Nurse practitioners are used in many countries with great results. Why is using them illegal ? of course it's because of regulatory capture and the general power doctors hold, which is probably the biggest reason why healthcare is so expensive(and also not very good).
You see it in million places: The limited number of medical schools, The lack of nurse practitioners doing the simple routine jobs in most specialties(dental, family, colonoscopy, anesthsia. Many others could exist), The lack of automation and expert systems[4] and automated patient interview[3] tools, the fact that family practitioners could replace a lot of the specialists work at lower costs[1], Many medical jobs could be done with a lot less training[2], the lack of use of proven processes like checklists[5], etc.
All those changes could save a lot of money, and raise quality. We know what to do, But how do we implement it ?
[1]http://www.rwjf.org/en/grants/grantees/project-echo.html
[2]Because there's a brain drain in africa to the west, some countries have started a 3 year surgeon degree program. Doctors who finished this degree seem to have equivalent results to fully trained doctors in simple/medium complexity surgeries.
[3]Research showed doctors only ask about half of the questions needed in a typical visit. Automated interview systems could at least gather more complete data.
[4]There's research review showing that correct implementation of decision support/expert systems could improve results.
[5]Peter provonost showed that checklists could reduce infection rates in one procedure from 8/12 percent to zero.This was around 10 years ago. I think gawande showed similar results in other stuff. checklists are still not commonly used.