The influence of multidisciplinary integration on patient optimization within a high variety - low volume environment

The influence of

multidisciplinary integration on

patient optimization within a high

variety - low volume

environment

Jeffrey Bos – S2957647 University of Groningen

Faculty of Economics and Business MSc Supply Chain Management 3-7-2019

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Abstract

This research aims to clarify the influence of multidisciplinary integration on patient optimization programs in a high variety – low volume environment. In a pancreas surgery case, including common complications, frequent readmissions and a complex patient group, the influence of integration on patient optimization practices was investigated. Prehabilitation, where patients are optimized before entering surgery, is a key subject of research because of its promising possibilities to reduce

readmissions and cost in healthcare. Prehabilitation is, like other interventions, also hard to realize and implement because of its multimodal character. To establish the importance of prehabilitation, the cost-effectiveness has been determined first by conducting literature research. Multidisciplined in-depth interviews were used to gather information to provide meaningful implications for implementing prehabilitation in the healthcare sector. Structured prehabilitation is shown to be cost-effective in the case of pancreas surgery, resulting in a return-on-investment of 155%. When implementing

multidisciplinary prehabilitation in a high variety low volume setting, trust and personal relationships are key aspects of integration to keep in mind. Also, motivation and willingness to cooperate are highly dependent on the structure of the prehabilitation centre. This includes how carefully the structure was considered and how much input every discipline had in this decision. Lastly, while organizational integration is important to ensure collaboration and institutionalized pathways, it is difficult to accomplish because of uncertain planning and potentially inefficient time distribution.

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Introduction

Pancreas surgeries lead, according to medical databases from the DPCA (Dutch Pancreatic Cancer Group), to complications in nearly 60% of cases (Dutch Institute for Clinical Auditing, 2019). High readmission rates, complex patient groups and low quantities make pancreas surgery an uncertain, high variety – low volume setting (Han, Klein, & Arora, 2011). Given the limited available healthcare resources, it is reasonable for hospitals to aim at reducing readmissions by focussing efforts on optimizing patients at higher risk of readmission (Kripalani, Theobald, Anctil, & Vasilevskis, 2014). These readmission reduction initiatives often require a multimodal approach, however, which has proven to be difficult to set up properly (Le Roy, Selvy, & Slim, 2016; Wong, Caesar, Bandali, Agnew, & Abrams, 2009). When organizing approaches where multiple disciplines need to work together, a high variety – low volume environment can be a complicating factor. Practical examples of this are the many different complications and complex patients resulting in a wide range of possible patient pathways. Moreover, high levels of variety and unpredictability can lead to a difficult assessment of the impact of interventions. These factors may subsequently lead to different opinions or levels of knowledge and willingness to cooperate, low investments in relationships or ineffective communication structures between departments or caregivers. This research aims to uncover the influence of multidisciplinary integration on readmission reduction initiatives in a high variety – low volume setting.

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prehabilitation centre is not yet determined. This leads to a first research questions that will be answered in this study;

Part 1: “What is the cost-effectiveness of a structured prehabilitation centre for pancreas surgeries?”

To implement interventions in the preoperative phase, it is important to keep in mind that approaches need to be multimodal in order to have a reasonable chance of success (Cui, Turney, & Griffiths, 2017; Silver & Baima, 2013). The implementation of multidisciplinary and multimodal interventions has proven to be difficult, as integration between departments and disciplines in the surgical pathway is often limited (Mellinger & Volk, 2013). Also, it is yet unknown how integration between disciplines should be coordinated, especially in high variety – low volume environments, despite its potential being proven (Lopes, Fernandes, & Santana, 2016; Lopes S. , et al., 2017; Pecorelli, et al., 2016). Questions on communication structures, relationships and the extent of integration are yet unanswered, while they remain crucial to accomplish successful multidisciplinary integration. The challenge remains to organize a situation where communication, relationships and overall integration between disciplines are sufficiently developed to implement care interventions. This situation of

multidisciplinary integration has been shown to improve outcomes, quality of care and preventive care programs (Mellinger & Volk, 2013). Previous literature suggests that integrative practices

significantly improve patient flow performance in high volume – low variety environments

(Drupsteen, Van der Vaart, & Van Donk, 2013). However, as mentioned by Drupsteen et al. (2013), there is a need for further research including patient groups with characteristics such as lower volumes and greater variety. The pancreas surgery network (hepato-pancreato-biliary or HPB surgery) offers an opportunity to fill that gap, as it is characterized by low volumes and high variety. These

characteristics are expected to complicate integration and also the implementation of patient

optimization programmes. Other than providing a cost-effectiveness analysis, this research also aims at improving understanding of multidisciplinary integration to implement patient optimization programs. We herewith aim to contribute to disentangling how a high variety – low volume

environment influences the level of integration needed to realise patient optimization practices, such as prehabilitation. Thus, the second research question is as follows:

Part 2: “What is the influence of multidisciplinary integration on the implementation of patient optimization in a high variety – low volume environment?”

In the next section, current knowledge on readmission reduction after surgery will be further

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Theoretical background

This research is aimed at improving knowledge on the cost-effectiveness of structured prehabilitation when applied in a multidisciplinary setting. Also, we aim to improve understanding of the possibilities to bring this knowledge into practice for realising a multidisciplinary prehabilitation centre. To clarify what prehabilitation encompasses in this specific setting, the nature of pancreas surgeries will be described first. Secondly, patient optimization and prehabilitation will be defined and different

improvement programs aimed at reducing readmissions after surgery will be explained. To clarify why patient optimization practices such as prehabilitation are difficult to bring into practice, we explain why these are multimodal problems requiring multidisciplinary integration. Also, specific attention is directed to integration literature. This entails information on interdisciplinary collaboration and care chain integration. Finally, the research into potential cost-effectiveness is described.

The nature of pancreas surgeries

Pancreas surgeries can be described as relatively low volume and high variety, with the University Medical Center Groningen (UMCG) carrying out around 539 surgeries in a 6-year period.

Countrywide measures from the Netherlands indicate a rise from 1.500 patients suffering from pancreatic cancer in the year 2000 to 2.400 in 2018 (Integraal kankercentrum Nederland, 2019). As stated before, the surgical procedure following the diagnosis is relatively difficult. Since pancreatic cancer is rather refractory to chemo- or radiotherapy, only resection of the tumor has a chance of cure (Seufferlein & Adler, 2009). The late complications of pancreatic resection can be connected with the operation and the extent of the tissue resection itself, the result of progressive underlying disease and behavioural aspects like continued alcohol and nicotine consumption. (Keim, Klar, Poll, &

Schoenberg, 2009). Complications are frequent and devastating and readmissions regularly occur (Enestvedt, et al., 2012; Santema, et al., 2015). With costs ranging from € 2.225 to € 5.880 for a readmission alone, pancreas related readmission expenditures are high (Nederlandse Zorgautoriteit, 2019). Patients with major complications had a median cost that was 48,35% higher than patients without complications (Enestvedt, et al., 2012). Because of this, Substantial research efforts have been driven into treatment of pancreatic cancer. These efforts will lead to improvements in clinical trial design and ultimately change the lives of patients (Oberstein & Olive, 2013).

Prehabilitation and patient optimization

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combination with risk factors such as poor physical and nutritional status have detrimental effects on short- and long-term aspects of recovery and quality of life. The process of increasing patients’ functional reserve in anticipation for surgery is referred to as prehabilitation. (Carli & Ferreira, 2018). A surgical prehabilitation program starts in the preoperative period and should be part of an integrated enhanced recovery after surgery (ERAS) program, to attenuate surgical stress, encourage patient autonomy and ultimately preserve function (Fearon, Jenkins, Carli, & Lassen, 2012). For this study, prehabilitation is defined as the process of enhancing a patients’ functional and mental capacity to buffer against potential deleterious effects of a significant stressor (Carli & Zavorsky, 2005). In the specific surgical setting, preoperative physical and psychological conditioning aims to increase body and mind reserves to prevent the anticipated surgery-related declines in function and well-being (Santa Mina, Scheede-Bergdahl, Gillis, & Carli, 2015). This patient-centred, multidisciplinary and integrated medical care program should start in the preoperative phase where vulnerable patients are identified, risk stratified and adequately assessed by an interdisciplinary team. The aim should be improving surgical outcome and promoting health behaviour throughout the continuum of cancer care (Minnella, Bousquet-Dion, Awasthi, Scheede-Bergdahl, & Carli, 2016).

The effects of prehabilitation on functional capacity can best be described with a figure provided by Santa Mina et al. (2015). This describes the continuing process of recovery in a situation with only rehabilitation and a situation with both prehabilitation and rehabilitation. This figure has been slightly adjusted to represent the situation for pancreas surgery.

Assessment Prehabilitation

Pre-disease Pre-diagnosis Pre-operative Acute postoperative Rehabilitation Post rehabilitation Functional life Func ti o na l c ap aci ty

Functional capacity during stages of disease

Prehabilitation No

prehabilitation Functional threshold

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Where the field of prehabilitation used to be a single-method subject targeting physical activity, it has transformed into a multimethod intervention subject that includes physical exercise, nutritional counselling with supplements and relaxation exercises (Silver J. K., 2014). To optimize a patient before surgery, specific dimensions of prehabilitation for gastrointestinal surgeries have been

developed. These are aimed at improving functional reserve (Fearon, Jenkins, Carli, & Lassen, 2012). Dimensions for this study are frailty, physical condition or fitness, nutrition, anaemia, psychological condition and alcohol/smoking behaviour.

Multimodal approach

Prior patient optimization literature reviews demonstrate the positive effects of prehabilitation on a variety of postoperative outcomes related to recovery. These include length of stay, postoperative complications, pain, quality of life and potential disability (Halloway, Buchholz, Wilbur, & Schoeny, 2015). Prehabilitation programs should take the state of the disease into account, including

comorbidities, functional capacity, current health status and the type of surgery (Carli & Ferreira, 2018). This requires regular multidisciplinary team meetings to coordinate and integrate properly. Thus, prehabilitation does require a multimodal approach where different stakeholders need to be engaged in preparing the patient for surgery (Le Roy, Selvy, & Slim, 2016). Internists, surgeons, geriatricians, anaesthesiologists, nutritionists/dietetics, kinesiologists/physiotherapists and hospital managers should all be involved to create an integrated, structured network (Carli & Scheede-Bergdahl, 2015). Pairing psychological and physical prehabilitation interventions in a multimodal approach is likely to offer the best overall outcomes. Unimodal interventions can be regarded as pieces of a puzzle, but when combined they form multimodal approaches, which have a higher success chance but are also harder to accomplish (Silver & Baima, 2013). Multimodal approaches may be hard to realize because of delayed, inaccurate or inadequate communication between multidisciplinary care providers within and across the continuum of care (Wong, et al., 2009; Berenson, Paulus, & Kalman, 2012). If accomplished properly, multimodal optimization has shown to be superior to conventional perioperative care, leading to earlier discharge and showing no increase in morbidity or subsequent readmission rates (Anderson, et al., 2003).

To organize multimodal approaches properly, integration is required between the cooperating care providers. Although there are many ways to approach integration practices, two main theories are considered here. These theories will also be able to provide a clear indication of the influence of the high variety – low volume environment. Firstly, the relational coordination model is aimed at mapping relationships and communication in an interdisciplinary coordination scenario. This is used to clarify the quality and possibility of relationships and motivations. Secondly, care chain integration

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organizational aspects, that integrate on a certain level to form a unified whole. This is used to clarify the scope and extent of integration. By using these theories, relational and organizational factors are distinguished.

Interdisciplinary collaboration

Integration of care focusses on the integration or sequencing of activities of care (Reid, Haggerty, & McKendry, 2002). According to a literature review on integration of care, the emphasis is on linking planning and management activities across different providers of care. This information should be recorded into a summative document such as a care plan, also linking those planning and management efforts and interventions into a care delivery system (Holland & Harris, 2007). This means that the cycle of care requires an interpersonal process through which members of different disciplines contribute to a common goal, that cannot be reached when individual professionals act on their own (Bronstein, 2003). The following definition is used for the interdisciplinary collaboration in the context of health care: “An interpersonal process characterized by healthcare professionals from multiple disciplines with shared objectives, decision-making, responsibility, and power working together to solve patient care problems” (Petri, 2010). This approach to healthcare has been found to reduce errors, improve quality of care and patient outcomes, reduce healthcare workloads and costs, while also increasing job satisfaction (Schroder, et al., 2010).

Another complicating aspect to interdisciplinary collaboration is the willingness to cooperate from all parties involved. Members might have different interests, goals, expectations and experiences which can complicate communication and generate conflict. Moreover, willingness to cooperate is

specifically determined by the psychological safety experienced, collegiality and the role valuing between care providers (Morley & Cashell, 2017). Since variety, and thus uncertainty, is high in the case of pancreas surgery, the experienced psychological safety is expected to be low. Also, since the current frequency of interdisciplinary communication is unknown and expected to be segmented due to the low volume environment, collegiality and role valuing could also complicate the willingness to cooperate (Boyce, 2006). These factors considered, it is expected that personal willingness to

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As the interpersonal process of interdisciplinary collaborative practice is mainly aimed at relationships, it can be described best with the relational coordination theory. This is the process of coordinating work through relationships and shared goals, shared knowledge and mutual respect (Gittell, 2006). Relational coordination is measured as a network of communication and relationship ties among workgroups engaged in a common work process (Gittell, Godfrey, & Thristlethwaite, 2013). Relational coordination is measured specifically by 7 items, distinguished by the topics of relationships and communication (figure 2). All of the seven aspects are aimed at the focal work process (Gittell, 2011).

Care chain integration

Integration can be defined as a situation where distinct and interdependent organizational components should constitute a unified whole, by employing activities and practices that allow functions within an organization to coordinate and cooperate with one another (Barki & Pinsonneault, 2005;

Braunscheidel, Suresh, & Boisnier, 2010). The organization in this case means the whole spectrum of care providers present in the patients’ care journey. In the most ideal scenario, an integrated

organization can function as a seamless system within which patients can move freely from outpatient to inpatient to subacute to home health services (Robinson & Casalino, 1996). In a situation with high complexity, as it the pancreas surgery environment, supply chain integration tends to have an

increasing effect on performance. (Gimenez, Van der Vaart, & Van Donk, 2012).

Integration means a merger of different contributions and efforts to produce an understanding of a patient’s situation, which enables the development, coordination, monitoring, and re-integration of a care plan (Lillrank, 2012). The different contributions and efforts could be in the form of different levels of collaboration, communication and concertation. Parties involved could be diverse and exceed organizational boundaries, covering primary-, secondary- and tertiary-care institutions (D'Amour, Goulet, Labadie, San Martín-Rodriguez, & Pineault, 2008).

Based on the paper of Stevens (1989), different stages of the extent of integration can be measured. In the first stage, there is no integration and members of the care chain act independently. In the middle stages, members of the care chain only integrate within their stage of care or integrate throughout the stages of care. In the final stage, members of the care chain fully integrate throughout the stages of care while also integrating with members outside of the hospital. The stages of care described by Drupsteen, van der Vaart & van Donk (2013) are diagnosis, preassessment and treatment. In the case

Figure 2; Relational coordination based on Gittell (2011).

Relationships

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of patient optimization for complex pancreas surgery, diagnosis, preassessment and prehabilitation should mainly be taken into account. This gives an indication of the organizational aspect of integration.

Conceptual model

Concluding the theoretical background for part 2 of the research, a conceptual model containing all relevant information for the purpose of this research is constructed (figure 3). This clarifies the actual contribution this research will provide in light of the influence of integration on patient optimization in a high variety – low volume environment.

Figure 3: Conceptual model

The main aim is to identify the effects of multidisciplinary integration, which has been operationalized into relational and organizational measures, on the organization and implementation of patient

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Cost-effectiveness

Before investing into integrated healthcare networks, the benefits and costs should be weighed. Health care executives should assess to what extent the increased benefit to patients, in terms of quality of care, health outcomes and satisfaction, can outweigh the added costs of integration (Wan, Ma, & Lin, 2001). An important step to begin is a cost-effectiveness calculation of a structured prehabilitation centre. To determine the cost-effectiveness of a structured prehabilitation centre containing those factors, they are first thoroughly discussed based on their characteristics and uses for

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Methodology

This study is divided over two main research questions and parts. Part 1 entails the cost-effectiveness of a prehabilitation centre focussed on pancreas surgery, while part 2 encompasses the influence of multidisciplinary integration on the implementation of such a network. Here, we will first describe how we conducted a literature review to determine the cost-effectiveness of a prehabilitation centre. The second part is focussed on the qualitative research conducted to discover the influence of multidisciplinary integration.

Part 1: Literature review

To achieve the first main goal of the study, a cost-effectiveness estimate of a structured prehabilitation centre, a literature review was combined with expert interviews. A literature review is important to understand the topic, know what has already been done and understand what key issues are to be addressed (Hart, 2018). Literature was first gathered on multimodal prehabilitation programmes and networks to gain insight into important determinants of success. The main search engine used was Google Scholar, which is a database containing theoretically all electronic resources, from all periods, focussed on a wide array of research fields (Falagas, Pitsouni, Malietzis, & Pappas, 2007). Important initial research terms were combinations of prehabilitation, pancreas surgery, gastroenterology,

complication reduction, pancreatoduodenectomy, pancreatic cancer, preoperative intervention, multimodal and multidisciplinary. These terms were mainly used in the exploratory phase. In the more

advanced stages of the literature research, the specific dimensions were explored thoroughly with guidance of the expert interviews. This led to a new range of search terms, specific to uncover the characteristics of each dimension of prehabilitation.

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care paths with no, light and severe complications. This eventually led to a total cost, calculated as the sum of the cost of all interventions and the cost of all patient pathways.

Part 2: Case study research design

The second main goal of the study was to explore the influence of multidisciplinary integration on the organization and implementation of patient optimization practices. To analyse the current situation of integration practices and the role of a high variety – low volume setting, qualitative information was examined. The most typical way to explore relatively undefined issues like this is by means of a case study (Tellis, 1997; Eisenhardt, 1989). Exploratory case studies are most ideal in situations where little knowledge exists, such as on the relationship between healthcare integration and structured forms of patient optimization, as prehabilitation is intended to be (Yin, 2003). A single case study was applied here, because of the rare occurrence of the phenomenon studied. Many hospitals have not yet

undertaken action to develop multidisciplinary integrative practices for patient optimization, thereby limiting the amount of viable study environments. A single case study is considered acceptable because it allows for full exploration of the situation, also establishing crucial variables for the effect of the high variety – low volume setting (Hamel, Dufour, & Fortin, 1993).

Case study selection

The unit of analysis is a network of care providing departments in a high variety – low volume surgery setting, focussed on pancreas surgery. The selected network provided a complete and thorough

overview since multiple different points of view were investigated. The main selection criterium adopted for this study was the existence of a high variety – low volume environment, which is characterized by uncertainty in multiple aspects. Based on this criterium, the selected network of care providing departments was a pancreas surgery network within the University Medical Center

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generalizable with similar care systems like the Netherlands (Leung, 2015). Some background information on the UMCG and its patient optimization programme is provided as context.

University Medical Center Groningen

In the context of the UMCG, a future

prehabilitation centre will be focussed around the patient and includes 7 disciplines. A visual representation can be seen in figure 4. This is not yet realized at the moment, although the current multidisciplinary meetings also focus on individual patients. These meetings include professionals from all involved disciplines and determine the care and type of surgery needed for individual patients.

In this multidisciplinary situation, all facets need to be investigated properly, not just from the prehabilitation centre but also other actors involved in pancreas surgery networks. This may include geriatricians, anaesthesiologists,

nutritionists or physiotherapists, depending on the scale of the interventions.

Data collection

In order to obtain perspectives and information from all facets of multidisciplinary integration, we focussed on retrieving information from each discipline that is involved in the prehabilitation centre. We conducted in-depth, semi-structured interviews which are considered a main instrument of data collection for qualitative research (Ritchie & Lewis, 2003). A thorough, extensive research design was needed because healthcare systems are very diverse, distributed and complex systems in nature

(Wickramasinghe, Chalasani, Boppana, & Madni, 2007). The general interview guide approach was structured but allowed room for flexibility (Gall, Gall, & Borg, 2003). This allowed for adapting questions, because questions could be changed based on responses to previous questions (Turner, 2010). Duplicate questions about central concepts were asked to apply triangulation and strengthen the validity of the interpretation (Griffee, 2005). Triangulation was also applied by using multiple sources of data, enhancing the reliability of results (Fusch & Ness, 2015).

Patient

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From the interviews, an overview was obtained on the impact of both operationalized aspects of the organization of integration. This encompassed the relational aspect with the relational coordination model and the organizational aspect with the extent of integration model. The questions asked were based on the relational coordination model of Gittell (2006) and the extent of integration model of Stevens (1989). Questions were asked about shared goals and knowledge, practical issues about integration, frequency of communication and accuracy of information. The interview protocol itself can be found in appendix 1. The goal of the interviews was to capture the influence of

multidisciplinary integration on the implementation of patient optimization. This was done by asking about current practices and systems, but also by discovering the potential and pitfalls for integration in the current system. The initial interview protocol was slightly adjusted to adequately assess the current situation. Accuracy of information was combined into the factors frequency and timeliness of

information. The question on problem solving behaviour was adjusted to find information about problems and problem solving in general. Also, the question about mutual respect was grouped together with the question on shared knowledge.

Multiple points of view needed to be investigated to obtain information from all relevant stakeholders of a possible integration process. Researching multiple points of view add to the strength of results by replicating the pattern-matching (Tellis, 1997). The first interviews were aimed at defining key elements and mainly target exploration purposes, whereas the later interviews were more targeting the analysis of the connection between these variables. Elements that required defining in the first round are ways of working in the hospital, like multidisciplinary meetings and collaborations. Variables that were analysed in the later interviews include the relationships between disciplines, characteristics of collaborations and potential for integration. This provided a complete overview of what de influence of multidisciplinary integration is on implementation of patient optimization. Sequential designs in which essential data is collected first can contribute to exploratory data collection in the next phase (Driscoll, Appiah-Yeboah, Salib, & Rupert, 2007). All scheduled interviews and meetings are seen in table 1 below.

Date Purpose Contact Location

19-2-2019 Exploration of research possibilities Contact for prehabilitation UMCG 5-3-2019 Exploratory (prehabilition network) Expert on prehabilitation UMCG 2-4-2019 Interview on detailed model specifications (RQ1) Expert on prehabilitation UMCG

17-5-2019 Interview frailty Expert on geriatrics/frailty UMCG

20-5-2019 Interview prehabilitation centre Expert on prehabilitation UMCG 22-5-2019 Interview physical fitness Expert on physical fitness UMCG

27-5-2019 Interview anaemia Expert on anaemia UMCG

29-5-2019 Interview nutrition Expert on nutrition UMCG

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Data analysis

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Results

First the results of the literature review will be discussed, followed by the outcome of the cost-effectiveness analysis. Afterward, the influence of multidisciplinary integration is presented.

Results of part 1: The literature review

Frailty

Frailty refers to the reduced capacity of balancing mechanisms to respond to pathological stressors and is recognised as an independent risk factor for post-operative morbidity, mortality and disability. It is also regarded as a geriatric syndrome, related to aging. It does, however, not exclusively occur in older patients (Velanovich, Antoine, Swartz, Peters, & Rubinfeld, 2013). Interventions are aimed at bed mobility, transfers, indoor gait and outdoor mobility. Improvements are safer, more effective techniques, training in the proper use of assistive devices and recommendations for environmental modifications. These interventions offered modest but consistent benefits for the prevention of

physical function decline (Gill, et al., 2004). Also, a general geriatric assessment may provide benefits because of improved knowledge of the patient and limitations of surgery. This might cause more attention for a patient and a more careful care path consideration. Therefore, a success rate of 100% is assumed for the cost-effectiveness analysis because a negative outcome of the frailty assessment automatically results in more attention. However, the importance of the frailty factor is low because the geriatric referral is not a solution to the problems experienced by patients. It is more of an

alleviating mechanism to reduce the harm the problems cause. Up to 50% of patients have potentially important geriatric assessment deficits. Knowing these deficits in advance can predict clinically relevant outcomes, such as likelihood of complications, ICU admissions or length of stay. By having a structured geriatric assessment, the care plan for frail patients can be optimized and morbidity can be better mitigated (Dale, et al., 2014). The cost of a geriatric referral is presumed to be € 245,00 (Nederlandse Zorgautoriteit, 2019).

Physical condition

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the postsurgical healing process (Mujika & Padilla, 2001). Important here is also that patients who are deconditioned require only moderate physical training to obtain a significant increase in functional capacity (Carli, et al., 2010; Carli, Brown & Kennepohl, 2012). Physical exercise therapy is of major importance to reduce post-operative complications. Complication rates can be reduced by as much as 50% (Luther, Gabriel, Watson, & Francis, 2018). Compliance to the therapy is variable but can reach rates as high as 97-100% for supervised sessions (Soares, Nucci, Silva, & Campacci, 2013; Dronkers, et al., 2010). According to other studies and information from within the UMCG, however,

compliance rate can realistically be assumed to be around 61.50% (Barakat, Shahin, Khan, McCollum, & Chetter, 2016). The percentage of people that is in an unfit condition at the time of diagnosis is around 40%, according to statistics from the UMCG. Also, the UMCG has implied that the costs for a 4-week program are around € 2000,00 and the costs for a 6-week program are € 2500,00.

The relative importance of the physical condition of a patient is assumed to be very high. The reason for this is perhaps best described by a quote from one of the experts; “If a patient is fit enough to walk up two stairs, he is fit enough to go into surgery”. The main reason for the high importance is the effect improved physical condition has on other dimensions of prehabilitation. Firstly, as stated by an expert in the UMCG, improved fitness is associated with more red blood cells and reduced anaemia. Literature confirms that anaemia is associated with reduced fitness for surgery (Otto, et al., 2013; Clevenger & Richards, 2015). Also, physical activity has been used in interventions designed to reduce alcohol and other drug dependence and enhance smoking cessation. In addition, there is extensive evidence linking psysical activity to improved sleep outcomes. Physical activity is a major determinant strongly recommended for the prevention and treatment of psychological problems (Biddle, 2016). Physical training in the form of both aerobic and resistance training also target specific components of frailty. Exercise reduces frailty by decreasing muscle inflammation, increasing

anabolism and increasing muscle protein synthesis at the molecular level (Fielding, Sieber, & Vellas, 2014). This means that patients become less frail by having more muscle and stronger bones, resulting in better balance and less falling over. Lastly, according to experts within the UMCG, physical

condition and nutritional therapy also have synergetic effects, as increased fitness could improve digestion.

Nutritional therapy

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metabolism (Carli & Scheede-Bergdahl, 2015). This means comorbidity is an important consideration when applying nutritional prehabilitation. The primary goal of nutrition therapy is to optimize nutrient stores preoperatively and compensate for postoperative catabolic response (Howard & Ashley, 2003; Weimann, et al., 2006). Thus, the purpose is to optimize the patient for surgery (Carli & Scheede-Bergdahl, 2015). The success rate of malnourishment treatment can be estimated due to a dropout rate of 15%, resulting in 85% success. This estimation is based on research on subtotal gastrectomy, total gastrectomy, pancreaticoduodenectomy, total pancreatectomy and surgical bypass patient (Klek, et al., 2011). According to patient diaries, compliance rates are confirmed to be between 72% and 96,6% (Luther, Gabriel, Watson, & Francis, 2018). Weight loss is common under pancreas surgery patients, as pancreatic cancer patients have lost approximately 15% of their pre-illness stable weight by the time of diagnosis. The percentage of patients who would be classified as malnourished is around 65% at the time of diagnosis (Wigmore, Plester, Richardson, & Fearon, 1997). This is the time prehabilitation could yield the first results, so 65% will be assumed as the standard percentage of the population that is malnourished. While high visceral fat may be an indicator of complications, there is no significant relation between obesity and surgical outcome (Kim, Chin, Hwang, & Jun, 2014). Thus, only malnourished patients are taken into account as patients needing nutritional treatment. The cost of malnourishment treatment is calculated as being 4 hours of dietitian work of € 72,50 each, resulting in a total cost of € 290,00. The importance of nutritional support can be very high, as postoperative complication rates can be decreased by as much as 50,59% by adequately treating malnourished patients (Jie, et al., 2012).

Anaemia treatment

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Kourlaba, Goumenos, Konstantoulakis, & Maniadakis, 2012). Both costs should be taken into account for prehabilitation, because the treatment is dependent on the patient’s condition. If a higher dose of FCM is needed, costs may increase to € 360,69 (Froessler, Rueger, & Connoly, 2018). Several large observational studies, including over 600,000 patients, have confirmed the presence of an association between preoperative anaemia and poorer postoperative outcomes, including morbidity and mortality and prolonged length of stay (Muñoz, Gómez-Ramírez, Campos, Ruiz, & Liumbruno, 2015). With a reduction in composite morbidity from 15,67% to 5,33% between anaemic and non-anaemic patients, the importance of preoperative anaemia treatment is substantial (Musallam, et al., 2011). This is a reduction of 65,99%.

Psychological condition

Psychological condition or psyche refers to the wide range of psychological therapies proposed in an attempt to provide patients with aids to alleviate their distress (Newell, Sanson-Fisher, & Savolainen, 2002). These interventions appear to affect immunologic function and certain patient-reported outcome measures after surgery. Psychological interventions result in patients being less anxious, yielding improvements in mental health, vitality and self-perceived health after surgery. There is no clear postoperative effect, but demonstrable gains have been seen in postoperative functional capacity (Tsimopoulou, et al., 2015). Also because of the lack of an agreement on outcome measures used, there is no consistent report of postoperative effects (Powell, et al., 2016). Patients diagnosed with pancreatic cancer report a notably higher distress level (28,8%) compared with other cancer diagnoses (18,5%) (Clark, Loscalzo, Trask, Zabora, & Philip, 2010).This emphasizes the need for psychological interventions. Expert opinions in the UMCG indicated that potentially, because patients feel more at ease, psychological interventions can result in a reduced length of stay. The cost of a psychologist referral has been assumed to be € 205,00 in total.

Alcohol/smoking behaviour

Continuing alcohol and nicotine consumption after surgery shorten the life expectancy of patients by around 10 years (Lankisch, 2001). Daily smoking and harmful alcohol intake increases the

development of post-operative complications by two to four times. Frequent problems for smokers are wound and lung complications. For drinkers, problems are infections, internal bleeding,

cardiopulmonary insufficiency and ultimately death (Tønnesen, et al., 2010).

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Nielsen, Lauritzen, & Møller, 2009). The prevalence of patients in Europe in a surgical setting with high levels of alcohol consumption has been reported to range from 7% to 49% for patients

undergoing elective surgical procedures. The effect on postoperative complications is capable of causing a reduction from 54,09% to 32,78%, or a 39,39% reduction (Egholm, et al., 2018). This number should be used cautiously, however, as effects of alcohol reduction cause the body to be in a better condition, which is also measures by other factors. A study on alcohol-related risk taking behaviour yielded intervention costs per participant of € 72,52 for standard care and around € 150,00 for more intense care (Neighbors, Barnett, Rohsenow, Colby, & Monti, 2010). At this point it is difficult to assume what is needed to generate sustainable abstinence programs under pancreas surgery patients.

Smoking interventions were found to reduce length of stay and postoperative complications, while improving exercise capacity. It is unclear what the influence of smoking cessation on multimodal prehabilitation programmes is, as potential synergistic effects are yet to examined (An, Ayob, Rajaleelan, Chung, & Wong, 2019). Smoking cessation intervention should start at least four weeks before surgery, as this is the minimum period to reduce postoperative complications (Thomsen, Villebro, & Møller, 2014). Smoking cessation programmes should have a duration of 4-8 weeks (Tønnesen, et al., 2010). Patients are considered to be more positive and motivated in high quality programmes at the hospital (Boel, Pia, Goldstein, & Andersen, 2004). The incidence of smoking is about 30% in the western world. In the Netherlands, this percentage lies near 22,9%

(Volksgezondheidenzorg.info, 2019). The quit rate is very dependent upon the type of intervention, varying from 40% to 89% (Tønnesen, Nielsen, Lauritzen, & Møller, 2009). According to another study which attempted interventions with multiple levels of intensity using cell phone communication, costs vary from 80 to €177. The success rate for the standard care was just 34,99%, however. (Daly, et al., 2019). A recent study on preoperative smoking cessation calculated costs to be €165,00, of which €76,00 for counselling an €89,00 for nicotine replacement. This study also set the probability of successful smoking cessation at 64%, which is relatively high compared to other studies (Boylan, Bosco III, & Slover, 2019).

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Summarizing table

2000 - 2500 61,50% - 100% 40% High (50% and synergetic effect on anaemia, nutrition, smoking, alcohol, frailty and psyche)

4

NUTRITIONAL 290 72% - 96,6% 65% High (50,59%) 2

SMOKING 80 - 177 34,99% - 89% 22,90% Low (25,6% but partly due to other factors)

0,5

ALCOHOL 72,50 - 150 90% 7% - 49% Low (40% but partly due to other factors)

0,5

FRAILTY 245 Presumed 100% 50% Low (mostly due to other factors)

0,5

PSYCHE 205 Presumed 100% 28,8% Minimal 0

Table 2: Summary of the literature review results

The uncertainty in intervention success, cost, percentage of population affected and the relative importance is another factor adding to the already difficult process of organizing multidisciplinary integrative practice.

Cost-effectiveness analysis

To determine cost-effectiveness, all discussed variables were brought together in a scenario tree. This scenario tree resulted in patient groups with all possible combinations of risk factors, as can be seen in figure 5 below. Risk factors go along with their respective interventions, as discussed above. For future use of the analysis model, all variables are changeable so new findings may be used to more accurately determine the outcome. The main outcome of the analysis was the total cost and the return-on-investment (ROI). The average total costs per patient in a scenario without interventions is

22

23

The total hospital cost of no complications, light complications and severe complications after

pancreatoduodenectomy were calculated in a previous study conducted in the Netherlands. These costs were €17.482, €28.380 and €57.060 respectively (Santema, et al., 2015). Expert interviews with the main physicians responsible for the prehabilitation project yielded important information on the likelihood of complications for patients. These experts indicated that the best possible scenario leads to a situation with 60% likeliness for no complications, 20% for light complications and 20% for severe complications. On the contrary, the worst possible scenario leads to 20% likeliness for no complications, 40% for light complications and 40% for severe complications. This means that patient suffering from all risk factors have a 20% chance for an episode of care without complications. Patients that suffer from no risk factors have a 60% chance for an episode of care without complications.

The experts also indicated that the standard situation as it is now is characterized by 30% light complications, 30% severe complications and 40% no complications on average. This statistic was used to determine the average likelihood for complications in a situation without interventions. The average patients risk score was calculated as a weighted average, where more common scenarios have a higher relative weight than uncommon scenarios. With this weighted average, the distribution of complication risks could be distributed equally over either the risk score range from average to maximum or from average to minimum. The weighted average risk score was equal to 43,3% of the maximum risk score, resulting in a distribution as can be seen in figure 6. Figure 6 clarifies this by visualizing that risk scores between the average (orange dotted line) and maximum (100%) were distributed over a larger range than risk scores between 0% and the average.

Figure 6: Distribution of complication risk rates of patient scenarios

The total costs were calculated as the sum of the total costs of interventions and the total treatment costs. The total treatment cost was determined as the number of patients predicted to have either no, light or severe complications multiplied by the total treatment cost of each possibility.

0% 20% 40% 60% 80% 100% 0% 20% 40% 60% 80% 100% C um ul at ive per centa ge o f pa ti ents

24

To determine what dimensions were most efficient in reducing complications, the complication reduction per invested euro was calculated (table 3). The number of complications reduced was calculated using a what-if analysis, showing the total complication reduction (both light and severe) per implemented intervention. The most efficient intervention is nutritional therapy, mainly because of the high success rate, low costs and high importance. Physical condition or fitness therapy has a low score because of the high cost of the intervention. Psyche currently has a score of 0, because no clear financial benefits for psychological interventions are currently documented.

Intervention Complications reduced per invested euro (*1000)

Nutrition 0,281 Anaemia 0,268 Frail 0,132 Smoking 0,102 Alcohol 0,091 Fitness 0,054 Psyche 0,000

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Results of part 2: The case study

Findings of the interviews are structured according to the theories presented in the theoretical background (appendix 2.1). These theories are aimed at distinguishing between the relational aspect and the organizational aspect of integration. Interdisciplinary collaboration and care chain integration are separately presented. Additionally, other relevant data regarded as determinants for implementing structured prehabilitation are also presented. To clearly analyse these determinants, they are

subdivided into data about the current situation, structure of the prehabilitation centre, the prehabilitation function and the importance of high variety or complexity (appendix 2.2).

Relational coordination

Frequency of communication

Most interviewees indicated that multidisciplinary communication should be more frequent than it currently is. Indicated methods to accomplish more frequent communication are digital

communication mechanisms, increased personal relationships and only discussing high-risk patients. It is also indicated that multidisciplinary communication should not take too much time. The only relatively frequent consults at the moment are geriatric consults. Geriatricians are automatically consulted when an elderly patient comes in. In the current, unstructured, system of multidisciplinary communication, personal relationships are said to be important. These result in more accessible contacts from other disciplines, increasing frequency of communication.

Timeliness of communication

26

Problems in collaboration

Potential problems in communication have different causes. One of these is the lack of transparency in the care process, which causes too much invasive behaviour, according to the frailty intervention specialist. The anaemia intervention specialist mentioned that there are few problems, only because of the limited function they have now. Other problems are more structure-based. At the moment, no clear pathway exists to coordinate multidisciplinary care paths. Also, communication is currently too shallow and focusses primarily on surgery instead of the patients’ situation. It is believed that collaboration would results in better performance, but the already busy schedule is an important limitation. As the geriatric and nutrition disciplines mentioned, they believe they are involved in the care process too late. It is believed that the head practitioner should coordinate the prehabilitation stage and also handle the problems associated with that. All disciplines mention that their respective interventions are undervalued by other disciplines. To coordinate a balanced way of communicating, it is important to develop an open culture and form personal relationships.

Motivational aspect

All disciplines believe in the idea of a prehabilitation centre. Multidisciplinary collaboration is regarded as a necessity and prehabilitation is believed to be both beneficial for patients and cost-effective. Complications are expected to be reduced and supplying prehabilitation care to patients is considered useful work. There are some requirements for the structure of the prehabilitation centre, though. It should be transparent, to be able to clearly show what the added value is. Also, the structure itself has to be composed together with the involved disciplines, so all disciplines agree. Finally, it is believed that trust between disciplines, but also trust between practitioners and the prehabilitation staff, is key to building sustainable collaboration.

Shared goals

27

path. Resource allocation per patient should be considered carefully and it should be clear that surgery is not always the best option. In this sense, preventing unnecessary care is currently a shared goal but the way to do this is not.

Shared knowledge

Most disciplines seem to think that the importance of their respective is not yet fully understood. Currently, geriatricians have s small role because the geriatric share of the process is not clear to others. The overarching role that geriatricians want, as a coordinator of frail patients, is unknown to other disciplines. For nutritional therapy, the importance is well defined in literature and the added value and importance are known. However, the involvement in multidisciplinary care is not as high as it should be and that should improve. The importance of iron therapy is unknown to other disciplines, but it is said that awareness is growing. The head practitioner mentioned that it is important that everyone knows what disciplines do, and that they deliver their share. The effects should be measurable and each discipline should have an evident and clear purpose. Prehabilitation is said to increase the shared knowledge about importance of disciplines, because it creates predefined roles. Shared knowledge is expected to come after the initial phases of the prehabilitation centre, when benefits are shown.

Organizational integration

The organizational integration part was split up and analysed in three main categories. These are the extent of integration, external integration and information on the stages of care. External integration is focussed on collaborations outside of the hospital. Information on the stages of care is aimed at describing the intra-hospital integration, as described in the papers of Stevens (1989) and Drupsteen, van der Vaart & van Donk (2013). The extent of integration category is targeting on all other structural information on the organizational extent of integration.

Extent of integration

28

co-practitioners. The extent of intervention, in the case of nutritional therapy, depends on the patients’ understanding of nutritional value. Nutritional therapy should be intensively coordinated with physical fitness therapy, as increased protein reserves are a shared goal.

External integration

It became clear that external integration is needed to form a prehabilitation centre. External parties such as physiotherapists at home, home care, general practitioners, social workers, dietitians and other hospitals should be involved. Other hospitals are mainly first-referral hospitals, which could start treatment of nutritional therapy or prescribe some form of physiotherapy. This way, when a patient is referred to a tertiary of quaternary referral hospital, some patient optimization has already been applied. External parties should know their role and they should not decide about the customized prehabilitation path. Strict guidelines should be followed when integrating with external parties. Causes for the need for external integration are logistical difficulties, the frequency and intensity of care and the frailty of patients.

Stages of care

While iron therapy, nutritional therapy and frailty interventions are perioperative programmes, physical fitness is regarded purely as a patient optimization intervention, executed from assessment to surgery. Risk assessments should be done before multidisciplinary meetings. With all information necessary, the head practitioner can determine a care path. For high risk patients, a shared treatment plan is considered useful. Frailty interventions are aimed at all stages of care, from the earliest involvement as a geriatric assessment to rehabilitation, reconciling medication and discharge. Nutritional support should ideally be provided as early as possible. It is often initially overlooked because of the focus on the disease itself, but it is already very important in that phase. Typically, nutritional therapy is given after diagnosis, but ideally some nutritional support could already be provided in a first referral hospital or from a general practitioner. Since early nutritional support is very important, surgery should even be postponed in order to have time to implement nutritional therapy.

Determinants of implementation

Current situation

Currently, there is no institutionalized collaboration and thus no structured multidisciplinary

29

based on patients’ problems or clinical history. Thus, consultation is situational. Currently, multidisciplinary meetings are the only moment of communication. These meetings are time consuming, however, and could be more frequent and shorter to better fit in the already extremely crowded schedule. Currently, there is also no eye out for prehabilitation potential,

High variety/complexity

Causes for a complex, high variety environment are the disease itself, the patient and its lifestyle and the available time. The risk assessment is complicated by complexity and uncertainty. Another result of high variety and complexity is the inability to schedule or plan ahead very well. Complexity also results in too much information to handle in a multidisciplinary meeting as it is now. Furthermore, complexity results in more treatment possibilities, more thoughtful intervention and more often the possibility to not perform surgery. Iron therapy consultation is more extensive and contains more counselling instead of digital-only consults when patient complexity is high. While nutritional support is dependent on patient complexity, the complexity itself makes little difference for the therapy. Complex patients can be supported by probe feeding or total parental feeding in extremely complex cases. Variety is expected to be less of a hindering factor when all disciplines get more experienced with the prehabilitation centre.

Prehabilitation function

The collective function of the prehabilitation centre is to make a patient wide screening and after that optimize the patient as much as possible. Identifying low-risk and high-risk patients to determine care paths for both groups is a key part of this. Screening should be digital or done by nurses to save resources for more complex care. The prehabilitation function of the head practitioner would be to determine a treatment path based on objective assessments and prehabilitation information. Anaemia intervention is based on the result of a blood test. The treatment itself is preferably an iron infusion, while oral iron therapy is less effective. Frailty intervention is in the hands of geriatricians, who can assist in reducing unnecessary care by choosing the right treatment path. Geriatricians have an overarching and supportive function, including judgement of screenings, scheduling and coordination of customized prehabilitation. This is a function as co-practitioner throughout the whole care chain. Nutritional specialists also have an overarching function, preventing patients from entering surgery in a catabolic state.

Prehabilitation structure

30

for a patient. This preoperative risk assessment involves screening by nurses and assessment by surgeons, anaesthesiologists and internists. These assessments should be digital where possible, to avoid a burdensome process for frail patients. Assessments will be conducted on 6 or 7 points of screening. After the assessments, there should be decisions on whether or not to perform surgery and what sort of prehabilitation process would be adequate. The triage system and prehabilitation process are all dependent on the available time. Risk stratification will be used to compose patient groups needing either standardized and plannable prehabilitation or customized, hard to schedule,

prehabilitation. Communication between disciplines should mostly be digital, as are consult requests. Communication for prehabilitation status should be separate from the current multidisciplinary meetings, but they should be connected. Only the high-risk, complex patients need to be discussed. It is important that prehabilitation should not be too much of a burden on the already busy schedule. Internists should have a role in choosing the adequate care path for the patient, as they are also involved in aftercare and process wide patient care. The prehabilitation centre should remain

accessible and easy to consult. This should be done by staying a decentralized association within the hospital. It should not become too abstract, because it is expected to only work if it is staffed with trustworthy or well-known employees. This should ensure reliability.

The organizational structure of the prehabilitation centre should be carefully defined and well considered, so all disciplines are content with the final outcome. The financial structure should be carefully considered as well to avoid ineffective relationships. The financial situation of the

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Summarizing table

Interdisciplinary collaboration FREQUENCY OF

COMMUNICATION

- Should be more frequent than it currently is - Could be digital

- Relationships are important for approachable contacting TIMELINESS OF

COMMUNICATION

- Assessments should be done before meetings - This can be accomplished by digital assessments

- Structured prehabilitation should prevent too late involvement PROBLEMS IN

COLLABORATION

- Disciplines act too independent from each other - Busy schedules

- No transparency

MOTIVATIONAL ASPECT - Patient optimization is supported

- Structure of prehabilitation should be well thought out SHARED GOALS - Shared goals are expected to form after initial learning period

- Preventing unnecessary care by not performing surgery is not always a shared goal

SHARED KNOWLEDGE - Importance of disciplines is unknown to other disciplines - Effect of interventions should be measurable to convince others Organizational integration

EXTENT OF INTEGRATION - Currently very independent from each other

- Internist and head practitioner should coordinate a shared care plan EXTERNAL INTEGRATION - Necessary

- External parties should be monitored closely - Strict guidelines on the role of external parties

STAGES OF CARE - Often perioperative role

- Highly dependent on the respective discipline Determinants of implementation

CURRENT SITUATION - No institutionalized collaboration - No patient pathways

- No eye for prehabilitation potential - Ad hoc consultation

HIGH VARIETY/COMPLEXITY - Caused by disease, patient, lifestyle and time available - Results in more thorough consulting

- Results in disability to plan ahead very well PREHABILITATION FUNCTION - Screening, identifying and optimizing patients

- Determining care path - Digital information exchange PREHABILITATION

STRUCTURE

- Triage system to identify high risk patients after screenings - Risk stratification

- Not too much of a burden on the already busy schedule - Accessible and easy to consult

- Digital interdisciplinary communication - Trusted, well-known staff

- Structure should be carefully considered

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Discussion

The main aim of this research has been to address two questions on prehabilitation and

multidisciplinary integration. The first main objective was to address the potential cost-effectiveness of a structured prehabilitation centre consisting of 6 or 7 different preoperative interventions. The results of a thorough literature review and expert interviews were used to create a model, visualizing the care process. These results also clearly show that, whilst not taking into account organizational structure or coordination, the return-on-investment per patient was 1,55 or 155%. This means that investing in structured prehabilitation is a relatively certain investment, besides resulting in improved care for patients. In absolute values, €2.442 is saved on average per patient when a structured

prehabilitation centre is implemented. Separately, all interventions yield a profit, except for the psychological intervention. While structured prehabilitation has great potential, its true capability is highly dependent on the structure and organization of the prehabilitation centre. These determinants are encompassed by the second objective of this research. The influence of multidisciplinary

integration on patient optimization programs in a high variety – low volume environment is examined by means of a case study. This yielded important results, which will be interpreted to determine the optimal structure of a prehabilitation centre.

The main problem at the moment is the lack of integration. All disciplines act independently from each other and consultation from other disciplines is ad hoc. While an institutionalized prehabilitation centre would entail a high level of integration, as was found with the organizational integration model, the relational and motivational aspects are very important as well to increase collaboration. The organizational integration factors showed that most involved disciplines have a perioperative role, which exceeds the solely preoperative role assumed with the prehabilitation centre. Thus, while it is theoretically a prehabilitation centre, disciplines are involved throughout all stages of care. Integration with external parties is also believed to be necessary, increasing the extent of integration. External integration should be applied within strict guidelines and with close monitoring. In terms of the stages of integration described by Stevens (1989), a prehabilition centre requires the highest level of

integration. This means that members of the care chain fully integrate throughout the stages of care while also integrating with members outside of the hospital. Currently integration is only in stage 1, where there is no integration and members of the care chain act independently.

33

deployment of the centre. Motivation can be improved by having an accessible, decentralized and transparent prehabilitation centre that shows clear benefits.

Relational aspects of integration have proven to be very important for organizing a prehabilitation centre. It is important for the prehabilitation centre to remain accessible and staffed with well-known, trustworthy employees. A solution to this requirement could be the use of a change champion of some kind. In healthcare, there is a long-held wisdom that ‘champions’ are a key aspect in realizing

organizational change (Hendy & Barlow, 2012). Main roles of key change agents are motivating others, which is highly relevant here, and implementing innovation, which is also important here (Birkinshaw, Hamel, & Mol, 2008). While a change champion could support the prehabilitation centre itself, the interdisciplinary collaboration should also be improved. Shared knowledge of the

importance of other disciplines is expected to increase after the initial phases. This will increase relationships by resulting in more frequent consults and better personal relations.

Four integrative mechanisms were identified by Drupsteen et al (2013), in a low variety high volume environment: sharing waiting list information, sharing planning information, cross-departmental planning and creating combined appointments. All of these integrative mechanisms are also needed in a high variety – low volume environment, in order to reduce the pressure on the already busy schedule while still being able to coordinate well. What is mainly found to be important in a high variety- low volume environment is personal relationships and trust. As discussed above, relational aspects and personal contact are key determinants of a successful collaboration.

34

Limitations and further research

To determine cost-effectiveness, a wide range of previous literature and study results were used. This results in relative uncertainty because previous study results have significantly different outcomes. Because it is difficult to estimate precise statistics about future interventions, results from the prehabilitation centre would provide important new insights in existing literature. Another important aspect yet missing in existing literature is research on the financial results of psychological

interventions. This data is yet missing, but is currently assumed to have some cost-effective potential. Thus, future research should target accurate measurement of results of psychological interventions in the field of HPB surgeries.

Another limitation is the stage of the prehabilitation project during which the research was conducted. Because of this, responsible physicians for the smoking cessation, alcohol cessation and psychological therapy interventions were not yet appointed and thus could not be interviewed. Conducting the research in a later stage could yield more accurate results. A final limitation is the busy schedule of the physicians responsible for the different disciplines. This resulted in difficulty during data collection and also reduced available time for interviews.

Theoretical implications

35

References

An, D., Ayob, F., Rajaleelan, W., Chung, F., & Wong, J. (2019). Preoperative smoking cessation as part of surgical prehabilitation. Canadian Journal of Anesthesia, 476-479.

Anderson, A. D., McNaught, C. E., MacFie, J., Tring, I., Barker, P., & Mitchell, C. J. (2003).

Randomized clinical trial of multimodal optimization and standard perioperative surgical care.

British Journal of Surgery, 1497-1504.

Barakat, H. M., Shahin, Y., Khan, J. A., McCollum, P. T., & Chetter, I. C. (2016). Preoperative Supervised Exercise Improves Outcomes After Elective Abdominal Aortic Aneurysm Repair: A Randomized Controlled Trial. Annals of Surgery, 47-53.

Barberan-Garcia, A., Ubré, M., Roca, J., Lacy, A. M., Burgos, F., Risco, R., . . . Martínez-Palli, G. (2018). Personalised Prehabilitation in High-risk Patients Undergoing Elective Major Abdominal Surgery: A Randomized Blinded Controlled Trial. Annals of Surgery, 50-56. Barki, H., & Pinsonneault, A. (2005). A model of organizational integration, implementation effort,

and performance. Organization Science, 165-179.

Bauer, M., Fitzgerald, L., Haesler, E., & Manfrin, M. (2009). Hospital discharge planning for frail older people and their family. Are we delivering best practice? A review of the evidence.

Journal of Clinical Nursing, 2539-2546.

Berenson, R. A., Paulus, R. A., & Kalman, N. S. (2012). Medicare's readmissions-reduction program - A positive alternative. New England Journal of Medicine, 1364-1366.

Biddle, S. (2016). Physical activity and mental health: evidence is growing. World Psychiatry, 176-177.

Birkinshaw, J., Hamel, G., & Mol, M. J. (2008). Management innovation. Academy of Management

Review, 825-845.

Boel, T., Pia, K. N., Goldstein, H., & Andersen, T. (2004). Smoking, alcohol overconsumption and obesity before elective surgery. Prevalence and patient motivation for risk reduction. Ugeskrift

for laeger, 3297-3300.

36

Boylan, M. R., Bosco III, J. A., & Slover, J. D. (2019). Cost-Effectiveness of Preoperative Smoking Cessation Interventions in Total Joint Arthroplasty. Health Policy & Economics, 215-220.

Braunscheidel, M. J., Suresh, N. C., & Boisnier, A. D. (2010). Investigating the impact of

organizational culture on supply chain integration. Human Resource Management, 883-911. Bronstein, L. R. (2003). A model for interdisciplinary collaboration. Social Work, 297-306.

Calleja, J. L., Selgado, S., del Val, A., Hervás, A., Larraona, J. L., Terán, Á., . . . Mearin, F. (2016). Ferric carboxymaltose reduces transfusions and hospital stay in patients with colon cancer and anemia. Inernational Journal of Colorectal Disease, 543-551.

Calvet, X., Ruiz, M. Á., Dosal, A., Moreno, L., López, M., Figuerola, A., . . . Gené, E. (2012). Cost-Minimization Analysis Favours Intravenous Ferric Carboxymaltose over Ferric Sucrose for the Ambulatory Treatment of Severe Iron Deficiency. Public Library of Science one, 1-5. Cappell, M. S. (2008). Acute pancreatitis: Etiology, clinical presentation, diagnosis, and therapy. The

Medical Clinics of North America, 889-923.

Carli, F., & Ferreira, V. (2018). Prehabilitation: a new area of integration between geriatricians, anesthesiologists, and exercise therapists. Aging Clinical and Experimental Research, 241-244.

Carli, F., & Scheede-Bergdahl, C. (2015). Prehabilitation to enhance perioperative care.

Anesthesiology Clinics, 17-33.

Carli, F., & Zavorsky, G. S. (2005). Optimizing functional exercise capacity in the elderly surgical population. Current Opinion in Clinical Nutrition and Metabolic Care, 23-32.

Carli, F., Brown, R., & Kennnepohl, S. (2012). Prehabilitation to enhance postoperative recovery for octogenerian following robotic-assisted hysterectomy with endometrial cancer. Canadian

Journal of Anaesthesia, 779-784.

Carli, F., Charlebois, P., Stein, B., Feldman, L., Zavorsky, G., Kim, D. J., . . . Mayo, N. E. (2010). Randomized clinical trial of prehabilitation in colorectal surgery. The British Journal of

Surgery, 1187-1197.