Comparison of the simplified International Index of Erectile Function (IIEF-5) in patients of erectile dysfunction with different pathophysiologies

BACKGROUND: The simplified International Index of Erectile Function (IIEF-5) is a convenient, reliable and validated diagnostic tool for erectile dysfunction (ED). However, few studies focused on IIEF-5 in ED patients with different pathophysiological causes. ,We aim to compare the IIEF-5 score among ED patients with specific pathophysiologies in this study. METHODS: The IIEF-5 score of 3,327 ED patients (median age 39 years) was analyzed. The primary causes of ED were determined by comprehensive diagnostic procedures in the urology/andrology clinics in five training hospitals. Patients with uncertain pathophysiologic cause were excluded. RESULTS: 176 patients were excluded, 3151 patients with ED history between 0.5 year and 20 years, were enrolled. The causes of ED was classified as psychogenic (59.2%), vasoculogenic (21.3%), neurogenic (4.1%), anatomical/structural (2.8%), hormonal (7.1%) or drug-induced (5.5%). A significant difference was detected in the median IIEF-5 score between psychogenic ED and organic ED (15 (IQR 13, 17) versus 12 (IQR 9.5, 14.5), P < 0.001). There was no significant difference of IIEF-5 scores among the organic groups (P = 0.073), or between arteriogenic and venogenic groups (13 (IQR 10.5, 15.5) versus 13 (IQR 11–15), P = 0.912 (adjusted α = 0.017)). However, the median IIEF-5 score of those with a mixed vascular cause was the lowest among vasculogenic patients (11 (IQR 8.5-13.5), scores for the three groups: P = 0.003.). CONCLUSIONS: The IIEF-5 scores of men with psychological ED are higher than those with organic causes, but there is no difference among patients with different organic pathophysiologies. Our data indicate that IIEF-5 is not a definitive diagnostic tool to discriminate the pathophysiological causes of ED.