Psychometric evidence of the International Index of Erectile Function (IIEF) in a Chilean representative sample

Abstract

Amongst many psychometric instruments to measure male sexual dysfunctions, the International Index of Erectile Function (IIEF) stands out for its utility and widespread use. However, its internal latent structure lacks consistency across studies. Furthermore, studies have yet to address its measurement invariance evidence. Moreover, no formal validation of the IIEF has been conducted in Chile. Therefore, the following study aimed to comprehensively evaluate its psychometric evidence in a Chilean sample of men and determine its measurement invariance across relationship status, age groups, and paraphilic interests. A sample of 650 sexually active males was derived from a broader Chilean study (CSSS). We used a confirmatory factor analysis to determine its structural validity, sexual satisfaction dimensions to establish its criterion-related validity, and Cronbach's alpha and McDonald's omega to assess the reliability of its scores. Results supported the five-factor latent solution. Meanwhile, criterion-related validity revealed subtle yet significant differences in sexual satisfaction, with younger men displaying higher satisfaction in various sexual domains, whereas middle-aged men and those in a relationship showed better sexual function. Finally, the IIEF was invariant across relationship status, age groups, and paraphilic interests at the factor covariance level. Limitations included a lack of clinical population and a sample predominantly younger, cisgender, and heterosexual. Altogether, this study highlights the IIEF's suitability for assessing male sexual function in Chilean male populations across diverse sociodemographic characteristics. Future research efforts should focus on expanding sample diversity, including clinical populations.