Here in Canada, in addition to MDs must follow guidelines set by the Ministry of Health of each province, there are also caps on the income of MDs.
I believe it is $400,000 for MDs, beyond which the MDs can only get a portion of the claims MDs submit, i.e. for each dollar MDs claim beyond $400,000 they only get a portion of it.
Plus, when the provincial government pay out too much to a particular MD, they will review the claims of that MD, and may launch an investigation ...
That's why medical costs in Canada is cheaper than the States ...
This system will "discourage" MDs from performing thousands of stents per year
You see, there are things that medicare or the American government can learn from the Great White North