The Normalization Process Model proposes that evaluating the implementation of complex interventions requires attention to more the measurement of outcomes and effectiveness, but also to the social relations and processes related to the work that leads to those outcomes. In particular, it guides attention to the processes by which complex interventions are made workable and integrated in everyday practice. Above, we defined the requirements of a theory. In the following section, we will describe the components of the Normalization Process Model, and show how it meets those requirements.
Description: what are the phenomena to be explained?
The model focuses on phenomena that are the products of co-operative and collective activities, but which are experienced and accounted for by individuals. Theories of individual preferences (in economics [14]), intentions (in psychology [15]), and interests (in sociology [16]) help us to understand how participants in these collective activities frame behaviour. Because such theories focus on individual and not group processes, they are inevitably much less successful in accounting for organizational processes characterized by complexity and emergence, where multiple confounders act upon behaviour. The Normalization Process Model is concerned with explaining those factors that promote or inhibit the implementation of complex interventions by reference to collective social action, and draws extensively on sociological research on group processes in structured organizational contexts. It thus includes those multiple confounders in its frame of reference. The unit of analysis of the model is therefore group processes leading to collective action.
In this context, a complex intervention is defined as a deliberately initiated attempt to introduce new, or modify existing, patterns of collective action in health care. Deliberate initiation means that an intervention is: institutionally sanctioned; formally or informally defined; consciously planned; and intended to lead to a changed outcome. Initiators of a complex intervention may seek to change the ways that people think, act and organize themselves in health care, or they may seek to initiate a process with the intention of creating a new outcome. There are three core components of such interventions:
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(i)
Actors are the individuals and groups that encounter each other in health care settings. Examples are health professionals, hospital managers and patients. Complex interventions aimed at individuals and groups may take the form of attempts to change the ways that people behave, for example, in trials of strategies for making 'expert patients' [17]; or they may take the form of a new ways of defining, classifying, and speaking about a problem, for example, in therapeutic attempts to recast the experience of chronic pain [18]. The aims of such interventions are often to change people's behaviour and its intended outcomes.
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(ii)
Objects are the institutionally sanctioned means by which knowledge and practice are enacted. Examples are established drug therapies, trial protocols, clinical guidelines and electronic medical records. Complex interventions relating to objects include trials of novel therapeutic agents and medical devices [19], and of decision-making tools and clinical guidelines [20]. The aims of such interventions often include changing people's expertise and actions.
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(iii)
Contexts are the physical, organisational, institutional, and legislative structures that enable and constrain, and resource and realize, people and procedures. Complex interventions relating to context include trials of new professional roles, mechanisms that mediate between health care organisations and professional groups, and organisational structures. The aims of such interventions are often to change the ways that people enact procedures to achieve goals in health care (or other) settings.
In relation to these components we must distinguish between normalization as an accomplishment, and normalization as a possible outcome of that accomplishment. A normalization process consists of the collective action – the work – involved in enacting a complex intervention. When that work leads to the routine embedding of an intervention in everyday practice, it may be said to have become normalized. Normalization does not, however, imply an evaluation of effectiveness or quality.
Normalization is only one possible outcome of collective action. Others include: adoption, where a complex intervention is taken up but does not become routinely embedded in everyday work; and rejection, where users disregard, subvert, or otherwise refuse a complex intervention. Thus normalization is not automatically the outcome of the initiation of a new or changed set of practices. De-normalization may also occur during the lifetime of a complex intervention when a previously normalized intervention is superseded, disturbed, disrupted, or atrophied. Thus normalization is neither an automatic outcome nor a permanent state.
Explanation: how does normalization come about?
The model is constrained by its focus on work as collective action, over time, in health care settings. It is based on three assumptions. First, the model assumes implementation. This is defined as a pattern of organized, dynamic, and contingent interactions in which individuals and groups work with a complex intervention, within a specific context or health system, over time. Second, the model assumes a set of factors empirically demonstrated to affect the outcome of the process. These four factors – defined below as constructs of the model – each have two dimensions: (a) Co-operative attributes that are oriented towards enacting the intervention through negotiations and agreements between people and the organizations and policymakers providing the context within which they work; and (b) Executive attributes that are oriented to attempts to project enacting the intervention outwards in time and space. The constructs and their dimensions are:
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1.
Interactional Workability – how does a complex intervention affect interactions between people and practices?
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a.
is concerned with interaction itself: what can legitimately be dealt with in an interaction (e.g. a consultation), what the form of the work is, what the role of each participant is, how the work is to be completed in the time and space available, and the formal and informal rules that govern the verbal and non-verbal conduct of an interaction.
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b.
of work is concerned with the effects of interactions. It considers the goals of an interaction (e.g. following a guideline, recording or processing data), how disagreement about the outcome of the work is minimised, when and where the goals and outcomes should occur, and shared beliefs about the meaning and consequences of the work. It can also relate to the interaction between the human and non-human actors (e.g. using a computer programme). For all these interactions whether the intervention promotes the ease/efficiency of the interaction is a key feature.
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2.
Relational Integration – how does a complex intervention relate to existing knowledge and relationships?
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a.
Accountability is concerned with the knowledge and practices of those enacting the complex intervention, what is the knowledge required by the work, who has this knowledge, are there disagreements about where (and with whom) the necessary knowledge lies, what contributions are required of participants, and what are the formal and informal rules that govern the distribution of knowledge and practice within relational networks.
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b.
Confidence refers to beliefs about the knowledge and practice required by a complex intervention. It considers agreement about the sources of authoritative knowledge and practice, the criteria by which their credibility can be assessed, and beliefs about the practical utility and reliability of the knowledge and practice mediated by the various networks in the health system. So for example, the perceived safety of the intervention is important.
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3.
Skill-set Workability – how is the current division of labour affected by a complex intervention?
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a.
Allocation is concerned with which tasks are performed by whom and how these decisions are made (e.g. whether a healthcare innovation is more appropriately used by a doctor or a nurse), the distribution of resources and rewards linked to status and authority, formal or informal agreements about the identification and appraisal of the necessary skills, and the definition and ownership of these skill-sets.
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b.
Performance considers the ability of an organisation and the people within it to effectively organise and deploy a complex intervention as part of their activities (e.g. do surgeons need extensive training to use a new piece of equipment?). It covers staff training needs, formal and informal policies that define the boundaries of competence of particular workers, the degree of autonomy these assigned to them, and how they deliver services.
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4.
Contextual Integration – how does a complex intervention relate to the organisation in which it is set?
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a.
Execution is concerned with the practicalities of integration (e.g. does the intervention require new money, a local or national policy sponsor), decisions about the distribution of resources, costs and risks within the organisation, managerial decision-making regarding the adoption of the intervention, and formal and informal mechanisms for its evaluation.
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b.
Realisation considers the allocation and ownership of responsibility for the implementation of a complex intervention (e.g. does the complex intervention require responsibility for a procedure to move from one professional group to another?), the negotiations necessary to modify existing systems and practices to make new ones possible, minimising the disruption and risk associated with change, and how new resources are obtained and used in practice.
Finally, it is assumed that variations in the outcome of an implementation process can be correlated to variations in the factors that affect its course. It is thus possible to determine the degree to which a complex intervention is ultimately normalized or not normalized, and to determine the probable degree to which specific factors affect outcomes.
Knowledge claims and empirical investigations
Determining the effect of the factors identified by the model may be undertaken by means of objective measures, or subjective investigations. Four propositions derived from the model were presented an elaborated in earlier papers [7, 8]. These propositions can be used as the basis of instruments to assess the effect of those factors that promote or processes and as the basis of hypotheses about the normalization potential of a complex intervention.
The practical utility of the model lies in the ability to make testable claims about the factors that promote or inhibit a complex intervention's potential for workability and integration in practice. The model is open to knowledge claims founded on empirical investigation. These may take its core constructs and test them retrospectively to make claims about processes with already known outcomes, or prospectively test them against processes where the outcome is yet to be determined. Here, even though variations in outcome may be correlated with observed variations in the factors defined by the model's constructs, the mechanisms by which those factors affect normalization outcomes must be described if the model is to be useful. These mechanisms are defined by reference to the dimensions that obtain to each of the core constructs of the model outlined above
The practical utility of the model depends on its adequate explanation of a set of complex, and contingent, social relations and processes at work in health care settings. Because this is a sociological approach that attends to the construction and embedding of practices by focusing on what the work is, how it is known, allocated and resourced – the starting point for empirical investigation is collective action. Such investigations will therefore involve modelling and mapping the relations between people, objects and contexts; understanding their conditions of action (defined as processes); and observing or measuring the effects of the factors that govern these (defined above as constructs and dimensions of the model).
The goal of many implementation theories is the prediction of outcomes [21], and this is a significant methodological and theoretical challenge [9, 22]. The Normalization Process Model generates hypotheses about the factors that affect the course of normalization processes. In real-world settings, predictions about outcomes are subject to multiple confounders that include complexity and emergence that lead to local variations in implementation processes. These confounders may include events or processes far beyond the purview of participants in the implementation of a complex intervention. Importantly, they include many external factors that are not amenable to control or modification. This means that predicting the course and outcome of complex social processes is problematic [13]. The Normalization Process Model is not excepted from this rule. However, although absolute prediction is outside of the field of application for the model, the probability of a practice to normalize can be calculated within limits. This means that claims about the future of a complex intervention must take the form of assessments of the potential of a practice to normalize in a specific setting, and of the readiness of actors to accept it.