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
Date results information initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
The Postpartum Sleep Study for Mothers (The POSSUM Project)
Scientific title
The Postpartum Sleep Study for Mothers (The POSSUM Project): A randomised controlled trial of interventions to improve sleep and wellbeing in sleep-disturbed first-time mothers.
Secondary ID [1] 294685 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Sleep disturbance 307529 0
Fatigue 307530 0
Insomnia 307782 0
Condition category
Condition code
Mental Health 306606 306606 0 0
Other mental health disorders
Reproductive Health and Childbirth 306825 306825 0 0
Childbirth and postnatal care

Study type
Description of intervention(s) / exposure
Interventions will be therapist-assisted with self-directed/automated components. A provisional psychologist trained in the study protocol under the supervision of a clinical psychologist, will interact with participants in the three intervention conditions via phone to personalise interventions, providing recommendations of certain modules through an orientation phone call which will take up to 90 minutes. Participants will be randomised to conditions.

Cognitive Behavioural Therapy intervention (CBT-only). The CBT material will be delivered via email over 6 weeks. Emails will be delivered as follows: 5 in the first week, 4 in week 2, followed by 3 emails per week in weeks 3-6. The materials will cover a range of information and strategies for improving sleep and its daytime effects. The orientation phone call will take up to 60 minutes.

Light & Dark Therapy intervention (LDT). Participants in this group will wear light therapy glasses for 20-30 minutes each morning for 6 weeks. Participants will be encouraged to continue using light therapy glasses until project completion in week 10. Light exposure strategies will be provided through an orientation phone call which will take up to 45 minutes. Participants will also be provided with a night light to use during nighttime awakenings (Dark Therapy).

The LDT condition will also receive weekly emails during the active intervention phase (i.e. an email at the end of each week over 6 weeks) to serve as a review of LDT strategies. Emails will be very brief and are designed as reminders to use different strategies such as gaining bright light in the morning and using dim lights in the evening.

Treatment adherence will be assessed for those in intervention conditions in the post-intervention (week 6) and follow-up (week 10) questionnaires. Participants will respond to how frequently they used (i.e., how many days in a typical week they have used strategies) different components of the intervention and how useful they found these. Email analytics will be used to supplement participants self-report information.
Intervention code [1] 300973 0
Treatment: Devices
Intervention code [2] 300974 0
Comparator / control treatment
Waitlist control - will complete all assessments and receive standard postnatal care (i.e., attending maternal and child health/doctor's appointments) as usual. The waitlist control will be offered the CBT emails following trial completion and all questionnaires have been completed i.e. week 10.
Control group

Primary outcome [1] 305611 0
Changes in sleep complaints measured via Insomnia Severity Index
Timepoint [1] 305611 0
6 weeks post-intervention commencement and an exploratory analysis at 10 weeks post-intervention commencement
Secondary outcome [1] 345896 0
Changes in sleep disturbance (assessed using the PROMIS Sleep Disturbance SF 8a).
Timepoint [1] 345896 0
6 weeks post-intervention commencement and an exploratory analysis at 10 weeks post-intervention commencement
Secondary outcome [2] 345907 0
Changes in fatigue (assessed using the Fatigue Assessment Scale-5 and the Visual Analog Scale of Fatigue)
Timepoint [2] 345907 0
6 weeks post-intervention commencement and an exploratory analysis at 10 weeks post-intervention commencement
Secondary outcome [3] 345909 0
Changes in depressive symptoms (assessed using the PROMIS Depression SF 8a)
Timepoint [3] 345909 0
6 weeks post-intervention commencement and an exploratory analysis at 10 weeks post-intervention commencement
Secondary outcome [4] 345910 0
Changes in anxiety symptoms (assessed using the PROMIS Anxiety SF 8a)
Timepoint [4] 345910 0
6 weeks post-intervention commencement and an exploratory analysis at 10 weeks post-intervention commencement
Secondary outcome [5] 345911 0
Changes in sleepiness (assessed using the Epworth Sleepiness Scale and Karolinksa Sleepiness Scale)
Timepoint [5] 345911 0
6 weeks post-intervention commencement and an exploratory analysis at 10 weeks post-intervention commencement

Key inclusion criteria
Inclusion criteria include (a) first-time mothers between four to twelve months postpartum; (b) aged 18 years or above; (c) singleton pregnancy; (d) ability to read and write in English; (e) regular access to phone, email and internet.
Minimum age
18 Years
Maximum age
No limit
Can healthy volunteers participate?
Key exclusion criteria
Exclusion Criteria:
• Currently pregnant.
• Fixed night shiftwork between midnight and 5am, or rotating work schedules that require night shifts during project participation.
• Insomnia Severity Index score of <8 at baseline.
• Participants who show the following current symptoms of sleep disorders as (assessed using the Duke Structured Interview for Sleep Disorders; Edinger et al., 2009):
• Sleep apnea: loud snoring OR observed gasping or pauses in breathing OR previously diagnosed with apnea hypopnea index >15 but not/inadequately treated.
• Previously diagnosed Periodic Limb Movement Disorder with arousal index >15 and currently untreated.
• Untreated Restless Legs Syndrome (RLS) occurring 3 times/week, with duration of at least one month.
• Current circadian rhythm disorders including:
• Irregular Sleep Wake Disorder.
• Non-24-Hour Sleep-Wake Syndrome.
• Advance Sleep-Phase Syndrome (if habitual bed time is earlier than 8pm and habitual wake time is earlier than 4am. Occasional deviation from this schedule is allowed).
• Narcolepsy
• Have unstable medical conditions that directly affect sleep.
• Take medication that affects sleep (including sleep medications, melatonin, steroid inhalers, antidepressant medications, cannabis, etc.).
• Report current Post-traumatic Stress Disorder, Panic Disorder (if > 4 times nocturnal in the past month), Bipolar Disorder, Psychotic disorders or Substance Use Disorders. Exclusion of those with current depression will only occur if risk issues are evident assessed during initial telephone interview – those with current suicidal ideation/self-harm behaviours or who pose a risk of harm to others will be excluded and referred to appropriate services.
• Have infants with medical conditions that affect sleep.
• Have been advised be health professionals to avoid exposure to bright light (including chronic migraines and eye conditions such as macular degeneration, eye diseases).
• Expresses personal preference or concerns regarding exposure to bright light.
• Suffer from epilepsy.
• Reports on average, 3 or more infant awakenings per night over the past month requiring parental assistance to reinitiate sleep
- Participants who pose a risk of harm to either themselves or to others will be excluded (assessed in a risk assessment during the telephone screening interview at baseline).

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Eligible participants will be randomized using a complete randomization scheme generated in advance. Specifically, block sizes of variable size (3, 6, or 9) will be used. Random seeds will be generated to assure allocation concealment and pre-guessing of the allocation sequence at the end of each block. Randomization will be stratified by baseline ISI (<15 and > 14) and infant age (< 8 months and >= 8 month). The randomization scheme will be generated and setup in REDCap by a member of the research staff who is (1) not involved in recruitment or delivery of intervention and (2) is not one of the study PIs. REDCap is a web application and back-end database model designed to support data capture for research studies. REDCap is an open source tool developed by Vanderbilt University to build and manage online forms for data collection ( REDCap was developed specifically around HIPAA-security guidelines with features such as data encryption. REDCap implements role-based security, which will be used to limit access based on user function to certain forms, reports and fields. To randomize a participant, an authorized research staff member will login to REDCap, enter eligibility and stratification data on the participant and will receive the group allocation. REDCap will only be used for participant randomization, the remaining data collection will be done on Qualtrics. Follow-up measures will either be self-completed or will be conducted by research staff who are blinded to the condition.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Permuted block randomisation
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people assessing the outcomes
Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Primary and secondary outcomes will be examined using mixed effects models. A piecewise time model will be used to allow two trajectories of change: (1) from baseline to post-treatment and (2) from post-treatment to follow-up. Two "condition" variables (one on the presence/absence of CBT-I, the other presence/absence of light therapy) and piecewise time by condition interactions will also be included in the model. The primary trial results will be tested by the time x conditions interaction from baseline to post-treatment. This interaction directly tests whether the change in outcomes over time is different with the presence/absence of CBT-I or light therapy. Effect sizes of the group difference at each time point also will be calculated. If the assumption of normality is violated, significance tests and confidence intervals will be based on non-parametric bootstrapping.

the same statistical analyses will be undertaken for exploratory outcomes as well, including assessments conducted at 10 weeks post-intervention commencement (i.e. follow-up assessment).

Recruitment status
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)

Funding & Sponsors
Funding source category [1] 299284 0
Name [1] 299284 0
Monash University Graduate Research Student Funding
Address [1] 299284 0
Monash University Wellington Road
Victoria 3800
Country [1] 299284 0
Primary sponsor type
Monash University
18 Innovation Walk, Monash University Clayton VIC 3800
Secondary sponsor category [1] 298554 0
Name [1] 298554 0
Address [1] 298554 0
Country [1] 298554 0

Ethics approval
Ethics application status
Ethics committee name [1] 300195 0
Monash University Human Ethics Research Committee (Monash Research Office)
Ethics committee address [1] 300195 0
Room 116, Level 1
Chancellery Building D
26 Sports Walk, Clayton Campus
Wellington Rd
Clayton VIC 3800, Australia
Ethics committee country [1] 300195 0
Date submitted for ethics approval [1] 300195 0
Approval date [1] 300195 0
Ethics approval number [1] 300195 0

Brief summary
Maternal sleep disturbance is a significant and widespread complaint during the postpartum period. Though some aspects of sleep eventually improve over time, some mothers continue to experience poor sleep with persistent difficulties in initiating and reinitiating sleep. These postnatal sleep complaints have been associated with a range of deleterious outcomes, including fatigue, sleepiness, and symptoms of depression/anxiety. Despite the prevalence and associated negative outcomes of postnatal sleep disturbance, research investigating potential interventions to promote maternal sleep is scarce, representing a significant gap in the current literature.

We plan to examine the efficacy of non-pharmacological interventions to improve sleep and wellbeing in sleep-disturbed mothers: (1) Cognitive Behavioural Therapy (CBT) and (2) Light and Dark Therapy (LDT). The CBT arm will involve strategies to target healthy sleep habits and management of daytime symptoms (including fatigue), delivered via emails with therapist assistance. The LDT arm will involve participants wearing light glasses each morning and adhering to recommendations for appropriate light exposure at night. Interventions will be personalised in an orientation call with a researcher in which specific recommendations will be made based on the participants’ individual needs.

There will be four conditions: (1) a CBT-only group; (2) a LDT-only group; (3) a combined CBT-LDT group; and (4) a waitlist control that will receive CBT emails following trial completion.

The active intervention phase will be six weeks, with four assessment time-points: (1) baseline; (2) mid-point – Week 3; (3) post-intervention – Week 6; and (4) follow-up – Week 10.

This aims of this study are to:

1) Investigate the efficacy of CBT, LDT, and the combinations of LDT and CBT in the reduction of maternal sleep complaints as the primary outcome, and maternal fatigue, sleepiness, and mood as secondary outcomes.
2) Explore predictors and mediators of treatment effects.
3) Evaluate whether the combination of CBT and LDT supersede the effects of either intervention delivered alone.
Trial website
Trial related presentations / publications
Public notes
Attachments [1] 2608 2608 0 0
/AnzctrAttachments/374954-10_Approval_9780.pdf (Ethics approval)
Attachments [2] 2609 2609 0 0
/AnzctrAttachments/374954-02_Screen_Consent_Form.doc (Participant information/consent)
Attachments [3] 2637 2637 0 0
/AnzctrAttachments/374954-01_Explanatory_Statement.docx (Participant information/consent)
Attachments [4] 2884 2884 0 0
/AnzctrAttachments/374954-01_Explanatory_Statement_V3.docx (Participant information/consent)
Attachments [5] 2885 2885 0 0
/AnzctrAttachments/374954-02_Screen_Consent_Form_V3.doc (Participant information/consent)

Principal investigator
Name 82874 0
Miss Sumedha Verma
Address 82874 0
18 Innovation Walk, Monash University, Clayton VIC 3800
Country 82874 0
Phone 82874 0
Fax 82874 0
Email 82874 0
Contact person for public queries
Name 82875 0
Miss Sumedha Verma
Address 82875 0
18 Innovation Walk, Monash University, Clayton VIC 3800
Country 82875 0
Phone 82875 0
Fax 82875 0
Email 82875 0
Contact person for scientific queries
Name 82876 0
Dr Bei Bei
Address 82876 0
Room 509, 18 Innovation Walk, Monash University, Clayton VIC 3800
Country 82876 0
Phone 82876 0
+61 3 9905 3903
Fax 82876 0
Email 82876 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
What supporting documents are/will be available?
No other documents available
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary