Measuring erectile function after radical prostatectomy: comparing a single question with the International Index of Erectile Function

Abstract

To present a single-question institutional erectile function scale, which was developed at Memorial Sloan-Kettering Cancer Center (MSKCC) before the availability of the International Index of Erectile Function (IIEF), and to compare its performance with the IIEF. Erectile function status assessment after radical prostatectomy is a significant challenge both for research purposes and in clinical practice. Recently, there has been a shift away from complex questionnaire use such as the IIEF and regression to single-item assessment of erectile function. Our erectile function score, a single question 5-point score based on physician-patient interview, was applied to 276 patients with prostate cancer after radical prostatectomy. Based on the erectile function score, patients were grouped into five groups. The mean IIEF score and the mean score of questions 3 and 4 of the IIEF were calculated and compared across the groups. Each score group was compared with the preceding group and tested for significant difference. The erectile function domain of the IIEF and the institutional score were tested for correlation. The complete erectile function domain score from the IIEF was available for 170 patients and scores from questions 3 and 4 were available for 220 patients. The institutional erectile function score categorized the subjects into distinct groups based on erectile function status. The institutional erectile function score was highly correlated with the IIEF erectile function domain score (r=-0.692, P < 0.001) and with the questions 3 and 4 combined score (r=-0.678, P < 0.001). The MSKCC erectile function scale is a practical, readily administered method to assess erectile function in patients with prostate cancer after radical prostatectomy. The erectile function score, as determined by this scale, is highly correlated with the IIEF erectile function domain score.