Purpose: The reporting of quality of life outcomes after prostate cancer treatment has improved with the use of validated instruments and third party data collection, and yet widely disparate continence and potency rates persist among providers. We assessed how well various definitions of these outcomes correspond with each other in the same patients.
Materials and methods: A longitudinal cohort of 269 men undergoing radical prostatectomy for early stage prostate cancer completed quality of life questionnaires, including the University of California-Los Angeles Prostate Cancer Index. Six definitions of urinary continence and 6 definitions of potency represented by individual or aggregated items in the survey were analyzed. Using 2,506 questionnaires patients meeting the criteria for continence or potency by each definition were compared.
Results: Correspondence among continence definitions varied widely. Of the men who reported using no pads only 42% leaked urine not at all. Other definitions had higher rates of concordance with 98% of patients who reported total control also claiming no pads. Correspondence among potency definitions was even more disparate. Only 5% of men with erections firm enough for intercourse reported having morning erection very often, while 61% rated their ability to function sexually as good or very good.
Conclusions: Variations in outcomes from items intended to measure the same domain reflect the idiosyncrasy of patient definitions of urinary and erectile function. Disease targeted, health related quality of life outcomes vary greatly depending on the specific definition used.