The aim of this evaluation is to test:

1. Whether using nasal pillows at high pressures has comparable outcomes to nasal masks
2. Patient mask type preferences at high pressures

Inclusion Criteria:

• Patients willing to give written informed consent
• Patients who can read and comprehend English
• Patients being treated for OSA for >6 months
• Patients ≥ 18 years of age
• Patients using nasal mask systems with fixed pressure ≥ 12 cm H2O
• Patients who can trial the trial masks up to 14 nights
• Patients naive to pillows mask systems

Exclusion Criteria:

• Patients using an inappropriate mask system
• Patients using Bilevel flow generators
• Patients who are pregnant
• Patients who have a pre-existing lung disease/ condition that would predispose them to pneumothorax (for example: COPD, lung cancer; fibrosis of the lungs; recent (< 2years) case of pneumonia or lung infection; lung injury)

14 days

Adverse events were collected for the study participation period of 14 days. Adverse events were collected/ assessed through clinical interview. No adverse events were reported or observed during the study.

This study only included established CPAP users.