If you want to know the answer to that headline question, go here to Dr. Doug Perednia masterful analysis of a large study of how P4p worked out in Britain's NHS. The bottom line was that P4P had no useful effect at all.None.
If the so-called thought leaders and powers that be in such organizations as AMA and ACP and others supported ( continue to support?) P4P because of a belief that patient care would improve they should now take a strong stand against such programs. P4P does not work.
Implicit in P4P program is the concept of target goals. Goodhart's Law stands the test of time and logic. When a measure ( as in a purported measure of "quality") becomes a target it looses its value as a measure.