The Female Sexual Function Index (FSFI): linguistic validation of the Italian version

Introduction: Although several new measurements for female sexual dysfunction (FSD) have recently been developed, the Female Sexual Function Index (FSFI) remains the gold standard for screening and one of the most widely used questionnaires. The Italian translation of the FSFI has been used in several studies conducted in Italy, but a linguistic validation of the Italian version does not exist.

Aim: The aim of this study was to perform a linguistic validation of the Italian version of the FSFI.

Methods: A multicenter cross-sectional study conducted in 14 urological and gynecological clinics, uniformly distributed over Italian territory. We performed all steps necessary to determine the reliability and the test-retest reliability of the Italian version of the FSFI. The study population was a convenience sample of 409 Italian women.

Main outcome measures: The reliability of the questionnaire was calculated using Cronbach's alpha, which was considered weak, moderate, or high if its value was found less than 0.6, between 0.6 and 0.8, or equal to or greater than 0.8, respectively. The test-retest reliability was assessed for all women in the sample by calculating Pearson's concordance correlation coefficient for each domain and for the total score, both at baseline and after 15 days (r range between -1.00 to +1.00, where +1.00 indicates the strongest positive association).

Results: Cronbach's alpha coefficients for total and domain score were sufficiently high, ranging from 0.92 to 0.97 for the total sample. The test-retest procedure revealed that the concordance correlation coefficient was very high both for FSFI-I total score (Pearson's P = 0.93) and for each domain (Pearson's P always >0.92).

Conclusion: For the first time in the literature, our study has produced a validated and reliable Italian version of the FSFI questionnaire. Consequently, the Italian FSFI can be used as a reliable tool for preliminary screening for female sexual dysfunction for Italian women.