I think the issue isn't data, its the "packaging". Going through the NHS website, it's useful if you already know what you have. I'll use myself as an example because I had an ingrown hair on my neck a few weeks back, went on google and I didn't search for "Ingrown Hair" because at that stage, I didn't know that it was an ingrown hair. I searched for "bumps on your neck" which led me to conclude that it was an ingrown hair (followed by a doc telling me the same thing).
One idea I've had for a long time is the US Gov't (and all major governments) should have a large data gathering/distribution operation. This data would be things like medical research, and other data that would be in "the public interest" (basically all the data we have now, just in one place), everything from meeting notes, congressional bills, etc.
With a wealth of data from a single source, companies like WebMD could stop focusing on how to get the data, and shift their focus to how to "package" the data. A list of conditions with symptoms is nice, but lets repackage that into a "medical graph" that lets you explore related conditions through symptoms. Companies could then compete on the "packaging". You could go to FreeMD and get the same data as you could on WebMD, but WebMD has a much better search engine for X thing so they are worth the $4.99/month cost.
It would be expensive, and probably be a decade long multi billion dollar operation. But imagine the revolution in government services if there was a single source of truth for data.
There are arguments against this, mainly do you want a government to have that much power. But I think it could be done with some strict limits and checks. Data in this API would only be public government data, so IRS data and other private information is not on there.
NHS already offers a (fairly rudimentary, last I checked) diagnostic tool in the form of NHS 111, which as well as being a phone number that people in the UK can call to talk to someone, is also a website (https://111.nhs.uk/) where you can give your symptom(s) and get a suggestion if possible causes.
It may not yet be good enough in all cases, I'm not sure, but is that what you're asking for? I'm not quite sure as you dived into things like data licensing without being clear on your actual hoped end result.
(Of course, the 111 site is designed as part of the wider NHS system, so when in doubt it's more likely to give advice to speak to a GP / call to speak to a nurse / visit a hospital, than to say "not sure, here are all the conditions it could be". But as it gets better I expect it to be able to do both.)
Not to mention that the main NHS site also lets you search for symptoms in the main search bar, so you don't need to know the condition to use it to search for possible conditions. edit: as better pointed out by jjar here https://news.ycombinator.com/item?id=32650958
One idea I've had for a long time is the US Gov't (and all major governments) should have a large data gathering/distribution operation. This data would be things like medical research, and other data that would be in "the public interest" (basically all the data we have now, just in one place), everything from meeting notes, congressional bills, etc.
With a wealth of data from a single source, companies like WebMD could stop focusing on how to get the data, and shift their focus to how to "package" the data. A list of conditions with symptoms is nice, but lets repackage that into a "medical graph" that lets you explore related conditions through symptoms. Companies could then compete on the "packaging". You could go to FreeMD and get the same data as you could on WebMD, but WebMD has a much better search engine for X thing so they are worth the $4.99/month cost.
It would be expensive, and probably be a decade long multi billion dollar operation. But imagine the revolution in government services if there was a single source of truth for data.
There are arguments against this, mainly do you want a government to have that much power. But I think it could be done with some strict limits and checks. Data in this API would only be public government data, so IRS data and other private information is not on there.