This is a randomized crossover trial of children diagnosed with positional obstructive sleep apnea (POSA) on a baseline polysomnogram (PSG). Participants will undergo two further PSGs in random order over 4 weeks to assess the efficacy of a positional sleep therapy belt compared to a control for treating POSA.

Obstructive sleep apnea (OSA) is highly prevalent, and the gold standard therapy is continuous positive airway pressure (CPAP) for persistent OSA. Although CPAP is highly efficacious, long-term effectiveness is limited by poor adherence rates. Given the burden of untreated OSA in children, novel alternative therapies that are effective, acceptable and comfortable are urgently required.

OSA is characterized by recurrent obstruction of the upper airway associated with intermittent hypoxia and chronic sleep deprivation. OSA occurs in 1-4% of healthy children and in up to 80% of children with medical complexity (e.g. Down syndrome). It has significant health, societal, and economic impacts. CPAP is the gold standard therapy for persistent OSA but is poorly tolerated.

There is distinct clinical phenotype of OSA characterized by the predominance of obstructions in supine position, as measured by the obstructive apnea-hypopnea index (OAHI) on polysomnography (PSG). Up to half of children with OSA meet criteria for this phenotype which is termed positional OSA. Positional sleep belts that prevent children from adopting supine position may be beneficial for treating OSA but have not yet been studied in children.

The primary aim of this study is to assess the efficacy of a body positional sleep belt for the treatment of moderate to severe positional OSA in a paediatric population. This is a randomized crossover trial of children aged 4-18 years diagnosed with positional OSA. Participants will undergo two PSGs in random order over 4 weeks with a control and positional device therapy to assess treatment efficacy. Perceived comfort will be evaluated with surveys.

This novel research addresses a critical knowledge gap regarding the rigorous evaluation of alternative therapies beyond CPAP for managing OSA. Positional therapy has the potential to change clinical practice as an effective, cost-efficient, and non-invasive treatment option for children with positional OSA, particularly for children intolerant of CPAP.

Inclusion Criteria:

1. Consent provided by patient or caregiver. If consent provided by caregiver, assent will be provided from patient whenever possible.

2. Children aged 4 to 18 years old

3. A diagnostic polysomnogram with obstructive apnea-hypopnea index of 5-30 events/hour.

4. Diagnosed with positional obstructive sleep apnea on baseline diagnostic polysomnogram as defined as:

   1. supine-to-nonsupine obstructive apnea-hypopnea index ratio of 2 or greater
   2. 10-90% total sleep time in supine position

Exclusion Criteria:

1. Current upper respiratory tract infection
2. Requires bilevel positive airway pressure in the opinion of the child's physician (e.g. diagnosed with co-existing central sleep apnea, chronic respiratory failure, or bradypnea for age)
3. Requiring oxygen therapy
4. Unable to reposition independently
5. Total sleep time < 4 hours on diagnostic polysomnogram
6. Unable to tolerate electroencephalogram montage on diagnostic polysomnogram
7. Adherent to continuous positive airway pressure therapy (> 6 hours nightly usage)
8. Distance travelled to study site > 200 km