Refining and Optimising a behavioural intervention to Support Endocrine Therapy Adherence (ROSETA) in UK women with breast cancer: protocol for a pilot fractional factorial trial

Samuel George Smith, Sophie M.C. Green, Rachel Ellison, Robbie Foy, Christopher D. Graham, Ellen Mason, David P. French, Louise H. Hall, Hollie Wilkes, Emma McNaught, Erin Raine, Rebecca Walwyn, Daniel Howdon, Jane Clarke, Nikki Rousseau, Jacqueline Buxton, Sally J. L. Moore, Catherine Parbutt, Galina Velikova, Amanda FarrinMichelle Collinson

Research output: Contribution to journalArticlepeer-review


Introduction: Women with breast cancer who do not adhere to adjuvant endocrine therapy (AET) have increased risks of mortality and recurrence. There are multiple barriers to AET adherence, including medication side-effects, beliefs about medication, memory, and psychological distress. We developed four intervention components, each targeting a different barrier. This pilot trial is part of the preparation phase of the Multiphase Optimisation Strategy (MOST), and aims to establish key trial parameters, establish intervention component adherence, establish availability and feasibility of outcome and process data, estimate variability in planned outcome measures, and estimate cost of developing and delivering each intervention component.

Methods and analysis: The four intervention components are: SMS text reminders (target: memory); a written information leaflet (target: medication beliefs); a guided self-help Acceptance and Commitment Therapy programme (target: psychological flexibility to reduce distress); a self-management website (target: side-effect management). To evaluate the feasibility of recruitment, acceptability of the intervention components and the availability of outcome data, we will conduct a multi-site, exploratory pilot trial using a 24-1 fractional factorial design, with a nested process evaluation. We will randomise 80 women with early-stage breast cancer who have been prescribed AET to one of eight experimental conditions. This will determine the combination of intervention components they receive, ranging from zero to four, with all conditions receiving usual care. Key outcomes of interest include medication adherence and quality of life. Progression to the optimisation phase will be based on pre-defined criteria for consent rates, patient adherence to intervention components and availability of medication adherence data.

Ethics and dissemination: The study was reviewed by the Wales Research Authority Research Ethics Committee 3 (21/WA/0322). Written informed consent will be obtained from all patients before randomisation. The results of this trial will be disseminated in a peer-reviewed journal.
Original languageEnglish
JournalBMJ Open
Publication statusAccepted/In press - 18 Jan 2023


  • medication adherence
  • breast cancer
  • Multiphase Optimisation Strategy (MOST)
  • Acceptance and Commitment Therapy
  • SMS reminders
  • information leaflet
  • self-management website
  • pilot
  • feasibility
  • quality of life
  • factorial


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