Quality, interpretation and presentation of European Organisation for Research and Treatment of Cancer quality of life questionnaire core 30 data in randomised controlled trials.

Aim: To review reporting standard, presentation and interpretation for quality of life (QOL) outcomes in randomised controlled trials (RCTs) using the European Organisation for Research and Treatment of Cancer quality of life questionnaire core 30 (EORTC QLQ-C30).
Methods: Cancer RCTs reporting EORTC QLQ-C30 data were identified and reviewed against a reporting quality checklist. Interpretation/presentation methods for QOL data were also recorded.
Results: Eighty-two papers were reviewed. Seventy percent met criteria for high quality reporting; 94% reported mean scores; 84% presented results in tables/graphs; 80% reported p-values or statistical significance. Clinical significance was addressed in 38%. Where clinical significance was not addressed, reliance was usually on statistical significance to interpret the results.
Discussion: EORTC QLQ-C30 results are generally reported well, although it was common to rely on statistical significance alone for interpreting results. Whilst interpretation in terms of clinical significance has improved in recent years, there is still a lack of robust clinical interpretation of QOL results even in papers reported to a high standard.