From the March 6, 2008
New England Journal of Medicine:
"In the United States, 125 million people are living with chronic
illness, disability, or functional limitation. The nature of
modern medicine requires that these patients receive assistance
from a number of different care providers. Between 2000 and
2002, the typical Medicare beneficiary saw a median of two primary
care physicians and five specialists each year, in addition
to accessing diagnostic, pharmacy, and other services. Patients
with several chronic conditions may visit up to 16 physicians
in a year. Care among multiple providers must be coordinated
to avoid wasteful duplication of diagnostic testing, perilous
polypharmacy, and confusion about conflicting care plans."
These 125 million people are not the unfortunate "other." They are not only our partners, children, sisters, brothers, parents, and friends. They are us.
A friend who has worked in the rehabilitation field for decades likes to shock people by saying that there are no dis-abled people, only temporarily abled people. And none of us has the algorithm for figuring out how long we will be abled.
So what's a person to do when the outcome is so fearsome and so certain:
"Keep walking, though there's no place to get to. Don't try to see through the distances. That's not for human beings. Move within, but don't move the way fear makes you move."
Rumi (13th century Persian poet)

...and it wouldn't hurt to consult with a long term health care/financial planner; build a strong relationship with a primary care provider; find a health care facility that has a geriatric service that provides case management (like
John Muir Health Senior Services in California); talk to your family before a crisis hits about your wishes and the kinds of help family members can offer.