Hello Luis, welcome to the Seven Forums.
I would do this with Saved Searches
Save all patient information as you had planned, each patient having own folder with all relevant information. Name each main (patient) folder using sort options you need to use as for instance John Doe - Dr. Kildare - Stroke
(patient - doctor - diagnosis).
Now create Saved Search
links. To search all stroke patients, open the folder containing all patient folders and type type:folder filename:stroke
to search field. When search is done, click Save Search
Now you you have a link to all folders of stroke patients:
Do the same with all sort criteria you need to. Saved searches appear on the left pane of Explorer window, on top under the title Favorites