Assessment of quality of life in clinical trials

This paper is intended as an overview of developments in the assessment of quality of life (QOL) in clinical trials over the last decade from the viewpoint of clinical biostatistics. In the first part we deal with aspects of obtaining adequate measurements of quality of life. A literature survey shows that a large number of quite heterogeneous measurement approaches for use in clinical trials exist, a substantial percentage of which cannot be regarded as sufficient for their actual measuring purpose. In the second part we review statistical methods applied to and adapted for the analysis of QOL data. Underlying the analysis should be the assumption of QOL as a stochastic process. Applied analysis procedures are again investigated in a literature survey. Finally, critical conclusions are outlined and suggestions for further research are given.