Assessing Functional Capacity in [ME/CFS]: A Patient Informed Questionnaire [FUNCAP], 2024, Sommerfelt et al

I think the only two I might have marked myself down on at that time would have been 52 (TV) and 54 (concentrate for 2 hrs). But whether or not I marked myself down would have depended on how well I was pacing. To put it another way, I might have scored better on this section when I stopped work compared to when I was still working part-time, not because I was more capable, but because I had less of a drain on my energy/cognitive processing and was able to do that cognitive processing in a quiet room alone with infinite time rather than a busy workplace.

If I put myself in the shoes of someone who is keen to get people working/off benefits, then I might get excited at the look of a section where the person is only marked down slightly on one or two areas. Whereas I was not able to work part time when I would have scored that way on the concentration section, and concentration was one of the areas I was well aware of having significant difficulty with at the time.

Here's where I think the issue lies: the questions ask about the impact of individual tasks on activity for the rest of the day/following days, whereas PEM, for me anyway, is cumulative. You're supposed to answer for an average day, not a good one or a bad one, so I can answer each item assuming some degree of built-up exertion. There are certain tasks that will finish me off, or reliably induce PEM by themselves, so the answers to those items are clear. But for others, the problem is not that I would get PEM from them alone, but that if I do, say, three of them, I'll get PEM. For part-time work, being able to read and respond to one text wouldn't be enough. You need to be able to have multiple text, email and verbal conversations in a row while remembering all those much-longer-than-one-page documents you read/people you met while upright with intermittent mowing and alarms and dog-barking and bleeps.

Don't get me wrong, I think they have done a great job of covering areas that are not usually covered, involving patients etc.

I'm not doing a good job of explaining my point because brain is now mush! I do have one, though, somewhere...

 

We are very aware of the cumulative aspect of PEM.

I have ME myself, and the best analogy I know is having a current account and a credit card with energy, and that you can get into debt both all at once and a little at a time - and that debt will have to be paid back with interest, and that you cannot spend normally until the debt is paid.

We have played around with ideas on how to ask about this in a way that will highlight the cumulative effect - but were unable to come up with something that was easy to ask and to answer. If anyone have ideas on how to handle this, we are more than happy to try to work it into FUNCAP mark II!

We are also aware that the disease varies a lot over time, and that days seldom are the same. Again, incorporating this into the form was not easy. We did have some questions about variation in capacity - but the answers did not correlate either to selv-reported severity or to any of the domains, while there was great correlation between domains, and betwween domains and self-reported severity. In other words - everyone experioenced variation, and it added nothing. Again - good ideas appreciated

 

Tweet in the post above is first in a thread explaining why someone on Twitter thinks this questionnaire is really good.

 

One can now calculate one's score online:
https://raffbenato.github.io/funcap55/

 

Useful to be able to test the questionnaire like this. Thanks to raffbenato for coding this.

 

I score well with things like concentration, so while I might consider that I'm closer to moderate overall I came out mild. But as is often said: even mild with this disease represents a significant loss of function.

Thank you to Rafael Benato for coding this up (GitHub source repo here for those interested).

 

This looks very useful.
One question - I tried using this to score a severely ill patient I know and wasn't sure how to address the cumulative effect of multiple activities in a day. So for instance, they can't do multiple things at the same time (toilet and brush teeth) - they have to rest in between just to try to minimize the extent of PEM. But this is scoring on one activity at a time.

How would you score that?

 

What do folk think about specifying that the tool offers an indication of maximal functional capacity?

I got my result by answering as if I was having a reasonable day. I usually get several of these a week, but never seven; sometimes there are none, often because something outside my control has affected my pacing.

The reasonable day approach seems to be a good way to use the tool, but it still skews the picture a bit. If someone's capacity rarely gets much better but is sometimes worse, might using 'maximal' help to clarify it a bit? (Or is it just shrouding it in fog? )

 

d worst e best

worst for me knowing what to ans was the answer depends on context. idk how much test-retest variation i'd produce.

Your Score: 0.90.

would be lower if took average day seriously. can do little on any day and nothing without pem. i scored it as "delta from usual". every day having to do for tenuous survival significantly more than should. most would be 0.

 

A few comments, all with the proviso that I understand creating a good questionnaire is challenging.

Given that the questionnaire says, "Items described include necessary activities to perform them. Example: "Going to a shop for groceries" includes getting dressed and as necessary travelling."

"Standing up for approx. 5 minutes, e.g. while queuing or while cooking" - the intention of this item seems confused. Is it merely about standing for 5 minutes, or as seems to be the case, standing for 5 minutes as part of other activity. If it is the later then queuing could be part of much higher activity, e.g. shopping in store, than cooking at home, or standing up for 5 mins at home.

"Participating in a conversation with three people for approx. half hour"
"Socializing with friends for approx. 1 hour"
"Participating in a dinner party, party or family event"

For many participants, the three items above might be rated differently if these events took place in the participants home or somewhere else. Context is important.

"Doing enjoyable leisure activities, such as going to a cafe, non-essential shopping etc"

Just a personal opinion, neither of the examples in the item above have ever been enjoyable leisure activities for me. I'm therefore not sure what they are asking about, perhaps the equivalent of a leisurely walk in the countryside?

"Using public transport (bus or train)" - As part of an activity, or just for the sake of using public transport?

"Staying in an environment with the sound of a few people in quiet conversation for approx. 1 hour"
"Staying in a noisy environment, (shopping mall, cafe or open plan office) for approx. 1 hour"
"Going to a cinema, concert etc. with high noise levels"

The above three items are in the sensitivities section. I would be concerned about whether or not participants would take into account the travelling, if any, to these locations - I suspect some would and some wouldn't, making comparisons between results inaccurate.

"Managing a full working day (non-physical work such as office work, classes or lectures)" - At home or away from home? For many there will be a difference.

 

Yes, mine was 2.85, which I think is fairly accurate – though it's skewed a bit by a walking impairment that I don't think can be explained fully by ME alone.

 

Now published, Assessing Functional Capacity in Myalgic Encephalopathy/Chronic Fatigue Syndrome: A Patient-Informed Questionnaire, open access, https://www.mdpi.com/2077-0383/13/12/3486

Abstract

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is an acquired disease with significant morbidity that affects both children and adults. Post-exertional malaise is a cardinal symptom of ME/CFS and impacts a patient’s functional capacity (FC). The absence of effective tools to assess FC has significant consequences for timely diagnosis, clinical follow-up, assessments for patient disability benefits, and research studies. In interventional studies, the inability to assess FC can result in an incomplete assessment of the potential benefit of the intervention, leading to beneficial treatment outcomes being missed.

Methods: Using extensive, repeated patient feedback, we have developed a new questionnaire, FUNCAP, to accurately assess FC in ME/CFS patients. The questionnaire consists of eight domains divided by activity types: A. personal hygiene/basic functions, B. walking/movement, C. being upright, D. activities in the home, E. communication, F. activities outside the home, G. reactions to light and sound, and H. concentration.

Results: Through five rounds of anonymous web-based surveys and a further test–retest validation round, two versions of the questionnaire were developed: a longer version comprising 55 questions (FUNCAP55), developed for improved diagnostic and disability benefit/insurance FC assessments; and a shorter version (FUNCAP27) for clinical patient follow-up and potential use in research. Good reliability and validity and negligible floor and ceiling effects were found, with comparable findings in all aspects in both a large Norwegian (n = 1263) and a separate English-language international sample (n = 1387) demonstrating the validity and reliability of FUNCAP.

Conclusions: Our findings support the utility of FUNCAP as an effective, reliable and valid tool for assessing FC in ME/CFS patients.

 

Very pleased to see this finally published. I hope lots of researchers use it.
Sure, there are a few things I would have cut and sliced or phrased differently but perfect being the enemy of the good and all that. No single instrument is ever going to cover everything for everyone. This is a major improvement on all those awful questionnaires we've been subjected to for so long