Outcomes of an Opt-Out Chlamydia Testing Program Across 21 Northern California Pediatric Clinics

Purpose: To determine if implementation of opt-out chlamydia testing increased diagnoses among female pediatric patients at the Palo Alto Medical Foundation in Northern California.Methods: We conducted a retrospective study of 21,660 active female patients aged 16-24 at 21 pediatric clinics.Chi-square tests with degrees of freedom (df) assessed changes preimplantation (2023) and postimplementation (2024) of opt-out testing and across demographic subgroups.Results: Testing more than doubled, from 12.9% in 2023 to 31.7% in 2024 ( 2 df = 1,089.51;p < .001),with increases across all age, insurance, and racial/ethnic groups.Gains were largest among patients with private insurance and those identifying as Hispanic/Latino or non-Hispanic Asian.Although the proportion of diagnoses declined from 1.6% to 0.9% ( 2 df = 5.41, = .02),the number of diagnoses rose from 22 to 30.Discussion: Embedding opt-out testing in pediatric visits is a scalable strategy to advance sexually transmitted infection prevention goals.