I don't fall asleep like some in the thread that's been linked, I do (so I'm told by my wife) stop breathing for 10-20 seconds. Hospital said the same. If I was that few more % over the line for help I'm pretty sure I would be using the oxygen machine at night. That's doesn't sound like much fun though, but if it gives them a good night sleep.....
Which hospital did you go to Dave?
There are many signs to look for if someone has OSA (Obstructive Sleep Apnoea) - snoring (accompanied by stopping breathing for a while, then gasping for air and start snoring again), weight gain, tired all the time to the point where you can fall asleep mid conversation, concentration problems and memory loss. The condition can also get worse if not treated, and there can be several causes, collapsing of the soft palette being very common.
I am not quite sure what you mean when you say "% over the line for help", because if you have worn an oximeter for a night, then it should show various things - pulse, respiration and most importantly the number of times per hour that you stop breathing and the time span for each incident.
The CPAP/APAP macine doesn't use oxygen as such, it is just like a very clever compressor which supplies the patient with filtered air, via a hose (sometimes humidified air which helps stop getting a dry throat/mouth) attached to a mask. The machine can be set to cope with all levels of OSA, and it stores information so that the hospital can see how compliant the patient is - hours per night usage, missed nights etc.
If you are not getting enough sleep and you are stopping breathing at nights, then you might try getting referred to another sleep specialist, because untreated OSA can be quite serious, and not just in the obvious ways like falling asleep whilst you are driving. If you have serious OSA (above 30 AHI - Apnoea Hypopnea Index), then you could have heart problems, high blood pressure etc.
http://en.wikipedia.org/wiki/Apnea–hypopnea_index