Disability Prevalence:An examination of measurement purpose and process

The purpose of this paper is to help clarify how our understanding of disability prevalence is influenced by disciplinary definition, theoretical models, measurement purpose and process and the data used. Although the simplicity of a single solution to these problems is appealing, the reality of the multiple policy perspectives and multiple disciplinary approaches that create disability definitions and measurements make such a solution unlikely. Rather, the answer lies not in creating another new “precise” definition or measure of disability, but in understanding how the multiple domains of disability relate to each other in the whole construct and the limited representation of any one measure. The medical, functional, and social models are not so much conflicting approaches to studying disability (although they have been portrayed as such for quite some time), but constructs which highlight different aspects of a complicated phenomena. They are not competing elements but rather areas of focus with diverse research applications. Within appropriate specific contexts they address many of the major questions or problems that occur. In the more general context, what is lacking is the understanding by a multidisciplinary audience of the translation of model components to measurement, the application of measures to research questions and the relationship among the variety of measures. This paper reviews definition, unit of analysis and purpose of research and translation of concept to measure in order to develop a more integrated approach to diverse disciplinary findings.