It'd still occur in a single-payer system. The problem is fees for services instead of fees for results.
How else would you measure it? Survival rates? Doctors now have a strong incentive to avoid taking on sick patients.
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....
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)