Overall, compliance is high compared with other chronic therapies. There are, nevertheless, huge variations from one patient to another, presumably related to side effects as well as to the perception of clinical improvement. Patients using CPAP commonly report significant side effects, such as nasal obstruction, dry nose or throat, and discomfort associated with cold air (these side effects affect CPAP-related compliance). Most may be managed when education, adaptation to treatment and appropriate medical and technical follow-up are adequately implemented. In Europe, CPAP compliance has been reported to be relatively high – frequently above five hours per night on average – which reflects a compromise between compliance and longterm tolerance.¹

There have been several studies looking at compliance determinants. In long-term studies, the most consistent correlation of daily use of CPAP was with objective measures of OSA severity at diagnosis, such as the apnoea/hypopnoea index (AHI), movement arousal index or nocturnal oxygen saturation (disease-related compliance). A patient’s initial experience with CPAP treatment, and in particular the degree of improvement in sleep during CPAP titration, may also be crucial factors in determining their subsequent use.² In most studies, multiple sleep latency test (MSLT) or score of sleepiness at diagnosis were not significantly correlated with subsequent use of CPAP. The combination of factors contributing to the variance of the rate of use explained less than 10% of the variance, suggesting that long-term compliance is multifactorial or affected by other factors not included in the analysis, like the perceived clinical benefit.³ It has also been shown that intensive support when initiating the treatment is critical and provides a substantial benefit in terms of daily use.1 Because CPAP is an aid not a cure, significant behaviour change on the part of the patient and the patient’s family is necessary. Indeed, the sleep community is beginning to recognise the importance of the ‘human factor’ in CPAP compliance, e.g. the beliefs and behaviour of the patient, and professional/patient interactions.⁴