Feasibility of Good Boost+ for Adults Awaiting Total Knee Replacement

Knee replacement surgery can greatly reduce pain and improve mobility for people with severe knee arthritis. However, NHS waiting times for surgery are often long, and many people experience worsening pain, reduced ability to work or take part in daily activities, low mood, and increased reliance on strong painkillers while they wait. These challenges can also affect recovery after surgery. Exercise programmes undertaken before surgery, known as 'prehabilitation', may help people feel better during the waiting period and may support better outcomes after surgery. Despite this potential, prehabilitation programmes are not widely available across the UK, and existing provision varies depending on where people live.

There is currently limited evidence about how best to deliver prehabilitation in a way that people waiting for orthopaedic surgery find acceptable, practical, and motivating. It is not yet clear which types of programmes people are most likely to use and stick with while waiting for knee replacement surgery. The Good Boost+ programme offers an approach that combines water-based group exercise in local swimming pools with flexible land-based exercise that can be completed individually or by joining a virtual group. The programme uses digital technology, and pool-based sessions are delivered in community leisure facilities rather than hospital settings. Exercising in water may be more comfortable for people with knee pain, and group sessions supported by refreshments afterwards provide opportunities for social interaction and peer support.

Early pilot work suggests this approach may be promising, but more evidence is needed to understand whether people awaiting knee replacement surgery are willing and able to take part, attend regularly, and complete the programme as intended when delivered alongside usual NHS care. With increasing demand for knee replacement surgery and long waiting times placing strain on patients and the NHS, there is an urgent need to explore new ways of supporting people during the waiting period.

This study is a two arm, parallel group, randomised controlled feasibility trial implementing the Good Boost+ programme for adults awaiting primary total knee replacement. An embedded mixed methods study will explore the acceptability of the intervention and identify determinants influencing the implementation of Good Boost+. The investigators aim to recruit 48 participants from orthopaedic services at NHS Trusts in South London. Participants will be randomly allocated in a 1:1 ratio to receive either usual NHS pre operative care alone or usual NHS pre operative care plus the Good Boost+ programme.

Participants allocated to the intervention group will receive usual NHS care plus the Good Boost+ programme. This includes an initial assessment and goal setting session with an NHS physiotherapist; six weekly group based water exercise sessions delivered in a leisure centre swimming pool using the Good Boost HUB app on a waterproof tablet computer; three home-based land exercise sessions per week using the Good Boost Move Together app on a smartphone or tablet computer; and weekly one to one support sessions with a physiotherapist delivered remotely. Following aquatic sessions, refreshments will be provided to encourage informal peer support. Participants in the control group will continue with usual NHS pre operative care.

Data collection will focus on feasibility outcomes, including recruitment, retention, adherence to the Good Boost+ programme, and completeness of data collection. Participants will complete weekly exercise diaries and short questionnaires at 6 and 10 weeks after randomisation. Patient and public contributors helped select the outcome measures and confirmed that the timing and burden of data collection would be acceptable to people awaiting knee replacement surgery. Adherence to the programme will be assessed using participant completed exercise diaries, direct participant contact, and usage data from the Good Boost digital applications.

Intervention fidelity will be monitored to ensure the programme is delivered as intended. Selected pool based sessions will be observed using a structured template, and a sample of remote physiotherapist support sessions will be audio recorded and assessed using the Motivational Interviewing Treatment Integrity (MITI) 3.3.1 coding system.

Qualitative interviews will be conducted with a sub sample of participants who received the intervention, and with NHS and leisure centre staff at sites where the Good Boost+ programme is being delivered and evaluated. These interviews will explore experiences of the programme, perceived acceptability, and barriers and facilitators to implementation. Approximately 25 to 30 NHS and leisure centre staff will also complete an adapted version of the Theoretical Framework of Acceptability questionnaire at two time points during the intervention delivery period.

The study will include the following stages: study set up and staff training; participant recruitment and baseline assessment; intervention delivery and data collection; qualitative interviews and fidelity assessment; and data analysis, interpretation and reporting. No formal interim analyses are planned, but feasibility metrics will be monitored throughout to ensure safe and effective conduct.

The findings from this feasibility trial will determine whether a larger, multi site effectiveness implementation trial of Good Boost+ is appropriate and will help refine the programme and its delivery model to best support people waiting for knee replacement surgery.

Alongside this feasibility trial, the research team is conducting a qualitative case study under a separate IRAS application to scope the barriers and enablers relevant to the future implementation of Good Boost+ for NHS patients awaiting total knee replacement across diverse geographic settings. The qualitative study is non-interventional and does not meet the definition of a clinical trial; therefore, it is not registered on ClinicalTrials.gov. It will be reported separately using appropriate qualitative research standards.

• Acceptability of Good Boost+ / Usual NHS care to patients using Theoretical Framework of Acceptability (TFA) questionnaire scores [Срок оценки: Baseline, Week 6 post-randomisation, Week 10 post-randomisation]
• Acceptability of Good Boost+ to NHS staff and leisure centre staff. [Срок оценки: Baseline (at the start of intervention delivery at the relevant site); Mid-intervention (during month 4 of the 8-month intervention delivery period)]
• Acceptability of Good Boost+ to patients wait listed for knee replacement, NHS staff and leisure centre staff using qualitative interviews [Срок оценки: 8 weeks post-randomisation onwards (within 1 month of final pool based session)]
• Change in pain, function and stiffness (WOMAC score) [Срок оценки: Baseline, Week 6 post-randomisation, Week 10 post-randomisation]
• Change in Musculoskeletal Health (MSK HQ Score) [Срок оценки: Baseline, Week 6 post-randomisation, Week 10 post-randomisation]
• Change in Generic Health Status (EQ 5D 5L Score) [Срок оценки: Baseline, Week 6 post-randomisation, Week 10 post-randomisation]
• Change in Mental Well Being (WEMWBS Score) [Срок оценки: Baseline, Week 6 post-randomisation, Week 10 post-randomisation]
• Change in Patient Global Assessment (PGA Score) [Срок оценки: Baseline, Week 6 post-randomisation, Week 10 post-randomisation]
• Change in Social Support (MOS Social Support Survey Score) [Срок оценки: Baseline, Week 6 post-randomisation, Week 10 post-randomisation]
• Change in Pain Intensity (Numerical Pain Rating Scale) [Срок оценки: Baseline; Weekly during the 6-week intervention period; Week 10 post-randomisation.]
• Healthcare Resource Use [Срок оценки: Baseline, Week 10 post-randomisation]
• Barriers and enablers to implementation [Срок оценки: 8 weeks post-randomisation onwards (within 1 month of final pool based session)]