Responsiveness to change in health-related quality of life in a randomized clinical trial: a comparison of the Prostate Cancer Specific Quality of Life Instrument (PROSQOLI) with analogous scales from the EORTC QLQ-C30 and a trial specific module. European Organization for Research and Treatment of Cancer.

INTRODUCTION: The Prostate Cancer Specific Quality of Life Instrument (PROSQOLI) was developed to be a pragmatic outcome measure for clinical trials in symptomatic men with advanced hormone-resistant prostate cancer.

DESIGN AND SETTING: A comparative assessment of responsiveness was made with longitudinal data from a positive multicenter randomized trial of palliative chemotherapy in 161 symptomatic men with advanced hormone-resistant prostate cancer.

INSTRUMENTS: The PROSQOLI, the European Organisation for Research and Treatment of Cancer (EORTC) core quality of life questionnaire (QLQ-C30), and a specific quality of life module for advanced prostate cancer [QLM-P14] were administered every 3 weeks while patients received their allocated treatment.

FINDINGS: Sixteen of the 19 health-related quality of life (HRQL) scales demonstrated improvements in palliative responders. All three pain scales detected a beneficial effect of palliative chemotherapy. The relative efficiency statistics favored the PROSQOLI for physical symptoms and physical function but the QLQ-C30 for emotional function, social function, and global perceptions. The PROSQOLI linear analog scale was the most responsive measure of pain. Bootstrap confidence intervals for the relative efficiency statistics were wide.

CONCLUSIONS: Both the PROSQOLI and the analogous scales from the QLQ-C30 were responsive to improvements in HRQL. Differences between the instruments were generally subtle. The PROSQOLI is a short, simple, responsive measure of HRQL in men receiving systemic treatment for advanced hormone-resistant prostate cancer.