Improving rates of HIV testing in emergency departments in a health system using clinical decision support

Background Sexually transmitted infections (STIs) remain a public health priority. The Centers for Disease Control (CDC) recommends comprehensive screening for STIs and HIV, defined as testing for gonorrhoea/chlamydia (GC‐CT), syphilis and HIV in persons undergoing STI evaluation. Many patients utilize emergency departments (EDs) for STI evaluation; however, HIV co‐testing rates remain low. Electronic Health Record (EHR)‐based clinical decision support (CDS) can help providers implement best practices. We assessed the impact of two CDS tools on HIV co‐testing rates with GC‐CT in freestanding EDs (FSEDs) of a statewide health system. Methods CDS Interventions included Comprehensive STI Order Set made available 1/2024 and a Comprehensive STI Pathway made available 1/2025. We included FSED encounters for adult patients with GC‐CT NAAT 1/1/2022–11/21/2025 and measured HIV co‐testing rates. Process measures included overall CDS utilization by FSED type (urban Denver sites, Metro; outlying Colorado sites, Outlying; aggregated sites, All Sites). Analysis included statistical process control charts and descriptive statistics. Results GC‐CT testing occurred in 11 087 patient encounters between 1/1/2022 and 11/21/2025. HIV co‐testing rates averaged 2.6% 2 years before the intervention (2022–2023). After the first intervention (2024), HIV co‐testing rose to 13.1%, with a positive shift in SPC charts across All Sites, Metro and Outlying. After the second intervention (2025), HIV co‐testing rose to 18.3%, with greater impacts at Metro FSEDs; positive shifts in SPC charts were seen across All Sites and Metro but not Outlying EDs. Conclusions EHR‐based CDS was effective for increasing HIV co‐testing in freestanding EDs.