Google recently changed its rules regarding star ratings, restricting first-party sites.
Announcement on the Google Webmaster Blog
How does this impact search results for physician profiles on hospital websites?
I researched search results for 20 hospital sites, ranging from small community hospitals to large systems.
Results:
Bottom line - minimal impact on hospital sites. If you're missing stars, check the new guidelines at Search Engine Journal and work with your developers to get it implemented.
Google employs humans to research your site and evaluate it for EAT, YMYL and beneficial purpose .
Hospitals rank high on EAT, are 100% focused the "L" in YMYL and should rank high for beneficial purpose. That's probably why the majority of Hospital sites are still showing star ratings. (More info at Search Engine Journal)
See the chart below for all data (direct link to Google sheet)
Note - the embedded chart may load slowly.