There are quite a few articles with information about him, but nothing fits, nothing...especially at his age. The one thing I did find interesting was the fact that he had a doctor "on retainer". He paid him yearly for open access - what does that even mean?
It probably means that SP had a private "concierge" doctor.
These doctors often don't accept insurance, and instead only accept cash. Most of their patients are high income individuals sans insurance who have money to pay for extra and immediate attention. As a result, such doctors also offer house calls and if the patient needs to come into the clinic, extended hours with private waiting rooms replete with the expected amenities and immediate service.
My understanding is that there is a growing number of these types of doctors and that for some doctors this type of practice is attractive: never deal with insurance forms, charge more for the same services, most high income people tend to have healthy life styles thus fewer health complications (SP may have somewhat bucked that trend). Sure, some of the wealthy are high maintenance jerks, but some poor and middle class people also have these personalities.