Impact of Cognitive Behavioural Therapy for Insomnia on Endocrine Therapy Adherence

December 4, 2025 updated by: Sommer Agnew, University of Strathclyde

Impact of Cognitive Behavioural Therapy for Insomnia on Endocrine Therapy Adherence: a Mixed Methods Pilot Study

The aim of this study is to investigate the impact of cognitive behavioural therapy for insomnia on adherence to endocrine therapy medication in breast cancer survivors.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Approximately 70% of breast cancer cases are hormone-receptor positive, therefore treatable with endocrine therapy medication. When taken as prescribed, this is effective in reducing the risk of breast cancer recurrence following primary treatment. However, research indicates that nonadherence (not taking medication as prescribed, whether due to forgetfulness or deliberately missing a dose) is an issue, with side effects being a consistent predictor of nonadherence. Sleep problems are one of the most common endocrine therapy side effects. The aim of this study is to explore the influence of cognitive behavioural therapy for insomnia (CBT-I) on endocrine therapy adherence in breast cancer survivors.

Participants will be randomised to 1 of 2 groups: intervention, or waitlist control. Both groups will complete measures of sleep and other endocrine therapy side effects (depression, anxiety, fatigue, musculoskeletal pain, and vasomotor symptoms) at baseline, post-intervention, and 12-week post-randomisation follow-up. Following randomisation, the intervention group will receive 4 weekly group CBT-I sessions remotely through videoconferencing, whereas waitlist control participants will receive the intervention after 12 weeks, once all measures are completed.

Primary outcome will be self-reported endocrine therapy adherence, with secondary outcomes including insomnia symptoms and other endocrine therapy side effects.

Study Type

Interventional

Enrollment (Actual)

35

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
    • County (Optional)
      • Glasgow, County (Optional), United Kingdom, G1 1XQ
        • University of Strathclyde

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Diagnosed with breast cancer
  • Aged 18 or over
  • Currently prescribed endocrine therapy medication
  • Experience symptoms of insomnia
  • Self-reported nonadherent to ET medication (e.g. forgetting to take, or deliberately taking a break from medication)
  • Proficient in English language
  • Access to videoconferencing

Exclusion Criteria:

  • Undertaking shift work (i.e., irregular or night shifts)
  • Pregnancy or breastfeeding
  • Other unstable physical or mental health problem (including substance misuse)
  • Received CBT-I within past 12 months
  • Received chemotherapy or radiotherapy within past 4 weeks

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Supportive Care
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Cognitive behavioural therapy for insomnia
Following randomisation, participants in the intervention group will receive the CBT-I intervention, delivered over 4 weeks.
Behavioral: Cognitive behavioural therapy for insomnia
CBT-I is a multi-component, evidence-based intervention which incorporates both cognitive and behavioural techniques to address symptoms of insomnia, aiming to improve satisfaction with the duration and quality of sleep by reducing trouble falling and/or staying asleep. CBT-I will be delivered over 4 weekly 1-hour sessions, via videoconferencing. Session 1 will include psychoeducation about sleep (the relationship between sleep and mental health, the '3P' model of insomnia), and begin to explain components of CBT-I (sleep restriction and relaxation). Session 2 will reinforce previous learning about these components and introduce stimulus control. Session 3 will introduce sleep hygiene and its importance in preventing poor sleep. Session will 4 discuss cognitive therapy techniques and relapse prevention.
No Intervention: Waitlist control
Participants in the waitlist condition will complete all measures at the same timepoints as the intervention group. They will receive the CBT-I intervention after completing the 12-week follow-up assessment. This will then be used as a baseline measure for these participants to compare to their post-intervention and follow-up after receiving the treatment.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Endocrine therapy adherence
Time Frame: 12 weeks
Primary outcome will be self-reported adherence to endocrine therapy medication, measured using the Medication Adherence Report Scale (MARS-5). Items are scored from 1-5. Responses are summed to create a total ranging from 1-20, with higher scores indicating better adherence.
12 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Insomnia symptoms
Time Frame: 12 weeks
Severity of insomnia symptoms, measured using the Sleep Condition Indicator. Items are scored from 0-4. Responses are summed to create a total score ranging from 0-32, with higher scores meaning better sleep.
12 weeks
Depressive symptoms
Time Frame: 12 weeks
Measured using the Patient Health Questionnaire (PHQ-9). Items are scored from 0-3. Responses are summed to create a total score ranging from 0-27, with higher scores meaning more severe depressive symptoms.
12 weeks
Anxiety symptoms
Time Frame: 12 weeks
Measured using the Generalised Anxiety Disorder Assessment (GAD-7). Items are scored from 0-3. Responses are summed to create a total score ranging from 0-21, with higher scores meaning more severe anxiety.
12 weeks
Fatigue
Time Frame: 12 weeks
Measured using the Flinders Fatigue Scale (FFS). This measure includes 7 items. Six items are scored from 0-4, whereas item 5 includes a checklist which is scored from 0-7. Responses are summed to create a total score of 0-31.
12 weeks
Musculoskeletal pain
Time Frame: 12 weeks
Measured using musculoskeletal subscale of Breast Cancer Eight Symptom Scale. This subscale includes 3 items, scored from 1-3. Scores are summed, multiplied by the number of items in the subscale, and then divided by the number of questions answered, with higher scores indicating worse symptoms.
12 weeks
Vasomotor symptoms
Time Frame: 12 weeks
Measured using vasomotor subscale of Breast Cancer Eight Symptom Scale. This subscale includes 3 items, scored from 1-3. Scores are summed, multiplied by the number of items in the subscale, and then divided by the number of questions answered, with higher scores indicating worse symptoms.
12 weeks
Sleep efficiency
Time Frame: 12 weeks
The proportion of time spent in bed which is spent sleeping, measured using Consensus sleep diary. This calculated by dividing the time spent sleeping by time spent in bed, then multiplying this by 100 to generate time spent sleeping as a % of time in bed.
12 weeks
Total sleep time
Time Frame: 12 weeks
Time spent asleep, measured using Consensus sleep diary.
12 weeks
Sleep onset latency
Time Frame: 12 weeks
Time taken from getting into bed to falling asleep, measured using Consensus sleep diary.
12 weeks
Wake after sleep onset
Time Frame: 12 weeks
Amount of time spent awake after initially falling asleep, measured using Consensus sleep diary. This is calculated by adding up the length of all night-time awakenings to create a total in minutes.
12 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Strathclyde

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 23, 2023

Primary Completion (Actual)

April 23, 2024

Study Completion (Actual)

April 23, 2024

Study Registration Dates

First Submitted

May 9, 2023

First Submitted That Met QC Criteria

May 31, 2023

First Posted (Actual)

June 2, 2023

Study Record Updates

Last Update Posted (Actual)

December 12, 2025

Last Update Submitted That Met QC Criteria

December 4, 2025

Last Verified

December 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • UEC23/09

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Subscribe