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

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.