Exploring the Optimal Erectile Function Domain Score Cutoff That Defines Sexual Satisfaction After Radical Prostatectomy

Introduction: The International Index of Erectile Function (IIEF) is the gold standard validated instrument for defining erectile function (EF) and its response to treatment. The EF domain (EFD) contains six questions and is a sensitive and specific measurement of treatment-related changes in EF. The EFD score has been widely used as a primary assessment end point for clinical trials of EF recovery after radical prostatectomy (RP). Various EFD scores have been used to define functional erections. Recently, an EFD score of at least 22 has been used as a threshold in major post-RP penile rehabilitation studies. Aim: To define the EFD score that optimally defines "functional" erections after RP. Methods: We assessed men 24 months after RP using the IIEF and specifically analyzed the scores of the EFD and intercourse satisfaction domain (ISD). Main Outcome Measures: We used two questions on satisfaction (score = 0-5) and enjoyment (score = 0-5) from the ISD to classify IS (score = 0-10). We tested the following intercourse satisfaction classifications: ISD score equal to 10, ISD score of at least 8, and a score of at least 4 for the ISD questions on satisfaction and enjoyment. We used the classification that produced the largest area under the curve (AUC) using a receiver operating characteristic (ROC) curve. Then, we used a three-step process to determine the optimal EFD score cutoff using sensitivity and specificity analysis. Results: One hundred seventy-eight men had an average age at RP of 58 +/- 7 years and a 24-month EFD score of 20 +/- 9. Sixty-four percent had complete nerve-sparing surgery, 35% had partial nerve-sparing surgery, and 1% had the nerves fully resected. Thirty-three percent had laparoscopic RP and 67% had open RP. The ROC curves produced AUCs of 0.80 (ISD score = 10), 0.85 (ISD score >= 8), and 0.86 (ISD scores for satisfaction and enjoyment >= 4; P<.001 for all comparisons). Using the IS criterion of ISD scores for satisfaction and enjoyment of at least 4 (largest AUC), the sensitivity and specificity values were 0.89 and 0.66 for an ESD score equal to 22, 0.78 and 0.71 for a score equal to 23, 0.78 and 0.80 for a score equal to 24, 0.77 and 0.82 for a score equal to 25, and 0.73 and 0.85 for a score equal to 26. The scores of 24 and 25 met the criteria outlined in the first two steps of analysis. The score of 24 was selected as the cutoff using face valid judgment and the previous literature. Conclusion: These data support an EFD score of 24 as a valid cutoff defining "functional" erection in men with erectile dysfunction after RP. These data are important for clinicians in counseling patients and to researchers to define inclusion criteria and treatment end points for trials of erectile dysfunction after RP. Copyright (C) 2017, International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.