Chapter 2

A rehabilitation framework: the International Classification of Functioning, Disability and Health

William J. Taylor1 and Szilvia Geyh2,3

1 Associate Professor in Rehabilitation Medicine, Rehabilitation Teaching and Research Unit, University of Otago Wellington and Consultant Rheumatologist and Rehabilitation Physician, Hutt Valley District Health Board, Wellington, New Zealand; 2 Affiliated Teaching Fellow, Department of Health Sciences and Health Policy of the University of Lucerne, Switzerland; 3 Group Leader at Swiss Paraplegic Research, Nottwil, Switzerland

2.1 There is a need for a common language of functioning

It is hard to overestimate the importance of good communication between ­rehabilitation health professionals from different disciplines involved in the care of the same client. The different ‘life worlds’ of people from diverse backgrounds can lead to talking past each other, miscommunication or misunderstanding. Imagine the following conversation at a weekly inpatient rehabilitation team meeting.

DOCTOR:

  When is Mr Brown likely to be ready to be discharged? He is walking well now and does not seem especially disabled.

PHYSIOTHERAPIST:

  Yes but he is still getting stronger and will be able to walk better if he receives more therapy. His ankle dorsiflexors are still not functioning very well at all.

NURSE:

  He is totally independent with self-cares.

DOCTOR:

  Well then we could plan to discharge tomorrow then.

OCCUPATIONAL

THERAPIST:

  He manages fine in the ward but he has stairs at home and I don’t know how well he will cope with that environment.

SOCIAL WORKER:

  He wants to be home as quickly as possible and back at work because financially things are tight for his family. He is actually doing some work in hospital since most of it is computer-based.

PHYSIOTHERAPIST:

  Well, what are the priorities – shouldn’t we be getting him as functional as possible? Isn’t that our job?

In this exchange, a number of words relating to the concept of ‘functioning’ are in italic. There appears to be different concepts about what this means among the different health professionals, yet many would probably agree with the physiotherapist’s belief that the primary task of rehabilitation is to maximize the person’s level of ‘functioning’. A key issue then, in order for rehabilitation teams to work productively together, is to agree upon what is meant by this important term. As we see in this hypothetical exchange, ‘functioning’ can refer to how well a person walks, the strength of a particular muscle, ability to perform a task within one environment ­compared with a different environment, self-care activities or actual performance of productive work.

The doctor and nurse seem to believe that accomplishment of a particular task (such as walking or self-care activities) renders the person non-disabled, irrespective of how difficult or how ‘well’ that task is managed. Furthermore, they ignore the ­possibility that a person can function quite well in one environment but not in another. Contextual factors are clearly more important than they realize. The occupational therapist is much more aware of the more nuanced notion of disability in which the environment can render the person disabled rather than the intrinsic abilities of the person. In such situations, improving a person’s function may have nothing to do with more therapy, but rather requires a change to the environment, such as building a ramp rather than steps. Functioning must therefore be seen as an interaction between the person and their context. One other important consideration of ‘context’, which was not raised by the team discussion, is the context of the person himself. That is, what attributes (not directly related to the issue at hand) does the client bring. This can involve his age, co-morbidities and personality traits among a range of ­possibilities. This context too is very important in determining the actual functioning of the person.

The social worker introduces two additional concepts. The first concerns a distinction between more basic activities such as walking and those that are more societal in orientation – fulfilling a role such as paid work or being part of a family. Accomplishing such a role may often have little relation to more basic activities, and therefore cannot be seen as hierarchical. In this example, it is simply not necessary for the person to be able to walk well in order for him to perform his paid work. Of course, in other kinds of work, walking will be a pre-requisite. But the relationship between specific disturbances of basic activities (which we might consider as those occurring at the level of the whole organism), and other kinds of activities such as work (which we might consider at the level of organism within his/her social world) cannot be assumed and needs to be evaluated carefully as part of good rehabilitation practice for each client. The second concept that the social worker introduces is the notion of ‘actual performance’ perhaps, as if this was a more impressive observation than ‘is capable of’. Certainly, the two concepts are distinct. Direct observation of performance is possible but determining capacity is rather more judgemental and involves making a prediction rather than describing what is observed. Whether observation of performance is better than prediction of capacity is unclear and almost certainly depends upon what the evaluation is used for – is it fit for purpose? Often a determination of performance is not possible, since the particular activity occurs very infrequently or is potentially dangerous. For example, how could the team respond to Mr Browns’s request for some guidance as to whether he can engage in his hobby of skydiving?

Returning to the physiotherapist again, the common use of the term ‘function’ that is synonymous with ‘operate’ means that how well or poorly parts of the organism are working also comes under the umbrella of ‘function’. Again, the relationship between the operation of parts of the organism and the whole of the organism are not ­necessarily hierarchical or linear. Walking is possible without all components of the walking mechanism working normally (or at all). Entire loss of a lower limb does not preclude walking. It is often critically important for therapists to consider carefully the primary targets of their treatment and to constantly re-evaluate the relevance of that target in relation to the overall rehabilitation plan.

It is clearly necessary, therefore, to organize these different concepts of ‘­functioning’ into a schema that all disciplines can understand and use. We might consider this a common language of functioning where each term is precisely defined and meaningful across the different discipline-specific languages. For example, when ­occupational therapists talk about the ‘Model of Human Occupation’ (Kielhofner, 2008), can the language be translated into the same terms that psychologists would use when ­discussing ‘cognitive–behavioural therapy’?

From the perspective of populations, healthcare systems and payers such a ­language is also important. For example, a means of how to classify, categorize and enumerate all the ways people are affected by health conditions is necessary in order to properly understand the health and functioning of a population. A descriptive ­language that contains all the manifestations of health and disease would be complementary to a descriptive system of pathological diagnoses contained within the International Classification of Disease (ICD) (WHO, 1992).

This chapter discusses such a language. The International Classification of Functioning, Disability and Health (ICF) introduced by the World Health Organization (WHO) in 2001 was a landmark achievement towards comprehensively understanding and describing ‘functioning’ (Ustun et al., 2003). With this language, it is now possible for different disciplines to understand what each other does and begin to form rational commonalities across discipline-specific models of thinking. Further­more, an acceptable language of functioning enables a more scientific ­discourse to determine the nature of functioning in its totality and in its component parts. The better way of describing functioning that the ICF provides can permit an investigation into the connections between its component parts, the determinants of functioning and the effectiveness of interventions that might improve functioning. It may not be overstating the case to say that the ICF is a central pillar of rehabilitation theory and practice.

This chapter will describe the origin of the ICF, describe the ICF in more detail, explain the core set and other approaches to making the ICF more usable, and how the ICF relates to measurement of functioning and health status. We will discuss some...