So we have looked at the numbers  and it is very clear that most often Continuous Positive Airway Pressure (CPAP) is found unacceptable or unusable by the time a year has past. Comments from those who use and administrate the use of CPAP that I have run across on the web indicate that the numbers get worse as the years progress.
So what are the chances if making CPAP work for those who need it? I think a lot depends upon the quality of the medical support that you are able to obtain. If you have little real support I believe you have a chance of about one in three of making CPAP work long term. If you have good medical support I believe that your chances raise to perhaps two in three. And if you yourself become involved monitoring your own CPAP therapy and making it a single part of a multifaceted pursuit of a new healthy lifestyle then perhaps eight out of ten times you would succeed with CPAP.
Since I wrote my little list of “What Helped CPAP Work” I have also found that chronotherapy is helpful and believe that it is likely that further work on eating well to facilitate a better microbiome will also prove helpful.
While my first couple of years with CPAP proved fortunate likely due to high Apnea–hypopnea index (AHI) and Body Mass Index (BMI) (tends to limit ventilatory gain issues) by becoming a victim of crime and loosing much of that BMI CPAP then became much harder for me to use and benefit from. Had I not found enhanced expiratory rebreathing space (EERS) I would likely have forsaken CPAP or simply died at about the seven year mark. As it is I may well last many many more years.
 Gilmartin G, McGeehan B, Vigneault K, Daly RW, Manento M, Weiss JW, Thomas RJ.
Treatment of positive airway pressure treatment-associated respiratory instability with enhanced expiratory rebreathing space (EERS).
Source: J Clin Sleep Med. 2010 Dec 15;6(6):529-38. Division of Pulmonary, Critical Care and Sleep Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.