Esther Crawley (2019) Physical activity patterns among children and adolescents with mild-to-moderate CFS / ME [baseline accelerometer MAGENTA data]

Illness beliefs are the basis of the BPS view, not deconditioning. They might be content with merely getting a patient to believe that ME is something that can be reversed with lifestyle changes, instead of the patient believing that they have an incurable neurological illness.
 
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Forbin said:
I wonder what an invalid weekday is.
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A day on which the child was an invalid. On such days the child may not think there's much point in wearing an accelerometer, or have the energy to think about it and put it on for the entirety of the day. I don't suppose there's any mention in the paper about excluding that potential bias. Esther always likes to give herself an edge.
 
This study examined physical activity patterns of young people with mild-to-moderate CFS/ME. Although some patients with CFS/ME are meeting physical activity guidelines, the majority are doing less than half the recommended amount. Compared with being ‘inactive’, there was some evidence to suggest being classified as ‘active’ was associated with greater physical function but also greater anxiety, while being ‘lightly’ active was associated with greater physical function and lower levels of fatigue. Paediatricians need to recognise that physical activity varies between patients with mild-to-moderate CFS/ME when they recommend treatment.
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Have only skimmed it but noticed that they say kids in the 'more active' group had higher anxiety than in the 'low activity' group; could this be the 'tired but wired' aspect that a lot of us experience when we do too much? I can see how they might confuse this with 'anxiety'.

Also don't these results just illustrate the 'energy envelope'; something they previously refused to accept.
 
Previous studies with adult patients with CFS/ME identified a ‘fluctuating active’ or ‘boom-bust’ physical activity pattern 17 ; however, this pattern did not emerge from the present analyses, most likely due to the relatively small sample size and missing days of accelerometer data
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So they couldn't find a boom-bust activity pattern. I also think they don't use that reference correctly. 17 refers to Van der Werf et al. 2000 which found no differences in day-to-day fluctuations between ME/CFS patients and controls. There's another Belgian study that also used objective actigraphy and found "no evidence for important variations in the activity pattern of patients with CFS."

The second important finding is that a significant proportion of patients (approximately 10%) had activity levels that were high enough to meet government recommendations. Something similar was found in the adult study by Van der Werf et al.: "The results also showed that a proportion of CFS patients had activity patterns and parameters comparable to those of controls."

So I'm thinking about writing a letter to ask the authors to comment on these findings.

Given the above findings, what is rationale of the MAGENTA-trial for targetting the activity pattern of these ill adolescents?

According to the MAGENTA trial protocol, activity management aims to convert a ‘boom–bust’ pattern of activity. How should one interpret this now that the data showed that, on average, the activity pattern of these ME/CFS patients does not show a boom–bust’ pattern of activity? Were patients instructed to correct behavior they didn't display?

Were the patients who had an activity pattern high enough to meet government health recommendations, also instructed to gradually increase their activity, up to levels that are higher than what health recommendations prescribe? Isn't it unethical to do this with adolescents and children that are unwell?
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[Edited to make it easier to read]
 
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I've only skimmed it but they seemed to like the idea of getting the more active ones to slow down before gradually building up, and the less active ones to start building up straight away.

And with only 3 or even 7 days of useful data from not much more than half the trial participants, they really wouldn't be expecting to find any boom and bust pattern anyway. That would require wearing the actometer consistently every day all the time for a month or more, I think.

I think the only thing that can be concluded from this is that the less active kids were also the sicker kids. And that they need to find a way to persuade participants to actually wear the actometers, and for much longer, to get anything useful out of it.
 
Trish said:
And with only 3 or even 7 days of useful data from not much more than half the trial participants, they really wouldn't be expecting to find any boom and bust pattern anyway. That would require wearing the actometer consistently every day all the time for a month or more, I think.
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That's possible.

If you focus on 1 patient then you certainly have to follow up on him/her for a longer period of time to see boom-bust patterns. But they had activity data from 135 patients for 3-7 days. So some of these should have been in the phase of first doing too much and then suddenly crashing and doing little. I suspect one should see bursts of activity followed by long rest periods in some of the participants. The MAGENTA protocol describes it as follows: "Activity management aims to convert a ‘boom–bust’ pattern of activity (lots 1 day and little the next)"
 
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My statistics may be a bit rusty as it's 2 years ago that I took a statistics course. But, I don't think that the use of regression analysis is even appropriate for this paper. You need to have solid grounds for treating one variable as the dependent variable in a regression, and the others as predictor variables. But she - through how she has constructed her statistical model - is assuming that physical activity is the predictor variable and that pain/fatigue/depression/anxiety are dependent variables. In order to have grounds to conduct a regression analysis like that, you really need to have done a longitudinal study, so that you know that your predictor variables actually preceded your dependent variable (unless your predictor variables are just things like gender and age which obviously belong as predictors not dependents). Of course that wouldn't really work in ME/CFS though because the variables of physical activity and pain levels, or physical activity and fatigue levels, tend to both influence each other! My old statistics lecturer would have a fit if he saw this paper! :emoji_face_palm:

Edit: I do understand why she did it though, as she wanted to control for age and gender, and (if I recall correctly) you can't do that in a correlation analysis. I had the same problem in my undergraduate dissertation - not knowing which variable I should treat as predictor and which as dependent (and I should have thought about that more thoroughly when designing my project. But I was only an undergraduate doing my first ever research project!) I ended up having to run the regression analysis in both directions. But I did at least make the problem clear in my write-up!
 
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Trish said:
Do they give the individual data, or group averages? I would think that group averages would smooth out and therefore hide such individual boom bust patterns.
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They don't give any data on this. It isn't even mentioned in the results. Bit it isn't my Interpretation that there was no boom and bust pattern, the authors mention this in the discussion section. they have the individual patient data so i assume that is what their statement is based on. Or am i overinterpreting things?
 
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I think there is a boom and bust pattern but it doesn't involve anything that could be considered a boom in activity, and may involve only occasional transitions from an above average activity level (for that patient) to below average activity levels (for that patient). So it's something that happens but if you're looking to explain disability with this you won't have much to work with. They could plausibly fail to find the boom and bust pattern that they imagine is there, but not because it's not real but because it's not how they imagine it. When a patient says they did too much and then crashed, what really happened is that they did a little bit more, so hardly a boom.

Boom and bust pattern has not been clearly defined as far as I know so we don't know what they mean.
 
The fact that they reported these negative findings - which speaks against their hypothesis - suggest that their data could have shown a boom and bust pattern, no? I also suspect that their view of a boom and bust pattern is somewhat different from what patients describe as PEM crashes, in that it is about fluctuations in a shorter time span.
 
Sly Saint said:
Have only skimmed it but noticed that they say kids in the 'more active' group had higher anxiety than in the 'low activity' group; could this be the 'tired but wired' aspect that a lot of us experience when we do too much? I can see how they might confuse this with 'anxiety'.

Also don't these results just illustrate the 'energy envelope'; something they previously refused to accept.
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I was thinking that too.
 
In terms of "boom and bust", what they probably imagine is us loafing around in our PJs all day, binging on TV box sets, enjoying ourselves not working, until we suddenly decide to try to do "all the things!" that we haven't been doing, and then we crash immediately afterwards.

What is probably happening for most of us is that, day to day, we are operating just below that exertion limit that is likely to cause us to crash, doing as much as we possibly can, and then every so often something unavoidable, and most probably unpredictable, comes along that means we have to do a bit more, which takes us over the limit, and we crash from that, whether that is immediately or up to 48 hours following.

Boom and bust as a concept is just so insulting to our intelligence, it's infuriating.
 
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