Functioning is a central dimension in patients experiencing or likely to experience disability. Accordingly, concepts, classifications and measurements of functioning and health are key to clinical practice, research and teaching. Within this context, the approval of the International Classification of Functioning, Disability and Health (ICF) by the World Health Assembly in May 2001 is considered a landmark event. The ICF establishes the beginning of a new era of patient-oriented clinical practice, research, and teaching.
The ICF is based on the integrative bio-psycho-social model of functioning, disability and health of the World Health Organization (WHO). Functioning is the human experience related to body functions, body structures, and activities and participation. It is viewed in terms of its dynamic interaction with a health condition, personal and environmental factors. Disability, on the other hand, is the human experience of impaired body functions and structures, activity limitations and participation restrictions in interaction with a health condition, personal and environmental factors. Although distinguishing between functioning and disability is often helpful when reading medical literature, in the bio-psycho-social perspective of the ICF, functioning is implicitly addressed when disability is mentioned and vice versa.
Functioning and disability according to the integrative bio-psycho-social model of the ICF corresponds to the perspective of rehabilitation medicine i.e. functioning is seen as closely interacting with the environment and the person’s characteristics. Moreover, functioning represents not only an outcome, but also the starting point of the clinical assessment, intervention management, the post-intervention evaluation and quality management.
- Bickenbach J. What is functioning and why is it important. In: ICF Core Sets: Manual for Clinical Practice. Bickenbach J, Cieza A, Rauch A, Stucki G. ed. Göttingen: Hogrefe; 2012.
- Stucki G. International Classification of Functioning, Disability, and Health (ICF): a promising framework and classification for rehabilitation medicine Am J Phys Med Rehabil. 2005; 84(10): 733-740.
- Stucki G, Cieza A Melvin J. The International Classification of Functioning, Disability and Health (ICF): a unifying model for the conceptual description of the rehabilitation strategy J Rehabil Med. 2007; 39(4): 279-285.
- Stucki G Melvin J. The International Classification of Functioning, Disability and Health: a unifying model for the conceptual description of physical and rehabilitation medicine J Rehabil Med. 2007; 39(4): 286-292.
- World Health Organization. International Classification of Functioning, Disability and Health, Geneva, World Health Organization; 2001.