Immunization Coverage and Clinical Documentation of Vaccine Refusal in Pediatric Clinics: A Retrospective Analysis in the Midwestern United States, 2022-2024.

Objective: Vaccine hesitancy has increased in recent years, prompting some pediatric practices to implement strict immunization policies. Accurate documentation of vaccine refusal is essential for monitoring trends and informing interventions. This retrospective analysis assessed immunization coverage and refusal documentation among pediatric patients in a Midwestern health care system with a policy requiring adherence to the Centers for Disease Control and Prevention immunization schedule. Study design: We analyzed electronic health record data for patients born in 2022 who received primary care at pediatric clinics within the system. We assessed immunization coverage through 24 months of age and used International Classification of Diseases, Tenth Revision, Clinical Modification Z codes to identify documentation of underimmunization and refusal. We used logistic regression to examine associations between refusal documentation and patient characteristics. Results: Among 2164 eligible patients, 300 (13.9%) had documented vaccine refusal. Coverage for most immunizations was comparable with national estimates. Refusal documentation was more common among White non-Hispanic patients and those with Medicaid or self-pay insurance. Patients from greater-income neighborhoods had greater odds of documented refusal. Among refusal codes, 39.6% used the designation "patient refusal," a code intended for individuals making their own health care decisions. Conclusions: This analysis highlights the frequency of vaccine refusal documentation and variation by sociodemographic characteristics. Use of International Classification of Diseases, Tenth Revision, Clinical Modification codes to document refusal limited interpretability by not specifying the immunization refused or whether it was a true refusal or delay. Improved coding specificity and integration of refusal tracking into electronic health records may enhance the utility of clinical data for monitoring immunization trends and informing policy.