Evaluation of a Self-Test Technology for Chlamydia and Gonorrhea Testing: Observational Before-and-After Study

Abstract Background Chlamydia remains highly prevalent, and the prevalence of gonorrhea is increasing. Declining testing rates alongside rising positivity in Denmark highlights the need for accessible testing solutions. Self-test technologies (STTs) may reduce stigma and improve testing uptake. Objective This study aimed to examine the effects of implementing an STT on activity-related outcomes, including test volume, testing frequency, and positivity rates for sexually transmitted infections (chlamydia and gonorrhea) at a sexual health clinic. Methods A retrospective before-and-after study evaluated the implementation of an STT located in a sexual health clinic at a university hospital over the period of 2022 to 2025. The evaluation consisted of 3 phases: preimplementation phase (phase 0), self-test with booking (phase 1), and drop-in self-test (phase 2). Outcomes included testing volume, frequency, positivity rates, staff resource use, and costs, assessed using descriptive statistics and chi-square tests. Results The monthly tests increased from a mean of 163 (SD 51) before implementation to 246 (SD 42) and 283 (SD 78) in phases 1 and 2, respectively. The proportion of patients tested multiple times increased significantly ( P =.001). Positivity rates declined from 15.7% (180/1144) to approximately between 12% (652/5417) and 12.6% (464/3689; P =.003). Weekly staff time decreased from 102 to 63.75 hours, and annual personnel costs declined by 37%. Despite increased testing volume, the cost per test decreased from DKK 1179 (US $185) to DKK 501 (US $79). Conclusions Implementation of an STT increased testing activity and efficiency while reducing costs and staff resource use, suggesting that self-testing is a scalable and resource-efficient strategy for sexually transmitted infection diagnostics in clinical settings.