The MSHQ was administered to 1245 men in the Men’s Sexual Health Population Survey, 179 gay/bisexual men in the Urban Men’s Health Study, and 6909 men with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH) in the BPH Registry & Patient Survey. Factor analysis, scale reliability, construct and discriminant validity, and the correlation between the MSHQ-EjD Short Form and the MSHQ ejaculatory function domain were assessed.
Factor loadings of greater than 0.5 were demonstrated for four ejaculatory function items (force, volume, frequency, and delay). The force and volume of ejaculation had the greatest factor loadings (range 0.77 to 0.81), followed by frequency of ejaculation (0.64 and 0.66). These three ejaculatory function items had a high degree of internal consistency (Cronbach alpha ≥0.78) and test-retest reliability (r = 0.72). The three items discriminated between men with none/mild LUTS and those with moderate/severe LUTS (P <0.001). After adjusting for age, depression, and erectile function, the odds ratio for a diagnosis of moderate/severe LUTS was 0.68 (95 % confidence interval 0.49 to 0.96; P <0.05). The three items had a correlation coefficient of 0.95 with the 7-item MSHQ ejaculatory function domain. The MSHQ ejaculation bother item, an independent domain, showed moderate correlation with the three ejaculatory function items (r = −0.41 and r = −0.45).
The results of our study have shown that the MSHQ-EjD Short Form, with three ejaculatory function items and one ejaculation bother item, has excellent psychometric properties and should be a useful instrument for assessing EjD in clinical and research settings.