[Definition, classification and epidemiology of disability].

How can we define disability and handicap? What are their different forms? What are the figures for the persons concerned? This paper reviews the key conceptual advances and classification developments as well as new French nationwide surveys on disability. Any attempt at defining what is handicap gives rise to heated debates. This layman word initially originating from the turf language has been prevailing in the medico-social field for the last fifty years. The French 2005 Law on disability has now provided a legal definition inspired by the recommendations of the World Health Organization (WHO). For thirty years, following the pioneering work of Wood, international classifications of disability have been an important activity within the WHO, thus revealing a growing interest for the consequences of health conditions. Following the ICIDH in 1980, WHO has moved towards an interactive model with ICF in 2001. Finally, disability issues open to new directions for epidemiology. In France, the investigations of the INSEE (National Institute on Statistics and Economic Studies), the HID survey "Disabilities-Impairments-Dependence", and tomorrow's "Disability-Health survey, bring issues of disabilities and loss of autonomy at the core of their concerns and allow for a better epidemiologic knowledge of the many faces of the disabled population.