Purpose: This paper provides a framework for understanding the impact of environmental factors on functioning when a person has a health condition. This understanding provides the rationale for including environmental factors in WHO's International Classification of Functioning, Disability and Health (ICF).
Method and results: This conceptual paper uses a review format to provide, firstly, an historical perspective on the integration of environmental factors into the understanding of disability and the ICF; secondly, a description of the overall ICF and, specifically, the environmental factors section; and thirdly, an overview of the interaction of a person with a health condition and the environment in which they live, and the outcome of disability.
Conclusions: The ICF is a classification that allows a comprehensive and detailed description of a person's experience of disability, including the environmental barriers and facilitators that have an impact on a person's functioning. The recognition of the central role played by environmental factors has changed the locus of the problem and, hence, focus of intervention, from the individual to the environment in which the individual lives. Disability is no longer understood as a feature of the individual, but rather as the outcome of an interaction of the person with a health condition and the environmental factors.