Introduction Optimal continuous positive airway pressure (CPAP) use is essential in the successful treatment of obstructive sleep apnoea (OSA), but optimising CPAP therapy is a challenge.

Methods We set out to outline our CPAP service trends in the last 10 years. We quantified the proportion of patients diagnosed with moderate or severe OSA from studies completed from samples from 2009. We recorded CPAP compliance at first review, and the time it took for patients to reach adequate treatment compliance.

Results We found an increasing trend in studies completed over the last decade, although the proportion of patients diagnosed with moderate or severe OSA did not reflect an increase, with only 20% of patients receiving a diagnosis of moderate or severe OSA recently. The majority of patients (61%) were compliant with CPAP therapy at their first review. Although it took on average 4 to 5 months for patients to reach adequate CPAP compliance, this trend decreased over 10 years. Almost half of patients prescribed CPAP 10 years ago remain under regular biennial reviews, and an average of 20% of patients were intolerant to CPAP.

Discussion Referrals to our service increased over the last decade. Although screening criteria for referrals became more specific for obstructive sleep apnoea, the proportion of moderate and severe diagnoses has shown a downward trend. There is an increasing demand on our service, with more referrals and more complex referrals unrelated to OSA. CPAP compliance remains a challenge, without improvements in compliance trends despite improvements in technology and equipment. Finally, our results highlight that although the majority of patients reach adequate compliance at their first review, a minority may need numerous reviews until adequate treatment is achieved, and one in five never achieve adequate CPAP compliance. A significant proportion of patients remain under review a decade later.