Background
There are limited data on long-term mortality in sleep apnoea (SA) patients with and without positive airway pressure (PAP) therapy. This retrospective cohort study investigated long-term hospitalisation and mortality rates in SA patients from a German statutory health insurance (SHI) database who did versus did not receive PAP therapy.

Methods
Patients had continuous insurance coverage from 01 January 2008 to 31 December 2013, complete medical records and ≥1 SA-related diagnosis in 2009. Those receiving PAP were matched with a control group not treated with PAP. Outcomes (hospitalisations including stays in the sleep laboratory) were compared between groups the year prior to and the 4 years after SA diagnosis. Mortality was assessed in the 4 years after SA diagnosis.

Results
2176 PAP therapy recipients were matched with 2176 controls. The PAP group had a higher rate of hospitalisation in the year before SA diagnosis than the control group (80.2% vs. 26.6%; p = 0.0016). After diagnosis, the PAP group had a higher hospitalisation rate only in year 1 (p < 0.05), and average length of stay per hospitalisation was lower in the PAP group (p < 0.05 vs. control at years 1, 2 and 4). Cumulative all-cause mortality after year 3 (3.4% vs. 4.6%; p = 0.0287) and after year 4 (4.8% vs. 6.5%; p = 0.0175) was significantly lower in SA patients receiving PAP versus controls (relative risk reduction for death after 4 years: 25.5%).

Conclusion
This real-world cohort study showed an association between long-term PAP therapy use and lower mortality, a higher rate of hospitalisations before and shorter hospital stays after treatment initiation.