Measurement timepoints for the pilot are baseline (T0) and 3 months (T1; operationalised as 12–16 weeks from randomisation). When a participant provides consent they will be sent URL links to online questionnaires via email (with option to complete these by phone with a researcher if they experience difficulties), and mailed weighing scales (Seca 803 if they weigh less than 150kg and Seca 813 if the weigh over 150kg), a tape measure (Seca 201) and an activPAL4micro accelerometer (PAL Technologies Ltd., Glasgow, UK) .
Sociodemographic & disease characteristics (T0)
Details of each participant’s cancer diagnosis, treatment(s), and other health conditions (including previous cancer diagnoses) will be recorded from their hospital medical notes.
In the online questionnaires participants will report their age, gender, employment, education, marital status, living arrangements, and ethnicity. Participants will be asked to self-report details of their cancer diagnosis, treatment and other comorbid health conditions. This is to capture any further health information that is not included in the hospital medical records (e.g. information that would otherwise be included in GP records, or records from other hospitals). Participants’ postcodes will be used to determine socioeconomic position (Index of Multiple Deprivation) (60).
Physical activity (T0 and T1)
Physical activity will be measured using thigh-worn activPAL4micro accelerometers that participants will be asked to wear continuously for seven days (PAL Technologies Ltd., Glasgow, UK). The activPAL protocol, which follows published recommendations for using the device and expert advice from the Trial Steering Committee, includes waterproofing the device using specially designed nitrile sleeves and waterproof dressings, asking participants to wear it continuously, and including the data for analysis if 3 days of data are available (61). Participants will be mailed instructions on how to wear the device, a log-sheet to record when the device was worn and bedtimes and waketimes, and a freepost envelope to return it. The primary outcome of the future full RCT will be activPAL-assessed average daily brisk walking (≥ 100 steps/minute). The activPAL has shown excellent reliability and validity in measuring step number and cadence (steps/minute) and has been used in other studies with people LWBC and clinical populations (62, 63). Other physical activity outcomes that will be explored are total daily steps, minutes of light physical activity, standing time and sitting time.
Participants will also complete the Godin Leisure Time Exercise Questionnaire (GLTEQ) (64), which has demonstrated favourable validity and reliability against objective measures of physical activity and is widely used in oncology research (64, 65). The questionnaire will be adapted to add a question about duration of activities to allow calculation of minutes of MVPA, in addition to the leisure score index, a practice that is common in oncology research (66).
Anthropometric outcomes (T0 and T1)
Participants’ height, weight (without outer clothing/shoes on) and waist circumference (at umbilicus) will be measured by participants in their own homes using the study weighing scales and measuring tapes provided. Written instructions will be included to help participants complete these measurements accurately. Studies suggest that self-reported weight is sufficiently reliable and accurate where objective measurement is not feasible (67, 68). BMI will be calculated using the standard formula of weight (kg)/height (m)2. Self-measured waist circumference is also appropriate for large-scale studies where objective measurement is not feasible (69).
Well-being (T0 and T1)
Health status will be measured using the five-level EuroQol-5D questionnaire (EQ-5D-5L), which has established reliability and validity from a review of 12 studies of cancer patients (70). This will be used to generate quality-adjusted life years (QALYs) to facilitate the cost-effectiveness analysis.
Cancer-specific quality of life will be measured using the Functional Assessment of Cancer Therapy-General (FACT-G) scale (71). The FACT-G is a 28-item questionnaire that has excellent test-retest reliability (r = .92) and has been validated against the Functional Living Index-Cancer (FLIC) (r = .79) (71, 72).
Fatigue will be measured using the 13-item fatigue subscale of the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) (previously Functional Assessment of Cancer Therapy-Fatigue (FACT-F)) questionnaire (73). The 13-item fatigue subscale of the FACIT-F has excellent test-retest reliability (r = .90), internal consistency (α = .93-.95), and has been validated against the Profile of Mood States (POMS) fatigue (r = − .74), POMS vigor (r = .66) and Piper fatigue (r = − .75) (73–75).
Sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI), an 18-item questionnaire that assesses sleep quality and disturbances over a 1-month time interval (76). The PSQI has been used extensively and has good psychometric properties in both clinical (including cancer) and non-clinical samples (77). In women with breast cancer, the PSQI has been demonstrated to have high internal consistency (α = .80) and good validity when compared against related constructs such as sleep problems (in the Symptom Experience Report; r = .65) and sleep restlessness (in the Center for Epidemiological Studies Depression Scale; r = .69) (78).
Anxiety will be measured with the Generalised Anxiety Disorder Assessment (GAD-7), which has good test-retest reliability (r = .83), excellent internal consistency (α = .92), and has been validated against the Beck Anxiety Inventory (r = .72) (79). Depression will be measured with the Patient Health Questionnaire (PHQ-9), which shows adequate diagnostic accuracy in cancer patients (80–82).
Physical activity self-efficacy will be measured using the Physical Activity Appraisal Inventory (PAAI), which has demonstrated excellent reliability in women with breast cancer (α = .96) (83). The PAAI also has established validity (83). Self-efficacy to self-manage cancer will be measured using the Cancer Survivors Self-Efficacy Scale (CS-SES), an 11-item questionnaire with excellent reliability (α = .92) (84).
Habit strength for walking (“going for a walk” and “walking briskly”) will be measured with the Self-Report Behavioural Automaticity Index (SRBAI), which has established reliability and has shown to be sensitive to hypothesised effects of habit on behaviour (85).
Health and social care service use will be measured using the Client Service Receipt Inventory (CSRI), which has been validated against objective primary care records and is also recommended for usage of hospital and other community health services (86).
App Use (T1)
Participants in both groups will also be asked to report their usage of any physical activity app during the study period. Intervention group participants will be asked to complete brief intervention feedback questions (including a self-report question of whether they ever downloaded Active 10) and will be asked to self-report their usage of Active 10 throughout the study period (never, once, less than monthly, monthly, fortnightly (every 2 weeks), weekly, 3–4 times per week, almost every day or every day). Intervention participants will also be asked to complete questions from the Digital Behaviour Change Interventions Engagement Scale (87).
Qualitative interviews (Decliners at T0 and Participants at T1)
To further understand how a future intervention could be designed to be as inclusive as possible, individuals who decline to participate will be asked to briefly provide reasons if they are willing. They will also have the option to consent to participate in an interview to further explore reasons, and up to 30 interviews will be conducted. This method has been utilised succesfully in on ongoing exercise trial with myeloma patients (63).
Interviews will also be carried out with a purposive sample of up to 30 participants from the intervention arm and up to 20 participants from the control arm at the end of the trial. The interviews will take place after a participant has completed all other data collection at T1 and will be conducted to explore experiences of participation, being randomised and views on providing permission to access NCRAS/HES data. Intervention arm participants will also be interviewed about their experiences of using the app, the intervention materials and about their perceptions of app usage and engagement. All interviews will be semi-structured and based on a topic guide, take place via telephone and will be audio-recorded and transcribed verbatim.
Statistical Analysis
Baseline comparability of the randomised groups will be assessed using descriptive statistics (e.g. age (continuous), gender (categorical), key outcome measures (e.g. physical activity participation)). The outcomes outlined in Table 1 will be reported descriptively. Any reasons provided for declining not covered in the specific outcomes will also be reported, as well as details of answers provided to the feedback questionnaire, within the intervention group. Mean and standard deviation estimates for the intended primary outcome measure at 3 months (activPAL measured average daily minutes of brisk walking (> 100 steps/minute)) will be calculated and reported descriptively. These results will be used to inform a sample size calculation for the future definitive trial.
An initial economic evaluation will be conducted to provide an estimate of the potential cost-effectiveness of the intervention. QALYs will be estimated based upon the EQ-5D-5L combined with standard valuation sources (88, 89). Costs will include the costs associated with the intervention (promotional materials, time spent delivering the intervention recommendation) and other NHS resource use measured using the CSRI. Costs and QALYs will be combined in an analysis to estimate the incremental cost effectiveness ratio (ICER) associated with the intervention compared to the control group. Uncertainty in the results will be characterised using cost-effectiveness planes and cost-effectiveness acceptability curves (90). A value of information analysis will also be conducted at this stage. The expected value of perfect information (EVPI) and expected value of perfect partial information (EVPPI) will be estimated.