I don't see how the analogy works. The entire point is you have a medical record with objective characteristics that can be tied to the risk of any given procedure.
My entire point is that isn't true at all - you have a medical record with some objective characteristics, but it is not possible to calculate the risk of a procedure based on that information. Just like in software, we have a project requirements document with many objective characteristics and we are unable to calculate the time required based on those characteristics.
So what is the risk calculation based on? Presumably the doctors refusing to do procedures they deem high-risk are not determining completely at random. The risk calculation doesn't have to be perfectly accurate, and it seems to me as though heart procedures are better defined than software projects.
(And besides that, although software estimation is notoriously inaccurate, it is still done and written into contracts all the time, because it serves a useful purpose that outweighs its inaccuracy)
