Experiences of patients enrolled and staff involved in the prehabilitation of elective patients undergoing cardiac surgery trial: a nested qualitative study

The purpose of this study was to understand the views and experiences of patients enrolled and staff involved in the prehabilitation of elective patients undergoing cardiac surgery trial. This sub‐study was informed by normalisation process theory, a framework for evaluating complex interventions, and used consecutive sampling to recruit patients assigned to both the intervention and control groups. Patients and all staff involved in delivering the trial were invited to participate in focus groups, which were recorded, transcribed verbatim and subjected to reflexive thematic analysis. Five focus groups were held comprising 24 participants in total (nine patients assigned to the prehabilitation; seven assigned to control; and eight staff). Five themes were identified. First, preparedness for surgery reduced fear, where participants described that knowing what to expect from surgery and preparing the body physically increased feelings of control and subsequently reduced apprehension regarding surgery. Second, staff were concerned but trusted in a safe environment, describing how, despite staff's concerns regarding the risks of exercise in this population, the patients felt safe in their care whilst participating in an exercise programme in hospital. Third, rushing for recovery and the curious carer, where patients from both groups wanted to mobilise quickly postoperatively whilst staff visited patients on the ward to observe their recovery progress. Fourth, to survive and thrive postoperatively, reflecting staff and patients' expectations from the trial and what motivated them to participate. Fifth, benefits are diluted by lengthy waiting periods, reflecting the frustration felt by patients waiting for their surgery after completing the intervention and the fear about continuing exercise at home before they had been ‘fixed’. To conclude, functional exercise capacity may not have improved following prehabilitation in people before elective cardiac surgery due to concerns regarding the safety of exercise that may have hindered delivery and receipt of the intervention. Instead, numerous non‐physical benefits were elicited. The information from this qualitative study offers valuable recommendations regarding refining a prehabilitation intervention and conducting a subsequent trial.


Introduction
Over 35,000 patients undergo cardiac surgery in the UK every year [1]. Between 10% and 40% suffer postoperative complications, and have a mean hospital stay of over 9 days for elective surgery and 11 days for emergency surgery, posing a significant burden on the healthcare system [1,2].
The age and comorbid burden of this population is increasing, and both factors have been shown to adversely impact functional status before, during and after hospitalisation for surgery [3]. There is a growing recognition of an urgent need to develop techniques and strategies across the entire patient pathway to reduce postoperative complication rates and mortality and enhance the quality of life in this population.
The pre-operative period offers an opportunity to optimise exercise capacity, inspiratory muscle strength and balance, all of which have been shown in other populations to decrease complications and allow earlier mobilisation after surgery [4]. It is now recognised that prehabilitation may be a key component in reducing the risk of surgery [5].
However, the evidence underpinning prehabilitation in cardiac surgery is lacking, and clinicians and commissioners remain unconvinced of the safety, effectiveness and applicability of prehabilitation in this population.
The prehabilitation in elective patients undergoing cardiac surgery (PrEPS) trial is a randomised controlled trial that aims to establish whether a prehabilitation intervention improves the overall functional exercise capacity of patients before elective cardiac surgery [6]. This sub-study aimed to understand the views and experiences of patients enrolled in the PrEPS trial and the staff responsible for the delivery of the intervention, the outcomes, and the process and conduct of the trial, all aiming to illuminate the results and improve a future trial.

Methods
Detailed methodology of the PrEPS trial is reported elsewhere [6]. Patients were allocated randomly to receive prehabilitation (intervention) or routine care (control) before elective cardiac surgery. This qualitative sub-study was nested within the PrEPS trial which was delivered at a single centre between November 2019 and December 2022. Reporting complies with the consolidated criteria for reporting qualitative studies (COREQ) criteria. The study design and analysis were informed by the normalisation process theory, a framework for designing and evaluating complex interventions [7]. This enhances implementation potential by understanding the context (e.g. cardiac rehabilitation) within which an intervention is delivered.  [6]. Patients were invited to take part in focus groups of either those assigned to intervention or control. Patients' family members were not formally invited but could accompany patients if they wished.
Staff were invited via email by a member of the research team, who was not part of the clinical service and did not have a previous relationship with staff, to attend one of two focus groups. Informed consent was obtained from patients and staff before the commencement of the focus groups.
Staff focus groups were held first, followed by focus groups with participants assigned to the intervention and finally the focus group with participants assigned to the control group.
All focus groups took place after patients had completed the intervention and final assessment. We aimed to collect sufficient data to reach information power, which enables the required depth of information needed to address the research aim [8,9].
The topic guides were developed by a mixed-sex group comprising two academic physiotherapists experienced in rehabilitation and qualitative methods; an academic foundation doctor in cardiothoracic surgery; a surgeon in training; and a consultant cardiac surgeon and academic. Topic guides were informed by normalisation process theory and agreed by the trial management group (see online Supporting Information Appendix S1).
The focus groups were facilitated by two pairs of researchers who disclosed their roles to participants. One researcher acted as the facilitator, and another took field notes. All groups met in a quiet room located at the same hospital that hosted the intervention. The focus groups lasted between 60 and 140 min each and were recorded and transcribed verbatim by a professional transcriber.
There was no requirement for repeat focus groups.
Data were stored and organised using QSR NVivo (version 10; QSR International, Doncaster, Australia) and analysed using a deductive approach to reflexive thematic analysis. Codes were informed by the researchers' hypotheses based on previous research, clinical experience and normalisation process theory. The theoretical framework was agreed by the four researchers before initial coding. Analysis was iterative and facilitated by Braun and Clarke's six-phase process [10,11]: familiarisation with the data; generating initial codes; generating themes; reviewing potential themes; defining and naming themes; and producing the report. The first three phases were conducted for the three separate groups of participants.
Before the fourth phase, findings from the two patient groups (intervention and control) were merged to allow comparisons and contrasts to be made. This step was then repeated with the themes generated from the staff focus groups. The final themes were agreed on by all four authors involved in the analysis and credibility was checked. Finally, the agreed themes were mapped against the theoretical constructs of normalisation process theory. Figure 1 shows a coding tree diagram.

Results
Five focus groups were held in total with 24 participants; nine patients were assigned to the intervention group, seven patients to the control group and eight staff (Fig. 2).
One family member attended the focus group for the intervention group as an observer although their comments were not included in the analysis. One participant assigned to the intervention attended the focus group meant for those assigned to the control group. Data were analysed within groups and merged as part of the data analysis.
Patient and staff characteristics are displayed in Table 2.  These results also feed into the fidelity assessment of the main trial (Table 3).

Preparedness for surgery reduced fear
Surgery was viewed to be a frightening prospect, and some individuals from both groups described surgeons as dismissing the significance of the event as routine.

Monitoring and improving the intervention
Team who delivered the intervention were provided with a written protocol.
Data were collected during the focus groups held with staff members.
Staff reported two protocol deviations: 1. Offering additional education;`N o, as it happens we've given those talks throughout, those education talks´´(staff focus group) 2. One-to-one support for lower-level patients;`T hey couldn't really do the circuit as it is, they needed one-on-one which is difficult´´(staff focus group) Intervention delivery Intervention was designed to complement the existing cardiac rehabilitation service.
Exercise classes were observed twice in the first quarter of trial delivery period and checked against the protocol. A checklist was completed in the final quarter of trial delivery period to monitor any`slippageí n intervention delivery.
1. Home exercise was prescribed for 30 min rather than 45 min. 2. Target intensity level (Borg rate of perceived exertion scale) was not always met. This was fed back to those responsible for intervention delivery. The checklist identified the interventions that was being delivered in line with the protocol.

Receipt of treatment (comprehension of the exercise programme)
Intervention was delivered by trained clinicians.
Data were collected during the focus groups with those assigned to the intervention.
Unlike the control group, the intervention group expressed a clear understanding about what exercise involved, its specific benefits and how it differed from physical activity.`W e do a lot of walking on beaches, which is quite strenuous you know. But the exercise I found most beneficial was the one where you sit on a chair and you have to get out of that chair without using your arms. And you do a minute of that, you've done it, and you will have done it, and I found that most beneficial because I was having to do that at home after the operation´( intervention focus group) Enactment of treatment skills by patient (engagement in the exercise programme) Use of monitoring tools such as target heart rate and self-report diaries.
Data were collected during focus groups with those assigned to the intervention.
Intervention participants reported receiving a home exercise programme both during prehabilitation and in the lead up to surgery. Some but not all adhered to this.`. . .they had given us a booklet with about 11 different exercises in it. . . So, I bought some dumbbells and just did them every other day before I had a shower. I said to them, when I had my final pre-operation, I said,``Should I carry on doing these?´´they said,``Oh, yes, it's beneficial if you can carry on´´(intervention focus group)`W e were given a leaflet with the exercises to do at home. . . What was missing was the exercise room, that's all, with other people in it and nurses in it telling you what to do next, you know. . . It's self-motivation, and to be quite honest, once the exercise class was finished, I'm back to normal life again, just get on with normal life, don't we?´´(intervention focus group) exercise, increasing duration incrementally and advocating rest periods to navigate any onset of symptoms. Conversely, participants in the control group remained anxious during their wait for surgery, harbouring the belief that too much activity could cause problems that delayed surgery or caused fatal cardiac events.``You feel anxious coming up to it and then, of course, you have to wait and you think anything could happen between your diagnosis and the op.
And you need something to help me calm down. It came to a point where I was only sleeping three or four hours of a night-time because I was waking up thinking that I wasn't going to wake up´´(control focus group).

Rushing for recovery and the curious carer
Participants from both groups of the trial were eager to mobilise after surgery, to facilitate immediate and long-term recovery (intervention) or to return home quickly (control). Staff were curious to observe any benefits of the intervention, had built a close trusting relationship with those assigned to the intervention, and described visiting them on the hospital wards following their surgery. They relayed their surprise at observing participants who had`c onsiderable complications´´looking well and engaging in more activities than anticipated.
To survive and thrive postoperatively Two clear motivations for taking part in the trial were revealed across both groups, namely`selfish´reasons and to help others in the future. Both groups acknowledged that exercise elicits health benefits and that optimising their physical condition before surgery would be beneficial for recovery.``I did it to help the NHS but also for selfish reasons, I thought it would be good for me to get this knowledge and get into an exercise routine´´(intervention focus group).
Most participants in the control group were disappointed to have been randomised to control, with some reporting this as demotivating``. . . so, a demotivational aspect for those who are in the control group, you're kind of pushed to one side in that sense regarding exercising´´(control focus group). Other participants in the control group were relieved as the burden of taking part was reduced, e.g.
travel. Staff involvement was prompted by an interest in research and a belief that exercise is beneficial, although for some the trial became part of the service and they

Discussion
This study illuminates the main findings from the PrEPS trial, that there was no difference in pre-operative functional exercise capacity between those that had prehabilitation and those that did not. This qualitative study offers insight into potential reasons why the intervention was not superior to standard care. Patients and staff were fearful of exercise, potentially impacting patients' willingness to engage in exercise at home after the intervention ended. Importantly, these qualitative findings revealed potential benefits of the intervention extending beyond those that are physical, including psychological benefits and ones pertaining to recovery, which are challenging to capture using traditional outcome measures. The findings will inform the continued refinement of the intervention and subsequent trial designs by identifying ways in which both could be improved, with the caveat that feasibility and methodological robustness would need to be considered.
Apprehension regarding exercise is seldom reported as a reason for declining participation in a trial of prehabilitation or indeed any exercise-based intervention study, yet it is almost certainly a contributing factor. This can be offset somewhat by the security offered by trusted staff responsible for its delivery. Findings from this study, emphasising the key role staff had in eliciting knowledge and offering support, mirrors patients' and caregivers' preferences and priorities for cardiac surgery. In a review of the literature and subsequent consulting workshop, individuals highlighted the role of education in improving quality of life and placed value on the contact time they had with staff [12], raising a question about the relative efficacy of the unsupervised home-based element of the programme.
In a post-COVID-19 era, remote rehabilitation appears to be accepted by both patients and staff [13]. However, before surgery, patients express intense fear regarding the likelihood of experiencing a life-threatening cardiac event, so an unsupervised exercise programme is unlikely to be well adhered to. This contrasts with inspiratory muscle training which was enjoyed and where benefits to maximum inspiratory pressure were demonstrated in the trial [6].
There is a second question about capturing the more nuanced non-physical benefits of a complex intervention of this kind, such as a heightened sense of control and greater physical and mental resilience to deal with postoperative recovery, which was evident in participants' narratives.
Similar challenges have been reported by patients undergoing an exercise intervention during chemotherapy before surgery for example, who also felt empowered by doing something positive to influence their situation, reducing surgical risk and increasing survival [14].
Prehabilitation is a complex intervention and the challenges of delivering a randomised controlled trial of an intervention in clinical practice are well recognised [15].
Such challenges might be addressed by more coproduction with patients and delivery staff, which may help to identify and avoid issues such as protocol deviations and despondency felt by those assigned to a control group [16].
Limitations of this study include the fact that the sample consisted of almost all men and sampling occurred over a short time-period. This sampling occurred in the latter stages of the main clinical trial, therefore experiences and views may have evolved over the duration of the trial that may not have been captured. Second, given the focus groups were held after their final follow-up 12 weeks postoperatively, patients were relying on their recollections of the trial. However, focus groups are a useful way of gathering patient recollections as memories are triggered by the accounts of others. Twenty-four participants were included in total which is a relatively small sample size across the three groups, although the inclusion of eight staff from a single centre is a strength and researchers agreed that information power had been met. A convenience sampling method was applied and participants were selfselected, meaning those who possessed a positive view of prehabilitation, the trial and their surgical journey were most likely to participate in focus groups. Transcripts were not returned to participants and member checking, which involves returning transcripts to participants to check for accuracy, was not conducted as it was felt this imposed too much time on patients recovering from surgery and busy clinicians. Furthermore, member checking is no longer regarded as the only way to enhance trustworthiness; deviant data were considered and findings were corroborated by four researchers from two different professional backgrounds.
To conclude, these qualitative findings, alongside the fidelity assessment, offer possible explanations for why functional exercise capacity was not demonstrated to improve following prehabilitation in people before elective cardiac surgery. Concerns regarding the safety of exercise in this population may have hindered delivery and receipt of the intervention but findings also highlight other nonphysical benefits. Prehabilitation elicited a sense of control leading to improved psychological well-being, a faster return to daily activities and better physical and mental resilience to deal with postoperative complications. The information from this qualitative study offers valuable suggestions for refining a prehabilitation intervention and designing and conducting a subsequent randomised controlled trial.