Improving Immunization Rates in a Hospital-Based Primary Care Practice

OBJECTIVE: We implemented a quality improvement initiative aimed at reaching a 95% immunization rate for patients aged 24 months. The setting was a hospital-based pediatric primary care practice in Boston, Massachusetts. We defined immunization as full receipt of the vaccine series as recommended by the Centers for Disease Control and Prevention.

METHODS: The initiative was team-based and structured around 3 core interventions: systematic identification and capture of target patients, use of a patient-tracking registry, and patient outreach and care coordination. We measured monthly overall and modified immunization rates for patients aged 24 months. The modified rate excluded vaccine refusals and practice transfers. We plotted monthly overall and modified immunization rates on statistical process control charts to monitor progress and evaluate impact.

RESULTS: We measured immunization rates for 3298 patients aged 24 months between January 2009 and December 2012. Patients were 48% (n = 1576) female, 77.3% (n = 2548) were African American or Hispanic, and 70.2% (n = 2015) were publicly insured. Using control charts, we established mean overall and modified immunization rates of 90% and 93%, respectively. After implementation, we observed an increase in the mean modified immunization rate to 95%.

CONCLUSIONS: A quality improvement initiative enabled our pediatric practice to increase its modified immunization rate to 95% for children aged 24 months. We attribute the improvement to the incorporation of medical home elements including a multidisciplinary team, patient registry, and care coordination.