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Obstructive Sleep Apnoea and Difficult Asthma (OSADA)

Open-label Randomized Controlled Trial Investigating the Relationship Between Obstructive Sleep Apnoea and Difficult Asthma

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07160868
Acronym
OSADA
Enrollment
80
Registered
2025-09-08
Start date
2025-09-01
Completion date
2026-05-22
Last updated
2026-05-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Asthma (Diagnosis), CPAP Treatment, OSA - Obstructive Sleep Apnea

Brief summary

The OSADA (Obstructive Sleep Apnoea in Difficult Asthma) trial is an open-label, randomized control trial investigating the impact of diagnosing and treating obstructive sleep apnoea (OSA) on a asthma control in patients with difficult-to-control asthma. Participants will undergo home-based sleep studies to assess for OSA and are then allocated to one of three arms: 1) Patients with OSA treated with CPAP (intervention group), 2) Patients with OSA not treated for OSA (control group) and 3) Patients without OSA (reference group). The primary objective is to evaluate whether treating OSA improves asthma control, symptom burden, and quality of life compared to untreated OSA and to patients without OSA. Secondary outcomes include exacerbation rates, sleep quality, and healthcare utilization. This trial aims to clarify the contribution of OSA to poor asthma control and the potential benefits of integrated sleep and respiratory care in this complex population.

Detailed description

Obstructive sleep apnoea (OSA) and asthma are two of the most common respiratory disorders worldwide, with asthma estimated to affect 300 million, and OSA in the region of 1 billion people. As a result, these two disorders frequently coexist in the same person. Whilst most people with asthma achieve successful control of their condition with straightforward inhaler therapy, approximately 20% have Difficult Asthma, characterised by persistent symptoms despite high dose inhaler usage. These patients experience a significant degree of morbidity due to their asthma, with increased healthcare utilisation, limitations in activities of daily living, and an increased need for systemic corticosteroids compared to those with milder asthma. Although novel biologic therapies have improved outcomes for some of these patients, there remain significant unmet needs in the care of many. OSA is consistently listed as an important comorbidity in Difficult Asthma, with the suggestion being that it may have a significant detrimental impact on the ability to successfully achieve asthma control. However, there is a lack of systematic assessments of the relationship between the presence and severity of OSA on asthma symptoms in Difficult Asthma cohorts, and very little is known about the effect that treating OSA has in terms of airflow variability and asthma control. The investigators aim to conduct an open-label randomized controlled trial to study patients attending Difficult Asthma clinics. Participants will undergo home sleep studies to investigate for an underlying concurrent diagnosis of sleep apnoea. The investigators will examine baseline and longitudinal relationships between OSA and asthma exacerbations, variability of airflow (via home peak flow monitoring), patient-reported asthma control, lung function, and markers of airway inflammation over a 3-month period, allowing a comparison of patients with OSA and those without. Patients with confirmed OSA, as defined as an apnoea-hypopnea index of ≥10 events/hour will be randomized into treatment \[continuous positive airway pressure (CPAP) therapy\] and no treatment groups. Again, airflow variability, exacerbation frequency, asthma control, lung function and airway inflammation will be compared between OSA patients who receive CPAP therapy and those who do not.

Interventions

DEVICEContinuous positive airway pressure (CPAP)

Continuous positive airway pressure - device to be used at night in the treatment of sleep apnoea

Sponsors

St. James's Hospital, Ireland
Lead SponsorOTHER
Tallaght University Hospital
CollaboratorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 90 Years
Healthy volunteers
No

Inclusion criteria

* Patients must have a clinical diagnosis of asthma with supportive objective diagnostics including but not limited to, variable airflow obstruction, bronchial-hyper responsiveness and demonstrable eosinophilic inflammation via fractional exhaled nitric oxide or peripheral eosinophilia * Patients receiving step 4 or step 5 of 'The Global Initiative for Asthma' (GINA) treatment guidelines will be selected * Between the ages of 18 to 90 years of age

Exclusion criteria

* Patients with previous sleep study investigations * Excessive daytime sleepiness; ESS \>17 * Previous diagnosis of a sleep disorder * Resting hypoxaemia or need for long-term oxygen therapy * Inability to provide informed consent

Design outcomes

Primary

MeasureTime frameDescription
Change in airflow variability measured by home electronic peak flow monitoring3-4 monthsAirflow variability will be assessed using peak expiratory flow rate (PEFR) measured with electronic home peak flow meters. Variability will be calculated using the daily amplitude percent mean (DAPM) method. Participants will be asked to record PEFR twice daily (early morning and late afternoon) over the defined period to provide adequate data points. For each day, variability will be calculated using the DAPM formula, and the average daily variability across the collection period will then be derived.

Secondary

MeasureTime frameDescription
Change in asthma control3-4 monthsAs measured by; -Asthma Control test (ACT) scoring

Countries

Ireland

Contacts

CONTACTLaura Piggott, BM BS BSc MSc
laurampiggott@gmail.com+353876801786

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: May 27, 2026