Optimal Timing to Evaluate Prediagnostic Baseline Erectile Function in Patients Undergoing Robot‐Assisted Radical Prostatectomy

Abstract

Accurate assessment of prediagnostic baseline erectile function (EF) is crucial when evaluating postoperative changes of EF in patients undergoing bilateral nerve sparing robot-assisted laparoscopic radical prostatectomy (RLRP). Because score domains of the International Index of Erectile Function-5 (IIEF-5) can be affected by factors such as recall intervals and psychological stress or discomfort due to cancer diagnosis and treatment, it is important to assess the prediagnostic baseline EF at appropriate times. To determine optimal timing to evaluate prediagnostic baseline EF in patients undergoing bilateral nerve sparing RLRP. Between March 2009 and February 2010, 54 patients ranging in age from 48 to 74 years were asked to complete IIEF-5 questionnaires before prostate biopsy, 1 day before RLRP, and 1 month after RLRP to assess preoperative baseline EF. Differences in the mean scores of IIEF-5 were analyzed using paired t-tests. The strengths of the linear relationships among the three IIEF-5 scores were quantified using Pearson's correlation coefficient. An interrator agreement analysis in distribution was performed using the kappa statistic to determine the degree of agreement among the IIEF-5 scores. The mean IIEF-5 score before RLRP was significantly higher than the mean IIEF-5 score before prostate biopsy (P < 0.001). There was no significant difference between the mean IIEF-5 scores before prostate biopsy and 1 month following RLRP (P = 0.931). Scores of the IIEF-5 taken before prostate biopsy and 1 month following RLRP showed substantial agreement (kappa = 0.712), whereas scores of the IIEF-5 taken before prostate biopsy and before RLRP showed lower agreement (kappa = 0.325). To more accurately assess the prediagnostic baseline EF in patients with localized prostate cancer, the IIEF-5 questionnaire should be administered before prostate biopsy rather than before RLRP as cancer diagnosis-related symptoms and depression can affect IIEF-5 scores.