Radiation Therapy Oncology Group quality of life assessment: design, analysis, and data management issues.

The Radiation Therapy Oncology Group (RTOG) has embarked on seven phase II or phase III multicentre clinical trials involving a quality of life component. Each quality of life trial used questionnaires or examinations that have been tested for reliability and validity by independent investigators. Each trial includes questionnaires that examine the patient's physical, functional, social, and emotional status, and that measure a specific quality of life issue pertinent to the patient's diagnosis or treatment. Two trial designs have been implemented for studies with quality of life endpoints. One design involves companion trials to the primary treatment study pertaining solely to the quality of life endpoint. The second design integrates the quality of life component into the primary trial design. The RTOG has found a need for education of individuals and institutions expected to administer and obtain the quality of life data. Once the data have been collected several methods for the analysis of the quality of life data are available. However, there is no one best method for analysing quality of life data, thus more than one method should be used in order to provide insight into the data.