ProHealth: a co-designed online home-based healthy eating and exercise programme for men with prostate cancer treated with androgen deprivation therapy – a study protocol for a feasibility and preliminary efficacy randomised controlled trial

Abstract

Background

Androgen deprivation therapy (ADT) improves survival in advanced prostate cancer but may lead to debilitating side effects, including sarcopenic obesity and a 10–45% increased risk of other comorbidities. Guidelines recommend exercise and nutrition interventions during ADT, but access to these services is often limited, and referral pathways are unclear. This study aims to evaluate the feasibility and preliminary efficacy of an online, home-based, multi-faceted, exercise, nutrition and education programme (ProHealth) for men with prostate cancer treated with ADT. ProHealth was co-designed with consumers and healthcare professionals to include (i) education on prostate cancer and treatment-related side effects and (ii) multimedia behaviour change resources to support individualised nutrition and exercise behaviour change.

Methods and analysis

This 12-week randomised controlled trial (target n=50) will include men treated with ADT for >3 months or who have completed ADT in the last 24 months, are overweight or obese and are not under the care of a dietitian or exercise professional. Participants will be randomised (1:1) to the ProHealth intervention or usual care. The intervention group will receive four consultations with an Accredited Practising Dietitian to promote a high protein and energy reduced diet, and five consultations with an Accredited Exercise Physiologist to follow a home-based progressive resistance training and aerobic exercise programme. The primary outcomes are feasibility (recruitment rate, retention, data completeness, reach, safety, consultation attendance and adherence, and usage of the ProHealth web platform), acceptability and satisfaction of the ProHealth intervention. Exploratory secondary outcomes will be assessed at baseline and 12 weeks and include changes in body weight and composition (total and appendicular fat-free mass, fat mass), quality of life (Functional Assessment of Cancer Therapy (FACT)—General, FACT-Prostate, FACT-Fatigue), physical function (30-second sit-to-stand), dietary intake (3-day food diary) and physical activity (7-day accelerometer). Linear regression models will estimate differences between the intervention and usual care group. Qualitative interviews on participant satisfaction will be transcribed verbatim for thematic analysis.

Ethics and dissemination

This study is approved by Deakin University Human Research Ethics Committee (DUHREC2024-038) and registered on Australian and New Zealand Clinical Trials Registry (ACTRN12624000874516). Findings will be disseminated through peer-reviewed journals, scientific meetings and other public forums.

Trial registration number

ACTRN12624000874516.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• This initiative has been co-designed with consumers and healthcare professionals to align evidence-based prostate cancer–specific nutrition and exercise care with the needs of men undergoing androgen deprivation therapy.

• This study will provide insight regarding the feasibility, acceptability, experiences and satisfaction of an online home-based delivered nutrition, exercise and education intervention to inform future larger trials.

• Semi-structured interviews will evaluate patient experiences and satisfaction to understand whether ProHealth met consumer needs.

• Due to the nature of the exercise and nutrition intervention, blinding of participants is not feasible, which may introduce performance or detection bias.

• Secondary outcomes, including body composition, physical function and quality of life, are not adequately powered and will be treated as exploratory.

Background

Prostate cancer places a significant burden on Australian men, accounting for ~24 000 new diagnoses annually,¹ and is the fourth most diagnosed cancer globally.² The number of Australian men diagnosed, treated and living with prostate cancer is predicted to triple, surpassing 370 000 by 2040.^{3 4} Improvements in the early detection and treatment of prostate cancer extend survival after curative treatment (98% 5 years after diagnosis).³ Androgen deprivation therapy (ADT) is used in up to 65% of men diagnosed with prostate cancer⁵; however, the multiple interconnected adverse side effects from ADT offset the survivorship benefits.⁵,⁷ Significant weight gain with simultaneous muscle loss from ADT increases the risk of sarcopenia (reduced muscle mass, strength and function) co-existing with obesity,⁷ and has been associated with a 10–45% increased risk of co-morbidities (ie, diabetes, cardiovascular disease).⁸,¹⁰ In addition, clinically significant weight gain (>5% wt) after prostate cancer diagnosis has been associated with a 65% increased risk of mortality compared with men who are weight stable.¹¹ Combined nutrition and exercise interventions are the only strategy endorsed by clinical guidelines¹²,¹⁴ and national position statements¹⁵ that can simultaneously target, manage and improve multiple side effects and co-morbidities from ADT.¹⁶,²⁰ However, these interventions are not routinely implemented or adopted into practice.^{21 22}

Individualised nutrition and exercise interventions delivered by an Accredited Practising Dietitian (APD) and Accredited Exercise Physiologist (AEP), in men treated with ADT, have shown benefits in body composition through reducing body weight and fat mass,²³,²⁵ maintaining muscle mass^{25 26} and improving quality of life.^{23 25 27} Despite these promising results across trials, >60% of eligible men decline to participate in face-to-face delivered interventions due to their length and intensity (eg, fortnightly face-to-face consultations, 2–3 weekly supervised exercise sessions), travel, costs and/or the time-commitment to participate,^{23 24 26} all of which are well-known and common barriers.²⁸,³² As a result, the gap between intervention effectiveness and real-world uptake of programmes for men treated with ADT persists, highlighting the need for future approaches that are responsive to individual circumstances and needs as well as health service delivery capabilities.

Technology-supported nutrition and exercise interventions offer an alternative, and potentially equitable, sustainable and cost-effective opportunity to provide an evidence-based, remotely delivered model of healthcare. Online programmes have the potential to reduce common barriers (ie, travel time and costs) to participating in nutrition and exercise interventions.^{33 34} Previous systematic reviews have identified a benefit from technology-supported nutrition and physical activity interventions on dietary and exercise behaviour change in people with cancer.^{35 36} However, there remains a critical need to ensure that these programmes are truly fit for purpose, meet participant needs and can be sustainably implemented within health services. This necessitates a strong emphasis on consumer and healthcare provider input and co-design of the intervention, as recommended for the development of cancer initiatives.³⁷

The proposed ProHealth programme has been co-designed with 12 healthcare professionals and 10 men treated with ADT and includes education on prostate cancer and treatment-related side effects and resources to support individualised nutrition and exercise behaviour change guided by an APD and AEP. This study aims to evaluate the feasibility and preliminary efficacy of an online, home-based, multi-faceted, exercise, nutrition and education programme (ProHealth) for men with prostate cancer treated with ADT. The primary objective is to assess the feasibility, acceptance and satisfaction of the ProHealth intervention. Exploratory secondary objectives are to investigate the preliminary efficacy of the ProHealth intervention on body mass and composition, quality of life, physical function, physical activity and dietary intake.

Methods

The Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) 2022 guidelines were used to report this study protocol (online supplemental material A).³⁸ This study is an Australian-based feasibility and preliminary efficacy randomised controlled trial where men diagnosed with prostate cancer and treated with ADT will be recruited and allocated (1:1) to receive the intervention (ProHealth programme) or usual care during a 12-week period (figure 1). This study will be delivered entirely online using Zoom Communications Inc, 2016, which has shown to be a reliable video platform for healthcare delivery.³⁹ All equipment required to participate in the trial will be delivered to participants at home, with the trial managed remotely by the research team at Deakin University in Melbourne, Australia. This study has ethics approval from the Deakin University Human Research Ethics Committee (DUHREC2024-038) and is registered with the Australian and New Zealand Clinical Trials Registry (ANZCTRN12624000874516). Recruitment for this trial is planned to start in January 2025 with final follow-up expected to be completed in March 2026.

Figure 1. Schematic overview of study design. ^a Access to ProHealth’s platform from baseline to 12 weeks; ^b Consultations with an APD and AEP occur at weeks 0, 2, 4 and 8, with an additional 30 min AEP appointment scheduled at week 1 to discuss suitability of the exercise prescription.

Patient and public involvement

This programme of work has been co-designed with 12 healthcare professionals and 10 men treated with ADT. Two consumers are listed as authors and are investigators on the Victorian Cancer Agency Early Career Research Fellowship (ECRF22019). Both were encouraged to contribute their personal and community lived experience to the study design by attending investigator meetings, reviewing study protocols, all patient-facing materials and providing feedback on the ProHealth education content. Their involvement ensured that the programme remains grounded in consumer relevance and aligns with the National Health and Medical Research Council’s guidelines for consumer involvement.⁴⁰

Selection criteria

Patients are eligible if they are:

• Aged 18 years or older.

• Diagnosed with prostate cancer (including metastatic disease).

• Treated with ADT for >3 months or have completed ADT within the last 24 months.

• Body mass index 25 to <40 kg/m².

• Not currently meeting the dietary and exercise guidelines for cancer survivors or under the care of a nutrition or exercise health professional.

• Not taking any nutritional supplements other than a single multivitamin, unless for medical purposes (ie, vitamin D supplement for low bone mineral density).

• Free of any musculoskeletal, neurological, respiratory, metabolic or cardiovascular conditions that may prevent safe completion of the exercise demands of the study.

• Access to a smart device or computer with stable internet and video capabilities.

• Able to read and speak English.

Exclusion criteria

• Body weight >200 kg.

• Any electronic medical implant (ie, pacemaker).

Recruitment

Participants will be recruited Australia-wide from Prostate Cancer Foundation Australia (PCFA) Support Groups and by direct referral from prostate cancer nurses. Each PCFA support group will be emailed an invitation to disseminate an advertisement for the study, which will include the plain language and consent form (PLCF) and a secure link to the ProHealth web application for potential participants to read, check eligibility and register for the study. A follow-up email to all support groups will be sent 1–2 months after the initial email. Prostate cancer nurses will be able to directly refer participants to the ProHealth web application to screen and register. Additional recruitment strategies include social media posts on Facebook, LinkedIn and X that will be circulated through Deakin University’s Institute for Physical Activity and Nutrition accounts with the same secure online link to screen and register for the study.

Participant screening and enrolment

On the ProHealth web application, the PLCF is available to read and download. Men interested in the study will be invited to register for the programme by entering their contact details (ie, name, phone number, address and email). Following this, an eligibility screening questionnaire, developed in the Qualtrics XM Platform (Provo, UT), will appear for men to complete. An onscreen message will notify participants if they are eligible or not, and a member of the research team will contact all eligible participants via phone or email to confirm eligibility, answer questions and organise a time to complete the baseline measures.

Written informed consent

Written informed consent will be obtained only after participants understand the PLCF and have had a chance to ask any questions about the study. Consent will be obtained through either (i) electronic signature captured in Qualtrics (Provo, UT) or by signing, dating and returning a paper copy of the PLCF. Paper records of the PLCF will be kept in a secure filing cabinet at Deakin University.

Randomisation, allocation concealment and blinding

After participants have consented to the study, they will be randomly allocated to either the ProHealth intervention or the usual care group using a centralised computer system (Qualtrics). The randomisation sequence of 1:1, with no block restrictions or stratification, was developed in Qualtrics by a Deakin staff member external to the research team. An email detailing the group allocation will be sent to two external researchers for the purpose of outcome assessment equipment preparation (see below) and kept in an electronic password-protected file. Contact details for participants that are not eligible will be deleted once recruitment has finished. Participants and research staff members collecting the baseline measures are blinded to the group allocation until individual participant baseline measures are completed. Allocation will then be revealed to the participant and the research team members through email notification. The centralised computer system and notification timing will ensure allocation concealment. The research members overseeing the project will be unblinded to group allocation after baseline assessment as they are responsible for monitoring adverse events. The statistician will be blinded to group allocation for data analysis.

Blinding parcel preparation

All participants will be sent equipment to complete the study outcome measures. A blinded member of the research team will prepare a parcel containing the equipment required for the baseline measures (Bioelectrical impedance analysis, Tanita RD 545, Tanita, Australia; Seca 201 measuring tape, Seca GmbH & Co. KG, Hamburg, Germany; Actigraph GT9X Link accelerometer) and attach participant delivery details. One of two unblinded researchers (external to the research team) will complete the parcel packaging by either adding the resistance bands (intervention group) or not (usual care group) according to the group allocation, then sealing the parcel with a zip tie. The completed parcels will be collected and processed by Deakin University’s logistics department.

To maintain assessor blinding, instructions are printed on the exterior of the study parcel directing participants to open the package only in the presence of the research assistant during baseline testing. Participants are further instructed by the research assistant at the start of baseline testing to refrain from disclosing whether resistance bands are within the parcel. Any instances of accidental unblinding of assessors will be recorded by the assessor.

Intervention group

ProHealth evidence-based education content

Participants in the intervention group will have access to the ProHealth web application education programme for 12 weeks. ProHealth’s education programme (figure 2) contains (i) an overview of prostate cancer and where to find extra support; (ii) understanding ADT and management of side effects; (iii) other prostate cancer treatments and side effects; (iv) exercise and prostate cancer and (v) nutrition information specific to prostate cancer (split across two modules). Established behaviour change techniques following the CALO-RE (The Coventry, Aberdeen, and London—Refined) Taxonomy underpin the structure of the educational content,⁴¹ which includes skill development in self-efficacy, social support and outcome expectancies, skill development for nutrition and exercise behaviour change, goal setting, self-monitoring, problem solving through identification of barriers and facilitators in adherence to the nutrition and exercise prescription. The ProHealth content was co-designed with consumers and healthcare professionals to support educational needs and individualised advice provided in the study.⁴² Each module has been written by an APD or AEP with expertise in prostate cancer and reviewed by the research team, including consumer members (GR and GM).

Figure 2. Schematic overview of educational material in ProHealth. ^a Modules can be individually personalised by an accredited practising dietitian or accredited exercise physiologist. RPE, Rate of Perceived Exertion.

Two modules in the ProHealth programme have the capabilities to be individually modified by an APD (My Nutrition Programme) and AEP (My Exercise Programme) to support the behaviour change strategies developed in the nutrition and exercise video-consultations. The My Nutrition Programme has editable text that can be modified to generate individual nutrition goals, nutrient recommendations, a meal plan and education material with recipes to support dietary change. The My Exercise Programme also contains editable text to individualise goals for an aerobic and resistance exercise programme developed by an AEP. This module also contains a library of 120+narrated exercise demonstration videos provided by VALD Pty Ltd (VALD Performance, Brisbane, Australia), with closed caption, where the AEP can prescribe a safe home-based resistance exercise programme. The frequency, sets and repetitions for each exercise can be edited for personalisation.

Nutrition consultation frequency and prescription

Participants will receive individualised nutrition consultations from an APD at weeks 0, 2, 4 and 8 through video consultations (each 45–60 min) integrated into the ProHealth programme using Zoom Video Communications, Inc 2016. Participants will be asked to follow the nutrition programme developed by the APD for 12 weeks.

Intervention targets will be consistent with guidelines for management of overweight and obesity in cancer survivors.^{12 43} An APD will prescribe an individualised energy deficit of approximately 500–1000 kJ/day aiming for 2–4 kg weight loss over 12 weeks, or until a healthy body weight is achieved.⁴⁴ To encourage maintenance of muscle mass, a high protein intake (1.2–1.5 g/kg/day) will be prescribed alongside the exercise prescription.¹² Other nutrition targets include total fat intake <30% energy, saturated fat <7% energy, 30 g/day fibre and 2 and 5 servings/day of fruit and vegetables, respectively, for cardiometabolic health.⁴³ If participants are experiencing side effects from other previous treatments, symptoms will be managed with nutritional strategies where possible and documented. The study APD will be trained to deliver consistent structured nutrition therapy (ie, assessment, diet history, education and intervention) with motivational interviewing that emphasises goal setting and change in dietary intake that is shared. Progressive dietary behaviour changes will be encouraged to meet the nutrient or food group recommendations and promote sustained dietary behaviour change. At each consultation, the APD will check adherence to dietary goals to progressively change dietary intake where needed. All dietary goals, meal plans and supported education material will be available in the ProHealth ‘My Nutrition Plan’ module after the consultation.

Exercise consultation frequency and prescription

Participants will have consultations with an AEP at weeks 0, 2, 4 and 8 through video-consultations (each 60–90 mins) integrated into the ProHealth programme using Zoom Video Communications, Inc 2016. There is an additional 15–30 min check at week 1 from the AEP to monitor the intensity/volume of the exercises and modify the programme if needed. Participants will be asked to follow the exercise programme for 12 weeks.

Home-based exercise prescription will consist of three sessions/week of resistance-band training at a moderate intensity (12–15 Rating of Perceived Exertion) aiming for two to three sets of 8–12 repetitions of six to eight exercises targeting major muscle groups (ie, chest, back, shoulders and quadriceps).^{12 13 45} Participants will also be encouraged to perform two to three aerobic exercise (walking/cycling) sessions per week at moderate intensity (50–70% HRmax) progressing to 30 min per session (including a warm-up and cool-down). The AEP will prescribe and modify the exercise plan in ‘My Exercise Program’ for participants during or after each consultation using exercise videos from VALD Pty Ltd; provided in-kind and integrated into the ProHealth programme. The exercise videos include a range of instructions to performing safe exercise with a resistance band or body weight. In ProHealth, a template of exercise videos will be collated by muscle groups for the AEPs to use and modify based on individual needs and contraindications to exercise. The exercise template will consist of warm up (ie, marching on the spot, star jumps), upper body (ie, chest press, shoulder press, bicep curl), lower body (ie, squats, calf raises, chair raise, wall squat), core (ie, pelvic tilt, bird dog) exercises and cool down stretching.

The American Society of Clinical Oncology Exercise Recommendations for People with Bone Metastatic Disease will guide the exercise prescription for participants with this condition.¹⁴ A risk assessment of where the bone lesion is located, number of lesions and pain will be assessed to devise an individual exercise programme that avoids or provides a low load of exercise resistance to the located site. Extra emphasis will be placed on postural alignment, controlled movement and correct technique to avoid adverse events. For exercises that may impact where the bone legion is located, the exercise will be avoided (if required) or start with a low load and progress slowly in the number of repetitions, sets and/or frequency under the guidance and expertise of the ProHealth AEP.

At the conclusion of each exercise session, participants will be instructed to log all exercises completed, sets/repetitions, level of pain (subjective visual analogue scale of 1–10) and difficulty (rating of perceived exertion, scale 6–20),⁴⁶ allowing the AEP to monitor the programme remotely. Prior to each consultation, the logged exercise sessions will be reviewed by the AEP. Low session logging will be explored during consultations to determine if it reflects low adherence with exercise training or low compliance with exercise logging. This will inform strategies to overcome barriers to perform or log exercise sessions. Similar to the nutrition component of ProHealth, the exercise plan will contain personalised exercise requirements targeting individual goals and key points discussed in each consultation to achieve the exercise plan.

Usual care group

Participants allocated to the usual care group for 12 weeks will be asked to continue their usual lifestyle and medical treatment. After the usual care period, participants will be offered access to the ProHealth education content via the web platform, for their ongoing use. In addition, they can receive a complementary consultation with either an APD or AEP.

Data collection

Table 1 describes the data collection timepoints at (i) baseline, (ii) throughout the study and (iii) after 12 weeks completion of the study. The medical history form (baseline-only), quality of life measures (Functional Assessment of Cancer Therapy (FACT)-G, F and P), body image and the Theoretical Framework of Acceptability (TFA) generic questionnaire (12 week only) will be self-reported online using a questionnaire built in REDCap (Vanderbilt University, Nashville, Tennessee, USA). Participants will have daily reminders for 14 days to complete any outstanding questionnaires. The anthropometry, body composition and physical function test (listed below) will be collected remotely, facilitated by a member of the research team at baseline and 12 weeks, using Zoom Video Communications, Inc 2016.

Table 1. Schedule of data collection per group allocation.

Assessment	Registration	Enrolment	Intervention			Usual care
			T1	During study period	T2	T1	During study period	T2
Screening
Inclusion criteria	X
Consent to contact	X
Eligibility screening		X
Informed consent		X
Medical history form and medications		X
Primary outcomes
Feasibility
Eligibility rate		X
Consent rate		X
Recruitment rate		X
Randomisation rate *		X
Retention					X			X
Data completion			X		X	X		X
Reach	X	X
Safety			X	X	X	X		X
Attendance				X
Adherence†				X
Web-platform usage				X
Acceptability
Theoretical Framework of Acceptability					X
Satisfaction
Semi-structured interviews					X
Secondary outcome
Anthropometry
Weight and body composition			X		X	X		X
Waist circumference			X		X	X		X
Calf circumference			X		X	X		X
Functional tests
Sit to stand test (30 s)			X		X	X		X
Patient report outcome measures
FACT-General			X		X	X		X
FACT-Prostate and Fatigue subscale			X		X	X		X
Modified Body Image Scale			X		X	X		X
Behavioural outcomes
Dietary intake (3-day food diary)			X		X	X		X
Physical activity‡			X		X	X		X
Sedentary behaviour‡			X		X	X		X

Timepoint 1=baseline; Timepoint 2=12 weeks.

^*Group allocation will occur after baseline assessment.

^†Includes the number of dietary goals achieved after being set by the APD. Adherence to exercise sessions include the number of logged exercises, with rating of perceived exertion.

^‡Actigraph GT9X Link+ActiLife.

APD, Accredited Practising Dietitian; FACT, Functional Assessment of Cancer Therapy.

Primary feasibility outcomes

Based on previous nutrition and exercise trials in ADT,^{23 24 26} we will assess feasibility based on the following criteria.

Recruitment, retention and data completeness

• Eligibility rate: the proportion of individuals confirmed as eligible relative to the total number of individuals screened.

• Consent rate: the proportion of eligible individuals who provide consent to participate in the trial.

• Recruitment rate: the average number of eligible individuals consented into the trial per month until the target sample size is reached.

• Randomisation rate: the proportion of consenting participants randomised into a study arm.

• Retention: the proportion of randomised participants that remain in the study at 12 weeks.

• Data completion: the proportion of completed secondary outcomes measures at baseline and 12 weeks, relative to the total number of secondary outcome measures required from all participants.

Feasibility benchmarks of high, moderate and low are set a priori for each measure. High feasibility will be defined as a rate of >80% for eligibility, consent, randomisation, retention and data completeness. Moderate feasibility will be defined as rates between 50% and 79% across these measures, and low feasibility will be defined as a rate of <49% for any of the criteria.

Reach

The characteristics of participants included in this trial will be evaluated (ie, demographic characteristics, number of side effects from treatment, co-morbidities, diet quality and physical activity levels) to describe the participants in our study. We will compare the data collected during the eligibility screening (from both eligible and ineligible individuals) which includes age, duration of ADT, weight and BMI, contraindicators to exercise and nutrition, and whether individuals are currently under the care of a nutrition or exercise health professional to identify any influential inclusion and exclusion criteria. Furthermore, we will compare the detailed medical, dietary and physical activity data of the enrolled sample against broader Australian data to contextualise the study’s findings.

Intervention consultation attendance and adherence

Participants in the intervention group are scheduled to receive four consultations with an APD and five with an AEP. The total number of consultations attended, missed and/or rescheduled will be documented by the study APD and AEP across the intervention period to determine attendance rates. Based on previous trials,^{23 24 26} we will classify attendance as high (≥90%, ≥8/9 sessions), moderate (89–60%, 5–8/9 sessions) or low (<59%, <5/9 sessions).

For exploratory purposes, the adherence to dietary goals developed by the APD will be assessed after each nutrition consultation using a 24 hours diet recall, guided by the APD, in accordance with standard practice.⁴⁴ Exercise adherence measures will include the number of exercise sessions logged, completed and with detailed reporting on the rating of perceived exertion that were self-directed outside of the consultations. The AEP will cross-check adherence data prior to each consultation.

Safety

Adverse events will be recorded from the ProHealth intervention group only. Adverse events will be identified through participant self-reporting, during scheduled consultations with an APD or AEP, or at the study’s conclusion. Each event will be graded using The National Cancer Institute’s Common Terminology Criteria for Adverse Incidents and Events (CTCAE) to describe the event, relationship to the intervention (determined by the research team) and severity (mild, moderate, severe, life-threatening, fatal).⁴⁷ All reported adverse events will be evaluated by the primary investigator via a phone call at the time of reporting. This is to ensure accurate classification of the event and to coordinate any necessary risk assessment and welfare support.

In accordance with reviews evaluating safety from remotely delivered exercise interventions,⁴⁸,⁵⁰ the ProHealth intervention will be considered safe based on the below parameters:

• High safety: zero intervention-related CTCAE grade 3 events; ≤10% of participants with intervention-related CTCAE grade 1–2; ≤5% withdrawals due to adverse events.

• Moderate safety: ≤1 intervention-related CTCAE grade 3 events; ≤20% with intervention-related CTCAE grade 1–2; ≤10% withdrawals due to adverse events.

• Low safety: ≥2 intervention-related CTCAE grade 3 events; >20% of participants with intervention-related CTCAE grade 1–2; ≥15% withdrawals due to adverse events.

Usage of the ProHealth web-platform

We will measure the number of views on the ProHealth education material (figure 2: total 41 education material) in the web-platform. At least 75% views of education material will be considered high usage, 74–50% moderate usage and <50% as low usage. For exploratory purposes, the Assessment of Data Usage of Cancer e-Interventions Framework⁵¹ will be used to guide analysis on usage patterns, logins and pages viewed of the web programme.

Acceptability

The TFA generic questionnaire^{52 53} will be completed by intervention participants at 12 weeks following completion of the ProHealth programme. The TFA assesses seven constructs of acceptability, including (1) affective attitude, (2) burden, (3) ethicality, (4) intervention coherence, (5) opportunity costs, (6) perceived effectiveness and (7) self-efficacy.

Experience and satisfaction

A subgroup of participants in the ProHealth intervention arm (estimated n=15) will be invited to participate in an interview after completing the study. Semi-structured interviews will explore participants’ experience of the study procedure, intervention components, education material, self-efficacy and alterations needed for future upscale.

Secondary outcomes

Anthropometry and body composition

Height will be self-reported at baseline only to determine eligibility and is a reliable measure.⁵⁴

Using Zoom (Video Communications, Inc 2016), a research member will guide participants to self-measure waist and calf circumference (left and right calf) using a handheld, retractable, measuring tape (Seca 201, Seca GmbH & Co. KG, Hamburg, Germany). To control for variability in self-measures, circumferences will be measured in accordance with the International Society for the Advancement of Kinanthropometry procedure to the nearest 0.1 cm three times on the waist and each calf, with the mean value recorded.⁵⁵

Body composition analyses using bioelectrical impedance analysis (BIA; Tanita RD 545, Tanita, Australia) will also be guided by a research member using Zoom Video Communications, Inc 2016. The measures collected from BIA include estimated total body weight (in kg), total body and appendicular (arms and legs) fat-free mass (in kg) and fat mass (%) and total water (%).

Physical function

The 30-second sit-to-stand test will be used to assess lower body strength and endurance⁵⁶ and is a safe and validated test to be collected remotely using video technology.⁵⁶ Participants will be asked to place a sturdy chair (ie, dining chair) against a wall and have the video camera positioned side-on to observe the participants’ backs touching the chair. Participants will be asked to cross their arms against their chest, have their feet shoulder width apart and demonstrate three practice repetitions to ensure the measure is performed safely. Once ready, the instructor will count down from three to start the timer and the test. The number of repetitions will be counted from standing up to sitting down within 30 s.

Quality of life outcomes

Quality of life measures include the FACT-G which is a 27-item questionnaire designed to measure four domains: physical well-being (seven items), social/family well-being (seven items), emotional well-being (six items), and functional well-being (seven items) on a five-point Likert rating scale.⁵⁷ Two additional FACT outcomes will be added and include the prostate cancer subscale (12 items)⁵⁸ and the fatigue subscale (13 items).⁵⁹

The modified Body Image Scale (BIS) is a nine-item scale that comprises affective items, behavioural items and cognitive items. The modified BIS questionnaire excludes the question ‘Have you been dissatisfied with the appearance of your scar?’ designed for women after breast cancer surgery.⁶⁰

All questionnaires will be administered through REDCap (Vanderbilt University, Nashville, Tennessee, USA), and participants will be instructed to complete them within 7 days of the anthropometry, body composition and physical function assessments.

Dietary intake

Dietary intake will be assessed using 3-day food records provided online or handwritten. The 3-day food record is recommended by the National Cancer Institute for prospective observational studies and is suitable for capturing total dietary intake over the short term, does not rely on memory and has low cognitive difficulty.⁶¹ This measure will be used to assess changes in dietary intake across timepoints. The 3-day food records will be cross-checked by an APD for accuracy in reporting (ie, quantity, serving size, name/brands of products) and participants may be called for further information if required.

Physical activity

Objective physical activity will be measured over a 7-day period during waking hours using an accelerometer (Actigraph GT9X Link+ActiLife), a small non-invasive device worn on the wrist. Participants will be asked to keep a record of their sleep/awake times, periods of removal of the accelerometer (if any), naps taken (if any) and other relevant information. Data for a minimum of any 4 valid days, with a valid day considered as 8 or more hours of wear time, will be required for analysis.⁶² Physical activity measured by the accelerometer will be examined in four ways: (i) minutes per day (min/day) spent sedentary, light and moderate-vigorous physical activity⁶³; (ii) physical activity energy expenditure (kcal/kg/day); (iii) steps per day (steps/day) and (iv) total activity counts per day.

Sample size and power calculation

This study will provide insight into the intervention feasibility, acceptability and satisfaction as well as preliminary estimates of efficacy of the ProHealth intervention on secondary outcomes to inform decisions about a larger trial. We plan to recruit 50 participants (25 in each group). Based on a 64% recruitment rate reported in a previous intervention,²⁷ we estimate screening a total of~100 men (5–6 per month for 18 months) to reach our sample size of 50 men with prostate cancer treated with ADT.

Power calculations for secondary outcomes are exploratory with the intent to provide insight for larger phase II/III trials evaluating minimal important differences in clinical and patient-reported outcomes. These calculations are not for hypothesis testing for the present study. Using the pwr package in R, V.4.4.1, secondary outcomes were powered based on a two-tailed α=0.05. Body composition estimates for power calculations were derived from previous trials using dual-energy X-ray absorptiometry, where men treated with ADT had a mean weight ranging from 87 to 92 kg, fat mass from 26 to 29 kg (~31–33%) and fat-free mass between 53 and 59 kg (~57–65%).^{23 25 26} This sample size (n=50) will provide at least 80% statistical power to detect a 3–5% clinically meaningful between-group differences in body mass (mean±SD 3±3 kg),^{64 65} fat mass (2.1±2.5 kg) and fat free mass (1.4±1.7 kg). This study will be underpowered for between-group differences in FACT-G, prostate and fatigue subscales.⁵⁷

Analysis

Demographic variables will be summarised descriptively (ie, mean, SD, range, IQR). Counts and percentages (with 95% CIs) will summarise data on recruitment, retention, web-programme usage data, adverse events (tabulated by severity grade) and other feasibility and acceptability outcomes. Linear regression models will be used for exploratory analysis to estimate differences between the intervention and usual care group for pre-post changes in secondary outcome measures over 12 weeks. For all body composition and quality of life outcomes, the linear regression models will include number of comorbidities and duration of ADT as covariates. Models with and without covariates will be reported. Intention-to-treat complete case analysis will be conducted. If there is >5% missing data for an outcome(s), sensitivity analyses will be conducted with missing data handled with multiple imputation. Statistical significance will be two-tailed and accepted at the p≤0.05 level.

Interviews will be transcribed verbatim and exported into NVIVO (QSR International, V.14). Interview data will be analysed using reflexive thematic analysis, which is a flexible analytic approach to qualitative analysis that can be used with a wide range of data.⁶⁶ Analysis will be guided by a phenomenological framework, and themes will be interpreted from participant reflections. Interviews will be coded line by line to identify key concepts emerging from the data. Analysis will be inductive and deductive as themes will not be predefined but led from the coding of participant responses. The preliminary codes will be identified (BB) and refined through collaborative analysis (NKK, VW and HK) and preliminary themes identified through review and discussion. Preliminary themes will be reviewed with the research team and discussed until final themes and sub-themes are confirmed. This component of the study will be reported according to the Consolidated criteria for Reporting Qualitative research (COREQ) guidelines.⁶⁷

Ethics and dissemination

This study has received ethics approval from the Deakin University Human Research Ethics Committee (DUHREC2024-038) and is registered with the Australian and New Zealand Clinical Trials Registry (ANZCTRN12624000874516). It will be conducted in full conformance to Australia’s National Health and Medical Research Council’s National Statement on Ethical Conduct in Human Research 2007, updated 2018, and the principles of the World Medical Association Declaration of Helsinki 2013. While online remotely delivered nutrition and exercise interventions are generally considered safe,^{34 48 49} there are potential risks for adverse events given the health status in this study population. To manage these risks, the welfare of participants will be the immediate priority. Any adverse events will be documented by the research team and reported to the primary investigator, who will follow-up with the participant to determine the nature of the event, its severity and its potential relationship to the intervention. All adverse events will be reported to the Deakin University Human Research Ethics Committee in accordance with university guidelines. Following any adverse event, a formal risk assessment will be conducted to develop a tailored action plan to support the participant and prevent recurrence. All data collected from Qualtrics (Provo, UT) and REDCap (Vanderbilt University, Nashville, Tennessee, USA) will be de-identified and stored in an Excel spreadsheet and R data file.

All identifiable data, including name, address, phone and email address, will be stored in a password protected Microsoft Excel document, saved to Deakin University, Faculty of Health, School of Exercise and Nutrition Sciences secure drive. This drive will only be accessible to the Principal Investigator and Project Manager. De-identifiable data will be shared with other investigators to support analysis, and the study statistician (blinded to group allocation) to complete analysis. All paper-based documents will be stored in a locked filing cabinet, accessible only to the Principal Investigator and Project Manager, located in The School of Exercise and Nutrition Sciences. Any protocol amendments will be submitted for approval to Deakin University’s Human Research Ethics Committee, with relevant changes sent to the Australian and New Zealand Clinical Trial Registry.

The results of ProHealth will be disseminated through several channels. Aggregated results of this study may be presented at scientific conferences, local hospitals, health services or organisations and shared with the community, consumer groups in public forums and through social media. Results will be submitted for publication in peer-reviewed journals. Participants can choose to receive a plain language summary of the findings and/or any publications from this research.