Objective: The purpose of the current study was to develop and evaluate a brief screening instrument for ME/CFS. The current study identified 4 symptom items that identify those positive for the IOM ME/CFS case definition. Study Design: A data set of over 2,000 patients with Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and over 350 controls were assessed for the 4-item DePaul Symptom Questionnaire-Brief (DSQ-Brief). All respondents also completed the longer 54-item DePaul Symptom Questionnaire (DSQ-1) as well as the 14-item DePaul Symptom Questionnaire-Short Form (DSQ-SF). These data sets were collected from multiple countries. We also examined the DSQ-Brief, DSQ-1, and DSQ-SF with other chronic illness groups [Multiple Sclerosis (MS) and Post-Polio Syndrome (PPS)] and those with Long COVID. Random Forest comparisons were employed in these analyses. Results: When contrasting ME/CFS from controls, high levels of accuracy occurred using the DSQ-1, DSQ-SF, and DSQ-Brief. High accuracy again occurred for differentiating those with ME/CFS from MS, PPS, and Long COVID using the DSQ-1 and DSQ-SF, buit accuracy was less for the DSQ-Brief. Conclusions: The DSQ-Brief had high sensitivity, meaning it could identify those with ME/CFS versus controls, whereas accuracy dropped with other chronic illnesses. However, it was possible to achieve better accuracy and identify those cases where misidentification occurred by administering the DSQ-SF or DSQ-1 following the DSQ-Brief. It is now possible to screen individuals for ME/CFS using the DSQ-Brief and in so doing, identify those who are most likely to have ME/CFS. Paywall, https://www.tandfonline.com/doi/abs/10.1080/21641846.2023.2252613?journalCode=rftg20
Since there's no way to clinically verify that the people supposedly having ME actually do have it, isn't the questionnaire just accurately identifying people who answer the questionnaire the "right" way?
I very much like the use of disease controls in this study. Historically, the problem with the dePaul symptom questionnaire was that the questions on PEM. couldn’t distinguish between PEM. and exertion intolerance (the latter is common in many illnesses,). However, I thought the current version of questionnaire uses much better questions to probe PEM. Have I got that wrong?
From ME Research UK: Could a questionnaire based on 4 symptoms really differentiate people with ME/CFS from those without, or from those with other chronic illnesses? In a recent study, Professor Leonard Jason and colleagues at DePaul University, Chicago, investigated https://www.meresearch.org.uk/can-a-brief-screening-scale-accurately-detect-me-cfs/
It's frequency and severity over the last 6 months for these symptoms: 1. Fatigue/extreme tiredness 2. Minimum exercise makes you physically tired 3. Feeling unrefreshed after you wake up in the morning 4. Problems remembering things I've attached a PDF.
Well, based on that, I don't have ME. My fatigue-like symptom varies, and is affected by foods and other factors, but lately I've been feeling fairly energetic. I did maximal exercise (sawed and moved a big tree) last evening, and felt quite well afterwards (and still feel well). I don't bounce out of bed, and wished I could sleep longer ... and wake up feeling more refreshed, but that never happens. Yes I forget things, but I think that's a normal amount for age 62. I did fit the Canadian criteria for much of my ME period. I managed to cure my PEM, but all the other symptoms remained the same, so I don't think I suddenly switched to a completely different disease. I never fit the 2nd item: my ME didn't limit my physical abilities, although it did give me brainfog, malaise, and aches 24 hrs later, but not what I would label "tired" or "fatigued". The problem I see with the screening tool is that it encourages people to answer the worst perception of their symptoms. Did you forget what you went into a room for? Yes! That happened! It must be due to ME! My guess is if you asked that same question to a bunch of random people without explaining what it was about, you'd probably get a similar set of replies. The same probably applies to the other questions. If you labelled the questionnaire "heart attack risk" or "happiness with your life", you'd probably get different results. I don't see questionnaires as being very useful for ME. That's also a leading question. How many of us feel unrefreshed when we wake up, but also feel that same symptom all through the day? I don't feel it's any stronger in the morning than at any other time of day, so I think that symptom has nothing to do with sleep. I think DSQ-Brief is an invalid tool for screening PWME, which means that the results will be invalid too.
The questionnaire for tired people. If they are recommending this seriously as a diagnostic questionnaire for ME/CFS, they have surely lost the plot. I have never much liked the DSQ in all its forms. They seem not to understand what PEM is and conflate it with PEF or fatiguability.
I would guess the value of this will depend on what use case they see for "a brief screening instrument". If it is intended to definitively identify ME/CFS then yes, that would be problematic; if it is intended as a list of questions to ask before a full investigation of symptoms then it might have some use, but even then I'm struggling to see the value. Hopefully it is better explained in the full paper, because at the moment it looks more like a list of questions a healthstyle magazine article might have.
If they want a brief screening instrument, don't they need to focus mainly on establishing whether PEM is present? Absence (or apparent absence) doesn't rule out ME, but if it is present the patient should undergo a full assessment. I'd like to see the word questionnaire retired for these initial screening tools, because using a set form of words—or worse still, handing patients a tick-box sheet—can't be the best way to use them. People just try to come up with the 'right' answers. Doctors usually tailor diagnostic questions to individual patients, and they know that approaching an issue obliquely or asking the same question more than one way sometimes gets a clearer or more considered response. The screening tools should be there to summarise the information they need to get, not specify the actual wording they need to use.
I would assume, based on their previous work that "Minimum exercise makes you physically tired" is meant to be asking about PEM.
Yeah, I'm sure you're right. It doesn't, though; "tired" is inappropriate, "exercise" is inappropriate, and that's before we get to the problem of cause and effect not being obvious to anyone who doesn't already know there can be a one- or two-day delay. All the questions probably need to be about the various aspects of PEM, to separate it properly from other reasons minimal exercise can make people physically tired.
I thought of another potential problem: the "test" would be likely to produce too many false positives, because it's easy to exaggerate symptoms to qualify. Any business (medical insurance) or institution (hospitals that don't profit from false positives) would aggressively fight against its use, and would likely result in negative impacts on the ME community. Whenever the ME community asks for something in the future, those opponents would bring up "that attempt to inflate ME numbers" or some such thing.
