i dont understand it either.

if your health is worse check that its worse.

https://secure.ssa.gov/poms.nsf/lnx/0440502001

go almost to the bottom of the page to this section (about 1/5 of the way up the page from the bottom)

d. DE/DEC/DC review and decision-making

look at the boxes below it, that may answer some of your questions about the 6 questions.