Measuring the consequences of illness.

The International Classification of Impairments, Disabilities, and Handicaps (ICIDH) was developed as a means for measuring the impact of illness and its consequences, although there was much delay before the classifications became at all well known. After giving an outline of how the ICIDH came into being, this article considers the basis of different types of health problem and of the potential of the International Classification of Diseases (ICD) and the ICIDH to reveal useful information on such problems. The ICIDH is based on a tripartite distinction between impairment, disability and handicap. It can be used as a resource at four different levels--for enlightenment about the nature of disablement problems and how they might relate to policies and services; as three detailed classification schemes to facilitate structuring of data about impairment, disability and handicap respectively; as a framework which provides an agenda for appraisal and assessment; and for facilitating management functions, perhaps especially the evaluation of care. Philosophical and ideological criticisms of the ICIDH are discussed, and means for applying what has proved to be the most controversial component or dimension, the handicap code, are illustrated. At the root of many difficulties is people's failure to appreciate that the same pieces of information can be used to illuminate complementary aspects of problems when the data are regarded from different perspectives. Further experience along the lines currently being undertaken should not only resolve many of the difficulties, but should also encourage more widespread adoption of the approach underlying the ICIDH.