Measurement of activities of daily living

An ADL scale is a measure of disability, not of impairment or handicap. By convention, ADL assessments have come to include mobility, selfcare activities and, more controversially, continence. This construction has been extended to include housework, shopping and leisure acttvities, but the emphasis is still on performance of the common activities of everyday life. One way of demonstrating that these activities belong together is to show that they have a ’natural’ order of difficulty. The consistency of this hierarchy can be determined by a mathematical procedure known as Guttman scaling2 and some ADL assessments, such as the Katz index, the Rivermead scale4 and the Nottingham 10-point scale5 were specifically designed to form ordinal scales using this technique. In similar assessments such as the Barthel index,6 the hierarchy may be preserved to some extent,7 but it will be disrupted if items which fall outside the domain of disability are introduced. Thus hybrid assessments such as the PULSES profiler which includes sections on medical problems and social background and support, cannot be regarded as true