Analysis of the International Index of Erectile Function: psychometric evidence and measurement invariance across relationship status and age generations in a Chilean sample.

Background: The International Index of Erectile Function (IIEF) stands out for its utility and widespread use to measure sexual function in men. However, it lacks consistency in its internal latent structure across studies, has not been evaluated for measurement invariance, and has not undergone psychometric validation for its 15-item form in Spanish among South American countries.

Aim: To examine the IIEF's psychometric evidence (ie, structural/criterion validity and reliability) in a sample of adult men and determine its measurement invariance across relationship status (single vs in a relationship) and age generations (generations Z, Y/millennials, and X).