Are commonly used patient-reported outcome assessment instruments for the assessment of quality of life in surgically treated patients with localised prostate cancer really valid? (#102)
Introduction and objectives
Published articles and conference presentations frequently state “we used a validated questionnaire” without a true understanding of what this means. Whether an instrument displays appropriate measurement properties is not a fixed attribute, but is dependent upon the context and population being studied. Little attention has been paid in the urologic literature to explaining the scientific rigour involved in selecting a questionnaire for use with patients with prostate cancer. Our objective is to describe which of the most commonly used PRO instruments have been appropriately validated for use in patients having surgery for
localised prostate cancer.
Methods
To select the most commonly used QoL instruments a hand search was conducted of six peer-reviewed journals from January 2000 to August 2012: European Urology, Journal of Urology, BJU International, Lancet Oncology, Journal of Clinical Oncology, and Medical Care. The published measurement properties of the selected instruments were reviewed.
Results
Validation of the EORTC QLQ-PR25 revealed problems with the internal consistency of the bowel and hormonal treatment scales. The current version of the FACT-P has not been validated. The UCLA-PCI, EPIC and Clark instruments have all undergone some validation in samples of patients with localised prostate cancer.
Conclusion
Many of the instruments used to assess outcomes following surgical treatment for localised prostate cancer have not been validated for use in this population. Studies using questionnaires that have not been validated in the population of interest may be subject to measurement error and any conclusions drawn cannot be made with confidence.