Any evidence for that claim? The issue is not whether there is administrative overhead, but the amount of it. It’s not obvious to me that completely different funding models would incur the exact same amount of overhead on the practitioners.
It does happen in a fashion in the Canadian system where family doctors at least operate as private businesses that bill the gov't, and because of that have to spend quite a bit of time on paperwork which then requires a whole edifice which there has been a lot of complaint about recently.
A search will find you plenty of articles about this.
That and the nature of the relationship introduces conflict. Plus the bulk of provincial governments administrating the thing are ideologically biased against it because they are conservative or neo-liberal in bent, and have been chronically underfunding it for years....
If I only earn when I treat, then I have an incentive to over-diagnose. Insurance thus forces me to document my diagnoses, and I spend much of my time on documentation and appealing denials.
So the wealthy can finally cheat death efficiently once and for all ;-)
On a more serious note: that might be hard in medicine per se to pay for “results”. And I found some of the insights from “Outlive” quite interesting: how we focus in cure but not prevention; and how in the bigger scheme of things Antibiotics was almost the only “real big invention” in western medicine for a very long time (e.g., in terms of actual medical impact)
How else would you measure it? Survival rates? Doctors now have a strong incentive to avoid taking on sick patients.