Outcome Measurement

Smartwatch oxygen saturation monitoring is intended to capture fluctuations and longitudinal trends not available from PSG alone. Polysomnography is the gold-standard method for measuring AHI but is costly, labour-intensive, and impractical for routine paediatric follow-up. The RBS-R is a 44-item caregiver questionnaire covering multiple repetitive behaviour domains including SIB. Valid smartwatch data require at least 30 minutes of continuous exercise recording and at least 6 hours of overnight wear time. The primary intention scale uses four adapted items and has Cronbach's alpha of 0.84. The trial's primary outcomes are changes in AHI and nocturnal oxygen saturation after intervention and at three-month follow-up. Secondary outcomes include sleep quality, daytime functioning, fatigue, airway muscle measures, CPAP and exercise adherence, quality of life, muscle strength, psychological distress and usability. IES-IDs is preferred because it has been adapted and validated for people with intellectual disabilities. The RBS-R was chosen because caregivers identified it as the most relevant quantitative continuous measure of the broader repetitive behaviour spectrum. MoCA was selecte…