I assume that the question is targeted at the financial aspect of health care?
Just a quick reasponse, I think hospitalisation insurance is essential, especially for the older folks. I have an aging parent and my sis and I have covered her for hospitalisation as well as out-patient treatment. Took a load off our financial burden when she was hospitalised for stomach flu; also medication is covered when she goes to a GP.
If we're talking about getting on top of all the possible ailments they might pick up, well I just google the symptoms and see what they might be. I'm not a doctor and have no experience with medical terms, but it helps to have some background knowledge (no matter how vague) when bringing them to a medical professional.