This study synthesised the theoretical assumptions of the RMIC and the Triple Aim into one overarching framework to specify the concept of VBIC. The framework distinguishes the following integrated care domains: 1) type of integration and 2) enablers of integration and the interrelated outcome domains, 3) experience of care, 4) population health and 5) costs. The different domains provide a crucial differentiation for clarifying and interpreting the mechanisms and the three dimensional value perspectives (patient, social and economic) of integrated care. Based on the framework, a rapid review was conducted to identify the integrated care strategies and outcomes used in renal care. The results showed that integrated renal care interventions particularly focused on ‘micro’ operational integration processes and technical (functional) enablers. Evidence regarding the outcomes of integrated renal care is rather weak and dominantly focused on the physiological dimensions of health. In addition, there is a general lack of measures and outcomes to identify the patient perceived and economic benefits of integrated renal care.
Contribution of research findings
The revised RMIC presented in this article provides a theory on how integrated care plays complementary roles at the micro level of clinical integration, the meso level of professional and organisational integration, and the macro level of system integration to improve outcomes in terms of patients’ experience of care, population health and costs per capita. Whereas previous models on integrated care tend to focus solely on isolated macro, meso or micro levels of integration [
30‐
32], the revised RMIC highlights the fact that the different levels and perspectives are, in fact, interrelated. In addition, this theoretical analysis also led to the recognition that the value of integrated care can be defined from a patient, social and economic perspective. This multidimensional value perspective contrasts sharply with the traditional mechanistic views of integrated care and value-based care, which promote that standardising the delivery of care leads to better outcomes [
33‐
36]. Existing models tend to overlook the inherent multifaceted social, political and economic factors that influence people’s health and well-being as well as the dynamic complexity of developing integrated care. In addition, industrial quality improvements founded on strategies of cost leadership and differentiation are unachievable when caring for people with complex and multiple problems and illnesses. This kind of logical approach can actually lead to fragmentation. Since the revised RMIC reconfigures the VBIC perspective through the identification of the gaps in care among a targeted, at risk population, integrated services can be better tailored to the end-users’ needs beyond the current unidimensional corporate efficiency approach [
37,
38].
The findings of the literature review indicated that, in the field of integrated renal care, there is a prime focus on clinical ‘micro’ integration processes, while the ‘meso’ organisational and ‘macro’ system were generally not considered. These findings are not surprising, given the prime focus of practice, science and policies on the clinical and professional domain of integrated care [
6,
14,
15,
39]. However, previous research has highlighted the need to develop a multilayer commitment (e.g. professionals, managers and policymakers) when leading effective integrated care efforts [
6,
16,
20,
21,
33,
39‐
41]. In line with the RMIC, this implies that more emphasis needs to be placed on theorizing, studying and modelling interaction patterns within and between the clinical, professional, organisational and system levels of integrated renal care. Research also has suggested that the barriers to effective integrated care strategies are political rather than technical [
13]. This means that ‘soft’ normative (e.g. cultural values) mechanisms are critical enablers for encouraging widespread implementation of integrated care. Previous research has indicated that normative integration mechanisms indeed influence the effective development of integrated care across various political, organisational, professional and clinical fields [
42,
43]. However, most studies within the field of integrated renal care tend to focus on ‘hard’ functional aspects (e.g. IT) and have barely taken into account the normative enabling mechanisms. This finding emphasises the need to monitor the normative enabling mechanisms between different professional and organisational groups when developing integrated renal care services. In addition, the present study shows that less emphasis has been placed on ‘macro’ system integration processes. In contrast, research has suggested that political influences are essential preconditions for developing effective integrated health systems [
13,
33,
44]. This implies that integrative, rather than disease-specific, policies are needed in order to address the bio-psycho-socio-spiritual and somatic needs of people with CKD. We think further debate about how to develop such integrative policies would be extremely useful.
The integrated renal care evidence synthesis also showed that most of the outcomes reported focused on the physiological dimensions of health. We found this result not surprising given the prime focus of the included literature on the clinical micro processes and related bodily functions. However, there may be a need to revisit our understanding about the definition and operationalisation of the population health domain. Drawing from the new definition of health [
45,
46], health is operationalised as a dynamic concept consisting of six dimensions: 1) bodily functions, 2) mental functions and perception, 3) spiritual/existential dimension, 4) quality of life, 5) social and societal participation, and 6) daily functioning. This reconfiguration refers to the ability of people to contribute to their own health through lifestyle, behaviour and self-care, and by optimally adapting professional advice regarding their life circumstances. In this regard, the population health domain of the Triple Aim framework has a dominant focus on the physical and quality of life dimensions of health. This definition of health requires a further reconfiguration of the concept of population health that encompasses life as a whole with more of an emphasis on aspects such as meaningfulness and social participation.
Against this background, including the patient perspective is as important as any organising principle that aims to restructure services around the needs and values of people [
6,
47‐
50]. Notably, only a limited number of integrated renal care studies have attempted to describe or evaluate the experience of care from patients’ perspectives. This lack indicates the need to develop assessment tools and methods to evaluate individual preferences and experiences of care in the field of integrated renal care. Finally, the literature synthesis showed a paucity of research on the economic outcomes of integrated renal care. Consistent with prior findings in the field of integrated care [
51,
52], utilization and cost were the most common economic outcomes assessed, although the evidence on cost-effectiveness remains weak. Demonstrating the relationship between economic and health outcomes is generally considered a challenge, because integrated care typically involves multiple changes at multiple levels [
33,
51,
52].
Strengths and weaknesses of this study
It is important to consider the unique strengths and limits of a rapid review. The strength of the present review is that it was theoretically grounded on the RMIC. The revised RMIC has a solid base in the academic literature and expert opinion regarding the concept of VBIC [
14,
15,
21]. The present review shows that a theory driven rapid review approach is sufficient to gather and synthesise a broad range of heterogeneous interventions in the literature. The rapid review also identified several potential gaps in the integrated renal care literature consistent with reviews in the general field of integrated care [
6,
14,
33,
51,
52].
Due to time constraints, we may have missed some studies from the Scopus database. Moreover, the search was also not complemented by gray literature searches on the Internet. Nevertheless, we did hand search the reference list of the included studies. Another limitation of the rapid evidence approach in this study was that there was only one reviewer involved in the decision making process of including and excluding articles as well as extracting data from the included articles. Although this reviewer was knowledgeable about the content of integrated care and has experience conducting reviews, this limited the scope of the review. We acknowledge that a non-comprehensive evidence synthesis is more prone to bias than a comprehensive synthesis [
53]. However, the essential results of the review did not seem to differ extensively from the general field of integrated care [
6,
14,
33,
51,
52]. Therefore, we believe that our theory driven rapid review was a reasonable approach towards prioritising a research and development agenda for VBIC renal services.
Implications for practice and future research
Policymakers, managers, professionals and patients organisations can use the revised RMIC as a guide for developing VBIC in practice. Essential for all key stakeholders is the recognition that the local context matters the most when developing VBIC [
13,
54‐
57]. In other words, the development of VBIC should start with a careful analysis of the needs and system requirements, which can then be used to explore which integration strategy is best suited for whom.
Investment in pioneering research methodologies is necessary in order to reveal the complex interrelationships between the system, organisational, professional and clinical levels of integrated care. The subsequent inference is that research should extend beyond the golden standard of random clinical trials [
58] by using evaluation designs that focus on managing complexity by providing ways of monitoring and influencing system state, performance and stakeholders’ behaviour [
34,
59,
60]. The main reason for this is that we cannot control all the complexity within a Randomised Control Trial (RCT) design, as blinding and randomisation are impossible within this field. As an alternative to traditional rigid evaluation methods, rapid cycle-evaluations hold much promise for simultaneously evaluating and developing integrated care efforts in an increasingly fast-paced environment [
61‐
63]. Rapid-cycle evaluations can provide timely and actionable evidence as well as reveal possible adaptations to contingencies and, subsequently, help to customize VBIC strategies to local circumstances making them more effective. Future studies should, therefore, operationalise the proposed RMIC toward an analytical and implementation model for VBIC. Such an operationalisation is essential for guiding program implementation, policy formulation and research analysis in the field of VBIC. We plan further work to develop such a model for VBIC renal services, and invite anyone interested in helping to develop and validate the model to contact the authors.