Quality of life as an endpoint in EORTC clinical trials. European Organization for Research and Treatment for Cancer.

For more than 30 years the European Organization for Research and Treatment for Cancer (EORTC) has conducted, co-ordinated, and stimulated research on the experimental and clinical bases of treatment of cancer and related problems. For more than a decade the EORTC has included quality of life as an outcome measure in some of its trials. The number of clinical studies that include QOL as an evaluation endpoint has increased rapidly in the last few years, and is still increasing steadily. This necessitated a careful and critical evaluation of procedures and results so far in order to generate appropriate guidelines and procedures for incorporating QOL issues in all stages of the clinical trial process, including protocol writing, data collection, data analysis, and reporting of results. This paper provides an overview of the types and the design of studies, data management of quality of life assessment, compliance, missing data and lessons learned during the past years with respect to QOL assessments in the EORTC studies.