Reliability and Validity of the PORPUS, a Combined Psychometric and Utility-Based Quality-of-Life Instrument for Prostate Cancer

Urological Survey SOCIOECONOMIC FACTORS, UROLOGICAL EPIDEMIOLOGY AND PRACTICE PATTERNS Reliability and Validity of the PORPUS, a Combined Psychometric and Utility-Based Quality-of-Life Instrument for Prostate Cancer P. Ritvo, J. Irvine, G. Naglie, G. Tomlinson, A. Bezjak, A. Matthew, J. Trachtenberg, and M. Krahn, York University and Cancer Care Ontario, Division of Preventive Oncology, Toronto, Ontario, Canada J Clin Epidemiol, 58: 466 – 474, 2005 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. Editorial Comment: Researchers have developed many competing instruments to measure outcomes associated with prostate cancer management. Most clinicians are familiar with psychometric instruments that measure how patients describe problems with impotence or incontinence. Other instruments measure patient “utilities” or preferences. These instruments are much more commonly used in economic evaluations. The authors describe the psychometric properties of an instrument that attempts to combine patient preferences and standard descriptions of patient outcomes. The instrument appears to perform as well as many currently accepted tools and has several distinct advantages. Clinicians and researchers interested in the field of outcomes research should carefully review this contribution. Peter C. Albertsen, M.D.

ADRENAL AND RENAL PHYSIOLOGY, AND MEDICAL RENAL DISEASE Renal Physiology in Newborns and Old People: Similar Characteristics but Different Mechanisms C. G. Musso, L. Ghezzi and J. Ferraris, Adult and Pediatric Departments of Nephrology, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina Int Urol Nephrol, 36: 273–276, 2004 Five characteristics of neonate renal physiology, namely glomerular hypofiltration, low renal blood flow and alterations in water, sodium and potassium management, disappear during the first year of life but reoccur during senescence. However, the underlying mechanisms are different during the two periods. 0022-5347/06/1753-1073/0 THE JOURNAL OF UROLOGY® Copyright © 2006 by AMERICAN UROLOGICAL ASSOCIATION

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Vol. 175, 1073-1074, March 2006 Printed in U.S.A. DOI:10.1016/S0022-5347(05)00547-1