Aims: To study the use of the IIEF-5 questionnaire in the evaluation of post-RRP ED and to find possible variations in ED reporting when comparing IIEF-5 to single-item assessment.
Methods: At a minimum of 18 months post-surgery, patients completed a questionnaire on erectile function that included both single-item assessment and the IIEF-5. The study included sexually active patients who reported no pre-operative ED and who did not receive adjuvant or salvage therapy.
Main Outcome Measures: For the single-item assessment, potency was defined as “the ability to achieve erections firm enough for intercourse”. For the IIEF-5 questionnaire, potency was defined as a score >22 (out of 25) points. Results: Ninety-one patients were included in the study. The procedures consisted of bilateral nerve-sparing (55%) or unilateral or partial bilateral nerve-sparing surgery (45%). We found a striking difference in potency rates when using either IIEF-5 score or single-item assessment for reporting of potency after RRP. The results when using the IIEF-5 questionnaire indicated that 25.5% of all patients were potent. In contrast, single-item assessment indicated a potency rate of 53.8%.
Conclusions: Using the IIEF-5 questionnaire to evaluate ED following RRP results in a remarkably lower percentage of men being classified as having no ED. This might be the main reason IIEF-5 is not frequently used in the reporting of ED following radical prostatectomy. Literature search reveals that the IIEF-5 questionnaire is expected to have a higher level of validity, accuracy, and reliability, and may be more stable than single-item assessment. We think that the use of IIEF-5 in the reporting of ED following RRP enhances comparison of different series and of different treatment modalities. However, a prospective comparison between IIEF-5 and single-item assessment is needed to confirm this finding.