Introduction

The methodology of quality of life measurement has developed markedly in the last few years. Clinicians and researchers have increasingly acknowledged that the burden of illness can not be described only in terms of disease status. Measurement of psychosocial factors such as pain, restricted mobility, difficulties fulfilling family or work responsibilities, and psychological wellbeing provides a far more comprehensive and meaningful assessment of the impact of disease on the patient’s life. Similarly, such patient-based measures are increasingly replacing traditional clinical or disease indicators as the primary measures of outcome in clinical trials.