International Index of Erectile function (IIEF) among Filipino Men: A Reliability and Validity using Exploratory and Confirmatory Factor Analyses

Abstract

The International Index of Erectile Function (IIEF) has emerged as a pivotal instrument for the evaluation of erectile dysfunction (ED) in both clinical and research settings. However, its psychometric properties have not been extensively examined among diverse populations. This study aimed to investigate the validity and reliability of the IIEF among a sample of Filipino men, given the distinct socio-cultural perspectives associated with sexuality and ED in this demographic. A total of N = 1,463 participants, aged 18 years and older, from various regions of the Philippines were enrolled. Initial evaluations confirmed the internal consistency of the IIEF, with Cronbach's alpha values consistently ranging from .78 to .92 for each of the five domains. For construct validity, exploratory factor analysis (EFA) was first utilized, revealing three-factor structure (sexual intercourse, stimulation, and satisfaction [IIEF-SSS]). Cronbach’s alpha for each IIEF-SSS subscale ranges from .76 to .96. Subsequent confirmatory factor analysis (CFA) provided robust support for this structure, with fit indices suggesting a strong model fit (X2 = 252.95, df = 80, X2/ df ratio = 3.16, RMSEA = 0.059, NFI = .97, CFI = .98, IFI= .98, GFI = .95, AGFI = .92). The results of this comprehensive analysis underscore the IIEF-SSS’ robustness as a psychometric tool, confirming its reliability and validity within a Filipino context. Healthcare providers and researchers in the Philippines can, therefore, employ the IIEF-SSS with confidence when assessing ED. Additionally, the findings illuminate the instrument's cross-cultural adaptability, offering a precedent for its potential application in other diverse settings. Future studies could further delve into the cultural nuances impacting ED and its perception among Filipino men.