Introduction: Some men with premature ejaculation (PE) and normal erectile function record contradictory response/s to The Sexual Health Inventory for Men (SHIM) and may be incorrectly categorized as suffering from erectile dysfunction (ED).
Aims: The aim of this study was to evaluate the frequency of false positive SHIM diagnosis of ED in men with lifelong PE.
Main outcome measures: SHIM, stopwatch intravaginal ejaculation latency time (IELT).
Methods: A prospective observational study of men with normal erectile function and lifelong PE, diagnosed using the ISSM definition of lifelong PE, was conducted. The SHIM was self-administered at Visit 1. Mean per subject stopwatch IELT was determined from four subsequent intercourse attempts.
Results: Seventy-eight subjects with a mean age of 33.2 +/- 8.3 years and a geometric mean IELT of 15.9 +/- 2.3 seconds were enrolled. The mean SHIM score for all subjects was 20.4 +/- 6.0. Fifty-two subjects (66.7%) have SHIM scores of >21 (mean 24.3 +/- 1.1), consistent with normal erectile function, and a geometric mean IELT of 18.3 +/- 2.2 seconds. Twenty-six subjects (33.3%) had SHIM scores <22 (mean 12.7 +/- 3.7), consistent with a false positive diagnosis of ED, and a geometric mean IELT of 10.5 +/- 2.3 seconds. The incidence of false positive SHIM diagnosis of ED (SHIM < 22) was inversely related to the IELT. Although the geometric mean IELT for subjects with SHIM scores <22 was significantly less than that of all subjects and subjects with SHIM scores >21, there were no significant differences between the geometric mean IELT or the IELT distribution of all subjects vs. the normal erectile function IELT (SHIM > 21) cohort.
Conclusion: This study demonstrates a 33.3% false positive SHIM diagnosis of ED in men with PE. This is likely to limit subject recruitment in clinical trials by exclusion of subjects with low-range IELTs but is unlikely to result in significantly different baseline IELTs or IELT distributions.