Factors associated with COVID-19 vaccination in a national network of primary care safety net clinics

Context: Community health centers (CHCs) played an essential role in the COVID-19 response, including providing equitable access to vaccinations in the historically underserved communities hit hardest by COVID-19. However, there is substantial variation in COVID vaccination rates between CHCs.

Objective: To describe 1) COVID-19 vaccination rates, and 2) factors associated with variation in these rates within a national network of CHCs with a shared electronic health record (EHR).

Study Design and Analysis: Mixed-level cross-sectional study, 2020-2023.

Setting or Dataset: EHR data from the Accelerating Data Value Across a National Community Health Center Network (ADVANCE) clinical research network.

Intervention/Instrument: NA

Outcome Measures: Proportion of established clinic patients with completed the primary COVID vaccine series as of 12/31/2022.

Results: Among 1284 clinics and 2,459,306 patients, 48.5% (SD 0.65, IQR 32.5%-66.1%) of eligible patients had completed the COVID primary series by the end of 2022. Clinics in the bottom quintile of completion rates had an average of 12.5% (SD 0.5, IQR 4.3%-20.4%) patients who completed the primary series; those in the highest quintile had an average of 78.0% (SD 0.7, IQR 72.4%–81.8%). Clinics in the lowest quintile were more often located in the South (53.1% compared to 18.0% of all clinics), served a higher proportion of Black patients (23.8% compared to 16.3%), treated more patients aged younger than 18 (55.8% compared to 34.5%) and fewer aged older than 64 (3.8% compared to 9.1%). Clinics in the highest quintile were more often located in the western United States (81.3% compared to 55.5%), served a higher proportion of Asian patients (12.3% compared to 4.8%), and served fewer patients younger than 18 (24.3% compared to 34.5%) and more patients older than 64 (15.3% compared to 9.1%).

Conclusions: Diverse factors are associated with variation in COVID vaccination rates in safety net CHCs; research is needed to understand how these factors influence equitable access to vaccinations.