Enhancing the conceptual clarity of the activity and participation components of the International Classification of Functioning, Disability, and Health.

A key area left open in the International Classification of Functioning, Disability, and Health (ICF) is the distinction between activity and participation. This paper suggests characteristics to distinguish between the components in the ICF model which explicitly include the relationship of contextual factors to the different components. Ten distinguishing characteristics are presented which fall into three major groups: the construct of the component, individual effects, and contextual influences. Application of these suggests that there are four distinguishable components of functioning, disability, and health, which are labeled body functions and structures, acts, tasks, and societal involvement. The body functions and structures component is the same as the ICF component. Acts, tasks, and societal involvement are sub-components of the combined ICF components of activity and participation. Contextual influences operate both as facilitators or barriers (as suggested in the ICF) and as scene-setters. An enhanced model of the relationship between the components is presented, suggesting that there are reciprocal relationships between contextual factors acting as scene-setters, contextual factors acting as facilitators or barriers, societal involvement, tasks, and acts. Further research is needed to determine to what extent these characteristics can be operationalized to distinguish between items in the ICF combined activity and participation classification.