So there are various ways to boost up your attacks in combat. Simply having somebody flank reduces your foe's AC.
This doesn't apply to things like trip or disarm, as it targets the Reflex DC - not many ways to improve that; an ally could actively aid. And certain conditions like sluggish impart a Reflex penalty (and thus also a lower Reflex DC).
However, then we have things like being Asleep or Unconscious. These impart a -4 conditional penalty to AC. But no change to Reflex DC. "Asleep" does add that you automatically critically fail Reflex saves - but it isn't clear how (if at all) that impacts the Reflex DC.
Unconscious, which you'd assume is an aggravated form of Asleep, doesn't have a stated impact on Reflex saves at all.
...
A reasonable guess is that the Reflex DC becomes what it would be on a roll of "1". I haven't found any rules describing what actually happens though.