Measuring Illness Severity and Post-Exertional Malaise in Long COVID and ME/CFS

T

tomdedz

Established Member
I am a researcher in social psychology (and a patient). We are building a study on the psychologization of symptoms of long COVID and ME/CFS patients. We are seeking to measure the severity of the illness, as well as the presence/severity of PEM. Ideally, we would like to measure these two constructs with the same scale for both diseases. And, imperatively, the measurement scales must be short.

Do you have any measurement scales to recommend to me?

Thanking you for your help.
 
Jonathan Edwards said:
Hi @tomdedz, What do you want to do with the measurement? That would affect what measurement might be worth doing.
Click to expand...
Hi. I am not sure to understand your message (sorry I am French). We plan to use these 2 variables as control variables in a mediation model, or as moderators. So yes, I should have add that is a quantitative study so we need ideally continuous measures

For the disease severity, I was thinking about the Bell disability scale, which is I believe most commonly treated as ordinal
I was also thinking about the SF 12

For the PEM, I have no specific scale in mind
 
tomdedz said:
We plan to use these 2 variables as control variables in a mediation model, or as moderators.
Click to expand...

Those terms are a bit technical for me. My point is that the choice of measure will depend on what theory you are trying to test - maybe about cause of symptoms or impact of symptoms on life or whatever. A simple step count is robust and useful for some things but not others. A visual analogue scale is often the best option for subjective variables but has calibration issues etc.

Most of the popular clinical scales are very problematic mathematically.

What are you hoping to prove or disprove? That is really what we need to know before making intelligent suggestions, I think.
 
FUNCAP for severity and functional capacity.

The Bell scale is not useful, it's a made up scale based on a very skewed view of ME/CFS. In my opinion it focuses too much on a scale from healthy to very mild to mild ME/CFS, and only includes a few items at the bottom that are relevant to most people with ME/CFS from mild/moderate through moderate, severe and very severe.

To track changes in symptoms and function over time I would use a mix of
1. wearable activity tracker to track changes in function in those who are mobile
2. A simple numerical or visual analogue scale to be filled in once daily to report overal symptom severity compared to that individual's normal when not crashed.
3. Weekly or less filling in FUNCAP to track changes in function over time.

I think that would provide the best tracking of episodes of PEM over time, as it would pick up changes in both function and symptom severity. For someone with very severe ME/CFS the tracking of symptom severity and FUNCAP may have to be done by a regular carer.
 
Last edited:
Jonathan Edwards said:
Those terms are a bit technical for me. My point is that the choice of measure will depend on what theory you are trying to test - maybe about cause of symptoms or impact of symptoms on life or whatever. A simple step count is robust and useful for some things but not others. A visual analogue scale is often the best option for subjective variables but has calibration issues etc.

Most of the popular clinical scales are very problematic mathematically.

What are you hoping to prove or disprove? That is really what we need to know before making intelligent suggestions, I think.
Click to expand...
I cant display hypothesis here but I am going to send you a private message

Trish said:
FUNCAP for severity and functional capacity.

The Bell scale is not ordinal, it's a made up scale based on a very skewed view of ME/CFS. In my opinion it focuses too much on a scale from healthy to very mild to mild ME/CFS, and only includes a few items at the bottom that are relevant to most people with ME/CFS from mild/moderate through moderate, severe and very severe.

To track changes in symptoms and function over time I would use a mix of
1. wearable activity tracker to track changes in function in those who are mobile
2. A simple numerical or visual analogue scale to be filled in once daily to report overal symptom severity compared to that individual's normal when not crashed.
3. Weekly or less filling in FUNCAP to track changes in function over time.

I think that would provide the best tracking of episodes of PEM over time, as it would pick up changes in both function and symptom severity. For someone with very severe ME/CFS the tracking of symptom severity and FUNCAP may have to be done by a regular carer.
Click to expand...
Thank you. I will take a look at the Funcap
 
tomdedz said:
I am a researcher in social psychology (and a patient). We are building a study on the psychologization of symptoms of long COVID and ME/CFS patients. We are seeking to measure the severity of the illness, as well as the presence/severity of PEM. Ideally, we would like to measure these two constructs with the same scale for both diseases. And, imperatively, the measurement scales must be short.
Click to expand...
There are no questionnaires to identify the presence of PEM. DSQ is often cited, but it suffers from fatal construct validity issues that make the data virtually meaningless. See e.g. this graph/
IMG_0210.webp

What does the «severity of PEM» refer to?
 
You must log in or register to reply here.
Back
Top Bottom