The International Classification of Functioning, Disability, and Health (ICF) – a way to specify functioning in multiple sclerosis

Multiple sclerosis (MS) can follow a variety of clinical courses and is unpredictable in terms of prognosis. Impairment, activity limitations and participation restrictions are important consequences of MS. An important basis for the optimal management of MS is an in-depth understanding, systematic consideration and sound measurement of its consequences at different levels. Therefore, a widely agreed-upon tool for capturing these complex constructs would be important for the description and assessment of functioning of MS patients. With the International Classification of Functioning, Disability and Health (ICF) we can now rely on a globally agreed-upon framework and system for classifying the typical spectrum of problems in functioning of persons with MS given the environmental context in which they live. The ICF framework is based on a comprehensive and integrative perspective covering functioning and disability with its components Body Structures and Functions, Activities and Participation, and Personal and Environmental Factors (fig 1). The ICF classification contains more than 1400 ICF categories each allotted into those components with exception of the component the personal factors, which has not yet been classified. It is possible to generate lists of generally-agreed-upon ICF categories likely to be most relevant to patients having a particular health condition. Such lists can serve as ICF “Core Sets“ which are practical tools providing a range of purposes. They allow clinicians and researchers to classify and describe an individual's functioning using widely accepted terminology. Shared terminology and common definitions permit both international studies and studies comparing the consequences of different conditions. It can also be used to rate the content validity of health-status measures and, thereby, select appropriate instruments for the specific needs of MS. In the future, ICF and the ICF Core Sets may become the new base not only for the further development of such measures, but also for the creation of item banking relevant to individuals with MS. Furthermore, the ICF and practical tools based on the ICF such as the ICF Core Sets are important concepts and tools for the further development of clinical diagnostics and rehabilitation of MS. It is important to recognize that the ICF is a framework and the ICF Core Sets are practical tools which allow classifying and describing patients functioning.