first u have to decide wether u will cover in-patient or just clinic with out-patient. It is a good idea to imagine the operation of local hospital. So u can imagine which department to be used.
Based on this operation u can try to determine the table needed and all the screen needed
But first of all u have to make observation to the hospital itself
It is how i design my hospital projects
If you're in one of those predicaments where cls.__private attributes just aren't enough since they can easily be accessed through inst._cls__private, and you need something a little more secure, here's ...