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

Introduction: An instrument that can systematically capture the impact of sexual dysfunction on quality of life (QoL) in men is needed.

Aims: To psychometrically validate a sexual QoL instrument for men (SQOL-M) with premature ejaculation (PE) or erectile dysfunction (ED).

Methods: 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 < or = 2 minutes in > or = 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.

Main Outcome Measures: The internal consistency, convergent and discriminant validity, test-retest reliability, and known-groups validity of the instrument were assessed.

Results: 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 > or = 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).

Conclusions: The SQOL-M instrument is a useful tool for evaluating sexual QoL in men with PE and ED.