Paywall, https://journals.sagepub.com/doi/10.1177/1742395320949613 Sci hub, https://sci-hub.tw/10.1177/1742395320949613
It would be easier if the data was presented in the abstract. Interesting that fatigue severity didn't correlate well with the actigraphy, in contrast to an activity questionnaire. That seems to suggest that it isn't so much fatigue that determines patients' activity level and supports moving away from this symptom as the central feature of the illness.
In my opinion the fatigue severity scale poorly measures absolute fatigue. Measuring daily activity is probably much more accurate, especially if other reasons for low activity level are controlled for. Anyway I think exertion intolerance is the key feature, not fatigue.
From Leonard Jason's group. I find this separation a bit odd - I don't think there's enough evidence to differentiate two conditions. . It's not clear if people who met the requirement for both CFS and ME are included in this study. 35 children who met the Fukuda criteria and 15 healthy controls. Some bias in the samples I think: Patients: Male 42.9%; Female 57.1% Controls: Male 60%; Female 40% I know there's lots of variation, but I think in most Western cultures, female 13 year olds tend to be less active than males. Also the time of the year worn: Patients: During the school term 45.7%; school holiday 54.2% Controls During the school term 33.3%; school holiday 66.7% The controls were wearing the activity monitor for much more time in the holidays compared to the patients. Normal patterns of activity during school and holidays are different.
Certainly that's what I would expect. But I'm not sure that Figure 1 really shows a lot of night-time activity. Neither group is doing much between 10 pm and 6 am. The activity monitor was only worn for one day by each participant. This is acknowledged as a limitation by the authors - behaviour might easily change for a day when the participant knows their activity is being analysed. This could easily be a reason why the activity and fatigue levels didn't correlate. I don't think this finding can be extrapolated beyond this study. Here, the participants had no particular incentive or pressure to report a particular level of activity. That will probably not be the case with most unblinded intervention studies. This paper should not be used to justify self-reporting of activity levels in such studies. If you are going to spend a lot doing a study, spend a bit more to do it properly by using activity monitors (and use them for a lot longer than a day).
They were worn around the waist. Yeah, it isn't clear from the text if the selection was only of children who met the Fukuda definition but not a definition that they equate with ME. (Fukuda compliance but not CCC compliance) or (Fukuda compliance but not IOM compliance) is potentially quite different to (Fukuda compliance but not excluding those who also met more demanding criteria). I suspect, given the effort the researchers went to to diagnose against various criteria and apply different labels of CFS and ME, the cohort is (Fukuda compliance but not compliance with a criteria that requires PEM). But the way the Fukuda criteria works, some of the cohort still might have had PEM. It's not clear. It seems as though they are making their research less useful by trying to work within the confines of a criteria that doesn't mean much. I don't understand why good researchers still use Fukuda.
It makes no sense to me to do an actigraph over 24-hours. Alone we know they got $75. Maybe some had fatigue but went out to spend it. Some tucked it away. Already the study messes up the first day of it's results But also, maybe one just wanted to do more that day regardless of the study. Some days I do more despite having a lot of fatigue! It makes me angry and I go walk or something. I've had days where I've done a great deal, where I've had to, or simply wanted to in spite of my symptoms. I've even had weeks like that, but eventually it shows. It would look like the second day, the ones with fatigue are increasingly doing less than the controls.
Given that it was for a single day, I doubt it is generalisable. It's easy to report accurately for a day, but it might become tiresome after the 40th day. I wonder also whether children are going to suffer from greater social-desirability biases (including greater diligence in activity reporting)?
I can’t imagine they would have thrown away loads of data. If they had used a cohort that solely satisfied Fukuda but didn’t satisfy other criteria, there would have been a lot of other patients (i.e. who satisfy Fukuda and other criteria) excluded. So I suspect these were all of those who satisfied the Fukuda criteria. Also Leonard Jason likes to use “ME and CFS” language when he can.
Sure, but why would an experienced ME/CFS researcher who understands the consequences of the various criteria use a potentially mixed cohort? Some of the Fukuda sample may not have PEM.
I know of some children ( not all ME) who told the authority figure what they thought they wanted to hear, either to make them go away ( psychology and teachers seen to score high in this , bit may be age dependent ) , or to please In an asymmetric power balance it is not uncommon.
