Obstructive Sleep ApneaELSANCT03819361
Effect of Longitudinal Sleep Monitoring on Diagnosis and Treatment Decision in Patients With Suspected Obstructive Sleep Apnea
An observational study of Obstructive Sleep Apnea, run by Malcolm Kohler at 1 site in Switzerland.
Trial summary
Obstructive sleep apnea (OSA) is a highly prevalent sleep-disordered breathing disease, caused by recurrent episodes of partial or complete collapse of the upper airway during sleep, resulting in intermittent hypoxia, fragmented sleep, fluctuations in blood pressure, and increased sympathetic nervous system activity. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Obstructive Sleep Apnea
- What is being tested?
- pulse-oximetry
- How many people
- 130 participants
- Where
- 1 siteSwitzerland
- Study dates
- 1 Feb 2019to 31 Jul 2023
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Patients with suspected obstructive sleep apnea
Who may be able to join
- Informed consent
- Suspected obstructive sleep apnea
- ≥18 years old
Who cannot join
- Suspected or diagnosed sleeping-disordered breathing other than OSA
- Moribund or severe disease prohibiting protocol adherence especially COPD GOLD III-IV and heart failure NYHA III-IV
- Patients receiving oxygen therapy or home ventilation
- Continuous positive airway pressure treatment for OSA at baseline
- Physical or intellectual impairment precluding informed consent or protocol adherence
- Pregnant patients
Trial locations and contacts
1 site in 1 country.
Switzerland1 site
University Hospital Zurich
Zurich, Canton of Zurich, 8091
About this study
Official title: Effect of Longitudinal Sleep Monitoring on Diagnosis and Treatment Decision in Patients With Suspected Obstructive Sleep Apnea (ELSA)
Obstructive sleep apnea (OSA) is a highly prevalent sleep-disordered breathing disease, caused by recurrent episodes of partial or complete collapse of the upper airway during sleep, resulting in intermittent hypoxia, fragmented sleep, fluctuations in blood pressure, and increased sympathetic nervous system activity. A single-night sleep study (i.e. respiratory polygraphy or polysomnography) is currently considered to be the gold standard for diagnosing OSA. However, recent studies suggest a significant intra-individual night-to-night variability of respiratory events, leading to the hypothesis that one single-night study might not reflect an accurate picture of the disease.
Part A: Patients with suspected obstructive sleep apnea, referred to our clinic, undergo the regular diagnostic procedure recommended by the current guidelines. In addition to the in-hospital single-night sleep study, these patients will perform 14 nights of pulse-oximetry at home. By computing and analysing sensitivity and specificity of every additional night, the investigator will answer the questions how many nights of sleep monitoring by home oximetry are necessary to diagnose OSA reliably, and how longitudinal sleep monitoring could reduce the number of false-negative and false- positive results compared to the in-hospital single-night study.
Read more
Part B: Based on the patients' data of part A, the investigator will develop a questionnaire and present anonymized cases to experts in the field of sleep medicine. Thereby, the investigator will evaluate if the additional information of repeated nocturnal pulse-oximetries changes the experts' decision making regarding diagnosis and treatment of OSA.
In a second step, the investigator will perform a classical Delphi study with a panel of experts in sleep medicine to establish consensus on repeated sleep studies and how they should be used for diagnosis and treatment in patients with suspected OSA.
- Conditions
- Obstructive Sleep Apnea
- Being tested
- pulse-oximetry
- Keywords
- Night-to-night variability, Apnoea-Hypopnoea Index, Oxygen Desaturation Index, Pulse-oximetry
- Medical subject headings
- Sleep Apnea, Obstructive
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
pulse-oximetryDiagnostic test
Patients with suspected OSA will be monitored with 14 nights of pulse-oximetry prior to the already planned in-hospital single-night sleep study at the University Hospital Zurich
| Study group | Role | What they receive |
|---|---|---|
| Suspected OSA | Not described Receives: Diagnostic Test: pulse-oximetry |
What is being measured
The primary outcome is the main question the study is designed to answer.
The accuracy of 1-13 nights of pulse-oximetry compared to the mean ODI of 14 consecutive nights
"Sensitivity" and "specificity" for every additional night will be assessed
Measured: 14 nights of pulse-oximetry
Decision making of a panel of experts in the field of sleep medicine regarding diagnosis and severity of OSA (no OSA, mild, moderate, severe) with/without the additional information of longitudinal sleep monitoring
Measured: 14 nights of pulse-oximetry
Secondary outcomes (5)
ODI variability measured in 14 consecutive nights of pulse-oximetry
Measured: 14 nights of pulse-oximetry
Change of OSA severity class (no OSA, mild, moderate, severe OSA) during 14 nights of pulse-oximetry due to ODI variability
Measured: 14 nights of pulse-oximetry
Change of OSA severity class (no OSA, mild, moderate, severe OSA) diagnosed by in-hospital single-night sleep study vs repeated measurements by pulse-oximetry
Measured: 14 nights of pulse-oximetry
Decision making of a panel of experts in field of sleep medicine regarding treatment decisions (CPAP yes/no) with/without the additional information of longitudinal sleep monitoring
Measured: 14 nights of pulse-oximetry
Establish consensus on repeated sleep studies and their use in diagnosis and treatment in patients with suspected OSA
Measured: 14 nights of pulse-oximetry
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jan 2019
- Study start1 Feb 2019
- Primary completion18 Nov 2019
- Study completion31 Jul 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Obstructive Sleep ApneaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 130 participants (actual)
Sponsor and investigators
- Lead sponsor
- Malcolm Kohler
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Malcolm Kohler, University of Zurich
- Investigators
- Malcolm Kohler, Prof. Dr. med., Principal investigator, University of Zurich
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03819361
- Sponsor's protocol ID
- 2018-02305
- Other IDs
- 2018
- Acronym
- ELSA
- Status last verified
- May 2026
- First submitted
- 22 Jan 2019
- Last updated
- 1 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: on reasonable request only
Publications
Roeder M, Sievi NA, Bradicich M, Grewe FA, Siegfried S, Gaisl T, Kohler M. The Accuracy of Repeated Sleep Studies in OSA: A Longitudinal Observational Study With 14 Nights of Oxygen Saturation Monitoring. Chest. 2021 Mar;159(3):1222-1231. doi: 10.1016/j.chest.2020.09.098. Epub 2020 Sep 25.
PubMed 32980370
Study at a glance
From the registry record, last updated by the sponsor on 1 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Longitudinal Sleep Monitoring on Diagnosis and Treatment Decision in Patients With Suspected Obstructive Sleep Apnea (ELSA)
- ClinicalTrials.gov ID
- NCT03819361
- Acronym / sponsor ID
- ELSA / 2018-02305
- Conditions
- Obstructive Sleep Apnea
- Keywords
- Night-to-night variability, Apnoea-Hypopnoea Index, Oxygen Desaturation Index, Pulse-oximetry
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 130 participants (actual)
- Lead sponsor
- Malcolm KohlerUniversity, hospital or other
- Study start
- 1 Feb 2019 (actual)
- Primary completion
- 18 Nov 2019 (actual)
- Study completion
- 31 Jul 2023 (actual)
- First posted
- 28 Jan 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Obstructive sleep apnea (OSA) is a highly prevalent sleep-disordered breathing disease, caused by recurrent episodes of partial or complete collapse of the upper airway during sleep, resulting in intermittent hypoxia, fragmented sleep, fluctuations in blood pressure, and increased sympathetic nervous system activity. A single-night sleep study (i.e. respiratory polygraphy or polysomnography) is currently considered to be the gold standard for diagnosing OSA. However, recent studies suggest a significant intra-individual night-to-night variability of respiratory events, leading to the hypothesis that one single-night study might not reflect an accurate picture of the disease.
Part A: Patients with suspected obstructive sleep apnea, referred to our clinic, undergo the regular diagnostic procedure recommended by the current guidelines. In addition to the in-hospital single-night sleep study, these patients will perform 14 nights of pulse-oximetry at home. By computing and analysing sensitivity and specificity of every additional night, the investigator will answer the questions how many nights of sleep monitoring by home oximetry are necessary to diagnose OSA reliably, and how longitudinal sleep monitoring could reduce the number of false-negative and false- positive results compared to the in-hospital single-night study.
Part B: Based on the patients' data of part A, the investigator will develop a questionnaire and present anonymized cases to experts in the field of sleep medicine. Thereby, the investigator will evaluate if the additional information of repeated nocturnal pulse-oximetries changes the experts' decision making regarding diagnosis and treatment of OSA.
In a second step, the investigator will perform a classical Delphi study with a panel of experts in sleep medicine to establish consensus on repeated sleep studies and how they should be used for diagnosis and treatment in patients with suspected OSA.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Suspected OSA | – | Diagnostic Test: pulse-oximetry |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with suspected obstructive sleep apnea
Key inclusion criteria (3 listed)
- Informed consent
- Suspected obstructive sleep apnea
- ≥18 years old
Key exclusion criteria (6 listed)
- Suspected or diagnosed sleeping-disordered breathing other than OSA
- Moribund or severe disease prohibiting protocol adherence especially COPD GOLD III-IV and heart failure NYHA III-IV
- Patients receiving oxygen therapy or home ventilation
- Continuous positive airway pressure treatment for OSA at baseline
- Physical or intellectual impairment precluding informed consent or protocol adherence
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| pulse-oximetryPatients with suspected OSA will be monitored with 14 nights of pulse-oximetry prior to the already planned in-hospital single-night sleep study at the University Hospital Zurich | Diagnostic test | Suspected OSA |
Primary outcome
The accuracy of 1-13 nights of pulse-oximetry compared to the mean ODI of 14 consecutive nights
Time frame: 14 nights of pulse-oximetry
"Sensitivity" and "specificity" for every additional night will be assessed
Decision making of a panel of experts in the field of sleep medicine regarding diagnosis and severity of OSA (no OSA, mild, moderate, severe) with/without the additional information of longitudinal sleep monitoring
Time frame: 14 nights of pulse-oximetry
5 secondary outcomes
ODI variability measured in 14 consecutive nights of pulse-oximetry
Time frame: 14 nights of pulse-oximetry
Change of OSA severity class (no OSA, mild, moderate, severe OSA) during 14 nights of pulse-oximetry due to ODI variability
Time frame: 14 nights of pulse-oximetry
Change of OSA severity class (no OSA, mild, moderate, severe OSA) diagnosed by in-hospital single-night sleep study vs repeated measurements by pulse-oximetry
Time frame: 14 nights of pulse-oximetry
Decision making of a panel of experts in field of sleep medicine regarding treatment decisions (CPAP yes/no) with/without the additional information of longitudinal sleep monitoring
Time frame: 14 nights of pulse-oximetry
Establish consensus on repeated sleep studies and their use in diagnosis and treatment in patients with suspected OSA
Time frame: 14 nights of pulse-oximetry
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Jun 2026.
- Derived from this study: PubMed 32980370Roeder M, Sievi NA, Bradicich M, Grewe FA, Siegfried S, Gaisl T, Kohler M. The Accuracy of Repeated Sleep Studies in OSA: A Longitudinal Observational Study With 14 Nights of Oxygen Saturation Monitoring. Chest. 2021 Mar;159(3):1222-1231. doi: 10.1016/j.chest.2020.09.098. Epub 2020 Sep 25.
- Individual participant dataSharing planned: No. on reasonable request only
Related trials for Obstructive Sleep Apnea
RecruitingObservational study
Development and Validation of a Multimodal Deep Learning Model Using Peripheral Oxygen Saturation and Ballistocardiography Signals for Predicting Apnea-Hypopnea Index in Obstructive Sleep Apnea
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A Study to Learn About the Monthly Dosing Study Medicine Called Berobenatide in Adults With Breathing Problems During Sleep and Overweight or Obesity Who Do Not Use a Breathing Machine (PAP) (VESPER-OSA 2)
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Not yet recruitingPhase 2
Supplemental Oxygen for Sleep-Disordered Breathing in Adults With Chronic Opioid Use.
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Recruiting
Nightly Wearable Monitoring During Home-Based Submental Electrical Stimulation for Obstructive Sleep Apnea
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RecruitingPhase 1/2
DRonabinol Treatment of OSA
Obstructive Sleep Apnea
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Malcolm Kohler, Prof. Dr. med. principal investigator
University of Zurich
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Obstructive Sleep Apnea, run by Malcolm Kohler at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 1 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The accuracy of 1-13 nights of pulse-oximetry compared to the mean ODI of 14 consecutive nights (time frame: 14 nights of pulse-oximetry). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03819361, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Jun 2026.