Psychometric validation of a sexual quality of life questionnaire for use in men with premature ejaculation or erectile dysfunction

An instrument that can systematically capture the impact of sexual dysfunction on quality of life (QoL) in men is needed. To psychometrically validate a sexual QoL instrument for men (SQOL-M) with premature ejaculation (PE) or erectile dysfunction (ED). The main assessment populations were men participating in clinical trials of treatments for PE or ED. Men with PE had a confirmed intravaginal ejaculatory latency time of <= 2 minutes in >= 70% of attempts. Men with ED had a score of > 21 on the International Index of Erectile Function (IIEF). Confirmatory psychometric testing was conducted in further groups of men with PE. The internal consistency, convergent and discriminant validity, test-retest reliability, and known-groups validity of the instrument were assessed. An 11-item version of the SQOL-M was produced following factor analyses on men with either PE or ED. Psychometric testing showed no overlap between items and good item-total correlations. Factor analysis confirmed a one-factor solution. Excellent internal consistency was demonstrated, with a Cronbach's alpha of >= 0.82 in all groups. In men reporting no change in their symptoms, the SQOL-M showed excellent test-retest reliability: the intraclass correlation coefficient was 0.77 for men with PE, and 0.79 for men with ED. Convergent validity was also good. In men with PE, the SQOL-M correlated with the satisfaction and distress domains of the Index of Premature Ejaculation. In men with ED, the SQOL-M correlated with the overall satisfaction domain of the IIEF. The measure also demonstrated excellent discriminant validity between men with PE or ED and men with no sexual dysfunction (P < 0.0001). The SQOL-M instrument is a useful tool for evaluating sexual QoL in men with PE and ED.