There is another danger related to your second point. If you can't completely control for the risk of a patient, then you create an incentive for doctors to tu

There is another danger related to your second point. If you can't completely control for the risk of a patient, then you create an incentive for doctors to turn away high risk patients. This effect has been observed in real life: https://www.kellogg.northwestern.edu/faculty/satterthwaite/Research/2003-0520%20Dranove%20et%20al%20re%20Report%20Cards%20(JPE).pdf https://www.kellogg.northwestern.edu/faculty/satterthwaite/R...