COVID-19 studies are our top priority.

For new and updated trial submissions, we are processing trials as quickly as possible and appreciate your patience. We recommend submitting your trial for registration at the same time as ethics submission.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Exploring Treatment Options for Obstructive Sleep Apnoea in People with Psychosis
Scientific title
Exploring Treatment Options for Obstructive Sleep Apnoea in People with Psychosis
Secondary ID [1] 297652 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
obstructive sleep apnoea 312048 0
schizophrenia 312049 0
Condition category
Condition code
Respiratory 310609 310609 0 0
Sleep apnoea
Mental Health 310610 310610 0 0

Study type
Description of intervention(s) / exposure
This study will conduct a series of single case example designs with participants acting as their own baseline for comparison of treatment effects, using a bi-phasic A-B-A design for the Mandibular Advancement Splints, Night Shift and CPAP conditions (Arms 1, 3 and 4 respectively). It is expected that participants in each treatment phase (B) should show a difference on outcome measures such as lower OSA severity, improved clinical symptoms, cognitive functioning or quality of life compared to non-treatment phases (A).

For the Didgeridoo (Arm 2) condition, a multiple baseline A-B design will be used, as the physiological effects of didgeridoo playing on throat muscles cannot be withdrawn fully after exercise cessation, unlike the other three conditions (where physiological effects are directly and temporarily linked to the usage of the device). A multiple baseline design means that participants will have differing amounts of time for collecting baseline data, before the treatment begins (e.g. three baseline data collection for Participant A, four baseline collections for Participant B etc.), whereas, a classic A-B-A design collects the same amount of baseline data from each participant.

The study will comprise of one of the four treatment conditions, as well as four face-to-face appointments (baseline, pre- and post-treatment assessment and follow-up at the sixteenth-week time point), and seven short ‘check-up’ points (three times before treatment to establish a solid baseline, and every two weeks during treatment). The ‘check-up’ points will be conducted either via phone call or a text (according to the person’s preference), and will work to determine that participants are well, to help troubleshoot and answer any questions they might have, to check that participants are adhering to their treatment options, and to monitor changes in key symptom dimension across baseline and treatment phases (in addition to monitoring change more comprehensively during face-to-face appointments). At the check-up points, change in key symptom dimension will be assessed with questions about Health Status (7 items), and questions about treatment acceptability and side effects with Treatment Status (6 items). The check-up will be conducted with phone call or with text with link to an online survey (through secure REDCap server and comprising no personal identifying information).

After an initial telephone call verifying the screening and eligibility criteria, the participant and PI will mutually agree on an available time for Session One (baseline) at a mental health service location that suits them.

SESSION 1 (BASELINE) at the first face-to-face appointment (approx. 1.5 hrs), the session will include history taking (sleep problems and psychiatric issues) and questions about demographic info using a Clinical Sleep Interview.

A brief psychoeducation session ~30 minutes about OSA will also be delivered. Brief psychoeducation is necessary so as to ensure that all participants have the same basic level knowledge about OSA. The contents will be derived from the Australasian Sleep Association and Sleep Health Australia, and resources and flyers will be especially adapted for consumers, with consumer input and co-production.

Psychoeducation about OSA will comprise of: 1. OSA: What is it? Aim: to provide explanations about what is widely known about the sleep disorder within a normal continuum context. 2. What are the symptoms of OSA? Aim: to explain the common symptoms of OSA to help participants identify symptoms within themselves and others around them with similar mental health conditions. 3. How is OSA diagnosed? Aim: to explain the process of diagnosis for the sleep disorder using Polysomnography. 4. How is OSA treated? Aim: To explain the many things one can do to treat or reduce severity of OSA e.g. weight loss, drinking less alcohol, minimising use of sleeping tablets etc.

Participants will then be booked in for their next face-to-face visit (pre-treatment outcomes assessment) and will be told they will be contacted three times (by phone and texts) over the next week to collect baseline measures of ‘health status’.

CHECK-UP POINTS (pre-treatment): During the next week, The Principal Investigator will contact participants every 2 or 3 days (depending on participant or PI availability) by phone or texts to ask seven short questions (‘Health Status’ questions) using a 5-point Likert scale about the participant’s quality of sleep the night before, their impact of sleep on daily functioning and about night and daytime symptoms of OSA. These results will form a solid baseline measurement of OSA symptoms and severity pre-treatment. The same questions (Health Status) will be asked every two weeks during treatment phase, again at post-treatment assessment (week 9) and at the one month follow up (week 12) (with additional questions asking about treatment adherence and any issues with the devices).

CHECK-UP POINTS (during-treatment): In addition to a Health Status questionnaire (as above), every 2 weeks during treatment, questions will be asked about ‘Treatment status’ at check-up points. Six 5-point Likert scale questions and one open-ended question will ask about the participant’s acceptability, usage, tolerance of their treatment as well as any issues encountered.

SESSION 2 (PRE-TREATMENT). At the second face-to-face session, participants will complete their pre-treatment outcome measures assessment.

The same measures will also be collected face-to-face at post-treatment assessment and follow-up. Questionnaires and tasks are outlined in step 4.

In addition, all participants will be asked to undergo three optional overnight sleep studies with a portable home based device (ApneaLinkTM). ApneaLink is a simple, light weight device, which is worn as a chest belt while the person is asleep in the person’s own home/bed. The ApneaLink device measures nasal airflow (with nasal cannula), oxygen saturation, snoring, and pulse (finger oximeter), and chest breathing effort (with chest belt), from which it derives an apnoea-hypopnoea index (AHI). This is comparable to the AHI that is derived from participant’s initial diagnosis mechanism: Polysomnography. The device will be given to them during the first session, with explanations on how to fit it before bed time. ApneaLinkTM data will only be recorded at pre- and post-treatment outcome assessment (weeks 3, and 9 respectively). The ApneaLink devices will need to be picked up from participant’s the day after they have been used so that the Principal Investigator can download the sleep study data.

Participants undertaking CPAP and Night Shift also have their own objective measures built into each device. Measures included for CPAP are: hours device is used throughout the night, number of nights where hours used is >4hrs, pressure and leak of the mask, and an Apnoea-Hypopnoea Index (AHI). For Night Shift positional therapy, objective measures are broken into three categories: sleep quality, positional feedback and snoring. The measures are further broken down into: number of supine (lying on back) attempts, sleep movement and intensity, sleep position (supine, upright, left, right or prone) and snoring intensity (decibels) and frequency.

All participants will be given their respective treatment device in week 1 although each condition will require different time commitments (see below), and measurements:

Arm 1: Mandibular advancement splints: Require one consultation prior to study by a dentist including an X-Ray, and mold fitting of the splint (occurring around 2-3 days before pre-treatment assessment). A second consult for appliance adjustment will be needed by a Dentist two weeks after receiving the device.

Arm 2: Oropharyngeal exercise (Didgeridoo): digeridoo lessons will be required, whereby participants will have to attend four lessons and practice at least five times a week in between lessons to build up their upper airway muscles.

Night shift Positional therapy device (Arm 3) and CPAP (Arm 4): Participants have the device available to them for the full 8 weeks of the study which they will be encouraged to use as much as they can (a minimum of 4 hours a night (e.g. half of the time based on an 8hr sleep cycle) in a 8 week period to determine that participants have used the devices and treatment was successfully implemented). CPAP has device check-up and adjustment points at week 2, 3 and 4 of the trial, whereas Night Shift has only one device review offered in week 2 of treatment.

SESSION 3 (POST-TREATMENT). At post-treatment assessment (week 9), participants will undergo questionnaires again as per pre-treatment, as well as an ApneaLink study. At this point all participant’s treatment trial has ended. The nature of the SCED’s is that they can be tailored to each participant and thus, the researcher can wait until the participant has finished their prescribed treatment trial to complete the post-treatment assessments.

SESSION 4 (follow-up). For the final follow up (week 13) after participants have gone 4 weeks without using the treatment device, participants will be invited to complete the questionnaires and ApneaLink overnight sleep study again.
Intervention code [1] 313965 0
Treatment: Devices
Comparator / control treatment
No control group [participant's act as their own control using the single-case experimental design)
Control group

Primary outcome [1] 319465 0
The primary outcome of this trial is to test the efficacy and tolerability of OSA treatment devices in people with psychosis. This will be analysed by looking at 1) the difference between pre- and post- intervention AHI measures, as derived from participant's portable Polysomnography device (ApneaLinkTM). 2) To assess tolerability, participants will complete a Treatment Status questionnaire which asks both closed-ended and open-ended questions about frequency of device usage, perceived impact of device usage on quality of sleep, and impact of side-effects on device usage.
Timepoint [1] 319465 0
For AHI measures using ApneaLinkTM portable polysomongraphy device, participants will compete this measure pre-treatment and post-treatment (Week 3 and 12 respectively).

For Treatment Status Questionnaire measures, these will be collected every two weeks during the treatment phase of the trial (Weeks 5, 7, 9 and 11) and will occur at post-treatment assessment and 1month follow up at weeks 12 and 15 respectively.
Secondary outcome [1] 368276 0
One secondary outcome of this trial is to show a difference on OSA severity between pre- and post- treatment and at follow up. This will be assessed using a 3 sleep questionnaires that examine both daytime and nighttime symptoms, and functional consequences of OSA.

The questionnaires include:
- The Epworth Sleepiness Scale (ESS)- assesses sleepiness/daytime symptoms of OSA
- The Berlin Questionnaire (BQ)- assess risk for OSA
- The Pittsburgh Sleep Quality Index (PSQI) – assesses sleep and impact of sleep problems and night time symptoms of OSA
Timepoint [1] 368276 0
The ESS, BQ and PSQI will be assessed at pre- and post treatment assessment (Weeks 3 and 12 respectively) and at 1 month follow up after treatment (Week 15).
Secondary outcome [2] 368482 0
One secondary outcome of this trial is to show a difference on severity of psychosis from pre- to post-treatment and at follow up. This will be assessed using the Brief Psychiatric Rating Scale (BPRS) which is a type of clinical interview.
Timepoint [2] 368482 0
BPRS will be assessed at pre- and post treatment assessment (Weeks 3 and 12 respectively) and at 1 month follow up after treatment (Week 15).
Secondary outcome [3] 368483 0
One secondary outcome of this trial is to show a difference on quality of life from pre- to post-treatment and at follow up. This will be assessed using the Short-Form Health Survey (SF-12).
Timepoint [3] 368483 0
SF-12 will be assessed at pre- and post treatment assessment (Weeks 3 and 12 respectively) and at 1 month follow up after treatment (Week 15).
Secondary outcome [4] 368484 0
One secondary outcome of this trial is to show a difference on cognition from pre- to post-treatment and at follow up. This will be assessed using a battery of small individual cognitive tests focusing on the area of attention, memory, and executive functions. These measures have been carefully selected because they are brief (less than 20 minutes total), well tolerated in this clinical group, are sensitive to change, and likely to be impacted by OSA.
The cognitive tasks include the following:
- Digit Span (forward/background) – assesses attention
- Trail Making Task (Reitan, 1955) – assesses attention, speed, and executive functions
- Memory passage learning – with 1 and 5 minute recall, and recognition – assesses memory
- Verbal Paired Association Learning Test (Weschler, 1997) – assesses memory and fluency
- Category Fluency (Strauss, 2006) – assesses executive functions and fluency
- Symbol Digit Modality Test (Smith, 1999) – assesses speed of responding
Timepoint [4] 368484 0
The cognitive tasks battery will be assessed at pre- and post treatment assessment (Weeks 3 and 12 respectively) and at 1 month follow up after treatment (Week 15).

Key inclusion criteria
Inclusion criteria for participants include:
• A current diagnosis of psychotic disorder (schizophrenia-spectrum disorder, other psychosis, including anxiety or mood disorders with psychotic features, as diagnosed by their mental health worker)
• All participants must have a formal diagnosis of OSA confirmed by sleep study (PSG). We will ask them to sign a ‘consent to release’ document, seeking the results of the PSG detailing their sleep disorder diagnosis.
• Those in the Mandibular Advancement Splint and CPAP will need to have been prescribed those treatments prior to participating in the study (as evidenced in the sleep study results letter)
• Night Shift participants will need to have a diagnosis of Positional OSA as determined by their PSG data which will be obtained with participant’s consent from the provider of the diagnosis.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Exclusion criteria include:
• Inability to provide informed consent
• Inability to communicate adequately in English
• Currently experiencing crisis or clinical instability (as assessed by their case manager)
• Aggression, problematic drug/alcohol usage associated with behavioural or security issues

Study design
Purpose of the study
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Participants recruited from mental health services will be invited to take part in one of two of the studies being conducted, depending on their preference. The aim is to have approximately 13 sourced participants (four per treatment arm except for MAS which is only able to support 1 participant) .
Data will be downloaded to an SPSS database and de-identified at regular intervals and backed up to prevent loss of data. Statistical analyses will be conducted in SPSS, and will involve correlation, regression, and analyses of variance.

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 13419 0
Graylands Selby-Lemnos & Special Care Hospital - Mount Claremont
Recruitment hospital [2] 13420 0
Sir Charles Gairdner Hospital - Nedlands
Recruitment postcode(s) [1] 26021 0
6010 - Mount Claremont
Recruitment postcode(s) [2] 26022 0
6009 - Nedlands

Funding & Sponsors
Funding source category [1] 302181 0
Name [1] 302181 0
University of Western Australia
Address [1] 302181 0
35 Stirling Highway, Crawley, WA 6009
Country [1] 302181 0
Primary sponsor type
University of Western Australia
35 Stirling Highway, Crawley, WA 6009
Secondary sponsor category [1] 302023 0
Government body
Name [1] 302023 0
North Metropolitan Health Services - Clinical Research Centre
Address [1] 302023 0
Clinical Research Centre
Gascoyne House, West Wing
Graylands Health Campus
Brockway Road
Mount Claremont WA 6010
Country [1] 302023 0
Other collaborator category [1] 280609 0
Commercial sector/Industry
Name [1] 280609 0
Absolute Dental
Address [1] 280609 0
1/34 Outram St.
West Perth,
WA, 6005
Country [1] 280609 0
Other collaborator category [2] 280610 0
Commercial sector/Industry
Name [2] 280610 0
Creative Native
Address [2] 280610 0
158 Murray St, Perth WA 6000
Country [2] 280610 0

Ethics approval
Ethics application status
Ethics committee name [1] 302863 0
North Metropolitan Health Services Human Research Ethics Committee
Ethics committee address [1] 302863 0
North Metropolitan Area Mental Health Services Human Research Ethics Committee
Gascoyne House
Brockway Road
MOUNT CLAREMONT Western Australia 6010
Ethics committee country [1] 302863 0
Date submitted for ethics approval [1] 302863 0
Approval date [1] 302863 0
Ethics approval number [1] 302863 0
Ethics committee name [2] 302932 0
University of Western Australia Human Research Ethics Committee
Ethics committee address [2] 302932 0
Office of Research Enterprise
The University of Western Australia
M459, 35 Stirling Highway
Crawley WA 6009 Australia
Ethics committee country [2] 302932 0
Date submitted for ethics approval [2] 302932 0
Approval date [2] 302932 0
Ethics approval number [2] 302932 0

Brief summary
The overall aim of this research is to explore alternative treatment options for OSA in people with psychotic disorders. Specifically, the aim is to test the efficacy and tolerability of three previously unexplored treatment options for Obstructive Sleep Apnoea (OSA) and previously tested Continuous Positive Airway pressure (CPAP) in people with psychosis. The non-CPAP treatment arms include: oropharyngeal exercises, positional therapy and dental appliances. The outcome measures in this study will look at 1) OSA severity, 2) Quality of life, 3) Cognitive Functioning and 4) Severity of Psychosis Symptoms.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 91646 0
Miss Jamilla Giles
Address 91646 0
Sanders Building, Office 1.13,
University of Western Australia
35 Stirling Highway
Crawley, Western Australia 6009
Country 91646 0
Phone 91646 0
+61 08 6488 1420
Fax 91646 0
Email 91646 0
Contact person for public queries
Name 91647 0
Miss Jamilla Giles
Address 91647 0
Sanders Building, Office 1.13,
University of Western Australia
35 Stirling Highway
Crawley, Western Australia 6009
Country 91647 0
Phone 91647 0
+61 08 6488 1420
Fax 91647 0
Email 91647 0
Contact person for scientific queries
Name 91648 0
Miss Jamilla Giles
Address 91648 0
Sanders Building, Office 1.13,
University of Western Australia
35 Stirling Highway
Crawley, Western Australia 6009
Country 91648 0
Phone 91648 0
+61 08 6488 1420
Fax 91648 0
Email 91648 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
As this study relies on single case-experimental designs, each individual case will be highlighted with the final written thesis and/or journal articles. The PI is able to be contacted for any data or information not provided.
What supporting documents are/will be available?
Study protocol
Informed consent form
Ethical approval
How or where can supporting documents be obtained?
Type [1] 1625 0
Study protocol
Citation [1] 1625 0
Link [1] 1625 0
Email [1] 1625 0
Other [1] 1625 0
Type [2] 1626 0
Informed consent form
Citation [2] 1626 0
Link [2] 1626 0
Email [2] 1626 0
Other [2] 1626 0
Information and Consent Form - CPAP Condition
Type [3] 1627 0
Informed consent form
Citation [3] 1627 0
Link [3] 1627 0
Email [3] 1627 0
Other [3] 1627 0
Information and Consent Form - Didgeridoo
Type [4] 1628 0
Informed consent form
Citation [4] 1628 0
Link [4] 1628 0
Email [4] 1628 0
Other [4] 1628 0
Information and Consent Form - Mandibular Advancement Splint
Type [5] 1629 0
Informed consent form
Citation [5] 1629 0
Link [5] 1629 0
Email [5] 1629 0
Other [5] 1629 0
Information and Consent Form - Night Shift
Type [6] 1630 0
Ethical approval
Citation [6] 1630 0
Link [6] 1630 0
Email [6] 1630 0
Other [6] 1630 0
NMHS HREC Approval
Type [7] 1631 0
Ethical approval
Citation [7] 1631 0
Link [7] 1631 0
Email [7] 1631 0
Other [7] 1631 0
UWA External Ethics Approval
Summary results
No Results