Expanded Prostate Cancer Index Composite versus Incontinence Symptom Index and Sexual Health Inventory for Men to measure functional outcomes after prostatectomy.

PURPOSE Evaluating quality of life outcomes following prostate cancer treatment is important because different treatments provide similar survival outcomes. A wide variety of quality of life surveys are used with an unknown correlation between domain specific and broad domain instruments. We compared the urinary and sexual outcome measures of the Expanded Prostate Cancer Index Composite, a broad domain instrument, to those of the Incontinence Symptom Index and the Sexual Health Inventory for Men, which are domain specific instruments. MATERIALS AND METHODS A total of 640 patients undergoing radical prostatectomy at our institution completed a combination of the Expanded Prostate Cancer Index Composite, Incontinence Symptom Index and Sexual Health Inventory for Men questionnaires. Matching functional domains were compared and correlation coefficients were calculated. Subgroup analysis was performed to compare specific information pertinent to recovery from prostatectomy. RESULTS Correlations between measures of incontinence were 0.26 to 0.84, while indicators of sexual function were 0.70 to 0.84. Subgroup analysis comparing measures of irritative symptoms demonstrated weaker correlations. Analysis in patients reporting no sexual activity also showed a significantly lower correlation of scores than that in patients reporting sexual activity. CONCLUSIONS Expanded Prostate Cancer Index Composite scores generally demonstrate strong correlations with corresponding Incontinence Symptom Index and Sexual Health Inventory for Men scores, indicating similar measurements of information. Divergent correlations between irritative scores as well as scores in men who are not sexually active may indicate that the Expanded Prostate Cancer Index Composite has more descriptive validity in this population. Wider use of a single broad domain instrument such as the Expanded Prostate Cancer Index Composite to assess outcomes after prostate cancer treatment may improve clinical efficiency and allow comparative quality of life research across treatment types in the future.