Combined causal related disorders
Dear Jim & Bruce
I am sorry to trouble you about this again, but there are almost 300 rubrics within ICD 11 pertaining to combined disorders which have a causal relationship and I am still finding it difficult to consistently apply Occam's razor as to whether they should also be modelled as co-occurrent. I appreciate that there have been many previous discussions about this so forgive me if what I am suggesting has already considered and rejected in the past.
I seem to be able to make more repeatable decisions if the default modelling of combined causal related disorders is co-occurrent and due to; and the exception are circumstances where the ‘primary’ causative disorder is no longer present (and thus not co-occurrent).
The attached short document details my rationale in more depth.
Philip Bayliss Brown
Comments
Thanks.
All that's being suggested is a change from a default position of 'X due to Y' to 'X due to and co-occ with Y' (and thus a default assumption that Y is necessarily present throughout the effective duration of X). I suppose this changes the 'direction' of the reasoning that follows when each specific example is then considered, but if the justifications are the same the eventual judgement reached shouldn't be any different. Interesting that it 'feels' more reproducible - probably need to test the two default positions on a common sample of examples and see what comes out.
Looking at the list at the end of the paper I'm already coming up with different answers; any of the 'due to biliary calculus' examples could plausibly be 'X due to Y' if we regard Y as meaning 'known presence of a calculus in the biliary tree (a 'disordered structure' in SDP terms)' - the calculus itself could well have been passed before resolution of the inflammation it caused. If by contrast the assumption is that Y means 'the disposition/propensity to form biliary calculi (SDP = disposition)' then I would probably agree with 'due to and co-occ'.
I'm even less inclined to agree with 'chronic pancreatitis due to acute alcohol intoxication' being 'due to and co-occ', and am incidentally concerned to see this term was added a synonym for a concept (235952002) that is the parent of 154211000119108 | Chronic pancreatitis due to chronic alcoholism (disorder).
Ed, I agree that there will still be challenges in assigning the correct pattern even if x co-occurrent and due to y is taken as the default position. I would agree with all of the examples you state as well as adding Chronic kidney disease due to hypertension (e.g. renal hypertension can resolve after angioplasty but the CKD will persist). I think the main advantage of defaulting to the x co-occurrent with y pattern is more frequently capturing the causative condition as an additional parent.
Bruce
Phil, thanks for sharing this. I like your idea of making co-occurrent and due to the default based on the transitory nature of the cause in comparison with the effect. Of course if both cause and effect are transient (Allen's pattern equals) this would also be co-occurrence but these are generally easy to discern e.g. obstruction co-occurrent and due to hernia. My initial thought when our model was developed was that the simple due to pattern would prevail as we considered chronic conditions as potentially curable and were able to find rare examples such as for diabetes "cured" with an islet cell transplant for which the complications would persist. In most cases, chronic conditions are not or are only potentially curable and the fate of their complications are speculative. I think the advantage to what you suggest. is not only that it might be easier to reproducibly assign this pattern but that it would also result in a majority of the combined disorders inheriting 2 parents which would aid in data retrieval which was in my opinion a major goal of this project.