Rich people, regardless of race, tend to come from rich places. The rich population is typically the most medically overserved, because they overpay for medical care (poor people get it for free). Rich people are more willing and likely to practice in rich areas, where the demand for doctors is highest (rich people in rich areas pay them extra to practice over there). Achievements from high SES individuals should be taken with more impact since they typically have much less extrinsic motivation and work at hospitals not because they need to to support their families, but because medicine is a higher calling for them. And still find time to fit in studying, research, etc, because they're actually good at time management.