Background: Although utility-based quality-of-life instruments are often used in economic evaluations and psychometric instruments in treatment evaluations, these are complementary approaches to assessing outcomes. In this study we developed and tested these two forms of quality-of-life instruments, both based on a single, validated, health classification system.
Objectives: To assess the measurement properties (reliability and validity) of two newly developed psychometric and utility-based instruments for assessing outcomes associated with prostate cancer.
Methods: 141 men with cancer of the prostate (CaP), treated with radical prostatectomy, radiation therapy, hormonal therapy, and/or chemotherapy were assessed with both instruments and other standard psychometric and utility-based instruments.
Results: Analyses indicate the test instruments are reliable and valid. Full-scale correlations between the instruments and standard instruments indicate validity, as do correlations of key subscales, and an evaluation of linear associations with the UCLA-Prostate Cancer Symptom Scales.
Conclusion: Evidence from this study supports the reliability and construct validity of the tested instruments. Prostate cancer outcomes can now be assessed by a combination of psychometric and utility-based methods, allowing a ready comparison of derived outcomes.