Reliability and structural validity of the Female Sexual Function Index in Spanish female university students

The Female Sexual Function Index (FSFI) is a questionnaire designed to assess sexual response in women and is widely used in both research and clinical settings. A systematic review has questioned the reliability of the instrument. The aim of the present study was to examine the reliability and factor structure of the questionnaire in Spanish female university students.

The sample consisted of 263 female university students, with a mean age of 22.67 years (SD = 6.08). The original 19-item version of the Female Sexual Function Index was used. The questionnaire assesses six different domains: Sexual desire, arousal, lubrication, orgasm, satisfaction, and pain.

Item analysis showed that item-total correlations ranged from 0.498 to 0.921. The reliability of the questionnaire, assessed using Cronbach's alpha, was 0.975, while the reliability coefficients for each of the scales ranged from 0.803 to 0.972. The statistical indicators used to assess the suitability of conducting factor analysis were satisfactory. Finally, the confirmatory factor analysis indices indicated a good fit of the questionnaire to the six-factor structure of the original model.

The results indicate that the FSFI demonstrates good psychometric properties, supporting its use in both research and clinical settings. Future studies are recommended to replicate the validation to verify the continued validity of the instrument, as well as its adaptation to the updated criteria of the main diagnostic manuals.