Figure 2. (a) The mean successful erectile response rates in sildenafil and placebo groups (no carryover [P = 0.33] or period effects [P = 0.86] were found). The successful erectile response rate was significantly higher with sildenafil than with placebo (P = 0.008, Wilcoxon test). (b) The mean successful intercourse rates in sildenafil and placebo groups (no carryover [P = 0.07] or period effects [P = 0.11] were found). The successful intercourse rate was significantly higher with sildenafil than with placebo (P < 0.001, Wilcoxon test). Vertical bars represent SD.
