The ICIDH-2: developments for a new era of outcomes research.

This article reviews the important concepts that led to the development of the International Classification of Impairments, Disabilities, and Handicaps (ICIDH), explicates the International Classification of Functioning and Disability (ICIDH-2), and discusses implications of the ICIDH-2 as a conceptual framework for outcome measures. The original ICIDH opened the door to include factors outside the traditional classification boundaries of disease, illness, and functional limitations that have framed the concept of disability. The new factors in the ICIDH-2 include a dimension for participation in social activities and a listing of environmental factors that are important for understanding the complexity of disability. The ICIDH-2 offers an opportunity for building a consensus on the terms used to describe disability and on the scope of factors to include in studying disability.