A general thread on the PACE trial!

The next tweet say:
Deale A, Chalder T, Marks I, et al. Am J Psychiatry. 1997;154(3):408-14. Sharpe M, Hawton K, Simkin S, et al. BMJ. 1996;312(7022):22-6. The PACE trial: White PD, Goldsmith KA, Johnson AL, et al. 2011;377(9768):823-36.

I just asked for the source and see you have done so too, @Arvo.

 

Yes, although I don't think a 6 minute walk test is very good for measuring changes in function. Most people willing to participate in a trial where they might be expected to undertake exercise are going to be able to walk for 6 minutes. And, because it's a walk test, there's a ceiling on how far people can go in 6 minutes. So, even if there had been improvements in function, I wouldn't expect to see a whole lot of increase in that measure.

Of course, choosing a poor objective outcome is the fault of the trial designers. But, focusing in on just the 6-minute walk makes it a bit hard to really nail home that argument about no objective improvement versus some subjective improvement.

 

True.

It's just that I've tried doing the test in my hallway in the past, and it seems such a subjective thing. If the person has a fairly good capacity to walk, it seems that things like motivation or encouragement with some setting of the expectation (or the allowance of breaking into something closer to running) would have a bigger impact on distance covered than actual physical capacity. It doesn't make sense to me as an outcome for trials with people with relatively mild ME/CFS or chronic fatigue; I don't think 6 minutes walking is long enough for the loss of power and coordination to kick in.

To me, something like 'unaided sit to stand' with repeated intense use of thigh muscles and more demands on balance and coordination possibly makes more sense as a measure.

 

So maybe the short physical performance battery (below)?



When not crashing, I think I would do within normal on the Short Physical Performance Battery of tests, but if I have overexerted I'd likely not be able to complete it. And for most healthcare professionals I've met it seems they are unable to understand that level of functioning can vary so much.

I usually classify myself as mild/moderate.

Edit: Image from "Multi-domain lifestyle intervention in older adults after myocardial infarction: rationale and design of the PIpELINe randomized clinical trial"

 

That's the problem with a one off test. It needs to be repeated on several consecutive days to demonstrate whether that level of activity can be sustained without deteriorating. That's why the 2 day CPET is valuable. We need to be able to demonstrate that ME/CFS is not just about deconditioning, though some of us who have been more severe for years inevitably are very deconditioned.

 

I also wish someone would have to demonstrate deconditioning plays a part at all. Sure deconditioning is what makes me unable to walk two minutes to the grocery store when I earlier in the week could bike uphill 30 mins to the university..

Ugh. I still remember the switch like feeling going home, uphill and suddenly losing my energy and struggling to breathe. Believing I was just extra tired that day, but then I got over the top of the hill, and managed to roll more or less the whole way home still having air hunger. Last time I biked that way

 

That includes the Chair Stand test, which is what I was thinking of. But it still only requires 5 repetitions. I don't think that's anywhere near enough to pick up fatiguability in well-rested people with mild ME/CFS.

Yes. Which is quite a problem for outcome measuring.

 

Even for well rested mild patients, unless assessed at home travel + waiting times would also have to be taken into account. Making it even more of a problem.

 

Short Physical Performance Battery

I could pass that test most days. It is possible, at least for me, to often be able to over ride or push through the physical stuff temporarily, which is going to skew results from tests like that hugely.

Which is why a repeat test protocol is so important.

Try repeating that test every day for a week and see what happens.