The 15-D Measure of Health Related Quality of Life: Reliability, Validity and Sensitivity of its Health State Descriptive System

The 15D is a generic, 15-dimensional, standardised, self-administered measure of HRQOL, that can be used both as a profile and as a single index score measure. This paper examines the acceptability, reliability, validity and sensitivity of two versions (15D.1 and 15D.2) of its health state descriptive system as a profile measure compared with the Nottingham Health Profile (NHP), SF-20 and EuroQol by using several data sets and methods. The response and completion rates show that the acceptability is comparable to NHP, SF-20 and EuroQol. Reliability in terms of repeatability is high, even higher than for NHP. There is substantial evidence of content and construct validity (cross-sectional and longitudinal) and depression-related criterion validity. On roughly comparable dimensions the discriminatory power of 15D.1 appears to be superior to NHP, at least equivalent to SF-20, that of 15D.2 superior to EuroQol and 15D.1, and the responsiveness of 15D.1 to change seems to be similar to NHP and SF-20. The remaining 9-10 dimensions of 15D provide a large extra reserve in these respects. It is concluded that as a profile measure 15D performs equally well as NHP and SF-20, in some respects even better. The properties as a single index score measure will be explored separately.