I've been on CPAP now since early June. My sleep study AHI was 37. My first CPAP machine gave me scores consistently below 5 and a pressure of 8. After a month I talked by doctor into letting me switch to the ResMed S9 Autoset. At the same time they reduced my pressure to 6. Now virtually all my AHIs are less than 1. Don't know if it's the way the S9 record data or if the change in pressure makes that much difference.
Whatever the case, I pretty much hooked now and I probably couldn't go to sleep now without my CPAP.
Still, 0.0 hardly seems possible.