoms we experience due to PEM.

There follows a series of symptoms, for each you are asked to answer the following 2 questions:

Frequency: Throughout the past 6 months, how often have you had this symptom due to post-exertional malaise?
0
None of the time
1
A little of the time
2
About half the time
3
Most of the time
4
All of the time

Severity: Throughout the past 6 months, when this symptom is present, how severe is it?​

0

Not present
1
Mild
2
Moderate
3
Severe
4
Very severe

The symptoms listed for which you have to answer the above 2 questions are:
Reduced stamina and/or functional capacity
Physically fatigued while mentally wired
Cognitive exhaustion
Problems thinking
Unrefreshing sleep
Insomnia
Muscle pain
Muscle weakness/instability
Aches all over your body
Dizziness
Flu-like symptoms
Temperature dysregulation
Physical fatigue

This is a list of symptoms of ME/CFS, so by definition, most of us will experience most of them most or all of the time, not just during PEM episodes.

Given that I experience almost every symptom on the list all the time, how am I supposed to answer this? Do I pick the few that I only get during PEM episodes, and say I don't get the others 'due to PEM'. But that's not right because I have them during PEM also.

And the severity question makes no sense either. If I have reduced stamina, does severe mean I can no longer work, or does it mean I'm bedbound? You need to give benchmarks if the data is to mean anything. Otherwise, why ask about severity?

The second set of questions was even more confusing:

Question 21 of 43
You will now be presented with a series of Post-Exertional Malaise case definitions. For each one please rate how often (frequency) and how intensely (severity) you have experienced this symptom over the past 6 months.

For each, you are asked these 2 questions:

Frequency: Throughout the past 6 months, how often have you had this symptom?​

0
None of the time
1
A little of the time
2
About half the time
3
Most of the time
4
All of the time

Severity: Throughout the past 6 months, when this symptom is present, how severe is it?​

0

Not present
1
Mild
2
Moderate
3
Severe
4
Very severe

Symptoms for which you are asked to answer the above 2 questions:

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
You can interpret the word exercise as any daily activity you do such as even walking around in your house.
Minimum exercise makes you physically tired
You can interpret the word exercise as any daily activity you do such as even walking around in your house.

You describe each of the statements asked about as 'a series of PEM case definiitions'. They are no such thing, at least not in any definition I've seen, or in my experience. They are descriptions of fatigability which for many if not all pwME is part of what ME/CFS is. I experience all of them all the time during and after every activity.

I think the problem I and others are having with this questionnaire is a fundamental difference in understanding the phenomenon of PEM. You define it as

PEM involves a worsening of symptoms after physical, cognitive, or emotional exertion.

To me, and I think many others, that sentence describes what happens to us all day every day whenever we do anything physical or cognitive.

That description is incomplete according to the definitions used by the CDC and NICE, for example, which make it clear that they are talking about the usually delayed much worse episodes we experience when we have done a bit more exertion than usual, that is usually delayed after the triggering exertion and that usually lasts for days or much longer before the episode eases.

I hope you will take the time to read the fact sheet on PEM our members produced, linked below. Can you explain to us how your questionnaire would be able to determine whether someone experiences PEM of the sort we describe, and the frequency, severity and duration of the episodes of PEM, and whether your questionnnaire can distinguish this from the daily fatiguability and symptom fluctuations with each activity we do. My experience of filling it in tells me you will learn nothing about my experience of PEM episodes from my attempts at answers.

PEM_Factsheet.pdf

 

[hotblack]

Agree that focussing on predefined activities is the wrong path. Different people of different severities with different levels of support prioritise different things.

This just isn’t an accessible questionnaire, in size or structure. I gave up on it. I believe there will be self selection in who chooses and is able to complete it.

Question 4 was a bit of wall simply because there isn’t a good answer to how long my PEM lasts available because it depends. It isn’t a set amount just like there isn’t a set amount of activity that triggers it.

The way a lot of these questions are phrased the answer is often ‘it depends’ and asking about a typical or most often occurence I don’t think would be the right approach. As it is that it depends which is the important information.

Others have raised great points on aims, data protection and overall questions so I won’t repeat them.

@TheDePaulGroup We have spent a lot of time discussing questionnaires, definitions of PEM and different people’s experiences and ways of measuring patient experiences and outcomes on the forum. I’m sure there’s valuable info for the team if they want to engage further.

 

[Kitty]

Question 4 was a bit of wall simply because there isn’t a good answer to how long my PEM lasts available because it depends. It isn’t a set amount just like there isn’t a set amount of activity that triggers it.

That's the trouble with trying to come up with in-depth data on PEM. Everything is contingent on everything else.

It's possibly most usefully compared to an injury. It's essential to develop ways to describe injuries and work out how best to treat them, of course, but beyond that it all becomes conditional. How long it takes a patient to recover depends on how old and fit they were, how badly they hurt themselves, and how well they complied with medical advice afterwards. How much they aggravate the injury if they try to do too much too soon depends on all the above, plus how much they did and what stage of the recovery curve they were at.

Trying to analyse all that would probably produce nothing that's of use in treatment or management, beyond an advisory statement such as "Further damage to the injured area may delay your recovery". People already know that.

 

[Creekside]

From the survey questions Trish posted, I'd guess that the results will be quite misleading and open to misinterpretation. I expect that two people with exactly the same ME&PEM symptoms might fill out the questionnaire quite differently, based on different personalities. One will say they have "temperature dysregulation" once a month, meaning a really strong feeling of overheating or chilling, while another person claims they have it several times a day, but they're referring to a tenth of a degree variation (and they use a medical-grade thermometer several time per hour). Without those details, I can imagine researchers imputing more relevance to the data than actually exists. So, I'm not convinced that the questionnaire is going to produce useful data.

 

[Kitty]

@TheDePaulGroup – there is one type of long term PEM study that could potentially be really useful.

That would be a simple web tool that allows newly ill people who're not severely affected, and possibly those who've been ill some time but have never been severely affected, to log their more severe PEM episodes over time. As many people as possible, anywhere in the world.

So they get prompted to complete the FUNCAP perhaps twice a year, and the only other input they need to have is to record PEM that impairs them enough that they couldn't do even half their normal activities—but only starting when they've already had it for at least three days.

They don't need to describe it, just click the calendar for that day's date. Every day until they can do most of their usual activities again. (Maybe the tool only tags the episode for inclusion when it's lasted at least five or six days, but asking people to wait that long before starting recording would be difficult. Days merge into one other when you feel like death dug up.)

Analysis of that over several years might give us some evidence of whether or not frequent episodes of long-lasting PEM reduces people's underlying function. We suspect it does, but we don't have the data. A study like that could be criticised as having any number of limitations, but it might still have some value. It's lightweight enough to be usable too.

 

[MrMagoo]

Hello all,

I am part of the team that created and deployed this survey (DSQ-PEM 2). I have been reviewing all the feedback across forums, comments online, and comments left on the survey. I would like to pass on a message from Dr. Leonard Jason:

I would like to thank the patient community for their participation in our recent surveys—one focused on criteria for measuring illness severity and burden, and the other on post-exertional malaise (PEM). More than 4,000 individuals responded to the first survey, and over 600 to the second. My team and I are deeply appreciative of this remarkable response and the thoughtful comments we received. Several participants asked how we have collaborated with patient groups on these and other efforts. Below, I provide a brief overview of this broader participatory process, followed by the rationale for doing our two most recent studies.

For more than 35 years, our group has been privileged to work closely with the patient community on a wide range of initiatives. Beginning in 1990, patients alerted us to the harm caused by the CDC’s inaccurate prevalence estimates and the stigmatizing media portrayal of ME/CFS as “Yuppie Flu.” With financial support and encouragement from the largest patient organization at that time—the CFIDS Association—we conducted a pilot study that challenged the CDC’s estimate of only 20,000 affected individuals. With these pilot data, we were able to successfully obtain NIH funding, and we carried out our community-based epidemiologic research demonstrating that ME/CFS prevalence was far higher than originally reported. The effort took our group a decade. This major shift in understanding the prevalence of ME/CFS would not have been possible without the sustained engagement and guidance of the patient community. When patients raised concerns about the stigmatizing effects of the term “chronic fatigue syndrome,” we conducted research showing that labeling indeed influenced public perceptions—validating patient experiences and supporting the use of “ME” as the preferred term. These two foundational projects were both patient-driven. More details on this early collaborative work can be found in: Jason, L.A. (2015). Ethical and diversity challenges in ecologically sensitive systems-oriented interventions. American Psychologist, 70, 762–775. PMCID: PMC4863698.

In part due to these efforts, I was later appointed Chairperson of the U.S. Research Committee of the CFS Advisory Committee, which advised the Secretary of Health and Human Services. At those meetings, patients repeatedly voiced concerns about the limitations of the Fukuda criteria used in research and clinical trials. Guided by these concerns, our team spent the next decade evaluating the adequacy of these criteria. We found that many studies using Fukuda’s definition recruited participants who did not experience PEM or cognitive impairment—core symptoms of ME/CFS. Moreover, the criteria relied on symptom “occurrence” rather than precise frequency and severity measures. Our research demonstrated that such measures failed to distinguish ME/CFS from major depressive disorder, while frequency/severity metrics could make that distinction.

Addressing our work on measuring post-exertional malaise (PEM): The original DSQ was not designed as a comprehensive PEM measure, though it included ten relevant PEM items. Rather, it was a measure of the multiple symptoms that occur among patients. Just before the pandemic, we published what we call the DSQ-PEM, a short PEM tool derived from the DSQ survey. But this brief scale did not cover key issues such as the delay of onset of symptoms and triggers for symptoms. Recognizing the need for a more complete instrument, we sought patient input through social media, inviting suggestions for additional questions and refining the measure iteratively based on feedback. Once a patient-led effort had developed the PEM questionnaire, we then posted it on my Facebook account, and 1,534 patients completed the resulting comprehensive PEM questionnaire. Details on this patient-generated measure are available in:
Holtzman, C.S., Bhatia, S., Cotler, J., & Jason, L.A. (2019). Assessment of post-exertional malaise (PEM) in patients with Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS): A patient-driven survey. Diagnostics, 9(1), 26. However, it is a lengthy questionnaire of 8 pages.

When the pandemic began, few validated PEM measures were available, but as we know, PEM is a key symptom of Long COVID. As there were very few PEM-validated measures at the time, Long COVID researchers worldwide adopted our brief 5-item PEM scale and the 10-item DSQ-PEM, both of which have since been translated into 28 languages. These instruments that been used in dozens of articles over the last few years. However, our comprehensive 8-page PEM questionnaire proved too lengthy and was not used by researchers. This led our group to explore whether a balanced, intermediate solution could be developed—a more current and comprehensive measure than the DSQ-PEM, yet briefer and more practical than the full 8-page version. Using data that we had already collected on the 8-page version, we just examined core PEM domains, so we were able to keep it to 2 pages. We finished this study in the summer, and it has been accepted for publication in a journal. We are now working on the page proofs, but it will be released shortly.

After finalizing this briefer version, which we now call the DSQ-PEM2, we wanted to collect new data with this briefer PEM instrument. That is the instrument that I circulated last week on my Facebook page, and the items originally had been recommended by patients when we created the more comprehensive 8-page instrument, but of course, it was briefer at just two pages, with the hope that this briefer instrument might be used by investigators, and it certainly is more comprehensive than the DSQ-PEM that has been so widely used.

I also want to acknowledge the thoughtful feedback we have received regarding this new PEM instrument, and all comments are being carefully reviewed. Some participants mentioned they would have preferred to be able to skip items, and several respondents requested more details clarifying items. Several mentioned it was difficult to differentiate a PEM occurrence from the overall ME experience, and this certainly is a difficult task to differentiate in a self-report questionnaire. While we did include a question about whether pacing was effective in reducing PEM, we did not ask for each question what it would be like if a patient were not pacing, but to do so would have doubled the number of questions on our brief 2-page questionnaire. These suggestions reflect fundamental measurement issues and reinforce that operationalizing PEM in a way that matches lived experience remains a challenging process for these types of surveys. However, self-report questionnaires do have the advantage of being less expensive than many other methods, such as two-day cardiopulmonary exercise tests.

We are immensely grateful to the more than 600 participants who completed the survey. Although this version (the DSQ-PEM-2) is less detailed than the 8-page comprehensive measure, we hope it will serve as a practical and scientifically valuable tool for future research on PEM. Fortunately, there are more PEM instruments today than when we began working on the creation of DSQ in 2009.

Warm regards,

Lenny Jason

That’s a lot of info about you.

Can you explain briefly please?