I think that what adult children and others should do is try to talk to the partner or spouse in terms of what they're ready to talk about. Stay focused on the problem and don't force the person to come all the way out of their denial. Don't mention the elephant in the living room. Go ahead and tip toe around the elephant, but reach out to the person on the level they're ready to deal with. I find it tremendously more helpful than trying to force someone to face what's happening.
Denial is often one of the big barriers.
If you let someone else come in and care for your husband, his true level of deficit is going to become known. I'm not facing the fact that my husband wouldn't even find his way to the bathroom without me. If I hire someone else to come in and stay with him while I'm gone, all of that's going to become apparent. As soon as I have to speak that sentence, my denial crumbles. So, I think that's why a major barrier to leaving the house is all the instructions you'd have to give to someone else.