Ohnut Versus a Waitlist Control for the Self-management of Endometriosis-Associated Deep Dyspareunia: Protocol for a Pilot Randomized Controlled Trial

BACKGROUND: Endometriosis-associated deep dyspareunia is associated with reduced sexual quality of life, lower self-esteem, and impaired sexual function. OBJECTIVE: The primary objective is to assess the acceptability of a phallus length reducer (brand name: Ohnut [OhnutCo]), which is a buffer worn over the penis or a penetrating object to reduce endometriosis-associated deep dyspareunia, and the feasibility of a definitive randomized controlled trial (RCT). The secondary objective is to obtain estimates of the effectiveness of the buffer. An embedded substudy will explore the acceptability and the preliminary validity and reliability of a vaginal insert for the self-assessment of deep dyspareunia. METHODS: Ours is an investigator-initiated, 2-arm RCT. We will recruit 40 patient participants with diagnosed endometriosis between the ages of 19 and 49 years, as well as their sexual partners. The participating couples will be randomized in a 1:1 ratio into the experimental arm or the waitlist control arm. The length of the study period will be 10 weeks, during which time all participants will record deep dyspareunia severity following each episode of sexual intercourse. In weeks 1 to 4, all patient participants will record deep dyspareunia severity at each sexual encounter. In weeks 5 to 10, participants in the experimental arm will use the buffer during vaginal penetration; participants in the waitlist control arm will continue engaging in vaginal penetration as usual. Participants will complete questionnaires for assessing measures of anxiety, depression, and sexual function at baseline, at 4 weeks, and at 10 weeks. In the substudy, patient participants will self-assess dyspareunia by using a vaginal insert on 2 occasions, at least 1 week apart. The primary outcomes—the acceptability and feasibility of the buffer—will be assessed with descriptive statistics, and the secondary outcome—phallus length reducer effectiveness—will be assessed by using an analysis of covariance–based approach. For the vaginal insert, we will assess acceptability, test-retest reliability, and convergent validity via correlation analyses comparing the use of the insert to clinical examination in terms of dyspareunia assessment outcomes. RESULTS: Our pilot will provide initial data on the acceptability and effectiveness of the buffer and the feasibility of the study methodology. The results from our study are expected to be submitted for publication by the spring of 2023. As of September 2021, we have consented 31 couples into the study. CONCLUSIONS: Our study will provide preliminary evidence for the self-assessment and management of endometriosis-associated deep dyspareunia. The findings will inform the decision to proceed to a definitive RCT. TRIAL REGISTRATION: ClinicalTrials.gov NCT04370444; https://clinicaltrials.gov/ct2/show/NCT04370444 INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/39834