4 Person-environment-occupation models
As with most occupational therapy models, the models reviewed in this chapter centre on the influence of person, environment and occupation on people’s abilities to act in the everyday world. However, these models emphasize the importance of the environment to a greater extent than the models reviewed in the previous chapter (with the proviso that the Occupational Performance Model (Australia) (OPMA) could have been placed in this chapter). Baum and Christiansen (2005) identified these types of models as person, environment, occupation or PEO models and Brown (2009) described them as ecological models. They have also been described as transactional models as they emphasize the mutually influencing transaction that occurs between person and environment when engaged in occupation. The three models reviewed in this chapter are the Person-Environment-Occupation-Performance (PEOP) model by Christiansen and Baum, the Person-Environment-Occupation (PEO) model by Law and others, and the Ecology of Human Performance (EHP) by Dunn and others.
Person-Environment-Occupation- Performance (Peop) Model
We have placed this model first in the chapter as it appears to provide a bridge between the Occupational Performance (OP) model and ecological models. It acts as a bridge in sharing a trend with OP to analyze in detail the capacities of the individual. However, whereas OP provides comparatively little attention to the environment, the PEOP model provides a similar level of detail for analyzing the environment as it does for the person. The PEOP model was listed as an ecological model by Brown (2009). However, as discussed later in this chapter, this model differs from the other two models presented in this chapter through its conceptualization of the relationship between person, environment and occupation. In discussing this relationship, the other two models emphasize that person, environment and occupation should not be considered separately. The PEO emphasizes a transactive relationship between the three (rather than interactive) and EHP presents context as something through which person and occupation should be seen. Although similar to some of the other occupational therapy models, PEOP conceptualizes person and environment as joined by occupation (and performance and participation). That is, occupation is the medium through which person and occupation connect. In comparison with PEO, this model is interactive rather than transactive.
The PEOP model is described as “a client-centred model organized to improve the everyday performance of necessary and valued occupations of individuals, organizations, and populations and their meaningful participation in the world around them” (Baum & Christiansen, 2005, p. 244). This definition demonstrates the importance of two concepts: occupational performance and participation in daily life. While many occupational therapy models explicitly focus on the enhancement of occupational performance as their main goal, this model explicitly identifies enhancing participation as a second primary goal. This model makes explicit that the goal of occupational performance is to enable participation in the social, cultural, financial and political world in which people and organizations exist. Therefore, a major contribution of the model is its acknowledgement that occupational performance might not be an end in itself but might gain meaning through its role in facilitating participation.
The focus of the model is the complex interaction between a person and his or her environment, which influences occupational performance and participation. This interaction forms the basis for occupation, in that intrinsic and extrinsic factors, respectively, form the foundation for what people do. Intrinsic factors (neurobehavioural, physiological, cognitive, psychological and emotional, and spiritual factors) and extrinsic factors (built, natural and cultural environments; societal factors; social interactions and social and economic systems) can “support, enable or restrict” (Baum & Christiansen, 2005, p. 244) performance by individuals, organizations and communities.
As suggested by its title, the four components of the model are person, environment, occupation and performance. Figure 4.1 shows the most recent diagram available at the time of publication. One useful way to think about this model is to interpret the four components (and diagram) as if lying in three dimensions. Upon a foundation of person and environment (first layer) lies occupation and performance (second layer) and on top of these are occupational performance and participation (third layer). First, person and environment, which interact in a mutually influencing way, form the foundation for what people do. The concept of ‘person’ includes the various capacities (neurobehavioural, psychological, etc.) that a person might have, which can influence what a person can and is inclined to do. These are referred to as intrinsic factors. The environment also has features that can affect performance (extrinsic factors). The extrinsic factors include physical, cultural and societal aspects of the context that surrounds them.
Christiansen CH, Baum CM, Bass-Haugen J. Occupational Therapy: Performance, Participation and Well-Being, Third Edition, Thorofare, NJ: SLACK Incorporated; 2005. Reprinted with permission from SLACK Incorporated.
The second layer in the PEOP model comprises the components of occupational performance, that is, occupation and performance. The model makes clear distinctions between the concepts of occupation, performance and occupational performance, the last located in the third layer. Occupations were defined by Christiansen and Baum (2005) as “human pursuits that (a) are goal-directed or purposeful, (b) are performed in situations or contexts that influence how and with whom they are done, (c) can be identified by the doer and others, and (d) have individual meaning for the doer as well as shared meaning with others” (p. 5). They proposed that occupations can be classified according to what is done and how, why, where and when it is done. However, it is important to note here that occupation is not the same as performance. Where occupations and actions are done, performance refers to the actual doing of them. As Baum and Christiansen (2005) stated, “To be able to do requires that an action or a task be performed. Performance can come from either capacity intrinsic to the individual or by support provided by the environment or a combination of both.” (p. 246.)
The top layer of the model, and the culmination of the previous layers, comprises occupational performance and participation. In the diagram provided, occupational performance and participation result where occupation and performance overlap. As Baum and Christiansen (2005) stated, “when occupation and performance are joined in the term occupational performance, it describes the actions that are meaningful to the individual as he or she cares for him- or herself, cares for others, works, plays, and participates fully in home and community life” (p. 246). In making the distinction between occupation, performance and occupational performance, they emphasized the meaning and purpose of occupational performance in the context of people’s roles. Therefore, their statement that occupational performance is “the central construct of participation” (p. 246) places occupational performance within the context of meaningful and purposeful participation in an individual’s broader societal context.
Baum and Christiansen’s hierarchy of occupation-related behaviours and supportive abilities (2005; Christiansen & Baum, 1997a) is central to understanding the distinction between occupation and performance and occupational performance. This hierarchy places roles, occupations, tasks, actions and abilities in order from highest to lowest in complexity. As “occupations have a purpose” (Baum & Christiansen, 2005, p. 252), the top three levels on the hierarchy – roles, occupations and tasks – would be conceptualized in the occupation part of the model because they are linked to purpose. The next level in the hierarchy – actions – would be attended to in the performance part of the model, because they do not have a separate purpose. The lowest level of the hierarchy – abilities – would be considered in the person part of the model, as they lie within the person (as intrinsic factors). All of these occupation-related behaviours occur within a specific context or environment, which can support, enable or restrict the performance of occupations and tasks and, hence, affect participation in everyday life.
The model provides details of both person and environment, located in the first layer. A major technique in occupational therapy practice is the analysis of both person and environment for the purpose of facilitating occupational performance and participation. Therefore, this model provides substantial detail to guide occupational therapists in undertaking such analysis. The factors that contribute to a person’s capacities are called intrinsic factors and those factors that relate to the context of occupational performance and participation are called extrinsic factors.
The external factors listed are social support, social and economic systems, culture and values, the built environment and technology, and the natural environment. The various external factors influence occupational performance and participation by placing demands or providing affordances.
The internal and external environments are not inherently facilitatory or inhibitory. Occupational performance and participation are dependent upon the interaction between the internal and external factors in relation to the demands of the occupation being performed. This model provides substantial detail about both internal and external factors to support occupational therapists to analyze the interests, skills and capacities of the person, the demands of the environment and how they interact to facilitate or inhibit occupational performance and participation.
The PEOP is presented within the context of a larger text (as with CMOP-E, presented in the next chapter). The text, called Occupational Therapy: Performance, Participation and Well-being (Christiansen et al., 2005) relates to occupational therapy more generally and takes the reader through the fundamental assumptions of the profession relating to occupation before presenting the model. Thus, the PEOP forms one part of Christiansen’s and Baum’s broader conceptualization of occupation and occupational therapy.
This model commenced its development in 1985 (Baum & Christiansen, 2005). In 2005 the model was called Person-Environment-Occupation-Performance (PEOP) and it has undergone substantial changes and development in the three editions that were available at the time of publication. In each edition, it was called something different. The 1991 version was called a “Person-Environment-Performance” framework (Christiansen, 1991, p. 18) and was not referred to as a model. In 1997, it was called the “Person-Environment Occupational Performance Model” (Christiansen & Baum, 1997a). In 2005, it was called the “Person-Environment-Occupation-Performance Model” and provided with the acronym PEOP. The concepts of person, environment and performance appear to have remained the fundamental components of the model but the emphasis on occupation in the title as a separate concept has only recently emerged.
The distinction between occupation, performance and occupational performance is evident in all three editions of the model. The distinction between these concepts can be traced back to the model’s use of Nelson’s 1988 work, in which he distinguished between occupational form and performance. Christiansen (1991) stated, “all the elements comprising the context of the occupation are what Nelson (1988) terms the form of occupation. Occupational performance consists of the doing of occupation.” (p. 27, italics in original.) In an adaptation of Nelson’s work, Christiansen conceptualized occupational form as “the objective context of occupation consisting of: materials, environmental surround, other humans involved, temporal dimension, and sociocultural reality derived from social or cultural consensus” (p. 26).
In the first version, a binary distinction appears to have been made between the doing (performance) and a second concept (Christiansen’s adaptation of occupational form) that includes what is done, the context in which it is done and the meaning of the doing to an individual. In this way, the first edition appears to have distinguished between performance and a broad conceptualization of occupational form, with the latter being ascribed meaning by an individual and occurring within a particular content.
In the second edition, a trio of concepts was presented. These were person, environment and occupational performance. This version emphasized that the performance of occupation is affected by a complex array of factors that influence performance, “as well as the many dimensions of occupation” (Christiansen & Baum, 1997a, p. 49). Christiansen and Baum stated, “Occupational performance consists of the ‘doing’ of occupation; whereas occupational form concerns the context of the doing” (1997b, p. 6). In the second edition, the concept of occupational form has been explicitly presented as involving the interaction between person and environment. This is consistent with Christiansen’s earlier interpretation of Nelson’s concept of occupational form to include the meaning that the occupation has for an individual. In the second edition, the concept of occupation is like the invisible focus of the model. Using the metaphor of the window presented in the Introduction, occupation is like the window through which one might look without making the window itself explicit in the description of what one sees. Consequently, the concept of occupation was not specifically included in the diagrammatic representations of the model but was integral to it, in that it was present in all three parts of the model – person, environment and occupational performance.
In the first and second editions, the concept of occupational form appears to have been separated into person and environment (conceptualized as mutually influencing) and contrasted with performance. By the third edition of the model, the separation of concepts is most obvious. In that version, the capacities of an individual and the context in which something is done (sociocultural and physical environment) are presented as separate but mutually influencing. They provide the background to the occupation and its performance, which combine to result in occupational performance and participation.
In the second edition, the model emphasized the importance of occupational performance to self-identity and a sense of fulfilment. (However, this emphasis might have become lost in the most recent edition or at least become subsumed under the concept of participation.) In the second edition, Christiansen and Baum (1997a) stated, “over time, these meaningful experiences permit people to develop an understanding of who they are and what their place is in the world” (p. 48).
This focus on self-identity, combined with the detailed explication of personal factors such as motivation, values and meaning, emphasizes the biopsychosocial nature of occupational therapy practice, as conveyed in this edition of the model. This focus is consistent with the link that is made between occupational performance (highlighted as function rather than impairment) and well-being (rather than just health), which are also consistent with a biopsychosocial approach to health. The second edition also provided a table showing the relationship between the “intrinsic performance enablers” that the model conceptualized as factors intrinsic to the person and the well-accepted occupational therapy concept of “performance components”. These intrinsic factors remained present in the third edition of the model and distinguish it from other PEO models such as the model published by Law et al., described later in this chapter.
In all three versions of the PEOP model (with various different names), the model is linked to both a hierarchy of occupational performance and the WHO classification of the time. In the 1991 version, this hierarchy is presented (from lowest to highest) as activities, tasks and roles. In the second and third editions (1997 & 2005), the hierarchy presents abilities, actions, tasks, occupations and roles. The first and second editions of the model are linked to the International Classification of Impairments, Disabilities and Handicaps (ICIDH) and the third edition to the International Classification of Functioning, Disability and Health (ICF).
The PEOP is the third edition of the model of practice created by Charles Christiansen and Carolyn Baum. The model conceptualizes the focus of occupational therapy as occupational performance and participation. It provides guidance for practice by breaking down these concepts into the components of occupation and performance and by identifying the factors internal to the person and within the environment that influence occupational performance and participation. All four components of the model are seen as separate but interacting. The PEOP model has similarities with the OP model through the way it breaks down factors internal to the person. However, its focus on the environment and the external factors that influence occupational performance and participation are more extensive than in the OP model. Therefore, it has been described as a person, environment, occupation model.