@discographer-- Of course it doesn't develop on its own. The founders and directors of the institution help shape organizational culture by establishing certain rules and protocols. They also decide whom they hire and people who understand and work in accordance with the organization's culture will be hired. So the organizational culture has a lot to do with the directors' values, ideals and expectations.
The employees help shape organizational culture too. There may be cases where the organizational culture of a hospital is turning out to be different than what the founders had envisioned or approved. In this situation, the directors of the hospital need to make some structural and operational changes to make sure that the organizational culture matches the vision and mission of the hospital.
It's a good idea to look at organizational culture in healthcare institution by institution. Because no two institutions are exactly the same.