Choosing between the EORTC QLQ-C30 and FACT-G for measuring health-related quality of life in cancer clinical research: issues, evidence and recommendations.

BACKGROUND This review aims to assist cancer clinical researchers in choosing between the two most widely used measures of cancer-specific health-related quality of life: the European Organisation for the Research and Treatment of Cancer Quality of Life Questionnaire Core 30 and Functional Assessment of Cancer Therapy-General (FACT-G). MATERIALS AND METHODS Information on QLQ-C30 and FACT-G content, scale structure, accessibility and availability was collated from websites and manuals. A systematic review was undertaken to identify all articles reporting on psychometric properties and information to assist interpretability. Evidence for reliability, validity and responsiveness was rated using a standardised checklist. Instrument properties were compared and contrasted to inform recommendations. RESULTS Psychometric evidence does not recommend one questionnaire over the other in general. However, there are important differences between the scale structure, social domains and tone that inform choice for any particular study. CONCLUSIONS Where research objectives are concerned with the impact of a specific tumour type, treatment or symptom, choice should be guided by the availability, content, scale structure and psychometric properties of relevant European Organisation for the Research and Treatment of Cancer versus Functional Assessment of Chronic Illness Therapy modules. Because the FACT-G combines symptoms and concerns within each scale, individual items should always be reviewed within the context of specific research objectives. Where these issues are indecisive, researchers are encouraged to use an algorithm at the end of the current article.