With all due respect, I fear this to be another dangerous survey. No matter the results, napping and all its bad connotations (and few of its good) may be associated with sufferers of ME/CFS, along with a growing list of qualifiers like lazy and delusional. It may not be looked at in terms of how napping deviates from norms in ME/CFSers, and what that might signify, but, rather, just that ME/CFSers nap a lot - or complain about napping, too. Craft the abstract as well as you might, I suspect the take away for many will be two words: "Nap" & "ME/CFS."
It's like taking a survey of obese individuals and asking how many times a day they snack. Not eat, snack. The goal may be to see what underlying mechanisms are at play, but that won't matter.
Not that using the word sleep instead of nap would make all that much difference, but it might mitigate the damage a smidgeon.
Exhaustion, sleepiness, weakness etc are all telltale signs of infection or immune dysfunction. But what is being emphasized here, imo, will simply serve to re-enforce dangerous stereotypes. Regardless of the findings, I worry that healthy people will read "Lazy freeloaders complain about nap time."