Related Experiment Video
Updated: Mar 16, 2026

Generating Whole Bacterial Genomes from Clinical Samples using a Target Enrichment Workflow
Published on: August 15, 2025
Outcomes of an Opt-Out Chlamydia Testing Program Across 21 Northern California Pediatric Clinics
Adam Carl Sukhija-Cohen1, Amandeep Kaur Grewal1, Jane Vu1
1Center for Health Systems Research, Sutter Health, Sacramento, California.
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 preimplementation (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 (χ2[df] = 1,089.5[1]; 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% (χ2[df] = 5.4[1], = .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.

