A functional approach to assessing the impact of health interventions on people with disabilities

Abstract

Two indicators – the Activity Limitation Score (ALS) and the Participation Restriction Score (PRS) – are presented in this paper for assessing the impact of public health interventions on the lives of disabled people. These indicators, grounded in the International Classification of Functioning, Disability and Health (ICF), supplement previous indicators, in that they are sensitive to changes in people's functional status resulting from interventions that do not change an underlying medical condition. Using data collected from a national survey of living conditions among people with disabilities carried out in Zambia in 2006, we performed comparative analyses on two weighted summary scores: the ALS describing limitations in basic actions (sensory experiences, basic learning & applying knowledge, communication, and mobility) and the PRS describing restrictions in complex activities (self-care, domestic life, interpersonal behaviors, major life activities and community, social & civic life). These scores were created as the weighted sum of individual activity items under each of the activity domains listed above. High scores represent less capacity to perform basic functions and more difficulty in carrying out complex activities. Results from the Zambian data demonstrated how the ALS and PRS can depict the range of functioning within a country. Results also indicated that the ALS and PRS indicators are sensitive to changes in people's functional status resulting from interventions that do not change an underlying medical diagnosis and address, thereby a shortcoming inherent in the Disability-Adjusted Life Years (DALYs) measurement. Furthermore, the relationship between the ALS and PRS can provide important insight into the extent to which environmental conditions help translate functional limitations into disabilities. This could be an important approach to measuring the impact of various programs and policies.