Revision of the International Classification of Impairments, Disabilities, and Handicaps

Abstract

Variability in approaches to define and classify disability has constituted persistent problems in documenting the epidemiology of disability and providing appropriate services. The major institutions of health care, mental health, and welfare often have separate systems of classification and terminology related to defining eligibility for programs and funding for services. In 1980, the International Classification of Impairments, Disabilities and Handicaps-ICIDH was published by the World Health Organization as a companion document of the International Classification of Disease to document the consequences of illness or injury. Current problems concerning the classification of childhood disability in health, education, and related services have resulted in growing interest in the revision of the ICIDH as a classification tool. The strengths and limitations of the ICIDH are examined in general, as well as with specific reference to its ability to document the nature and epidemiology of childhood disability. This paper (1) describes the ICIDH taxonomy and representative contributions; (2) reviews issues and concerns contributing to its revision; (3) summarizes changes in the revised ICIDH2 draft document, and (4) identifies issues of particular relevance to children and public health applications.

Introduction

The growing issue of disability policy has emphasized problems of definition and documentation of its nature and distribution. These problems are evident in the highly variable and idiosyncratic definitions of disability in legislation and policies governing services for persons with disabilities. The major institutions of health care, education, mental health, and welfare often have separate systems of classification and terminology related to defining eligibility for services and payment for treatments. In the United States, definitions of disability vary as a function of different federal legislative acts and are often specific to the individual agencies responsible for services and or clients [1].

The International Classification of Disease ICD-10 [2] and the Diagnostic and Statistical Manual [3] provide a common terminology for medicine and psychiatry, respectively. A comparable taxonomy of disability has been recognized as necessary to systematize documentation in programs and services for persons with disabilities. In 1980, the International Classification of Impairments, Disabilities, and Handicaps (ICIDH) [4] was published by the World Health Organization as a companion document to the lCD to document the consequences of illness or injury. It was designed to provide an integrating framework and a common language with potential utility for consumers, service providers, researchers, and policymakers. The coverage of the ICIDH emphasized conditions based on physical and motor problems, with applications primarily involving adult populations.

There are growing concerns in health, education, and related services [1] regarding the need for consistent classification of childhood disability [5]. The prevalence of disability among children in Britain has been reported to be 3% [6], whereas 12.2% of the U.S. school population have been identified as students with disabilities. Of students aged 6 to 21 years, 4.7 million were in special education services in elementary and secondary schools, and 582,000 children under age 6 were in preschool programs [7]. These students have been assigned to various categories, including mental retardation and deaf-blindness, as well as to categories combining the prefixes orthopedic, visual, hearing, learning, and emotional with the terms impairments, conditions, disorders, and disabilities. This variability and the lack of a common classification system have created persistent problems in documenting the epidemiology of disability in children and in the provision of appropriate services. Illustrative of these problems are difficulties in making international comparisons of disability prevalence [8].

The above issues have contributed to growing interest in the revision of the ICIDH as a classification tool with the possibility of documenting the nature and severity of childrens' impairments, disabilities, and handicaps independent from the underlying illness or condition 9, 10. Consistent with related classification approaches of mental disorders, childhood and adolescence are recognized as unique developmental periods requiring separate consideration from adulthood [11]. The purpose of this paper is to (1) describe the ICIDH taxonomy and representative contributions; (2) review issues and concerns contributing to its revision; (3) summarize changes in the revised ICIDH2 draft document; and (4) identify issues of particular relevance for children and public health applications. Considerations of importance in this regard are the revised classification code of Participation and the role of the environment in restricting or facilitating participation.