Prehabilitation for frail patients undergoing hip and knee replacement in the UK: Joint PREP feasibility study for a randomised controlled trial

Objective: To determine the feasibility of conducting a randomised controlled trial (RCT) to evaluate a prehabilitation programme for frail patients undergoing total hip replacement (THR) or total knee replacement (TKR).

Design: Randomised feasibility study with embedded qualitative work.

Setting: Three National Health Service hospitals.

Participants: Adults aged ≥65 years, frail and scheduled for primary THR or TKR.

Intervention: Appointment with a physiotherapist to individualise a home-based exercise programme. Participants were encouraged to do the home exercises daily for 12 weeks pre-operative and were provided with a daily protein supplement. Participants were supported by six telephone calls over the 12-week intervention period.

Outcome measures: Eligibility and recruitment rates, intervention adherence, data completion rates of patient-reported outcome measures, retention rates and acceptability of the trial and intervention. Qualitative interviews were conducted with participants and non-participants and analysed using thematic analysis.

Results: Between December 2022 and August 2023, 411 patients were sent a screening pack. Of the 168 patients who returned a screening questionnaire, 79 were eligible and consented to participate, and 64 were randomised. Of the 33 participants randomised to the intervention, 26 attended the intervention appointment. Eighteen participants (69%) received all six intervention follow-up telephone calls. Nineteen participants (73%) completed an intervention adherence log; 13 (68%) adhered to the exercise programme and 11 (58%) adhered to the protein supplementation. The overall retention rate was 86% (55/64 overall) at 12 weeks. The 12-week follow-up questionnaire was returned by 46 of the 55 participants (84%) who were sent a questionnaire. Interviews with 19 patients found that the trial processes and intervention were generally acceptable, but areas of potential improvements were identified.

Conclusions: This study demonstrated that a larger study is possible and has identified improvements to optimise the design of an RCT.

Trial registration number: ISRCTN11121506.