[Patient-reported clinical trial endpoints--the current state of affairs in research and practice]

Patient-reported outcomes are increasingly considered as endpoints for clinical studies. Instruments for measuring patient-reported outcomes range from simple assessments of discrete symptoms or signs to complex measures addressing multidimensional constructs such as health-related quality of life. While generic measures are designed to be applicable across a wide range of clinical conditions, disease- or population-specific instruments address health problems which are relevant for a particular disease or target group. Patient-reported outcomes can provide supplementary information from the patient's perspective when clinical endpoints are the primary focus of a study. As predictors and mediators of clinical outcomes they may contribute to the understanding of how patients benefit from treatment. They are included as primary endpoints when treatment effects comprise subjective phenomena such as pain, fatigue or psychological well-being. Current research activities in the field of patient-reported outcomes include the development of new (disease-specific) instruments, head-to-head comparisons of psychometric properties of measures, analysis of the context-dependence of results, and application of patient-reported outcomes in clinical practice.