Co-development of a programme to improve physical activity support for women after breast cancer treatment: a pre-protocol for PURE-EX

Overall aim

To co-develop a programme that integrates physical activity referrals into standard care for women after primary treatment for early-stage and locally-advanced breast cancer.

Objectives

Patient and Public Involvement

PPI has shaped this study and will remain central throughout. Feedback from women with breast cancer highlighted the lack of physical activity support. Many suggested that the end-of-treatment appointment could be an ideal time to offer physical activity referrals, as some feel a “sense of abandonment” after finishing primary treatment. Two patient representatives with lived experience of breast cancer are important members of our research team, having actively contributed to the study’s conception and design. These two representatives will co-chair a PPI panel of 10 women with varied experiences of early-stage and locally advanced breast cancer. The panel will provide ongoing PPI feedback into research team meetings as a dedicated rolling agenda item. Meeting every 3–4 months in a local café, the PPI panel will offer user perspectives across all WPs, including input on topics guides (WP2), co-development workshops (WP3), recruitment procedures and trial materials (WP4), and disseminations plans.

Approach

We intend to produce an evidence-based, theory-informed, person-centred intervention that has been co-developed with stakeholders. Aligning with guidelines for developing and adapting complex interventions^49,50, we will iteratively and systematically co-develop, refine, and evaluate PURE-EX programme components – including a referral pathway and online training course for community providers – through four inter-linked work packages (WPs): systematic scoping review (WP1); qualitative research (WP2); co-development workshops (WP3); and a feasibility trial (WP4) (Figure 1). We will test and refine the logic model during the intervention development process, informed by existing models and frameworks for understanding behaviour, including the COM-B model and Theoretical Domains Framework (TDF)^51,52. The logic model will outline how the intervention’s inputs, activities, and outputs are expected to improve physical activity levels in women with breast cancer, ultimately impacting longer-term outcomes, such as QoL (Figure 2).

Figure 1. Overview of the four work packages.

Figure 2. Preliminary logic model of change for the PURE-EX programme.

ACSM = American College of Sports Medicine; ASCO = American Society of Clinical Oncology; HCP = healthcare professional; MRC = Medical Research Council; NCCN = National Comprehensive Cancer Network; NHS = National Health Service; NICE = National Institute for Health and Care Excellence; NPT = Normalisation Process Theory; PPI = patient and public involvement; QoL = quality of life.

The aim of the referral pathway will be to enable HCPs to endorse, offer, and facilitate referrals to community-based physical activity programmes in a manner that is feasible within outpatient breast clinics. Drawing on the Moving Through Cancer initiative^34,35 and 3A’s approach³⁶, we intend for the referral to be brief (≈30-seconds) to address HCP concerns about time constraints and competing priorities³². We envisage that women who agree to the referral will have an initial consultation booked with the community provider before leaving the clinic. This approach draws on evidence from smoking cessation interventions, where uptake has been shown to be ten times higher when referrals are made at the clinic rather than leaving patients to instigate referrals themselves⁵³. Additionally, baseline consultations with the provider may be important to the success of exercise referral schemes^54,55. The process of making referrals and booking appointments will need to be compatible with, or circumvent, existing NHS IT systems. We will explore the acceptability of these methods with stakeholders and consider alternative or complementary options, such as self-referrals.

Physical activity programmes are widely available in community settings and are typically delivered by instructors with personal trainer qualifications (e.g., Level 3 Diploma in Personal Training) employed by charities, local councils, or independent leisure and fitness centres. These programmes vary but often involve group-based aerobic, resistance, or mind-body exercises (e.g., yoga), either alone or in combination. Adapting existing programmes to fit specific contexts, rather than creating new services, is both efficient and coherent with contemporary intervention development guidelines⁵⁶. Thus, we intend to co-develop an online training course with the aim of helping community providers adapt their existing physical activity programmes for women with breast cancer. We envisage that the training will cover breast cancer and its treatments, the physical and psychosocial effects, behaviour change techniques (BCTs), and recommended adjustments to physical activity programmes.

WP1. Systematic scoping review

Aim

To describe the characteristics of community-based physical activity interventions for women diagnosed with breast cancer reported in the literature.

Objectives

To describe:

Design

The review will be conducted in accordance with the Joanna Briggs Institute (JBI) methodology for scoping reviews and reported in line with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR)⁵⁷. The protocol was prospectively registered on Open Science Framework (OSF; https://osf.io/erjxu).

Search strategy

Two authors will independently search six electronic databases from inception: Embase (Ovid), MEDLINE (Ovid), PsycInfo, CINAHL (EBSCO), SportDiscus (EBSCO), and Cochrane Central Register of Controlled Trials (Wiley). The search string to be used in MEDLINE is displayed in Box 1, and searches for all other databases will be available on OSF (https://osf.io/xver2/). We developed the search strategy with guidance from a liaison librarian and piloted it in an initial search limited to MEDLINE and CINAHL databases. We will manually search the reference lists and forward citations of included studies and relevant reviews to identify other potentially eligible studies.

Eligibility criteria

Original research articles will be included if they meet the following inclusion criteria: (i) participants were women diagnosed with breast cancer and aged 18 years or older; (ii) the study reports on a community-based physical activity intervention; (iii) full-text is available in English. We define community-based interventions as those delivered within a community setting such as churches, schools, town/village halls, primary care centres, leisure centres, and parks. No restrictions will be placed on breast cancer stage or treatment, study design, intervention duration, geographical location, or outcomes assessed. Exclusion criteria were: (i) participants aged <18 years; (ii) non-intervention studies (e.g., cross-sectional); (iii) interventions that did not include a physical activity component delivered in a community setting (e.g., hospitals or University laboratories); (iv) interventions that exclusively involved therapeutic or physiotherapy-type exercise, such as targeted upper-limb rehabilitation for lymphoedema or stretching for cording; (v) prehabilitation studies where women received an intervention whilst awaiting primary treatment; (vi) interventions delivered exclusively at home or remotely; (vii) article has been retracted. We will identify retractions using the Retraction Watch Database (http://retractiondatabase.org/RetractionSearch.aspx) and using PubMed.

Study selection

After the literature searches are complete, citations will be collated and uploaded into a reference management tool (Endnote version 20, Clarivate Analytics, PA, USA). Following the removal of duplicates, the remaining studies will be uploaded into a web-based systematic review management tool Rayyan Systems Inc., Cambridge, MA, USA) to identify potentially eligible studies. Two reviewers will independently screen the titles and abstracts against the eligibility criteria. Full texts will be obtained for all studies that appear relevant or where there is any uncertainty. The same two reviewers will then independently examine each full-text manuscript against the eligibility criteria. Reasons for excluding full-text manuscripts will be recorded and reported in a PRISMA-ScR flow diagram⁵⁷. Any disagreements between reviewers will be resolved through discussion and, if needed, consultation with a third reviewer. If it is necessary to clarify aspects of the study in relation to the eligibility criteria or retrieve a full-text manuscript, we will contact corresponding authors via email on at least two occasions within a one-month period. We will report how many authors were contacted and, of those, how many authors responded and sent data/information. We will share the full search and selection history on OSF (https://osf.io/xver2/).

Data extraction

Data will be extracted onto project-specific data extraction forms (DEFs) in Microsoft Excel (Microsoft Corporation, Redmond, Washington, USA). DEFs will first be piloted; two reviewers will extract data independently from two studies and compare results. The data extraction forms will then be modified and revised if necessary. One reviewer will extract data from the remaining studies, which will be cross-checked in full by a second reviewer on completion. Discrepancies in data extraction between reviewers will be resolved through discussion and then, if needed, with input from a third reviewer. Any modifications to the data extraction forms will be detailed in the final report.

Data items extracted onto the primary DEF will include details on: title, authors, year of intervention implementation, year of publication, journal, country, study design, recruitment setting and method, eligibility criteria, participant characteristics, sample size, and reported outcomes including information on recruitment, retention, adherence, and adverse events. A secondary DEF will be used to capture data items related to the intervention development process (e.g., use of published intervention development approaches, if/how stakeholders contributed to the development process) and intervention characteristics (e.g., intervention rationale, theoretical basis, content, any concomitant interventions). Parameters for this DEF will draw on the Guidance for Reporting Intervention Development Studies in Health Research (GUIDED)⁵⁸ and the Template for Intervention Description and Replication (TIDieR)⁵⁹ checklists. If a manuscript cites a published protocol, manuscript, or a trial registration where details of the intervention are described in more detail, we will extract relevant information from these sources.

Data analysis and presentation

Extracted data will be narratively synthesized in tabular and text form. Where relevant, basic frequencies and percentages will be used to describe characteristics of the included studies. A narrative summary of the data will describe how the results relate to the review’s objectives.

Study status

As of 22 October 2024, we have registered the protocol, completed the searches, and screened studies for eligibility. Data extraction has not yet been undertaken.

WP2. Qualitative research

Aim

To explore barriers and facilitators to physical activity in breast cancer care from different stakeholder perspectives.

Objectives

To explore and understand:

Study design

We will undertake qualitative, in-depth focus groups (supplemented with one-to-one semi-structured interviews, depending on preference) with three stakeholder groups: (i) women who have finished treatment for primary breast cancer; (ii) HCPs involved in breast cancer care; and (iii) exercise professionals. Findings will be reported in line with Standards for Reporting Qualitative Research (SRQR) guidelines⁶⁰.

Study setting

We will recruit participants from across the UK through a variety of routes (see Recruitment and consent process). Newcastle University will sponsor this study. This study was approved on 12 December 2023 by the Faculty of Medical Sciences Research Ethics Committee, part of Newcastle University's Research Ethics Committee (ref: 39270/2023). Written informed consent will be obtained from all participants before data collection.

Participant eligibility

Eligibility criteria are presented in Table 1.

Sampling

Maximum variation sampling⁶¹ will be used to capture a wide range of perspectives and experiences. For women with breast cancer, we will aim to maximise diversity of age, socioeconomic status, ethnic background, and treatment received. For HCPs and exercise professionals, we will seek to maximise diversity based on professional role (e.g., nurse, surgeon, oncologist), years of professional experience, and geographical location. We will also seek to recruit exercise professionals working across different sectors.

Sample size

The final sample size will be guided by conceptual depth, which is a pragmatic decision based on the adequacy of the data (e.g., its richness, complexity, diversity)⁶². Based on recent sample size recommendations for qualitative research with homogenous populations and well-defined objectives^63,64, we anticipate that we may need to hold 4–8 focus groups with each stakeholder group, with each focus group involving approximately 4–6 participants, to generate adequate data. Most published guidance on sample sizes for qualitative research focus on data saturation⁶³; however, this concept has received criticism and is considered to be incompatible with the values and assumptions of reflexive thematic analysis, which does not consider codes to be fixed⁶⁵.

Recruitment and consent process

We will use multiple strategies to recruit women, HCPs, and exercise professionals, including sharing study information through: (i) social media platforms; (ii) Breast Cancer Voices’ monthly bulletin (breastcancernow.org/get-involved/volunteer-us/breast-cancer-voices); (iii) breast cancer support groups and PPI groups; (iv) snowballing within our existing clinical, academic, and patient networks; and (v) community leaders, established charities, and professional organisations. To maximise the diversity of women, we will: (i) specifically encourage and target women from minority ethnic backgrounds to participate through our study adverts; (ii) target support groups in areas of high socioeconomic and ethnic diversity; (iii) approach leaders of underrepresented communities, including those serving South Asian, Muslim, and other minority women.

Potential participants will be given access to an online form (Microsoft Forms, Microsoft Corporation, Washington, USA; https://forms.office.com) and asked to express their interest by providing their name, contact details, and permission to be contacted. A research team member will email interested participants a separate online form containing the full eligibility criteria, participant information sheet (PIS), consent form, and sociodemographic questionnaire, and request details of their time availability and data collection preferences (i.e., focus group or interview; online or in-person). After the participant has provided written informed consent and submitted the form, a research team member will email them an invitation to a focus group or interview. Participants will have the option of receiving the study documents via post instead and returning them in pre-paid envelopes. To identify and prevent potentially fraudulent participation, we will remain vigilant to ‘red flags’⁶⁶ and check photo ID before the start of focus groups.

Data collection

Sociodemographic details collected will include age, ethnicity, sex, postcode, highest level of education, employment status, date of diagnosis, tumour stage and hormone receptor status, treatment received, medial comorbidities, and disability status. For HCPs and exercise professionals, we will collect information on age, professional role, qualifications, years of experience, current employment status, and employer.

The default will be to conduct focus groups online with videoconferencing platforms, using either Zoom (https://www.zoom.com) or Microsoft Teams (https://www.microsoft.com/en-gb/microsoft-teams/group-chat-software). However, we will also consider holding focus groups in-person if enough participants within the same geographical area express as a preference for this approach. We will also offer the option of one-to-one semi-structured interviews held online, via telephone, or in-person in a public space of the interviewee’s choice (e.g., University campus, community centre). Offering multiple options for participation in qualitative research is an evidence-based strategy to increase participation in marginalised groups⁶⁷.

At the beginning of the focus group, the interviewer will spend time building rapport with participants to establish a secure and trusting environment⁶⁸. The interviewer will use a conversational-style approach whilst referring to stakeholder-specific topic guides to guide discussions, which will be informed by existing evidence^69–73 and the COM-B model⁵¹. Additionally, the topic guide for HCPs will be informed by Normalisation Process Theory (NPT)⁷⁴ to encourage participants to consider processes that could influence implementation. Topic guides will be used flexibly to allow participants to raise additional topics which they consider important. Participants will be encouraged to talk freely about their experiences and views, and topics will be discussed in the order that they arise naturally. Topic guides will evolve iteratively over the course of the study to allow any new issues raised to be explored in subsequent focus groups/interviews. Final topic guides will be made available on OSF.

Focus groups are expected to last approximately 90-minutes and interviews are expected to last approximately 60-minutes (this will be guided by how much participants want to contribute). Online focus groups will be audio-recorded through in-built recording features in videoconferencing software. Focus groups conducted in-person or via telephone will be audio-recorded using a digital voice recorder. Recordings will be transcribed verbatim by a Newcastle University-approved transcription service.

Data analysis

Anonymised transcripts from focus groups/interviews with the three stakeholder groups will be analysed separately using reflexive thematic analysis from a post-positivist epistemological perspective. Reflexive thematic analysis is compatible with the epistemological positioning of the research team and is able to capture latent and semantic meaning within the dataset⁷⁵. Analysis will occur concurrently with data collection to ensure any new issues raised are explored in subsequent interviews⁷⁶. Two research team members will work collaboratively to inductively identify and refine codes within each dataset and engage in constructive and reflexive dialogue (e.g., challenging assumptions) to construct initial themes. Final themes and subthemes for each stakeholder group will be agreed by the research team. Sub-themes relating to women’s barriers to, and facilitators, of physical activity, and HCP’s/exercise professional’s barriers and facilitators of providing physical activity support to women with breast cancer, will be mapped onto the COM-B model⁵¹. A phase of triangulation will then compare and contrast the themes/sub-themes across datasets to develop a comprehensive understanding of the barriers and facilitators to physical activity in breast cancer care, identify potential implementation problems, and inform intervention development. The Behaviour Change Wheel⁵¹ will be used to guide the selection of intervention functions, and the BCT Ontology⁷⁷ used to identify appropriate BCTs to support women’s attendance at the community-based physical activity programmes and subsequent maintenance of physical activity. Analysis will be facilitated by NVivo software⁷⁸.

Study status

As of 22 October 2024, we have completed 10 focus groups and one interview with 35 women in total, with qualitative analysis of anonymised transcripts being undertaken. We have held one focus group and 15 interviews with 19 healthcare professionals, with more interviews scheduled and qualitative analysis ongoing. We have not yet undertaken any qualitative research with exercise professionals.

WP3. Co-development

Aim

To co-develop, operationalise, pre-test, and refine components of the PURE-EX programme.

Objectives

To co-develop:

Design

We will hold a series of co-development events, using a sequential and systematic co-design approach⁷⁹, to collaboratively design a prototype referral pathway and online training course.

Co-development workshops

We will form a Clinical Advisory Group (CAG) comprising 6–8 HCPs involved in breast cancer care, a Physical Activity Advisory Group (PAAG) comprising 4–6 exercise professionals with experience of delivering physical activity programmes to people with cancer, and a User Advisory Group (UAG) including 12–15 women who had finished treatment for early-stage or locally-advanced breast cancer. CAG and PAAG members will be recruited through existing clinical and professional networks and new networks developed in WP2. We will aim to maximise diversity of CAG members in terms of professional role (e.g., clinical nurse specialist, oncologist, surgeon) and geographical location. We will recruit UAG members through various sources, including through our PPI panel and breast cancer support groups, as well as approaching women who registered an interest or took part in our focus groups in WP2, aiming to maximise diversity of member’s age, socioeconomic status, and ethnic background. We will work with the CAG, PAAG, and UAG, in a series of in-person and online workshops (60–90-minutes each), to co-develop, operationalise, and refine programme components. Workshops will be facilitated by an experienced co-design researcher, assisted by at least one other member of the research team, who will take notes. We will present initial ideas about programme components in the workshops, including the referral process and features of physical activity programmes for women after breast cancer treatment. These initial ideas will be informed by a range of evidence sources, including physical activity guidelines for cancer survivors¹⁹, the Moving Through Cancer Initiative^34,35 3A’s approach³⁶, findings from the scoping review (WP1) and qualitative research (WP2), expert knowledge, NICE recommendations on exercise referral schemes³⁸, and through discussions with our PPI panel. Refinements will be made in an iterative manner, with feedback obtained on the initial ideas, refinements made, and refined programme components being re-presented in the subsequent workshops until consensus is reached. We have previously used this approach successfully to co-develop multi-component interventions for women with breast cancer^80,81. We will hold a final ‘consensus’ workshop with all stakeholder groups, integrating findings from WP1, WP2, and the workshops, to present and consolidate features of the programme.

Pre-testing

We will pre-test and refine programme components before the feasibility trial. First, we will observe HCPs (n=2–3) offering a physical activity referral to a PPI panel member. Observations will provide information on how the benefits of physical activity are communicated, the acceptability of enacting the referral, and immediate perspectives of HCPs delivering, and PPI panel member receiving, the referral. Second, exercise instructors (n=2–3) will complete the online training course, and through brief discussions held remotely via telephone or videoconferencing (depending on preference), we will gather their feedback on its content and coherence. Third, after completing the training course, instructors will deliver a physical activity session to our PPI panel members (n=10). We will explore immediate perspectives of instructors delivering the session, and women who took part, through brief surveys, comprising Likert-like and free-text items. Two to three days later, through brief discussions held remotely via telephone, videoconferencing, or asynchronous platforms (e.g., WhatsApp), we will ask instructors and PPI panel members to reflect on their experiences of the physical activity session. Following pre-testing and feedback, we will make refinements, finalise programme components (described using the TIDieR checklist⁵⁹), document BCTs in each component (using the BCT Ontology⁷⁷), and refine the logic model, if needed.

Study status

We are currently working with our PPI panel to co-develop workshop activities and materials. The workshops have not yet been undertaken.

WP4. Feasibility study

Aim

Explore the feasibility and acceptability of the PURE-EX programme from different user perspectives.

Objectives

To assess:

Study design

This is a prospective, single-arm, pretest-posttest feasibility trial with integrated process evaluation. Trial processes, including recruitment procedures, eligibility criteria, and outcomes, will be collaboratively developed and agreed with our PPI panel. Following co-development of the PURE-EX programme and trial processes, a detailed protocol will be prospectively registered on a public registry before the first participant is recruited. A potential study schedule is presented in Table 2. Trial findings will be reported in line with the Consolidated Standards of Reporting Trials (CONSORT) extension to randomised pilot and feasibility trials⁸².

Study setting

Participants will be recruited from outpatient breast cancer clinics at Newcastle Hospitals NHS Foundation Trust and Gateshead Health NHS Foundation Trust, UK. Newcastle University will sponsor the trial. We will seek Health Research Authority (HRA) approval, including ethical approval from an independent NHS Research Ethics Committee. Written informed consent will be obtained from all participants before data collection.

Participant eligibility

Inclusion criteria

Exclusion criteria

Sample size

There are no clear guidelines on sample size requirements for non-randomised feasibility trials. Our aim is to recruit 45 women into the study. Assuming a conservative loss to follow-up of 20%⁸³, the research team considers this number of participants sufficient to achieve the study objectives and evidence suggests it is likely to achieve adequate qualitative data in post-study interviews⁶⁴.

Participant identification and consent

A research nurse will identify potential participants via review of medical records ahead of routine follow-up appointments at the outpatient breast cancer clinic. Eligible participants will be sent an information sheet before their appointment and, if the participant is interested in taking part, written informed consent will be obtained at the clinic.

PURE-EX programme

The PURE-EX programme has two components: (i) a referral pathway, and (ii) an online training course for community providers. Research team members will train HCPs at recruiting sites to offer and enact referrals into community-based physical activity programmes. For this feasibility study, the physical activity programme will be delivered by a community health charity based in North East England (Healthworks, https://www.healthworksnewcastle.org.uk/). Healthworks employs qualified exercise instructors (Register of Exercise Professionals, Level 3 or 4) to deliver a range of physical activity programmes in community-based leisure centres, including for people with long-term health conditions, older people, and women. Healthworks-employed instructors will undertake the PURE-EX online training course to adapt their existing physical activity programmes for women with breast cancer (Figure 3).

Figure 3. Summary of the PURE-EX programme.

HCPs = healthcare professionals.

Baseline data collection

Prior to participating in the physical activity programme, an instructor (who will be delivering the programme) will collect baseline information from each participant, including height, weight, blood pressure, sociodemographics (age, ethnicity, sex, postcode, highest level of education, employment status), and medical history (comorbidities, disability status, musculoskeletal injuries). Clinical information will be extracted from medical records by a research nurse, including date of cancer diagnosis, tumour grade, stage and receptor status, and treatment received.

Outcomes and mediators

The primary outcome is the feasibility of the PURE-EX programme. Cardiorespiratory fitness, physical function, and muscle strength will be assessed by the instructor before and after the physical activity intervention. Paper copies of study questionnaires and an accelerometer (for measurement of physical activity) will be given to participants to take home and return by post in pre-paid envelopes, or participants will complete study questionnaires online (Microsoft Forms), depending on preference.

Feasibility

We will document recruitment rates, withdrawals (with reasons), and loss to follow-up. We will record the proportion of participants who accept the physical activity referral and attend the community-based physical activity programme. A research team member attending a random sample (≈20%) of physical activity sessions will assess fidelity to the delivery of the physical activity programme using a standardised checklist, informed by TIDieR⁵⁹. Reporting of adverse events will be conducted in line with the study sponsor’s policy on adverse event reporting for non-clinical trials of investigational medicinal products; we will record all serious adverse events, as well as all non-serious adverse events that are deemed to be related to study participation.

Acceptability

Acceptability of PURE-EX programme components will be assessed using a validated acceptability questionnaire based on the theoretical framework of acceptability (TFA)⁸⁴. The questionnaire consists of 9 items: one item reflecting each of the TFA constructs of affective attitude, burden, perceived effectiveness, intervention coherence, self-efficacy, and opportunity costs, two items reflecting ethicality, and one general acceptability item.

Patient-Reported Outcomes (PROs)

The Functional Assessment of Cancer Therapy-Breast (FACT-B) total score will be used to measure disease-specific QoL⁸⁵. Fatigue will be measured with the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) total score⁸⁶. Anxiety and depression symptoms will be assessed via the Depression, Anxiety and Stress Scale - 21 Items (DASS-21) total subscale scores⁸⁷. We will administer the EQ-5D-5L⁸⁸ and a modified version of the UK Cancer Costs Questionnaire (UKCC) to assess the feasibility of collecting health economics data.

Cardiorespiratory fitness

The six-minute walk test (6MWT) is reliable (intraclass correlation coefficient = 0.93) and correlates well (r = 0.67) with peak oxygen consumption achieved during a cardiopulmonary exercise test⁸⁹. Participants will be instructed to walk at a self-selected maximal pace back and forth along a flat surface, covering as much distance as they can in six minutes. All instructions, encouragement, and monitoring will adhere to American Thoracic Society Guidelines⁹⁰. At the end of the test, participants will be asked to stop where they are and the total distance covered will be measured in meters.

Physical function

The Short Physical Performance Battery (SPPB), a composite measure of standing balance, five chair stands, and 4-meter gait speed, will be used to assess physical function. Each test is assigned a categorical score from 0 (worst performance) to 4 (best performance) according to standardised criteria. A total score from 0 to 12 is obtained by summing the scores from the three tests.

Hand grip strength

Participants will use their dominant hand to squeeze a hand-held digital grip dynamometer as hard as possible for 3 seconds. They will remain seated with their arm fully extended by their side during the test. The maximum score from three trials will be recorded in kilograms.

Mediators

Device-based physical activity will be measured using a tri-axial accelerometer (Axivity AX3, Axivity Ltd, Newcastle upon Tyne, UK)⁹² worn on the non-dominant wrist for 7 consecutive days, which is a well-established proxy for habitual physical activity⁹³. Data will be considered valid if participants wear the accelerometer for at least 8 hours on at least 4 days⁹⁴. From the raw accelerometer data, we use the GGIR package⁹⁵ in the latest version of R (R Foundation for Statistical Computing, Vienna, Austria; https://www.r-project.org/) to derive time spent sedentary and time spent in light, moderate, and vigorous activity. Published cut-points based on metabolic equivalents (METs) will be used to demarcate the intensity of physical activity⁹⁶. We will also assess self-reported physical activity using the International Physical Activity Questionnaire – Short Form (IPAQ-SF)⁹⁷, which provides data on time spent sitting and MET-minutes per week of walking and doing moderate and vigorous activity. The Health-Promoting Lifestyle Profile-II (HPLP-II) total score will be used to assess the extent to which participants engage in health-promoting behaviours. The HPLP-II comprises 52 items that measure six dimensions of a health-promoting lifestyle: health responsibility, physical activity, nutrition, spiritual growth, interpersonal relations, and stress management.

Qualitative process evaluation

We will invite participants to take part in semi-structured interviews at two timepoints: (i) 1–2 weeks after receiving the referral; and (ii) 1–2 weeks after completing the physical activity programme. Interviews conducted after the referral will explore experiences of interactions with HCPs, the referral pathway, and barriers and facilitators to accepting the referral and accessing the physical activity programme. Interviews held after programme completion will explore experiences of the physical activity programme and barriers and facilitators to sustained adherence. The interview topic guide will be informed by COM-B and our findings from the qualitative research in WP2. We will interview HCPs (n≈4-6) to explore experiences of the carrying out the referral and how it fitted into routine care, with the topic guide structured around COM-B and the constructs of NPT. Additionally, we will interview instructors to explore views of the online training course and barriers and facilitators to delivering the physical activity programme. Interviews will last approximately 60-minutes and be conducted in-person or remotely via telephone or videoconferencing (depending on interviewee preference), audio-recorded, and transcribed verbatim.

Qualitative analysis

Anonymised transcripts will be analysed, concurrently with data collection⁷⁶, with thematic analysis using a combined deductive and inductive approach⁹⁸. Transcripts will be coded deductively line by line using a pre-established coding scheme that aligns with the research questions and is guided by process evaluation recommendations⁹⁹. Following coding completion, each section of the coding scheme will be subject to an inductive thematic analysis, in which salient themes and recurrent patterns within the data will be identified and sub-themes created within each section¹⁰⁰. Data will be mapped onto the COM-B model and TDF to identify mechanisms through which the intervention brought about change^51,52. NPT will also be used to structure the coding framework to identify how new behaviours and practices can be integrated within routine clinical care⁷⁴. Analysis will be facilitated by NVivo software⁷⁸.

Quantitative analysis

The flow of patients throughout the trial will be reported in a CONSORT flowchart⁸². Descriptive statistics will be used to present baseline characteristics and feasibility outcomes. A paired t-test or Wilcoxon signed-rank test (depending on data distribution, assessed via visual inspection of histograms and Q-Q plots) will be used to evaluate changes in outcomes from baseline to post-intervention, with the mean change and 95% confidence interval presented¹⁰¹. Participants with missing data will be excluded from the analysis. The analysis will be performed in the latest version of R.

Study status

We are currently co-developing the detailed trial protocol with our PPI panel.