Suggestions for modifications to the Female Sexual Function Index based on cognitive interviews with sexual and...

Patient-reported outcome measures for sexual health were often designed for research studies that included only heterosexual, partnered, and cisgender participants; as such, they may have limited applicability for clinical use among sexual and gender minority (SGM) individuals or those without a partner.

We aimed to conduct cognitive interviews with SGM persons and heterosexual women to determine the readability, comprehension, and applicability of questionnaire items to assess sexual function among diverse sexual and gender identities.

We conducted 4 rounds of cognitive interviews with 52 participants (28 SGM; 24 cisgender, heterosexual) who provided feedback on the comprehension and wording of questionnaire items and response scales. We used items from the Female Sexual Function Index (FSFI) and focused on establishing content validity of a modified measure. Participants made recommendations for changes to the questionnaire, which was iteratively revised between interview rounds. Two independent coders analyzed the transcripts using structural coding based on 5 predefined codes: satisfaction with item, specificity/language change needed, missing/suggested item, patient definitions of concepts, and confusion with item.

Content validity.

After 3 rounds of cognitive interviews and revisions to the questionnaire, participants found the final version acceptable and understandable, thereby reaching thematic saturation and establishing content validity of the modified FSFI. Modifications included the following: replacing all instances of "sexual stimulation" and "intercourse" with "sexual activity (alone or with a partner)," broadening the definition of "vaginal penetration" beyond penile-vaginal penetration, and adding skip logic to include the option "no sexual activity." Participants identified missing concepts important to their sexual health, such as use of an external lubricant.

The FSFI and similar questionnaires need to be adapted to broader clinical practice populations such that all persons' experiences are accurately reflected and assessed, ensuring that sexual health needs can be met more inclusively.

A strength of the study was using cognitive interviews engaging patient perspectives, which is considered the gold standard for establishing content validity. One limitation is that participants included predominantly White and highly educated women.

Feedback from interviews supports modifying FSFI items and further psychometric testing, and future studies should evaluate the measure among racially and educationally diverse groups.