To determine the reliability and validity of the Sexual Interest and Desire Inventory - Female (SIDI-F), a 13-item clinicianʼs rating with 30-day recall, for measuring severity of Hypoactive Sexual Desire Disorder (HSDD) in European women, using, for convergent validation, two standard self-ratings: Female Sexual Function Index (FSFI), Changes in Sexual Functioning Questionnaire-Female (CSFQ-F); for divergent validation, the Marital Adjustment Scale (MAS).

130 women with primary HSDD and 124 with no Female Sexual Dysfunction (no FSD) were studied in 11 European countries. Diagnosis and scales were performed on day 0 and 28.

For HSDD patients, all results for SIDI-F confirmed reliability and validity. Test-retest reliability between day 0 and 28 was demonstrated with an intraclass correlation coefficient of 0.67 and a Pearson correlation coefficient of 0.70. Convergent validity was demonstrated through correlation between SIDI-F and other tests at day 0: Pearsonʼs correlation to CSFQ-F (0.67) and FSFI (0.76). Low correlation of SIDI-F to MAS (0.23) showed divergent validity. SIDI-F showed more impairment in desire in HSDD than in no FSD women, with baseline values of 20.1 ±8.4SD and 41.8 ±5.2SD, respectively (p<0.0001), thus providing discriminant validity. The SIDI-F reliably distinguished women with HSDD from no FSD women (p< 0.0001) in each country (n=13-25 per country). Mean SIDI-F scores ranged from 11.6-27.0 in women with HSDD and from 36.4-46.3 in no FSD women.

This study provides strong support for the reliability and validity of the SIDI-F as a measure of HSDD severity in European women.