Did they also control across types of medicine? If the higher-scoring doctors go into types of care which are more competitive, could those practices have lower

Did they also control across types of medicine? If the higher-scoring doctors go into types of care which are more competitive, could those practices have lower patient mortality within 7 days? For example, maybe burn unit care is high-mortality and low-barrier, compared to sleep medicine which is low-mortality and high-barrier (I don't know how accurate this is, just providing some hypotheticals for clarity)