Ambulatory Versus Conventional Approach Diagnosing OSA

Study Overview
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Brief Summary
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Very few studies have examined different models of care involving initial ambulatory home-based diagnosis in diagnosing obstructive sleep apnea (OSA), identifying patients who benefit from continuous positive airway pressure (CPAP), and reducing the need for polysomnography (PSG). This study aims to assess the role of an ambulatory approach with home diagnostic sleep study. We hypothesize that the ambulatory approach is as good as the conventional approach in managing OSA in terms of improvement of clinical outcome but the former approach will lead to substantial cost savings.

Detailed Description
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We conducted a prospective, randomized, controlled continuous positive airway pressure (CPAP) parallel study on new referrals to the Respiratory Clinic, Prince of Wales Hospital, with suspected obstructive sleep apnea (OSAS). OSAS was defined by apnea-hypopnea index(AHI) 5/hr or more of sleep plus excessive daytime sleepiness or two of the following symptoms: choking or gasping during sleep, recurrent awakenings from sleep, unrefreshed sleep, daytime fatigue, and impaired concentration. All patients with suspected OSAS underwent assessment at the clinic with the Epworth sleepiness score(ESS) and symptoms evaluation. Patients who had ESS score>9 or at least two OSAS symptoms as described above were invited to join the study. They were randomized into either group A)home-based management approach or group B)hospital-based management approach by a random table by a third party not involved in the trial.

Official Title
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A Randomized Controlled Study Assessing the Role of an Ambulatory Approach Versus the Conventional Approach in Managing Suspected Obstructive Sleep Apnoea Syndrome

Conditions
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OSA

Intervention / Treatment
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* Device: Home sleep study
* Device: conventional polysomnography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: symptoms of OSA with home sleep study AHI >= 15/hr. Exclusion Criteria: unstable cardiovascular diseases (e.g. recent unstable angina, myocardial infarction, stroke or transient ischemic attack within the previous 6 months or severe left ventricular failure) neuromuscular disease affecting or potentially affecting respiratory muscles moderate to severe respiratory disease (i.e. breathlessness affecting activities of daily living) or documented hypoxemia or awake oxygen saturation of <92% psychiatric disease that limits the ability to give informed consent or complete the study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Conventional polysomnography<br>Conventional PSG will be performed as in-patient at Prince of Wales Hospital for every subject in this group, recording electroencephalogram, electro-oculogram, submental electromyogram, bilateral anterior tibial electromyogram, electrocardiogram, chest & abdominal wall movement by inductance plethysmography, airflow measured by a nasal pressure transducer & supplemented by oronasal airflow thermistor, & finger pulse oximetry. | Device: conventional polysomnography<br>* conventional type I sleep study according to international guidelines<br>|
| Active Comparator: Home sleep study<br>The home sleep study is a pocket-sized digital recording device. It is a multi-channel screening tool that measures airflow through a nasal cannula connected to a pressure transducer, providing an apnea-hypopnea index (AHI) based on recording time. It also detects both respiratory and abdominal efforts through the effort sensor and can differentiate between obstructive and central events. | Device: Home sleep study<br>* The home sleep study is a pocket-sized digital recording device. It is a multi-channel screening tool that measures airflow through a nasal cannula connected to a pressure transducer, providing an apnea-hypopnea index (AHI) based on recording time. It also detects both respiratory and abdominal efforts through the effort sensor and can differentiate between obstructive and central events<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Epworth Sleepiness Score (ESS) Before and After 3 Months of Continuous Positive Airway Pressure (CPAP) Treatment | The Epworth Sleepiness Scale (ESS) is a scale intended to measure daytime sleepiness that is measured by use of a very short questionnaire. The questionnaire asks the subject to rate his or her probability of falling asleep on a scale of increasing probability from 0 to 3 for eight different situations that most people engage in during their daily lives, though not necessarily every day. The scores for the eight questions are added together to obtain a single number. A number in the 0-9 range is considered to be normal while a number in the 10-24 range indicates that expert medical advice should be sought. | Baseline and 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in Healthcare Costs Between Ambulatory and Hospital Approach |  | within 24 months |