There are two huge issues that must be considered to provide any sort of meaningful information about doctor quality:
Doctoring is a human-powered service that relies on intuition 80% of the time. Therefore, doctors/surgeons have more in common with artists and barbers (what’s the “quality” of this barber?“) than with manufacturing machines. Is a barber that charges $80 better than a barber that charges $15?
Healthcare is an individualized experience that relies 20% of the time on population-level scientific evidence. We’ll never know how these population statistics will apply to your individual case in the 20% of the times that are backed by evidence. And the 80% of practicing medicine we’ve called the "art” is really just gut instinct or intuition backed by nothing more than tradition. Checklists and protocols are the most important component to ensure quality for the 20% of the time that is evidence-based. The other 80%, well, it’s unknown and unknowable.
So, when searching for a doctor or hospital and you’re wondering about quality, the most important things to consider are whether or not they use checklists and protocols and whether or not your personality jives with the doctor’s personality. Beyond that, you’ll never know.