I can’t say I am well read enough on the detail of GRADE but I would say that whatever system is used to put a ‘value’ on research should determine first what the purpose of the ‘grade’ is.
Pace is a bad trial in terms of flawed methodology so you could discount it completely or can you use it to provide proof that even flawed it shows that CBT and GET doesn’t work (based on the principle that a negative result is as useful as a positive one)? So I guess it all hangs on what your objective is ....do a thorough search of all known research and use it to establish what facts exist?
In this case it’s a bit moot since all the evidence we have says that we don’t know very much and there isn’t a lot of anything other than what little we have tried so far doesn’t work.
One thing I used to do when doing a literature search ahead of pitching for a research grant (food not medical) was to initially group past research in terms of quality/strength just so I could weigh things up. This was good because you could quickly filter out the wheat from the chaff and spot ‘career publishing’ by the same authors and genuine replication etc. but also negative results that showed what ideas had been disproved.
I can see that grouping evidence might be useful initially to establish a base and even to demonstrate at a high level what you are dealing with, but that’s probably where it ends.
The next bit (insight) should be based on skill, common sense and consensus. I.e free thought not some second rate algorithm that assumes that people are incapable of learning a skill
Looking at the BMJ 'What is GRADE' and the opening para of 'How does it work?' the following sentence is interesting:
An overall GRADE quality rating can be applied to a body of evidence across outcomes, usually by taking the lowest quality of evidence from all of the outcomes that are critical to decision making. (my bolding)
To me, the confusions involved in what GRADE is trying to do are apparent straight away. It is not clear whether the idea is to decide whether or not there is an effect or to decide what size it is, apparently assuming that there is one. Certainty and quality are also seen as interchangeable. The whole thing looks like a fail on a probability exam paper.
As I've pointed out before I haven't followed this carefully.
Let's say
@Jonathan Edwards has done a study in rheumatoid arthritis using rituximab. Patients were selected using objective measures (e.g. antibody levels and scans), their level of disability was assessed using an objective measure. Half were then given placebo and half were got treatment (rituximab). Study was unblinded, and data collated, and treatment showed improvement re antibody levels, scans and reduced disability.
Why do you need an algorithm to interpret the results? OK the two groups could be too small to be significant but presumably the maths, re what's explainable by chance (noise in placebo results), deals with that. That of course is Jonathan's point---what's the purpose of the grading system [GRADE]?
I can see a point in NICE highlighting the issue of PACE being flawed, since it didn't have objective outcomes (they were dropped!), and that, as others have pointed out, is spooking the [GRADE/PACE---] horses ---- this logically has a read across to research which does not have objective outcomes!
It's [GRADE/PACE---] a pile of poo so why defend it ---
a meal ticket lovingly polished for decades has been shown to be a cheap copy [Jonathan]
I hope NICE have the Cahoonas to highlight the read across to other guidance ---- it looks to be glaringly obvious even if it's a huge issue.
And no I don't accept that PACE couldn't have had objective measures --- they were dropped.