183 - Test of concept: a practical method for monitoring equity in quality improvement

Publication Number: 3176.183

David M. Gordon, University of California San Francisco, San Francisco, CA, United States; Taylor Clark, University of California, San Francisco, School of Medicine, San Francisco, CA, United States

Background: Equity is a cornerstone of high-quality healthcare. Several population-level equity evaluations have been reported, but sample size constraints have hampered efforts by quality improvement (QI) teams to detect inequity at the site level.

Objective: Test a practical, systematic method for monitoring equity using QI data at our site.

Design/Methods: Our pediatric urgent care (PUC) clinic offered routine immunizations to eligible patients from March 1, 2021 to November 17, 2024. Immunization screening data were collected monthly. We applied a novel approach called "longitudinal disparity analysis" (LDA) to identify screening disparities between Black/African American (BAA) and non-BAA patients. SPC charts were created for B/AA and non-B/AA patients, and center lines (CLs) were adjusted using Institute for Healthcare Improvement rules. We calculated minimum sample size (nmin) for proportions assuming effect size=0.5, power=80%, α=0.05, and encounter ratio=1:10. We created a "Δ chart" that plotted the difference in screening between groups. Consecutive intervals were merged until nmin was achieved. To avoid comparing groups under changing conditions, we did not merge across CL adjustments. Screening was compared at each merged interval using 2-tailed Fisher's exact test.

Results: The CL for visits by B/AA patients was 49.2% and no adjustments were made. Three CL adjustments were made in the SPC chart for non-BAA patients, resulting in CLs of 48.8% (baseline), 35.8%, 66.2%, and 48.9%. Adjustments corresponded to the COVID-19 omicron surge, the introduction of a dedicated nurse vaccinator (DNV), and the imposition of vaccine service restrictions, respectively. To achieve nmin at each Δ chart interval, we merged 41 4-week intervals into 12 intervals ranging in size from 8 to 28 weeks. Four intervals were modestly under-powered to avoid merging across CL adjustments. Lower screening rates were observed during visits by B/AA patients after screening duties shifted to the DNV and after service restrictions were imposed.

Conclusion(s): LDA identified inequitable immunization screening at our PUC. Investigation is warranted at our site. LDA may support equity-centered QI, but additional testing is needed using prospectively-collected data, and additional development is needed to accommodate continuous and rate measures.

P chart, percent of visits by eligible non-Black/African American patients during which immunization screening occurred, ZSFG pediatric urgent care, March 1, 2021 - November 17, 2024 (n=4605)


P chart, percent of visits by eligible Black/African American patients during which immunization screening occurred, ZSFG pediatric urgent care, March 1, 2021 - November 17, 2024 (n=556)


Δ chart, percent of visits by eligible patients during which immunization screening occurred, "visits by non-Black/African American patients - visits by Black/African American patients", ZSFG pediatric urgent care, March 1, 2021 - November 17, 2024 (n=5161)