International Classification Of Functioning.docx

International Classification of Functioning, Disability, and Health (ICF) The ICF was developed by the World Health Organization (WHO) and published in 2001. The WHO would like the ICF classification system to be considered a partner to the ICD (International Classification of Diseases and Related Health Problems) system used in the U.S. and abroad. Whereas the ICD classifies disease, the ICF looks at functioning. Therefore, the use of the two together would provide a more comprehensive picture of the health of persons and populations.

Key Points 

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The ICF is not based on etiology or "consequence of disease," but as a component of health. Thus, while functional status may be related to a health condition, knowing the health condition does not predict functional status. The World Health Organization defines "health" as "the complete physical, mental, and social functioning of a person and not merely the absence of disease." In this definition, functioning as classified in the ICF is an essential component of health. The ICF describes health and health related domains using standard language. The purposes of the ICF include: o Collection of statistical data o Clinical research o Clinical use o Social policy use The ICF is stated as the framework for the field in both the Scope of Practice for SpeechLanguage Pathology (2001) and the Scope of Practice for Audiology (2004).

Components of ICF The ICF framework consists of two parts: Functioning and Disability and Contextual Factors. These parts are further broken down in the following manner: Functioning and Disability includes:  

Body Functions and Structures—describes actual anatomy and physiology/psychology of the human body. Activity and Participation—describes the person's functional status, including communication, mobility, interpersonal interactions, self-care, learning, applying knowledge, etc.

Contextual Factors include:

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Environmental Factors—factors that are not within the person's control, such as family, work, government agencies, laws, and cultural beliefs. Personal Factors—include race, gender, age, educational level, coping styles, etc. Personal factors are not specifically coded in the ICF because of the wide variability among cultures. They are included in the framework, however, because although they are independent of the health condition they may have an influence on how a person functions.

ICF Coding ICF codes utilize an alphanumeric system to describe health and health-related domains, with the following letter codes: b=body functions s=body structures d=activities and participation e=environmental factors The letters are followed by a numeric code that starts with a one digit chapter number, a second level denoted by two-digits, and third and fourth levels represented by one digit each. Codes are only complete when a qualifier has been added. Qualifiers denote the severity of the problem and are represented by one or more numbers following a point or separator. The first number after the separator is a universal qualifier that ranges from 0 (no problem) to 4 (complete problem). If a code is not applicable, the code will be followed by a .9. Further qualifiers have different meanings, depending on the component being coded. For example, the second qualifier for body structures indicates the nature of the anatomical change, while the second qualifier for activity/participation denotes the person's ability to perform in a standard environment such as a clinic room without assistance. It is important to note that in the Activity/Participation construct, there is a distinction made between a person's ability to perform a skill in the clinic and their ability to perform the same skill in their natural environment. This is vital information about a person's true functional abilities.

Examples of ICF Codes Activity/Participation    

Speaking=d330 Communicating with–receiving spoken messages=d310 Conversation=d350 o Ending a conversation=d3502 Using communication devices and techniques=d360

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Using communication techniques (includes speech reading)=d3602 Producing messages in formal sign language=d340

Body Functions     

Quality of voice=b3101 Articulation functions=b320 Manipulation of food in mouth=b5103 Speech discrimination=b2301 Vestibular function of balance=b2351

Environment    

Sound intensity=e2500 Individual attitudes of people in positions of authority=e430 Assistive products and technology for communication (includes hearing aids and cochlear implants)=e1251 Communication services (includes TTD and TTY)=e5350

Again, a qualifier is needed to complete the codes. For example, a severe spoken language comprehension problem in the person's natural environment would be coded as d310.3.

ICF for Children and Youth (ICF-CY) In October of 2007, the International Classification of Functioning, Disability, and Health for Children and Youth (ICF-CY) was published by the WHO. The ICF-CY was developed to cover the developmental aspects of childhood. The ICF now is considered for persons 18 years of age and older and the ICF-CY for birth to age 17. The ICF-CY for children has the same organization as the ICF with the same hierarchical structure of codes:   

Body Functions/Structures Activities & Participation Environmental Factors

The modifications for children consist of:   

modifying existing descriptions assigning new content to unused codes modifying inclusion/exclusion criteria

As with the ICF, the ICF-CY had extensive field trials throughout the world. In addition to new codes, a few codes of the ICF are not included in the ICF-CY due to not being appropriate for children such as a code that dealt with behaviors surrounding menopause. An important addition in the ICF-CY is a possible use of the qualifiers to represent different degrees of developmental delay. Some examples of communication codes in the ICF-CY that are not in the ICF include the following:

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solitary, parallel, and cooperative play acquiring single words or symbols acquiring correct syntax orientation to objects acquiring skills to recognize symbols, characters and alphabet mouthing learning through actions and playing responding to human voice

Use of ICF by Government Agencies At this time, the ICF classification system is not widely used in the U.S. The WHO is leading the campaign to have the ICF universally adopted and utilized. In the United States, several leading medical advisory boards and government agencies have recommended that the ICF be used for health and educational records to describe functional health status, including: 

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The National Committee for Vital and Health Statistics (NCVHS), a medical advisory board of the Department of Health and Human Services. In their report entitled Classifying and Reporting Functional Status [PDF] it states that the ICF is currently the most developed system to be considered for use in recording functional health status. The report discusses one of the reasons for limited use of the ICF for clinical and administrative records-the lack of specific clinical guidelines. The WHO and the American Psychological Association are working on a joint publication entitled Procedural Manual and Guide for a Standardized Application of the ICF: A Manual for Health Professionals. This manual is expected to be published in 2009. The Institute of Medicine (IOM) has also provided support to the use of the ICF by health agencies. Their latest report was published in 2007 and is entitled The Future of Disability in America. This report recommends the use of the ICF for study to use in the US health system. The Department of Health and Human Services is government organization overseeing the Consolidated Health Informatics (CHI) Initiative. This initiative was designed to bring together experts from throughout the federal government to identify standards for the electronic exchange of health information. Their report [PDF] recommends formal government adoption of the ICF for federal US-wide use and that it is included in the National Library of Medicine's Unified Medical Language System (UMLS). In July 2007, the Interagency Committee on Disability Research, a subcommittee of the National Institute on Disability and Rehabilitation Research hosted a conference entitled "ICDR State of the Art Conference- New Federal Applications of the ICF." The invited speakers were experts in various aspects of the use of the ICF.

International Classification of Functioning, Disability and Health, also known as ICF, is a classification of the health components of functioning and disability. After nine years of international revision efforts coordinated by the World Health Organization (WHO), the World Health Assembly on May 22, 2001, approved the International Classification of Functioning, Disability and Health and its abbreviation of "ICF." This classification was first created in 1980 and then called the International Classification of Impairments, Disabilities, and Handicaps, or ICIDH[1] by WHO to provide a unifying framework for classifying the health components of functioning and disability. The ICF classification complements WHO’s International Classification of Diseases-10th Revision (ICD), which contains information on diagnosis and health condition, but not on functional status. The ICD and ICF constitute the core classifications in the WHO Family of International Classifications (WHO-FIC).

Overview The ICF is structured around the following broad components: 

Body functions and structure

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Activities (related to tasks and actions by an individual) and participation (involvement in a life situation)

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Additional information on severity and environmental factors

Functioning and disability are viewed as a complex interaction between the health condition of the individual and the contextual factors of the environment as well as personal factors. The picture produced by this combination of factors and dimensions is of "the person in his or her world". The classification treats these dimensions as interactive and dynamic rather than linear or static. It allows for an assessment of the degree of disability, although it is not a measurement instrument. It is applicable to all people, whatever their health condition. The language of the ICF is neutral as to etiology, placing the emphasis on function rather than condition or disease. It also is carefully designed to be relevant across cultures as well as age groups and genders, making it highly appropriate for heterogeneous populations.

Benefits of ICF There are benefits of using the ICF for both the client and the health professional. A major advantage for the client is the integration of the medical and social aspects of his or her health condition. All aspects of a person’s life (development, participation, and environment) are incorporated into the ICF instead of solely focusing on his or her diagnosis. A diagnosis reveals little about one’s functional abilities. Diagnoses are important for defining the cause and prognosis, but identifying the limitations of function is often the information used to plan and implement interventions [2] Once a rehabilitation team is aware of the daily activities a client is

required to participate in, the problem solving sequence set up by the ICF can be utilized. A rehabilitation therapist, for example, would observe a client performing his or her daily activities and note the client’s functional abilities. This information would then be used to determine the extent to which the individual’s abilities can be improved through therapy and to what extent the environment can be changed to facilitate the individual’s performance.[3] Intervention at one level (current abilities) has the potential to prevent or modify events at a succeeding level (participation). For example, teaching a deaf child manual signs will foster effective interaction and increase one’s participation with his or her family.[4] Rehabilitation therapists will be empowered with the ICF not only in their daily work with their patients, but also when working with other medical disciplines; hospitals and other health care administrations; health authorities and policy makers.[5] All items are operationally defined with clear descriptions that can be applied to real life evaluations with clarity and ease. [6] The language used in the ICF helps facilitate better communication between these groups of people.

Clinical relevance Knowing how a disease affects one’s functioning enables better planning of services, treatment, and rehabilitation for persons with long-term disabilities or chronic conditions. The current ICF creates a more integrative understanding of health forming a comprehensive profile of an individual instead of focusing on one’s health condition.[7] The implications of using the ICF include emphasizing the strengths of individuals, assisting individuals in participating more extensively in society by the use of interventions aimed at enhancing their abilities, and taking into consideration the environmental and personal factors that might hamper one’s participation.[8] Qualifiers: The ICF qualifiers “may be best translated clinically as the levels of functioning seen in a standardized or clinic setting and in everyday environments”.[9] Qualifiers support standardization and the understanding of functioning in a multidisciplinary assessment. They enable all team members to quantify the extent of problems, even in areas of functioning where one is not a specialist.[10] Without qualifiers codes have no inherent meaning. An impairment, limitation or restriction, is qualified from 0 (No problem; 0-4%), 1 (Mild problem: 5-24%, 2 (Moderate problem: 25-49%), 3 (Severe problem: 50-95%) to 4 (Complete problem: 96-100%). Environmental factors are quantified with a negative and positive scale denoting the extent to which the environment acts as a barrier or facilitator.[11] For insurance purposes, the qualifiers can describe the effectiveness of treatment. One can interpret the decreasing of a qualifier score to be an increase in the functional ability of a patient.

ICF Core Sets An ICF Core Set can serve as a reference framework and a practical tool to classify and describe patient functioning in a more time efficient way. ICF Core Sets can be used along the continuum of care and over the course of a health condition.[12] The ICF classification includes more than 1,400 categories limiting its use in clinical practice.[13] It is time consuming for a clinician to utilize the main volume of the ICF with his or her patients. Only a fraction of the categories is needed. As a general rule, 20% of the codes will explain 80% of the variance observed in practice.[14] ICF Core Sets contain as few as possible, but as many ICF categories as necessary,

to describe a patient’s level of functioning.[15] It is hypothesized that using an ICF Core Set will increase the inter-rater reliability when coding clinical cases as only the relevant categories for a particular patient will be utilized. Since all of the relevant categories are listed in an ICF Core Set, its use in multidisciplinary assessments protects health professionals from missing important aspects of functioning.[16]

Children and Youth Version (ICF-CY) As clinicians and researchers used the ICF, they became more aware of its limitations. The ICF lacks the ability to classify the functional characteristics of a developing child. Different ICF codes are needed across the first years of a child’s life to capture the growth and development of a disability even when the child’s diagnosis does not change.[17] The coding system can provide essential information about the severity of a health condition in terms of its impact on functioning. This can serve a significant role for providers caring for children with spectrum disorders such as autism or cerebral palsy.[18] Children with these conditions may have the same diagnosis, but their abilities and levels of functioning widely vary across and within individuals over time. The first draft of the ICF-CY was completed in 2003 and published in 2007. The ICFCY was developed to be structurally consistent with the ICF for adults. A major difference between the ICF-CY and ICF is that the generic qualifiers from the adult ICF now include developmental aspects for children and youth in the ICF-CY. Descriptions of codes in the ICFCY were revised and expanded and new content was added to previously unused codes. Codes were added to document characteristics as adaptability, responsivity, predictability, persistence, and approachability. “Sensing” and “exploration of objects” codes were expanded as well as the “importance of learning”.[19] Since a child’s main occupation is playing, it is also important to include more codes in this area. Different levels of play have separate codes in the ICF-CY (solitary, onlooker, parallel). This contrasts with the adult ICF as only one code existed in regards to leisure or recreation. Changes in ICF-CY codes over time reflect developmental effects attributable to the child’s interaction with the environment. Environmental factors influence functioning and development and can be documented as barriers or facilitators using the ICF-CY. The key environments of children and adolescents include their homes, day care centers, schools and recreation settings of playground, parks, and ball fields.[20] Children will transition between different environments many times as they grow. For example, a child will transition into elementary or high school or from one service setting or agency to another. Attention to these transitions of children with disabilities has been identified as an important role for health care providers.[21] A transition requires preparation and planning to find an appropriate and accommodating setting for a child’s needs. With a coding system such as the ICF-CY, the transition will be smoother and interventions can start where the previous health provider left off.

The WHO Family of International Classifications The WHO constitution mandates the production of international classifications on health so that there is a consensual, meaningful and useful framework which governments, providers and consumers can use as a common language. Internationally endorsed classifications facilitate the storage, retrieval, analysis, and interpretation of data. They also permit the comparison of data within populations over time and between populations at the same point in time as well as the compilation of nationally consistent data. The purpose of the WHO Family of International Classifications (WHO-FIC)is to promote the appropriate selection of classifications in the range of settings in the health field across the world. The basis for the WHO Family of International Classifications and the principles governing the admission of classifications are set out in the paper on the "WHO Family of International Classifications'. This paper also provides a protocol to those wishing to submit a classification for inclusion in the WHO-FIC.

Types of Classifications The WHO-FIC is comprised of: 1. Reference Classifications: Main classifications on basic parameters of health. These classifications have been prepared by the World Health Organization and approved by the Organization's governing bodies for international use   

International Classification of Diseases (ICD) International Classification of Functioning, Disability and Health (ICF) International Classification of Health Interventions (ICHI)

2. Derived classifications Derived classifications are based on the reference classifications( i.e. ICD and ICF) .

Classifications and Clinical Terminologies Classifications capture snapshot views of population health using such parameters as death, disease, functionality, disability, health and health interventions, which inform management and decision making process in the health system. Over time they also provide insight on trends, which informs the planning and decision making processes by health authorities. The multiplicity of possible perspectives on health results in a variety of classifications. Their necessary evolution poses challenges for consistency. More recently, the varied applications in

health information systems and the general availability of information and telecommunication technologies (ICT) has highlighted the need for increased interoperability. The base line information that is aggregated for public health purposes is increasingly derived from health records, which contain both patient care related information, and also information that is crucial for management, health financing and general health system administration. The accuracy and consistency of the health records is crucial to ensure the quality of care and sound management of health systems resources. This calls for accurate and consistent use of clinical terminologies and recognition of the particular importance of semantic interoperability. Possible synergies between classifications and clinical terminologies, have been identified crucial for future work, particularly in the perspective of a growing automation of information processing. WHO and its network of collaborating centers are taking steps in that direction.

Nagi’s Disability Model

In the 1960s and 1970s, Saad Z. Nagi developed an influential model of disability based on his research on rehabilitation outcomes (Nagi, 1964, 1965, 1976, 1987). Nagi differentiated among concepts of pathology, impairment, functional limitations, and disability, making them separate components of his model (Table 2-1). By using the term “disability” instead of “handicap,” he avoided giving the concept a negative connotation; that is, he did not suggest an absolute limitation, one that failed to take into account circumstances outside the control of the person with a given health condition. Nagi considered disability to result from the interaction of a person with a health condition with his or her environment, which includes family support, employer accommodations, and physical and sociocultural barriers. Nagi also acknowledged other factors affecting disability, including the person’s own characteristics and definition of the situation. He noted that not all impairments or functional limitations result in disability; two individuals with similar pathologies, impairments, and functional caTABLE 2-1 Comparison of Components of Models of Disablement Components of the Model

Cells/Tissue

Organ

Pathology

Impairment Functional limitation

Disability

IOM Modification Pathology of Nagi Model, 1991 ICIDH (WHO, Disease 1980)

Impairment Functional limitation

Disability

Impairment Disability

Handicap

Model Nagi, 1969

Person

Society

NCMRR, 1993

Pathophysiology Impairment Functional limitation

Disability

Vergrugge-Jette, 1994

Pathology

Impairments Functional limitations

Disability

IOM, 1997

Pathology

Impairment Functional limitation

Disabililty

ICF (WHO, 2001)

Activity Body functions and structures

External Barriers

Social physical environment

and

Participation Personal and environmental factors

pacities might have different patterns of disability, while similar patterns of disability might result from different kinds of health conditions. Nagi provided an update of his model as an appendix to the 1991 report of the IOM, Disability in America. In it, he noted that certain disfiguring or stigmatizing impairments could result in disability without causing functional limitations at the organism level (Nagi, 1991:315). The IOM report added several dimensions to the Nagi model. First, it proposed three interacting risk factors—biological, environmental (social and physical), and lifestyle/behavioral—that affect each element of the disabling process: pathology, impairment, functional limitation, and disability. Second, it added impact on quality of life as a part of the disabling process (IOM, 1991:84-91). In effect, it added another component to Nagi’s model—features of the social and physical setting affecting an individual’s degree of disability that could be targeted for change (Table 2-1). The IOM report helped bring Nagi’s conceptual model of disability to a wider audience and helped stimulate research on the environmental aspects of the disablement process. Nagi’s concepts strongly influenced other models of disability, including those of the WHO and the NCMRR (both described below) and were adopted by rehabilitation organizations, such as the American Physical Therapy Association. WHO’s International Classification of Impairment, Disability, and Handicap (ICIDH)

WHO developed the ICIDH to complement the International Classification of Diseases (ICD) (WHO, 1980). The ICD classifies diseases, disorders, and other health conditions by diagnosis and is used to identify acute illnesses and injuries that can be cured or prevented. The ICD is not, however, well suited to classifying and tracking chronic or progressive disorders (Whiteneck, 2006:51). Therefore, WHO developed the ICIDH to classify the kinds and levels of function and disability associated with health conditions (Jette, 2006:730). The ICIDH made conceptual distinctions, based on Nagi, among impairment, functional limitations (which, however, WHO called “disability”), and disability (called “handicap” by WHO), which allowed recognition that disability is based not just on the attributes of the individual (the medical model) but also on the interaction between the person and society (the biopsychosocial model) (Table 2-1). On the negative side, the ICIDH used the word “handicap” to label the result of the interaction between the person and the social setting. This label seemed to perpetuate the idea that the problem is more the inability of the person to fit into usual social roles rather than restrictions imposed by environmental barriers and social atti-udes, which could be modified to enable an impaired person to participate in work and other normal activities. The model was also still medically based (i.e., diseases, injuries, or other disorders result in impairment, which cause functional limitations, which, in turn, reduce the person’s ability to participate in society). This did not recognize the complexity of the disablement process, especially the role of contextual factors, or the fact that the correlations between degree of impairment, extent of functional limitation, and level of disability are low.

National Center for Medical Rehabilitation Research Model

NCMRR (1993) built on the Nagi model by including the impairment, functional limitation, and disability domains corresponding to the organ, person, and societal levels, but NCMRR added another level or “dimension,” called “societal limitation” (Table 2-1). In the NCMRR model, societal limitations are barriers to full participation in society that result from attitudes, architectural barriers, and social policies. The NCMRR model pulled external barriers out of the environmental domain for special emphasis, highlighting the fact that these barriers could be reduced or eliminated by public policy. Verbrugge and Jette’s Model of the Disablement Process

Verbrugge and Jette elaborated on Nagi’s model in “an attempt to attain a full sociomedical framework of disablement, which they defined as the impact that chronic and acute conditions have on functioning of specific body systems and on people’s abilities to act in necessary, usual, expected, and personally desired ways in their society” (Jette, 2006:729). Altman (2001) notes that Verbrugge and Jette focused on task orientation, while Nagi focused more on role orientation toward limitation. As already noted, Verbrugge and Jette accepted the elements of Nagi’s model: active pathology, impairment, functional limitation, and disability (Table 2-1). They operationalized the Nagi model by identifying various types of necessary, usual, expected, and/or personally desired roles and activities under Nagi’s concept of disability that should be tracked and measured. These included (Verbrugge and Jette, 1994):     

Basic activities of daily living—including behaviors such as basic personal care Instrumental activities of daily living—including activities such as preparing meals, doing housework, managing finances, using the telephone, and shopping Paid and unpaid role activities—including occupation, parenting, grandparenting, and student roles Social activities—including attending church and other group activities, and socializing with friends and relatives Leisure activities—including sport and physical recreation, reading, distinct trips, and so on

In addition Verbrugge and Jette (1994) tried to make the model more dynamic by identifying factors that affect what they called the “disablement process.” They posited three sets of variables that affected the “pathway” to disablement of a given individual. These were:

Risk Factors. Risk factors are “predisposing phenomena that are present prior to the onset of the disabling event that can affect the presence or severity of the disablement process. Examples include sociodemographic background, lifestyle, and biologic factors.”

Intra-individual Factors. Intra-individual factors “operate within a person, such as lifestyle and behavioral changes, psychosocial attributes and coping skills, and activity accommodations made by the individual following onset of a disabling condition.” Extra-individual Factors. Extra-individual factors are in the external “physical as well as the social context in which the disablement process occurs. Environmental factors relate to the social as well as the physical environmental factors that bear on the disablement process. These can include medical and rehabilitation services, medications and other therapeutic regimens (e.g., exercise or physical activity), external supports available in the person’s social network, and the physical environment.”

Verbrugge and Jette stimulated research into the impact of risk factors, intra-individual factors, and extra-individual factors on impairment, functional limitation, and disability and how they influence the disablement process. Jette (2006) cites a number of examples of this research: Lawrence and Jette (1996), Jette et al. (1998), Guralnik et al. (1994, 1995), Gill et al. (1995), and Ostir et al. (1998). IOM’s Enabling-Disabling Model (1997)

In 1997, an IOM committee issued a report, Enabling America: Assessing the Role of Rehabilitation Science and Engineering, which responded to a congressional request for an assessment of rehabilitation research and technology development efforts. The report extended the 1991 IOM model by making “clear reference to the importance of the environment in causing, preventing, and reducing disability” (IOM, 1997:1). The committee explicitly adopted the elements of Nagi’s disability model (but called them “components of the disabling process” in the report)—i.e., pathology, impairment, functional limitation, and disability—with disability defined as “a limitation in performing certain roles and tasks that society expects of an individual” (Table 2-1). The IOM report focused on the “enabling process,” by which it meant efforts to reduce disability. Enabling could be accomplished by either restoring function in the individual (i.e., traditional rehabilitation) or expanding access to the environment, or both. The report also introduced the notion of secondary conditions as “any additional physical or mental health condition that occurs as a result of having a primary disabling condition” and that “quite often increase the severity of an individual’s disability and are also highly preventable” (IOM, 1997:3-5). According to the report, “the committee enhanced the 1991 IOM model to show more clearly how biological, environmental (physical and social), and lifestyle/behavioral factors are involved in reversing the disabling process, i.e., rehabilitation, or the enabling process. The enhancements include bidirectional arrows between the various states of the enabling–disabling process to indicate that the disabling process (described in the 1991 IOM model) can be reversed with proper interventions (i.e., the enabling process)” (IOM, 1997:6).

The graphic representation of the new IOM model did not include a box for “disability,” in an effort “to help clarify the fact that disability is not inherent in the individual, but rather is a product of the interaction of the individual with the environment” (IOM, 1997:8). The report proceeded to recommend research and engineering needs and opportunities by domain: pathology and impairment research, functional limitation research, and disability research. Disability research would be “explicitly focused on the effects of the environment in producing or reducing disability” (IOM, 1997:12). In the report, the committee noted that the 1991 IOM model had some shortcomings. First, disability was depicted in the 1991 model as a linear process, which was fine for the 1991 report’s focus on ways to prevent disability but did not allow for reversal of disability through rehabilitation. Second, the earlier model gave a “limited characterization of the environment and the interaction of the individual with the environment.” Third, the 1991 model provided a limited “representation of societal limitations” (IOM, 1997:67). WHO’s International Classification of Functioning, Disability and Health (ICF)

ICF resulted from a substantial revision of the 1980 ICIDH. ICF is based on the premise, supported by studies, that diagnosis alone does not predict service needs, length of hospitalization, level of care, or functional outcomes (WHO, 2001). In addition, the presence of a disease or disorder is not an accurate predictor of receipt of disability benefits, work performance, return-to-work potential, or likelihood of social interaction. In the ICF, disability and functioning are seen as outcomes of interactions between health conditions and contextual factors. Contextual factors include external environmental factors, such as social attitudes, architectural characteristics, and the legal system, and internal personal factors, such as sex, age, coping styles, social background, education, profession, and other factors that influence how disability is experienced by an individual (WHO, 2001:214). ICF is a rather complicated classification system, because its elements are interactive. Its domains include (Table 2-1):

Impairments in Body Functions and Structures   

“Body functions are the physiological functions of body systems (including psychological functions).” “Body structures are anatomical parts of the body such as organs, limbs and their components.” “Impairments are problems in body function or structure such as a significant deviation or loss.”

Limitations on Activities and Limitations on Participation

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“Activity is the execution of a task or action by an individual.” “Participation is involvement in a life situation.” “Activity limitations are difficulties an individual may have in executing activities.” “Participation restrictions are problems an individual may experience in involvement in life situations.”

Environmental Factors. “Environmental factors make up the physical, social and attitudinal environment in which people live and conduct their lives.”

Although the ICF model is comprehensive, it is complex and difficult to operationalize. This and other shortcomings of the ICF are discussed in Whiteneck (2006). The main problem is distinguishing between activity limitations and participation limitations, which have shared activities in the model.