| Abstract: |
Introduction. The absence of a single brief measure that assesses function and health-related quality of life (HRQoL) hinders evaluation of the sexual experience in men with erectile dysfunction (ED). Aim. To psychometrically analyze the Sexual Experience Questionnaire (SEX-Q). Methods. Two data sets were Studied. A randomized, double-blind, placebo-controlled trial of flexible-dose sildenafil for ED treatment provided the final clinical trial data set (213 men enrolled, 4 of whom did not receive treatment) and the interim clinical trial data set (190 men screened and 165 men enrolled). The survey data set consisted of 902 respondents to a U.S. community health survey, of whom two-thirds had ED and one-third did not. Main Outcome Measures. Quality and distribution of responses, comparative fit, item-level discriminant testing, internal consistency (Cronbach alpha), test-retest reliability (intraclass correlation coefficient), known-groups validity (Vs. International Index of Erectile Function [IIEF] ED severity groups), convergent validity (Pearson correlation coefficients with scores on the IIEF, Self-Esteem and Relationship [SEAR] questionnaire, and Quality of Erection Questionnaire [QEQ]), responsiveness, and clinically important difference (CID). Results. The original 15 items were reduced to 12 items in three domains (erection, individual satisfaction, and couple satisfaction), which demonstrated good quality responses for all items; a strong factor structure; excellent internal consistency; good test-retest reliability, clear known-groups validity across the severity groups; moderate to strong convergent validity against the IIEF, SEAR, and QEQ; and high treatment responsiveness. The estimated CID ranged from 16.0 to 22.3 across domains. Conclusions. The SEX-Q is the first questionnaire to solely and exclusively combine functional and HRQoL concepts (erection, individual satisfaction, and couple satisfaction domains) in a brief questionnaire, which allows a more focused and less burdensome evaluation of the sexual experience, making it a potentially useful measure for clinical trial research. |
