A relative drop in rankings can easily be explained without concluding that the division is slowly falling apart (I know you aren’t saying that but it IS a possible conclusion . . .). For instance, every entity has improved in terms patient outcomes, breakthrough treatments, and funding, but others have improved faster than UChicago due to the latter’s smaller size and less aggressive advertising. Other institutions may have grabbed onto specialty areas that they are known for but can’t provide the breadth of both academic and clinical experience that UChicago’s medical center can provide to both med students and residents. And so forth. Obviously you can’t truly compare UChicago (where the med school competes with the B and Law schools, among others, for funding) with Mayo or Rush. There are probably a host of similar factors.
Perhaps the most important one to consider is why does UChicago have a med center to begin with. After all, Harvard doesn’t, but rather farms its medical personnel out to the myriad excellent hospitals throughout the Boston area (excellent, in large part, to the existence of Harvard Med). UChicago also has partnerships with other health systems (including the one that Evanston Hospital is part of) - it’s curious that Evanston Hospital ranks higher than UChicago Medical when there are Pritzker faculty teaching at both. At any rate, because the med. center - and med school - are not running their own show but in fact are under the division of medicine and bio. sciences, it seems clear that the medical center doesn’t exist autonomously the way that the B-school and Law school do, but rather serves the particular needs of the division. That might be incompetent organizaton - or it might be a different philosophy about the purpose of having a hospital in the first place. After all, the division is named “Medicine and Biological Sciences” not “Health Sciences”. A nuanced difference, but a difference nonetheless.