If you simply mean filling out the form, then a PDF properly created
for being filled out on the computer should work in Preview.
For a form not created for filling out on the computer, then:
- if it is not a protected PDF, then you can import it
into a word processor or DTP app and place text boxes
over the top where you ewant to type details.
- if it is a protected PDF, you might have to first
make screengrabs of each page in Preview, then import
those into the word processor / DTP app. They will
be screen quality though, so may be better to print
and rescan them ... in which case you may as well
simply handwrite the detail ont ot eh printed forms,
as they were probably designed to be filled out.
If you actually mean *editing* the forms, then you'll have to be a
hospital employee with permission to do so.