Defining and applying a functionality approach to intellectual disability

Background The current functional models of disability do not adequately incorporate significant changes of the last three decades in our understanding of human functioning, and how the human functioning construct can be applied to clinical functions, professional practices and outcomes evaluation. Methods The authors synthesise current literature on human functioning dimensions, systems of supports and approaches to outcomes evaluation for persons with intellectual disability (ID), and propose a functionality approach that encompasses a systems perspective towards understanding human functioning in ID. The approach includes human functioning dimensions, interactive systems of supports and human functioning outcomes. Results Based on this functionality approach the authors: (1) describe how such an approach can be applied to clinical functions related to defining ID, assessment, classification, supports planning and outcomes evaluation; and (2) discuss the impact of a functionality approach on professional practices in the field of ID. Conclusions A functionality approach can increase focus on the integrative nature of human functioning, provide unified language, align clinical functions and encourage evidence‐based practices. The approach incorporates a holistic view of human beings and their lives, and can positively affect supports provision and evaluation.