Accuracy and usefulness of the HEDIS childhood immunization measures

OBJECTIVE: With the use of Centers for Disease Control and Prevention (CDC) immunization recommendations as the gold standard, our objectives were to measure the accuracy ("is this child up-to-date on immunizations?") and usefulness ("is this child due for catch-up immunizations?") of the Healthcare Effectiveness Data and Information Set (HEDIS) childhood immunization measures. METHODS: For children aged 24 to 35 months from the 2009 National Immunization Survey, we assessed the accuracy and usefulness of the HEDIS childhood immunization measures for 6 individual immunizations and a composite. RESULTS: A total of 12 096 children met all inclusion criteria and composed the study sample. The HEDIS measures had >90% accuracy when compared with the CDC gold standard for each of the 6 immunizations (range, 94.3%-99.7%) and the composite (93.8%). The HEDIS measure was least accurate for hepatitis B and pneumococcal conjugate immunizations. The proportion of children for which the HEDIS measure yielded a nonuseful result (ie, an incorrect answer to the question, "is this child due for catch-up immunization?") ranged from 0.33% (varicella) to 5.96% (pneumococcal conjugate). The most important predictor of HEDIS measure accuracy and usefulness was the CDC-recommended number of immunizations due at age 2 years; children with zero or all immunizations due were the most likely to be correctly classified. CONCLUSIONS: HEDISchildhood immunizationmeasuresare,onthewhole, accurate and useful. Certain immunizations (eg, hepatitis B, pneumococcal conjugate)andchildren(eg, thosewithasingleoverdueimmunization),however, are more prone to HEDIS misclassification.