Opt-out HIV testing among pregnant emergency department patients: A retrospective pre-post implementation cohort study.

INTRODUCTION To evaluate the association between implementation of an emergency department (ED)-wide opt-out HIV testing initiative and HIV testing among pregnant patients presenting to an urban ED.

Methods

A retrospective pre-post implementation cohort study comparing HIV testing practices pre- and post-implementation of an ED-wide opt-out HIV testing initiative in September 2025. Eligible encounters included pregnant patients aged ≥18 years. Data were extracted from the electronic medical record and validated by dual chart review. The primary outcome was completion of HIV testing during the ED encounter. Generalized estimating equations were used to account for repeat encounters among individual patients.

Results

A total of 101 pregnancy-associated ED encounters representing 71 unique patients were included. HIV testing was completed in 17.8% of encounters. Testing increased from 8.9% pre-implementation to 28.9% post-implementation (OR 3.92, 95% CI 1.35-11.43; p = 0.012). In multivariable modeling, the post-implementation period remained independently associated with HIV testing (adjusted OR 4.04, 95% CI 1.58-10.34, p = 0.0036). Exploratory subgroup analyses suggested increased HIV testing across several clinically vulnerable groups after implementation; however, these analyses were limited by very small sample sizes.

Conclusions

Implementation of an ED-wide opt-out HIV testing initiative was associated with increased HIV testing among pregnant ED patients. Although testing remained below universal screening levels, the findings suggest that ED-based workflow interventions may reduce missed opportunities for recommended HIV testing.