Article Text
Abstract
Objective To assess the experience of moral distress among intensive care unit (ICU) professionals in the UK.
Design Mixed methods: validated quantitative measure of moral distress followed by purposive sample of respondents who underwent semistructured interviews.
Setting Four ICUs of varying sizes and specialty facilities.
Participants Healthcare professionals working in ICU.
Results 227 questionnaires were returned and 15 interviews performed. Moral distress occurred across all ICUs and professional demographics. It was most commonly related to providing care perceived as futile or against the patient’s wishes/interests, followed by resource constraints compromising care. Moral distress score was independently influenced by profession (p=0.02) (nurses 117.0 vs doctors 78.0). A lack of agency was central to moral distress and its negative experience could lead to withdrawal from engaging with patients/families. One-third indicated their intention to leave their current post due to moral distress and this was greater among nurses than doctors (37.0% vs 15.0%). Moral distress was independently associated with an intention to leave their current post (p<0.0001) and a previous post (p=0.001). Participants described a range of individualised coping strategies tailored to the situations faced. The most common and highly valued strategies were informal and relied on working within a supportive environment along with a close-knit team, although participants acknowledged there was a role for structured and formalised intervention.
Conclusions Moral distress is widespread among UK ICU professionals and can have an important negative impact on patient care, professional wellbeing and staff retention, a particularly concerning finding as this study was performed prior to the COVID-19 pandemic. Moral distress due to resource-related issues is more severe than comparable studies in North America. Interventions to support professionals should recognise the individualistic nature of coping with moral distress. The value of close-knit teams and supportive environments has implications for how intensive care services are organised.
- INTENSIVE & CRITICAL CARE
- Adult intensive & critical care
- Adult intensive & critical care
- ETHICS (see Medical Ethics)
Data availability statement
Data are available upon reasonable request.
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
Statistics from Altmetric.com
- INTENSIVE & CRITICAL CARE
- Adult intensive & critical care
- Adult intensive & critical care
- ETHICS (see Medical Ethics)
STRENGTHS AND LIMITATIONS OF THIS STUDY
This multicentre study included UK intensive care units of different sizes and subspecialty capabilities.
The mixed-methods design increased the richness and scope of the data and enabled triangulation of findings.
There is a risk of selection bias if healthcare professionals particularly affected by moral distress were more likely to participate.
The study will not have captured the views and experiences of health professionals who have left the profession because of moral distress.
The study represents a snapshot of moral distress, which may be influenced by specific contextual issues.
Introduction
The COVID-19 pandemic has highlighted the psychological challenges faced by intensive care professionals around the world, including moral distress.1–4 A survey conducted by the British Medical Association found that 78.4% of doctors experienced moral distress during the pandemic.5 The importance of staff wellbeing and combatting staff burnout was recognised prior to the pandemic and is a priority for healthcare services worldwide, including the National Health Service (NHS).6–8 A key contributor to burnout is moral distress.9–13 Moral distress is a constellation of emotional and psychological features that occur when a professional identifies an ethically correct course of action, but is prevented from following this course.14–16 It can also occur in situations where there is uncertainty or conflict regarding the ethically correct action.17–19 It can be deeply damaging to the individual and is associated with a tendency to leave the profession, with a consequent negative impact on patient care.9 20 Some authors have suggested the definition of moral distress is broadened to fully capture its experience and recognise that it may also occur in situations of moral uncertainty.19
The intensive care unit (ICU) is a place where patients with life-threatening conditions may be treated with a variety of invasive and burdensome interventions.21 Highly significant, complex and difficult decisions are made on a regular basis.22 Treatment in the ICU comprises complex interventions that require a multifaceted approach and interaction of a broad multidisciplinary team, which may include pharmacists, physiotherapists, dietitians and other allied health professionals. This environment is highly susceptible to moral distress and hence moral distress among ICU professions is of concern.14 18 23 24
Moral distress was first identified in ICU nurses in North America and has been most frequently studied in this population.14 18 23–25 Similar causes of moral distress have also been found among other ICU professionals, including physicians, respiratory therapists and healthcare students.20 26–30 Despite concerns over ICU staff wellbeing, burnout and moral distress in the NHS, moral distress remains poorly studied in the UK.19 31 32 Moral distress may be affected by specific contextual factors such as availability of resources and model of decision-making for patients lacking capacity. In the UK, the availability of intensive care provision is much less than in North America and the role of proxy decision-makers is much more significant.33–35 These, and other potential differences, may affect how moral distress is experienced by UK health professionals.
This study was performed prior to the COVID-19 pandemic and its primary aim was to assess the experience of moral distress among ICU professionals in the UK. Secondary aims were to (a) identify the most common causes of moral distress; (b) determine the relationship between demographic and professional characteristics and moral distress; (c) examine the relationship between moral distress and intention to leave the profession; and (d) identify potential interventions to mitigate moral distress.
Methods
Participants were recruited from four adult ICUs. Sites A and B are large tertiary care hospitals with major trauma and complex multispecialty surgical facilities, and sites C and D are smaller district general hospitals with fewer specialist services. Sites C and D are part of the same organisational trust so some staff work across both sites. Bed capacities of sites range from 12 to 80 beds. All full-time and part-time healthcare professionals working in the ICU were eligible. All grades and clinical professions were included, but students of any profession were excluded.
An anonymous paper questionnaire using the validated Measure of Moral Distress for Healthcare Professionals (MMD-HP) (online supplemental file 1) was distributed between February 2019 and February 2020.36 The MMD-HP is a 27-item questionnaire that uses a Likert scale of 0–4 points to assess the frequency with which situations arise and the intensity of the moral distress caused.25 36 These are summed to produce overall frequency and intensity scores. Individual item frequency and intensity scores are multiplied together to produce a composite item score and these summed to generate an overall moral distress score. A free-text section allows participants to describe additional scenarios not included in the MMD-HP inventory. The MMD-HP also includes two related questions concerning intention to leave the profession now or in the past due to moral distress.36 Participant demographics were collected including profession, grade, age, gender and years of ICU working experience.
Supplemental material
Descriptive statistics were used to summarise demographics and moral distress scores. Individual item scores were ranked for comparison. Moral distress scores were non-normally distributed, as found in previous studies,20 31 and hence are presented as medians with IQRs, and non-parametric statistical tests were used (Wilcoxon signed-rank, Kruskal-Wallis). A sample size requirement calculation was not performed as there were inadequate UK data using the MMD-HP. Multiple linear regression was used to investigate the relationship between age and ICU experience and moral distress scores. Multiple logistic regression models were fitted to determine the association between moral distress scores and tendency to leave the profession. Covariates were prespecified demographic and professional variables, with binary classification used for profession (nurse vs other) and hospital type (tertiary care vs district general). Discrimination of logistic regression models was assessed using area under the receiver operator curve (ROC AUC). For tendency to leave a previous position, an ordinal logistic regression was used in accordance with the ordinal dependent variable. Statistical analyses were performed using R V.3.6.1 (R Foundation for Statistical Computing) with the code for analyses available on request.
Questionnaire respondents willing to take part in an interview included their contact details on the returned questionnaire and from those respondents; potential interview participants were purposively sampled for hospital, profession, grade and overall moral distress score using a maximum variation approach. Written informed consent was obtained prior to interview. Semi-structured interviews with an interview guide (online supplemental file 2) were conducted face to face between July 2019 and February 2020 and explored participants’ experience of moral distress, the situations that cause it, strategies they use to cope with it and their views on possible interventions to alleviate moral distress. Interviews lasted approximately 30 min and were audio-recorded then transcribed verbatim. Interviews were conducted until no new themes emerged from the data. The Framework Method of thematic analysis was used.37 Transcripts were loaded onto NVivo and data initially organised into content areas informed by the study aims: experience of moral distress and coping with moral distress. Within each area, two main categories were explored: precipitating factors/causes of moral distress and the response to distress; coping strategies and interventions to support coping. This is described in online supplemental figure 1. Data within each content area were then reread and coded inductively, and codes compared and grouped to develop themes and subthemes. All transcripts were coded by AJB with 30% independently coded by AMS. The codes and emerging themes and subthemes were discussed at regular analysis meetings to improve the analysis validity and trustworthiness.
Supplemental material
Supplemental material
Patient and public involvement
The study received contributions from the patient and public representatives from the University Hospitals Birmingham Clinical Research Ambassador Group. The members supported the proposed study and saw the potential for the work to benefit staff wellbeing and patient care. The group contributed to the study design, development of study documentation, including the protocol and participant information sheet, and the dissemination plan.
Results
Two hundred and twenty-seven questionnaires were returned from a total of 772 questionnaires distributed across all sites, giving an overall response rate of 29.4% (site A 28.3%, site B 24.0%, sites C and D 34.6%). Participant demographics are described in table 1. Forty-one of the 227 participants completing the paper questionnaire indicated a willingness to take part in an interview, 21 were contacted with an invitation and further information about the interview study and 15 agreed to be interviewed. Interview participant demographics are summarised in online supplemental table 1.
The quantitative results from the MMD-HP are presented first, followed by the qualitative results grouped into experience of moral distress and coping with moral distress.
Moral distress items
Fourteen questionnaires were excluded due to missing responses preventing calculation of the moral distress score. Items are ranked by compositive score for nurses and doctors in online supplemental table 2. The most highly scored items by both nurses and doctors related to delivering aggressive treatment that was perceived as futile or not in the patient’s best interests. Other highly ranked items related to lack of resources, caring for more patients than is considered safe, excessive documentation, lack of administrative support and abusive patients/family members compromising care. Nurses generally rated moral distress frequency and intensity more highly than doctors. Only 4 of the 27 items had a greater composite score for doctors over nurses and there was no commonality in the root causes of these scenarios.
Moral distress score associations
Total composite moral distress scores were positively skewed with a median score of 108 (IQR 78.2, range 0–288). The relationship between overall moral distress score and demographic characteristics is summarised in figure 1. Moral distress was greater in women than men (111.5 (IQR 75.5) vs 94.0 (IQR 69.3), W=4755.5, p=0.043) and was significantly influenced by profession (H=11.89, p=0.018) with nurses reporting greater moral distress than doctors (117.0 (IQR 65.5) vs 78.0 (IQR 73.0)). There were differences in the distribution of gender across professions (nurse: 83.7% female; doctor: 40.0% female). Differences in moral distress between nurses and doctors persisted after statistical adjustment for differences in gender across professions (p=0.020). There was no relationship between overall moral distress score and participant age and ICU experience. This was confirmed with multiple linear regression where an interaction effects model of age and ICU experience against overall moral distress could only explain less than 1% of the variation in moral distress (adjusted R2 0.0089). Median moral distress scores were higher in larger tertiary care hospitals than district general hospitals; however, this did not reach statistical significance (114.5 (IQR 91.8) vs 98.0 (IQR 69.9), W=5012.5, p=0.23).
Intention to leave the profession
Seventy-one (33.3%) participants indicated their intention to leave their current post due to moral distress. Twenty-eight (13.1%) participants reported they had left a previous post due to moral distress and 101 (47.4%) reported they had considered leaving a previous post due to moral distress but did not leave. Overall, moral distress was significantly greater in those intending to leave their current post (135.5 (IQR 84.5) vs 88.9 (IQR 65.3), W=2771.5, p<0.0001) and this difference was confirmed in both univariate and multiple logistic regression analyses. Logistic regression model variable ORs are summarised in table 2. Multiple logistic regression included profession, gender, hospital type, age and ICU experience as covariates and had good discrimination (ROC AUC 0.722) and ability to predict intention to leave (online supplemental figure 2). Adjusted OR for moral distress score against intention to leave was 1.011 (95% CI 1.005 to 1.017, p<0.001).
A greater proportion of nurses were considering leaving their current post due to moral distress than doctors (37.0% vs 15.0%). Nurses had significantly greater odds of reporting an intention to leave the profession in both unadjusted (OR 3.013, 95% CI 1.442 to 6.810, p<0.01) and adjusted analyses (adjusted OR 3.023, 95% CI 1.243 to 8.014, p=0.019). There was no significant association between gender and intention to leave the profession in either unadjusted or adjusted models.
Moral distress score was significantly associated with the ordinal outcome of leaving a previous post in unadjusted and adjusted analyses (OR 1.010, 95% CI 1.006 to 1.015, p<0.0001; adjusted OR 1.009, 95% CI 1.004 to 1.014, p=0.001). Female gender and nurse profession were not significantly associated with leaving a previous post in adjusted analyses. Ordinal logistic regression model variable ORs are summarised in online supplemental table 3.
The qualitative results from interviews are reported below and are reported by content area: experience of moral distress and coping with moral distress.
Experience of moral distress
During analysis, two areas of experience were considered: precipitating factors/causes of moral distress and the response to distress. Three distinct themes emerged in relation to causes of moral distress. The dominant theme was of moral distress due to a perception that care provided was not in the patient’s best interests. Participants talked about a feeling of helplessness in the face of seemingly endless and potentially futile care, delivering care that disregarded patient wishes, and external pressure to provide care that is seen as not in the patient’s interests. The two other themes in this area were resource constraints compromising care and inability to protect more junior staff. Responses to moral distress were categorised in the following themes: negative emotional response; avoidance of patient and family; impact on future career decisions; moral distress changing over time. Experiencing moral distress led to a range of negative emotions and behaviours. Frustration and anger were the most frequently described emotions. Experiencing moral distress could also lead to avoidance of interaction with patients and their family. Some participants described this behaviour as ‘self-protection’. Experiencing and coping with moral distress had led some participants to question their future in intensive care. Junior doctors considering careers in intensive care had changed course after experiencing and struggling to cope with moral distress themselves or observing the impact on more senior colleagues, contemplating whether this was something they wanted for themselves. Some participants suggested moral distress got better with increasing ICU experience as they were better able to rationalise situations, manage emotions, and/or had improved coping strategies and resilience. Conversely, others felt that moral distress got worse over time, either because they were more aware of situations where patient care could be better, or because their increasing age made cases more personally relatable. Illustrative quotes for these themes within experience of moral distress are reported in table 3.
Coping with moral distress
Two areas were considered: coping strategies for moral distress and interventions to support coping with moral distress. Participants described a range of strategies for coping with moral distress, tailoring their strategy to the particular situation. Strategies could be classified as internally or externally focused. Internally focused strategies included personal reflection, mental compartmentalisation and self-care techniques. Personal reflection was commonly reported as a way of making sense of the distress experienced; however, mandatory reflection was less helpful than when it occurred in an organic way. Externally focused strategies include informal discussions with colleagues, talking to their friends/family and more formal debrief sessions. The most frequently described and highly valued coping strategy involved talking with colleagues informally, such as chatting in the coffee room. The culture of the team appeared critical to allow informal talking to be effective. Participants valued a supportive environment with a close-knit, honest and actively caring team. Smaller teams where staff knew each other well were reported as more supportive compared with larger teams where there was more movement of staff. Acknowledgement from a senior team member that a case was particularly distressing was powerful and reassuring. Conversely, seniors not wanting to engage in conversations was reported as detrimental to coping with moral distress.
Participants were asked about interventions to support coping with moral distress. Generally, participants felt that a personalised approach tailored to the particular situation was needed. Formal approaches were seen as more valuable for junior staff who perhaps did not have the same developed coping strategies. In general, however, participants felt that informal support would be more authentic, accessible, faster acting and efficacious. Facilitated discussion was suggested as a way of enhancing the effectiveness of informal talking with colleagues. Multiple participants proposed identifying a nominated group of senior and/or experienced ICU staff who could provide support and advice on an ad hoc basis with allocated time to deliver this role. Participants highlighted the importance of organisations valuing the wider working environment in supporting staff to cope with distress. Ensuring avoidable stresses were removed or reduced would enable staff to have more emotional and cognitive capacity to deal with the moral challenges that they faced in their work. For example, adequate car parking and responsive services, such as information technology, payroll and human resources, were all cited as areas that would improve overall staff wellbeing.
Illustrative quotes for these themes from coping with moral distress are reported in table 4.
Lack of agency
Throughout participant descriptions of the various facets of moral distress, a key overarching theme of lack of agency emerged. This was consistent across professions and persisted through different contexts of moral distress, descriptions of scenarios, responses to moral distress, and coping strategies and interventions for moral distress. This powerlessness and sense of a lack of control appears central in the development of moral distress and how individuals respond to and cope with it.
I came away feeling a bit guilty but equally knowing that there was nothing I could have done to avoid that. (Other 2)
Yeah the more you reflect on it, maybe it’s better not to reflect too heavily on it… your hands are essentially tied aren’t they? (Advanced Critical Care Practitioner 2)
I feel like somebody should be able to stop it but I don’t know who that might be. (Doctor 5)
Discussion
This is the largest study of moral distress in UK ICUs to date and the first to use a multi-centre approach with assessment across ICU professions. Included ICUs were at both district general and teaching hospitals and were of varying sizes and subspecialty capabilities. Moral distress was widespread across included sites and across ICU professions. Moral distress scores were highest in situations related to delivering aggressive treatment that was perceived as futile or not in the patient’s best interests, closely followed by lack of resources compromising delivered care. Interview data also identified inability of senior staff to protect their juniors as a cause of moral distress. Moral distress was significantly worse in nurses and was not influenced by age or years of ICU experience. The multiple negative emotions engendered by this repeated experience can lead to withdrawal from engagement with patients and families, likely leading to poorer clinical care, and ultimately to withdrawal from intensive care as a career choice. There was a strong association between higher moral distress scores and intention to leave a current post, or leaving a previous post highlighting the impact moral distress may have on ICU staff retention. It is concerning that one-third of participants reported an intention to leave their current post due to moral distress. Interview participants described a range of individualised coping mechanisms when experiencing moral distress. In general, informal support mechanisms were preferred to more formal arrangements. This study took place before the COVID-19 pandemic and it is possible the immense pressure on UK ICU services has had a further impact on the experience of moral distress. This should be recognised when considering how this study reflects the current welfare of UK ICU professionals.
The only other quantitative study of moral distress in UK ICUs to date also found moral distress was significantly associated with an intention to leave a post, a finding consistent with international literature.16 20 31 38 It is increasingly clear that the impact of moral distress appears damaging to staff retention and should be considered by employers.10 16 Colville et al31 were unable to detect a difference in moral distress scores between nurses and doctors and highlight the confounding impact of gender differences. Our larger study found that moral distress is greater in nurses and this difference remained statistically significant after accounting for differences in gender distributions. This finding is consistent with international studies showing that nurses report greater moral distress than doctors.20 36 38 It is also notable that nurses had a significantly greater intention to leave the profession, including in adjusted analyses. Indeed, 37% of nurses included in our study indicated they were considering leaving their current post due to moral distress, compared with 15% of doctors. This is consistent with research from Canada,20 and is a concerning finding that potentially has staff retention and workplace planning implications.
Compared with similar research in the USA also using the most up to date measure of moral distress, overall moral distress scores were higher in our study, and this was consistent across all professional subgroups.36 Almost all highly ranked individual item composite scores were higher in our study than that in the USA. This was most notable for resource-related items, specifically compromised care due to lack of resources/equipment/bed capacity, where the composite moral distress score was substantially higher in our UK study. This was ranked the second highest item by moral distress score in our study for both doctors and nurses, but ranked fifth in the comparative USA study. This could reflect differences in healthcare delivery and poorer provision of critical care beds per population in the UK.33–35 This high signal of moral distress raises a worrying concern that suboptimal care may be being delivered due to resource constraints. This study is unable to determine if this is occurring, nevertheless the high levels of moral distress due to resource-related issues should be noted.
Our finding that moral distress occurs frequently in situations related to delivery of aggressive treatment perceived as futile or not in the patient’s best interests is consistent with international research using the previous versions of the quantitative moral distress scale.14 25 31 It is also supported by other qualitative studies.18 19 26
It is increasingly clear that moral distress is widespread and detrimental within intensive care.39–41 A key question is therefore how to prevent and mitigate it. Given our finding of lack of agency as a driver of moral distress, one preventive strategy would be to improve agency and empower clinical staff to speak out. Hamric and Epstein report how a moral distress consultation service was successful in empowering staff in situations where they had felt unheard or powerless.42
Our qualitative findings suggest that interventions aimed at combating moral distress require a tailored approach that recognises the individualistic nature of coping with moral distress. Individualised informal support appears the most common coping strategy and is often effective if it takes place in an organisational culture that provides a supportive environment. Our participants frequently reported that smaller ICUs were more supportive and more able to permit informal coping compared with larger ICUs. This is noteworthy as UK intensive care services move towards regionalisation with larger ICUs on a ‘hub and spoke’ model to meet increasing care demands.43 It may be possible to replicate the benefits of smaller units at larger ICUs by working in smaller, close-knit teams caring for ‘pods’ of beds within the larger ICU. Embedding senior professionals who are nominated to facilitate discussion to cope with moral distress within these teams could be beneficial. Supporting effective coping could produce a positive feedback loop that encourages staff retention, therefore promoting a close-knit team and allowing formation of the staff relationships which appear so important in facilitating informal coping. Conversely, failure to control moral distress could produce a negative spiral due to its deleterious effects on career decisions.14 16 20
Our study has several limitations. First, the study is at risk of selection bias. Those experiencing high levels of moral distress may be unwilling to participate and relive their experiences, or alternatively those with low levels of moral distress may not appreciate its value and not take part. This may be reflected in the response rate. We only included those currently working in ICU and so cannot capture those that may have left ICU due to high levels of moral distress. We attempted to improve external validity by including multiple ICUs which had different operational characteristics. Purposive sampling ensured the interview sample reflected the total questionnaire sample and included representation of all hospitals, a range of professions, seniority, age and gender. Second, our study includes more nurses than other professions, however this reflects the distribution of ICU professions.21 Third, this study is a snapshot and may be influenced by how the participant is feeling at that time, or what clinical cases are present on their unit. Moral distress may be a reactive process and be influenced by experiences at that point in time.44 It is possible that moral distress may fluctuate and change as the clinical case-mix within an ICU changes. It remains unknown how moral distress changes over time and further study is warranted.
This study highlights the widespread nature of moral distress in UK ICUs and across ICU professions. Moral distress is worst in situations related to delivery of aggressive treatment perceived as futile or not in the patient’s best interests, and this finding is consistent with previous international research. Moral distress in UK ICUs appears to be more frequently experienced than in North America, in particular moral distress related to resource constraints. Moral distress is greatest in nurses and is independently associated with an intention to leave the profession, both at present and in the past. This study took place before the COVID-19 pandemic and even at that time, one-third of participants were considering leaving their current position. Moral distress is therefore a pressing problem for NHS trusts and policymakers seeking to retain and support an effective ICU workforce. In order to provide a healthy and sustainable intensive care workforce for the future, it will be important to acknowledge moral distress and provide environments that are supportive to staff and facilitate coping strategies. Policy decisions on the provision of intensive care services should take into account the importance of supportive environments and close-knit teams in facilitating coping with the almost inevitable moral distress and psychological pressures associated with working in intensive care.
Data availability statement
Data are available upon reasonable request.
Ethics statements
Patient consent for publication
Ethics approval
This study involves human participants but an Ethics Committee(s) or Institutional Board(s) exempted this study. Approvals were gained from the NHS Health Research Authority (IRAS: 238379). University Hospitals Coventry and Warwickshire NHS Trust acted as study sponsor. Local approvals from each study site's research and development department were sought. Participants gave informed consent to participate in the study before taking part.
Acknowledgments
We are grateful for the expert statistical support provided by Dr Georgios Bouliotis. We sincerely thank the healthcare professionals for voluntarily participating in this research and giving their time for interviews. The National Institute of Academic Anaesthesia kindly supported this study with an Association of Anaesthetists/Anaesthesia research grant awarded to AJB. The NIHR Clinical Research Network adopted this study onto their portfolio, and the support of the research teams at all sites is greatly appreciated. We are very grateful for the PPI input and contributions made by the University Hospitals Birmingham Clinical Research Ambassador Group.
References
Supplementary materials
Supplementary Data
This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.
Footnotes
Twitter @AdamBoulton17
Contributors Study design—AJB, JY, A-MS and CB. Study conduct—AJB, JY, A-MS and CB. Data analysis—AJB and A-MS. Drafting of the manuscript—AJB and A-MS. Review of the manuscript—AJB, JY, A-MS and CB. Guarantor—AJB.
Funding This work was supported by an Association of Anaesthetists/Anaesthesia research grant administered by the National Institute of Academic Anaesthesia (grant number NIAA19R102).
Competing interests AJB is supported by an NIHR-funded Academic Clinical Fellowship.
Patient and public involvement Patients and/or the public were involved in the design, or conduct, or reporting, or dissemination plans of this research. Refer to the Methods section for further details.
Provenance and peer review Not commissioned; externally peer reviewed.
Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.