ABSTRACT
The increasing use of health status questionnaires in the monitoring of outcomes has highlighted sensitivity to change over time, or "responsiveness", as a vital characteristic (Guyatt et al. 1987, Fitzpatrick et al. 1992). Not all of the questionnaires which are in current use were originally designed to tap this feature, having been intended to provide "snapshot" descriptions of the health of a population. However, since there are relatively few applications which do not involve the reliable assessment of change (Jenkinson et al. 1993b), there remains concern about the ability of some measures to respond to changes that are of clinical and subjective relevance.
