Mortimore 1998.

Methods	Randomised, crossover trial comparing nose and face mask CPAP therapy Duration of study: 4 weeks in each arm. Not stated if washout period used. Method of randomisation: Unclear Allocation concealment: Unclear Blinding of participants: Not possible to blind interface type; Patients were not informed that study designed to assess compliance Blinding of technicians: CPAP titration performed using standard protocol by staff who were unaware of the trials Blinding of investigators: Not stated Withdrawals: None. Intention to treat analysis: No withdrawals.
Participants	20 patients were enrolled in the study. Recruitment setting: Not stated Inclusion criteria: Newly diagnosed pts with sleep apnoea‐hypopnoea syndrome were enrolled after their CPAP titration night Exclusion criteria: Not stated Male/Female: Numbers not stated Age range: Not stated Mean age (SE): 52 (3) Mean BMI (SE): 32 (1) Mean AHI (SE): 34 (5.2)
Interventions	Nose mask (Resmed or Respironics) vs Face mask (Respironics) CPAP machine: Sullivan III, Resmed. Not stated if heated humidification used. Diagnostic study: CPAP titration performed using nose mask Therapeutic CPAP pressure: Not stated how this was determined.
Outcomes	1) CPAP compliance 2) Side effects (10 cm visual analogue scale) 3) Mask preference 4) Epworth sleepiness score
Notes	The study also compared nose & face mask CPAP in patients with unsuccessful uvulopalatopharyngoplasties ‐ but this part of study was not randomised
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomised; information not available
Allocation concealment (selection bias)	Unclear risk	Information not available
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Participants: Not possible to blind interface type; Patients were not informed that study designed to assess compliance Technicians: CPAP titration performed using standard protocol by staff who were unaware of the trials Investigators: Not stated
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants completed the study

AHI: apnoea‐hypopnoea index; CPAP: Continuous positive airway pressure; OSAHS: Obstructive sleep apnoea hypopnoea syndrome; PSG: Polysomnography; QoL: Quality of Life; RDI: Respiratiory disturbance index; vs: versus