Using evidence-based co-design to develop a hybrid delivered exercise intervention that aims to increase confidence to exercise in people with haemophilia

INTRODUCTION

Due to advances in treatments, people with haemophilia (PWH) are living longer. They are not as active as the general population due to joint damage and lack confidence to be active due to concerns about further bleeds and pain. There is a need to facilitate healthy aging through promotion of physical activity (PA) and exercise. Changing patient beliefs and increasing physical literacy and confidence to move are thought to be key to helping PWH become more active.

AIM

This paper describes the development of an exercise and behaviour change intervention to improve confidence to exercise in PWH.

METHODS

The 4-stage Medical Research Council framework for complex intervention development was used.

RESULTS

Stakeholders included 17 PWH and 7 physiotherapists working in haemophilia. Seven online focus group meetings were held. The final intervention is a hybrid 12-week physiotherapist led progressive exercise programme. Classes are 45 min including Pilates, High intensity interval training and balance elements, together with discussion sessions focusing on PA recommendations, the types and benefits of different exercise styles and the effects of PA, together with the effects of aging for PWH. The COM-B model of behaviour change was used to develop the intervention.

CONCLUSION

Co-design helps to produce an intervention that understands the stakeholders needs. Through this process the intervention developed to incorporate not only increasing PA but also confidence to exercise. The use of behaviour change theory identified the behaviour techniques included in the intervention and aims to increase physical literacy in this population.

Expert United Kingdom consensus on the preservation of joint health in people with moderate and severe haemophilia A: A modified Delphi panel

AIM

For people with haemophilia A (PwHA), bleeding in the joints leads to joint damage and haemophilia-related arthropathy, impacting range of motion and life expectancy. Existing guidelines for managing haemophilia A support healthcare professionals (HCPs) and PwHA in their efforts to preserve joint health. However, such guidance should be reviewed, considering emerging evidence and consensus as presented in this manuscript.

METHODS

Fifteen HCPs experienced in the management of PwHA in the UK participated in a three-round Delphi panel. Consensus was defined at ≥70% of panellists agreeing or disagreeing for Likert-scale questions, and ≥70% selecting the same option for multiple- or single-choice questions. Questions not reaching consensus were revised for the next round.

RESULTS

26.8% (11/41), 44.8% (13/29) and 93.3% (14/15) of statements reached consensus in Rounds 1, 2 and 3, respectively. HCPs agreed that prophylaxis should be offered to patients with a baseline factor VIII (FVIII) level of ≤5 IU/dL and that, where there is no treatment burden, the aim of prophylaxis should be to achieve a trough FVIII level ≥15 IU/dL and maintain a longer period with FVIII levels of ≥20-30 IU/dL to provide better bleed protection. The aspirational goal for PwHA is to prevent all joint bleeds, which may be achieved by maintaining normalised (50-150 IU/dL) FVIII levels.

CONCLUSION

The panel of experts were largely aligned on approaches to preserving joint health in PwHA, and this consensus may help guide HCPs.

Using theory of change to co-create a programme theory for a telerehabilitation intervention for pain management in people with haemophilia

BACKGROUND

Improved approaches for chronic pain management are a clinical and research priority for people with haemophilia (PWH). Involving people with lived experience in the design of a complex rehabilitation intervention strengthens the credibility and plausibility of the intervention, particularly in relation to rare disorders. Here we describe using a 'Theory of Change' (ToC) dialogue-based stakeholder process to create a programme theory for a telerehabilitation intervention.

METHODS

An online workshop was convened and stakeholders received a briefing document in advance. Five stakeholders took part (3 PWH and 2 physiotherapists). At the workshop the group first agreed the overall aim of the intervention. Discussions then identified the resources, activities, barriers and enablers needed to achieve this outcome. All discussions were recorded and annotated by the workshop moderator. Behaviour change techniques were mapped for inclusion in the theory.

RESULTS

A programme theory and narrative report were produced. All stakeholders reviewed these for clarity and to ensure a true reflection of the workshop discussions. Agreement was based on how meaningful, well-defined, do-able, plausible, credible, and testable each component was. Stakeholders highlighted the importance of issues unique to PWH. Key components included the need for physiotherapists to be knowledgeable of the condition, a range of exercises that were inclusive of all abilities, and the need for people to feel safe and supported whilst taking part.

CONCLUSIONS

Co-developed theory based approaches to intervention design offer an inclusive and transparent way to develop novel and meaningful interventions for people with complex health conditions. The ToC is wholly transparent in its design and content. Together with the identified behaviour change techniques, the theory informs the protocol for a feasibility study evaluating a telerehabilitation intervention. Importantly, it allows the opportunity to revise, adapt and improve the programme theory for further implementation and evaluation.

Educational needs of patients, families, and healthcare professionals to support the patient journey in haemophilia gene therapy in the UK

With the first gene therapies for haemophilia approved by the European Commission, the US Food and Drug Administration, and the Medicines and Healthcare products Regulatory Agency, it is important to consider the remaining unmet needs and challenges that may arise throughout patients' treatment journeys. We discuss existing unmet needs and important considerations prior to, during, and following haemophilia gene therapy treatment in the UK, and propose potential next steps. Key areas for attention are education, psychological support, and guidance on implementation. Strategies are urgently required to fulfil these needs. An immediate priority for information providers should be comprehensive education for people with haemophilia (PWH) and healthcare professionals (HCPs). Greater access to resources and training in psychological services will be required throughout the treatment pathway. More specific guidance is required to define the implementation model, criteria for accreditation, and responsibilities of care centres. Furthermore, PWH may revisit discussions with HCPs multiple times pre-infusion, thus the patient journey is unlikely to be linear. Consideration of these challenges, and of potential strategies to address them, will be integral to optimising the future success of this promising therapy.

Accreditation model of European Haemophilia Centres in the era of novel treatments and gene therapy

INTRODUCTION

The international certification of haemophilia centres in Europe is run by the European Association of Haemophilia and Allied Disorders (EAHAD) and European Haemophilia Consortium (EHC) since 2013. The centres are designated as European Haemophilia Comprehensive Care Centres (EHCCC) or European Haemophilia Treatment Centres (EHTC), based on the specific requirements which evaluate centres' ability to provide care for patients with haemophilia and allied disorders.

AIM

To establish the new protocol for accreditation of European Haemophilia Centres.

METHODS

EAHAD, in collaboration with EHC, established Accreditation Working Group with the aim to define necessary measures to safeguard quality and improvement of bleeding disorders care throughout Europe and to build a novel model for accreditation of European Haemophilia Centres.

RESULTS

The European guidelines for certification of haemophilia centres have been updated to guidelines for the accreditation and include all the requirements regarding facilities, laboratory and personnel needed for optimal management of novel treatment options, including the introduction of the hub-and-spoke model for delivery of gene therapy. A pilot project for the accreditation of haemophilia centres including on-site audit has been designed.

CONCLUSION

Implementation of the novel accreditation protocol of the haemophilia treatment and haemophilia gene therapy centres has been made to further improve the quality of care for patients with haemophilia and other inherited bleeding disorders.

Identifying performance-based outcome measures of physical function in people with haemophilia (IPOP)

INTRODUCTION

Recent recommendations of core outcome sets for haemophilia highlight the need for including measures of performance-based physical health and physical function sustainability. To date, there is no consensus on what outcomes might be of value to clinicians and patients.

AIM

To identify instruments of performance-based physical function to monitor musculoskeletal health in people with haemophilia that are practical in the clinical setting.

METHODS

Utilising components from the Activities and Participation Category of the WHO International Classification of Functioning (WHO-ICF), a consensus-based, decision analysis approach was used to: identify activities people with haemophilia have most difficulty performing; identify quantitative performance-based measures of identified activities via a scoping review; and obtain views on acceptability of the tests utilising a DELPHI approach.

RESULTS

Eleven activities were identified: maintaining a standing position, walking long distances, walking up and down stairs, walking on different surfaces, running, hopping, jumping, squatting, kneeling, undertaking a complex lower limb task, undertaking a complex upper limb task. Following a 2-round DELPHI survey of international physiotherapists, the 6-min walk test, timed up and down stairs, 30-s sit to stand, single leg stance, tandem stance, single hop for distance (children only) and timed up and go (adults only) reached consensus.

CONCLUSION

This study is the first step in defining a core set of performance-based instruments to monitor physical health and sustainability of physical function outcomes in people with haemophilia. Establishing the psychometric properties of the instruments and whether they are meaningful to people with haemophilia is essential.

Recommending swimming to people with low back pain: A scoping review

BACKGROUND

It is common practice for health professionals to recommend swimming to people with low back pain (LBP) despite limited evidence. The aim of this review was to gain an understanding of the current evidence base supporting the recommendation of swimming to people with LBP.

METHODS

A scoping review was conducted searching five electronic databases, CINAHL, MEDLINE, PEDro, PubMed, and SPORTdiscus using the keywords back pain AND swim*. The studies were grouped by study design and the following uncertainties were considered; the impact of swimming on the spine and LBP, evidence of swimming increasing or reducing the risk of LBP and the use of swimming in LBP rehabilitation programmes.

RESULTS

25 studies met the eligibility criteria; including sixteen observational studies exploring the relationship between swimming and LBP, three biomechanical studies investigating the impact of swimming on the spine, and five interventional studies of which four integrated swimming into a rehabilitation programme and one used swimming to modify lumbar lordosis.

CONCLUSION

The review confirmed there is limited research and only low-level evidence to support the recommendation of swimming to people with LBP. Observational studies make up the greater proportion of research undertaken in the field; the data indicates that swimming is a low-risk form of exercise but not without risk. The findings from biomechanical research suggest that lumbar lordosis does not increase excessively when swimming breaststroke, but certain swimming techniques could negatively impact LBP and interventional trials illustrate that there are various ways to integrate swimming into a rehabilitation programme.

Emicizumab prophylaxis in haemophilia A with inhibitors: Three years follow-up from the UK Haemophilia Centre Doctors' Organisation (UKHCDO)

INTRODUCTION

The UK National Haemophilia Database (NHD) collects data from all UK persons with haemophilia A with inhibitors (PwHA-I). It is well-placed to investigate patient selection, clinical outcomes, drug safety and other issues not addressed in clinical trials of emicizumab.

AIMS

To determine safety, bleeding outcomes and early effects on joint health of emicizumab prophylaxis in a large, unselected cohort using national registry and patient reported Haemtrack (HT) data between 01 January 2018 and 30 September 2021.

METHODS

Prospectively collected bleeding outcomes were analysed in people with ≥6 months emicizumab HT data and compared with previous treatment if available. Change in paired Haemophilia Joint Health Scores (HJHS) were analysed in a subgroup. Adverse events (AEs) reports were collected and adjudicated centrally.

RESULTS

This analysis includes 117 PwHA-I. Mean annualised bleeding rate (ABR) was .32 (95% CI, .18; .39) over a median 42 months treatment with emicizumab. Within-person comparison (n = 74) demonstrated an 89% reduction in ABR after switching to emicizumab and an increase in zero treated bleed rate from 45 to 88% (p < .01). In a subgroup of 37 people, total HJHS improved in 36%, remained stable in 46% and deteriorated in 18%, with a median (IQR) within-person change of -2.0 (-9, 1.5) (p = .04). Three arterial thrombotic events were reported, two possibly drug related. Other AEs were generally non-severe and usually limited to early treatment, included cutaneous reactions (3.6%), headaches (1.4%), nausea (2.8%) and arthralgia (1.4%).

CONCLUSIONS

Emicizumab prophylaxis is associated with sustained low bleeding rates and was generally well-tolerated in people with haemophilia A and inhibitors.

How to assess, detect, and manage joint involvement in the era of transformational therapies: Role of point-of-care ultrasound

BACKGROUND

Patients with haemophilia experience recurring hemarthroses, mainly involving knees, elbows and ankles, which lead to haemophilic arthropathy, the major chronic complication of haemophilia. With new approaches to haemophilia treatment leading to fewer joint bleeds and, in some cases, no bleeding events, assessing whether current outcome assessment tools provide adequate sensitivity and specificity for management and care of patients with haemophilia is needed.

METHODS

An overview of current imaging tools for monitoring joint health, novel osteochondral damage and synovial proliferation biomarkers, and the relationship between assessments for functionality and imaging modalities is provided. Usefulness and sensitivity of point-of-care ultrasound (POCUS) to complement other assessments and use of ultrasound to monitor haemophilic arthropathy are also examined.

RESULTS

This review provides rationale for haemophilia teams to move beyond traditional outcomes in joint imaging, as well as guidance and evidence on assessment of joint health for potential new treatment modalities, such as gene therapy. The role of POCUS in the existing paradigm for haemophilia care and management along with the use of ultrasound as a complement to other outcome assessment tools are also discussed. Finally, the clinical effects of subclinical bleeding on joint function are described, to motivate screening for synovial proliferation.

CONCLUSION

POCUS can facilitate the early detection of joint damage and can monitor disease progression while providing insights into the efficacy of treatment regimens, and should be considered as an essential assessment tool for managing the care of patients with haemophilia.

The experiences and beliefs of people with severe haemophilia and healthcare professionals on pain management, and their views of using exercise as an aspect of intervention: a qualitative study

PURPOSE

To explore the experiences, views and beliefs of people with severe haemophilia and healthcare professionals (HCPs) on approaches for pain management, as well as their views on exercise being used as an aspect of management.

METHODS

Taking a qualitative inquiry approach using focus groups and semi-structured interviews, participants included people with severe haemophilia living with chronic pain and haemophilia HCPs. Data were analysed using reflexive thematic analysis.

RESULTS

Fourteen men with haemophilia with a median age of 47 (range 23-73) and six haemophilia HCPs agreed to participate. Of the people with haemophilia, 11 attended two focus groups and three were interviewed over telephone. Healthcare professionals were interviewed face-to-face. Two themes were conceptualised from the data: (i) haemophilia management and pain management is discordant (imbalance between good haemophilia care but poor pain management, historical medico-social influences on pain management, the need for trust); (ii) uncertain about exercise but clear on what matters (conflicting views on exercise, the need for proof of safety, personalised care).

CONCLUSIONS

Options for effective pain management remain limited and what is used is heavily influenced by beliefs and experience. Exercise as a treatment option in pain management is conceptually acceptable for people with haemophilia. Effective pain management requires understanding of individual beliefs and fears, and a personalised approach supported by knowledgeable, trusted clinicians.Implications for rehabilitationMusculoskeletal joint pain and its relationship with bleeding in people with haemophilia continues to be a management challenge.Current pain management strategies are of limited effectiveness with little evidence of an approach that reflects the multi-modal pain experience.Whilst exercise and rehabilitation approaches are conceptually possible for people with severe haemophilia, barriers remain regarding perception of overall safety and effectiveness.People with severe haemophilia may consider exercise as part of a pain management strategy if it is individualised, and they are supported to do it by clinicians who understand them and their haemophilia.

How does a lifetime of painful experiences influence sensations and beliefs about pain in adults with severe haemophilia? A qualitative study

PURPOSE

To explore the life experiences of pain in people with severe haemophilia and understand how such experiences influence beliefs and sensation of pain in adulthood.

METHODS

A qualitative inquiry approach using focus groups and semi-structured individual interviews was used. Participants included people with severe haemophilia living with chronic pain. Data were analysed using reflexive thematic analysis.

RESULTS

Fourteen men with a median age of 47 (range 23-73) agreed to take part. Eleven participated in two focus groups and three were interviewed over telephone. Two themes were conceptualised from the data: (i) haemophilia and pain - an evolving life biography (the personal narrative, historical, social, and medical context, continuous adaptation of activity choices, surveillance of pain and its meaning); (ii) "My normal isn't normal" - identity and self-agency (pain as a feature of life and identify with severe haemophilia, loss of enjoyable activities balanced against staying active, barriers to participation).

CONCLUSIONS

Pain is a constantly evolving, lifetime feature for many adults with haemophilia and it is viewed as part of their identity with their condition. Healthcare professionals working in haemophilia should try to better understand the influence of an individuals lived experience with their haemophilia on beliefs and behaviours of pain.Implications for rehabilitationSevere haemophilia is a rare bleeding disorder that results in musculoskeletal joint disease.Adults with severe haemophilia have experienced multiple episodes of bleeding related musculoskeletal pain since childhood.Pain beliefs and behaviours in adulthood appear to be influenced by a lifetime of painful experiences associated with haemophilia.In order to better support people with haemophilia and chronic pain, healthcare professionals in haemophilia need to better understand how an individuals lived experience of pain helps inform their beliefs about it.

European principles of care for physiotherapy provision for persons with inherited bleeding disorders: Perspectives of physiotherapists and patients

INTRODUCTION

In their Chronic Care Model, the World Health Organisation states that people with chronic disorders and their families should be informed about the expected course, potential complications, and effective strategies to prevent complications and manage symptoms. Physiotherapists are a key professional group involved in the triage, assessment and management of musculoskeletal conditions of persons with a bleeding disorder (PWBD). Nevertheless, recent reports describe access to physiotherapy for those with these conditions is only sometimes available.

AIM

Access to high quality individualised physiotherapy should be ensured for all PWBD, including those with mild and moderate severities, male and female, people with von Willebrand Disease (vWD) and other rare bleeding disorders. Physiotherapy should be viewed as a basic requisite in their multidisciplinary care.

METHODS/ RESULTS

Following a series of meetings with physiotherapists representing the European Association for Haemophilia and Allied Disorders (EAHAD) and PWBD representing the European Haemophilia Consortium (EHC) and a review of publications in the field, eight core principles of physiotherapy care for persons with a bleeding disorder have been co-produced by EAHAD and EHC.

CONCLUSION

These eight principles outline optimum standards of practice in order to advocate personalised patient-centred care for physical health in which both prevention and interventions include shared decision making, and supported self-management.

Twelve-month prevalence of haemarthrosis and joint disease using the Haemophilia Joint Health score: evaluation of the UK National Haemophilia Database and Haemtrack patient reported data: an observational study

OBJECTIVES

To report the 12-month prevalence of joint bleeds from the National Haemophilia Database (NHD) and Haemtrack, a patient-reported online treatment diary and concurrent joint disease status using the haemophilia joint health score (HJHS) at individual joint level, in children and adults with severe haemophilia A and B (HA/HB) without a current inhibitor.

DESIGN

A 2018 retrospective database study of NHD from which 2238 cases were identified, 463 patients had fully itemised HJHS of whom 273 were compliant in recording treatment using Haemtrack.

SETTING

England, Wales and Scotland, UK.

PARTICIPANTS

Children (<18 years) and adults (≥18 years) with severe HA and HB (factor VIII/factor IX, <0.01 iu/mL) without a current inhibitor.

PRIMARY AND SECONDARY OUTCOMES

Prevalence of joint haemarthrosis and concurrent joint health measured using the HJHS.

RESULTS

The median (IQR) age of children was 10 (6-13) and adults 40 (29-50) years. Haemarthrosis prevalence in HA/HB children was 33% and 47%, respectively, and 60% and 42%, respectively, in adults. The most common site of haemarthrosis in children was the knee in HA and ankle in HB. In adults, the incidence of haemarthrosis at the ankles and elbows was equal. The median total HJHS in HA/HB children was 0 and in adults with HA/HB, were 18 and 11, respectively. In adults with HA/HB, the median ankle HJHS of 4.0 was higher than the median HJHS of 1.0 for both the knee and elbow.

CONCLUSION

Despite therapeutic advances, only two-thirds of children and one-third of adults were bleed-free, even in a UK cohort selected for high compliance with prophylaxis. The median HJHS of zero in children suggests joint health is relatively unaffected during childhood. In adults, bleed rates were highest in ankles and elbows, but the ankles led to substantially worse joint health scores.

The role of the physiotherapist in the management of people with haemophilia: defining the new normal

Physiotherapists aim to maximise quality of life and movement potential within the spheres of promotion, prevention, treatment/intervention and rehabilitation. Haemophilia care is witnessing a significant shift towards a new era of potentially life-changing treatments which offer a future of minimal or no bleeds for people with haemophilia. As such, physiotherapy intervention should be more proactive rather than reactive to treat and rehabilitate recurrent bleeding episodes. The role of the physiotherapist within the multidisciplinary team includes the differential diagnosis of musculoskeletal bleeding, supporting and encouraging higher levels of physical activity, rehabilitation to maximise physical potential and capabilities, assessment and treatment of non-bleed-related musculoskeletal issues, managing comorbidities and falls risk, and improving the longitudinal surveillance of musculoskeletal health. Encouraging and supporting people with haemophilia to become more active will improve wellbeing and improve health and health outcomes, and physical activity is becoming one of the most important outcomes for people with haemophilia. Recommendations on the best way to accurately capture these data are vital to ensure the full health benefits of new treatments for people with haemophilia are clear.

The Role of Physiotherapy in the New Treatment Landscape for Haemophilia

The physiotherapist plays an essential role for people with haemophilia, an inherited bleeding disease responsible for musculoskeletal complications. Yet, with the advent of new and advanced therapies, the medical landscape is changing, and physiotherapy must adapt alongside. This paper considers whether there will still be a need for physiotherapy in the era of advanced therapies, and discusses ways in which services should evolve to complement emerging treatment paradigms for haemostasis in people with haemophilia. Ultimately, physiotherapy will remain an important element of care, even for people with little joint damage and low risks in the era of the new mild phenotype. However, competencies will need to evolve, and physiotherapists in both primary care and specialist treatment centres should work with haematology colleagues to develop more sensitive tools for detecting early joint changes. Physiotherapists will also play a crucial role in counselling and physically coaching, monitoring the musculoskeletal status of people with haemophilia who have transitioned to new treatments.

Feasibility, safety and acceptability of select outcome measures in a physiotherapy study protocol for boys with haemophilia

Background

There is a lack of functional performance measures for children and young people with haemophilia (CYPwH) with associated control data from typically developing boys (TDB). The literature advocates development of a core set of outcome measures for different chronic conditions. As medical treatment improves, CYPwH are experiencing better outcomes; therefore, more challenging measures are required to monitor physical performance. Such testing is not performed routinely, due to practical and safety concerns.

Aim

Evaluate the feasibility, safety and acceptability of select outcome measures as part of a study protocol testing CYPwH; including myometry, 10 metre incremental shuttle walk test (10-m ISWT), iSTEP (an incremental step test, with data from TDB), and 1 week of accelerometry-wear at home.

Methods

Sixty-six boys aged 6–15 years with mild, moderate or severe haemophilia A or B (including inhibitors) attending routine clinics at Great Ormond Street Hospital were approached to participate. Descriptive statistics and content analysis were used to assess outcomes of feasibility, safety and acceptability, which included recruitment/retention rates, protocol completion within routine appointment timeframes, performance testing without serious adverse events/reactions (SAE/SARs), and acceptability to CYPwH of high-level performance measures.

Results

Outcomes were met: 43 boys completed testing at clinic review (Jan–Nov 2018) within a 10-month timeframe, retention was 95% at completion of protocol and no SAE/SARs were reported throughout testing.

Conclusion

Feasibility, safety and acceptability of the study protocol have been established in this population. Both high-level performance tests, iSTEP and 10-m ISWT, were an acceptable addition to boys’ routine clinic appointments and could be safe, acceptable choices of outcome measure as part of a core set of tests for CYPwH. Further investigation of the psychometric properties for the iSTEP is now justified, in order for it to be used as a standardised, validated, reliable outcome measure in clinical or research settings.

Trial registration

Retrospectively registered on September 3, 2019, on ClinicalTrials.gov (ID: NCT04076306).

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00831-1.

Acceptability and Feasibility of an Isometric Resistance Exercise Program for Abdominal Cancer Surgery: An Embedded Qualitative Study

Although it is recognized in the early stages of cancer recovery that changes in lifestyle including increases in physical activity improves physical function, there are no clear findings whether low versus moderate intensity activity or home or gym exercise offer optimal benefit. Isometric-resistance exercises can be carried out with very little equipment and space and can be performed while patients are bed-bound in hospital or at home. This embedded qualitative study, based in an English hospital trust providing specialist cancer care, was undertaken as a component of a feasibility trial to evaluate the acceptability and feasibility of an isometric-resistance exercise program and explore the suitability of functional assessments by drawing from the experiences of abdominal cancer patients following surgery. Telephone interviews were undertaken with 7 participants in the intervention group, and 8 interviews with the usual care group (n = 15). The gender composition consisted of 11 females and 4 males. Participants’ ages ranged from 27 to 84 (M = 60.07, SD = 15.40). Interviews were conducted between August 2017 and May 2018, with audio files digitally recorded and data coded using thematic framework analysis. Our results show that blinding to intervention or usual care was a challenge, participants felt the intervention was safe and suitable aided by the assistance of a research nurse, yet, found the self-completion questionnaire tools hard to complete. Our study provides an insight of trial processes, participants’ adherence and completion of exercise interventions, and informs the design and conduct of larger RCTs based on the experiences of abdominal cancer surgery patients.