The pathway from glandular fever to CFS: can the CBT model provide the map?

[Dolphin]

I think the whole thing with the IPQ-R is rather dodgy, mainly because it asseses patients views without relating them to reality eg how treatable an illness really is, how much disability it really causes. It takes us to a fantasy land where the illness itself has no bearing on the experiences of the patient.

Makes sense (your point, not theirs)

 

[Esther12]

@ Oceanblue... did you ever write to the journal or authors about this? I was just reading this thread, and it looks like you did all the work needed to. It would be interesting to get a response. Ta.

 

[oceanblue]

@ Oceanblue... did you ever write to the journal or authors about this? I was just reading this thread, and it looks like you did all the work needed to. It would be interesting to get a response. Ta.

I haven't written a letter yet, partly because the only predictive factor that was significant in the multiple regression model was "All-or-nothing", which is probably less affected by illness severity, one of my main points. I'm still thinking of writing but I'm trying to understand the way they've handled the statistics and since all the techniques are very complicated this is involving quite a lot of study (though I am now beginning to understand how stats are used in papers).

The "all or nothing" factor came up with an odds ratio of 1.9 which is relatively small, particularly as the factor they used in the mulitvariate regression analysis was a mish-mash of other factors combined through 'principal component analyis' - so it's not even clear exactly what behaviour it represents. By comparison, Gender came out with an Odds Ratio of 6.5 but his wasn't significant, for reasons I don't yet understand.

I'll post if I come up with anything good.

 

[oceanblue]

I'll post if I come up with anything good.

Maybe I have, at last:
Fatal Flaw in Glandular Fever model?

This study found that psychological factors at baseline (initial infection) predicted which patients went on to develop CF (Chronic Fatigue) or CFS, and which did not. Or rather which psychological factors had a rather modest impact on the risk of developing CF/CFS. But the authors' approach in this study might be technically flawed.

This is a bit geeky so bear with me
The used a modelling technique called Logistic Regression to work out which baseline factors were predictors of the binary outcome i.e. developing CF or CFS. For such models to work, they need a lot more subjects than predictors and their final model had 217 subjects and 8 predictors, which gives an apparently healthy ratio of 27 subjects per predictor.

Except, it turns out that things are different in Logistic Regression where you have binary outcomes (subjects either have CFS or they don't) as opposed to normal regression where the outcome is a continuous score (e.g. Depression score, 0-30 points). Specifically, in Logistic Regression, it turns out the relevant number of subjects is the number of events i.e CFS cases in this study. There were only 17 CFS cases and 8 predictors: a wholly inadequate ratio of 2.1 events per predictor.

This issue with Logistic Regression comes from a 2004 paper by Babyak, who points out that simulation studies show that:

When only 2 events per predictor were available, 30% to 70% of the
estimates had bias greater than 100%! At a minimum, these
results should make us very wary of an article that does not at
least meet the rough guideline of 10 to 15 events per predictor—
an all too common feature of many published articles.

Incidentally, this Babyak paper was cited by James Coyne, Psychology professor and scourge of flaky psychological research.

So, assuming Babyak is correct (I'd be very grateful for any views on this) then the Moss-Morris paper finding that psychological factors at infection predict development of CFS is deeply flawed. In any case their results are of rather modest effects, and the predictors of CF at 3 months are completely different from the predictors of CFS at 6 months, suggesting the model isn't up to much. It may be because they have vastly overfitted data to produce their model.

 

[snowathlete]

What a load of crap this paper is.
That is all.

 

[Esther12]

Unless there was a really strong association, I think that's a fair point OB. (eg: if al 17 of those who developed CFS had evidence of perfectionist all of nothing approaches outside of population norms, then that would still be significant). I'd assume that there was not anything like this sort of association.

There is also the danger of confounding factors, eg: if measures of 'perfectionists all or nothing' approaches were also picking up those who genuinely had external demands which could not be dropped and so needed to push through their feelings of fatigue in a way which caused long-term physical harm.

I've forgotten so many of the details of this paper now though, that I could just be repeating myself. Good to know your still working on it!

 

[Holmsey]

In the usual Psycological and grandious way we have a title to the article which suggests a 'Pathway' to CFS has been uncovered when in actual fact all that has been done is ill people have been studied during their illness.
We have no idea when one illness gives way to the other, until we understand what CFS is this study means nothing. That's the problem with almost all of these studies, they start from a point of presumed knowing, the knowing that this is a psycological condition, a knowing which is not based on any undisputed evidence.

 

[Esther12]

@ Oceanblue... did you ever write to the journal or authors about this? I was just reading this thread, and it looks like you did all the work needed to. It would be interesting to get a response. Ta.

This is now the third time I've forgotten all about this thread, and then re-read it thinking 'this should have bit written up as a letter'.

The "all or nothing" factor came up with an odds ratio of 1.9 which is relatively small, particularly as the factor they used in the mulitvariate regression analysis was a mish-mash of other factors combined through 'principal component analyis' - so it's not even clear exactly what behaviour it represents. By comparison, Gender came out with an Odds Ratio of 6.5 but his wasn't significant, for reasons I don't yet understand.

I still don't really understand this either.

 

[Snowdrop]

The year is 2013.

The author is the same as before.

Same old, same old.

All that work and money ~ for what? To prove that people who are constantly ill don't always think what's good for them?

Plenty of physically well people have behaviours that could use modifying because they cause pain and suffering to themselves or others. Go offer them your care and concern for their wellbeing. As it is we are highly overwhelmed with help at the present moment.

Walk a mile in my shoes lady ~ you'll go screaming for your mama.

https://kclpure.kcl.ac.uk/portal/en...me(665b44c1-a023-4afe-a619-012a55c25b39).html

 

[Snowdrop]

Apologies. I'm talking to someone who isn't there.

Sigh.

I should know better.

 

[IreneF]

I've just skimmed thru this thread and have a couple of thoughts: I had "infectious mononucleosis" (EBV) when I was 16 and developed CFS when I was about 50. Quite a long time to spend brooding about my health.

There seems to be an underlying assumption that no one with CFS has ever been sick before, and hasn't a clue about how to manage illness.

It is easier to be sick when you're young, since you get time off school. Not so much if you have a job/kids/other obligations.