[paulmd]

as someone who worked in this area (not ML on records, but aggregating and ingesting EHR/ELR data) the problem is not just "the standardized record" but getting providers and hospital systems to use the record in standardized ways.

HL7 and FHIR are sort of like XML or CSV - they're just formats that define fields and delimiters. You can still emit HL7 or FHIR that can't really be consumed by anything else, and there's a huge amount of work to getting it "right". One of our perennial projects was a validator tool to help onboard facilities to produce data that was actually compliant with state/CDC systems. Unsurprisingly, from memory (that wasn't really my direct fief) basically every single system (from memory it was something like 80% of attempts) failed their first couple times and needed hand-holding to get it right.

https://fhirblog.com/2014/03/28/pictorial-representation-of-...

One of my projects was integrating a clinical recommendation tool with various EHR systems. That project didn't really end up going anywhere, but even just from the sample data being used in the various sandboxes I could tell that it was gonna be a massive slog actually getting it onto client systems, because every single client system was coded differently and there was different "quirks" to the data/etc. Fixing that wasn't really my task, just dealing with it, but the point is that even if you define a system that allows these relationships/etc to be expressed, there's no guarantee that a client system is outputting well-formed, properly normalized/denormalized data. It's rough.

And unfortunately it's 1000% a XKCD "there are 14 standards and systems still can't intercommunicate, we need a 15th standard" effect. There is already so, so much work mapping around between the various editions of ICD, CPT (procedures), and usually there are instance-specific (specific to the hospital system usually) coding systems underneath that (since in many cases eg CPT does not really convey enough information about the exact specific procedure - it's enough for billing but not enough for a radiologist to actually know what scan to perform in a medical sense). And the existing coding systems are already super generic and can express basically anything in multiple ways, which just feeds into the "it's possible to emit valid records that nobody else can really consume" problem.