High immunization rates versus missed immunization opportunities in a private pediatric office.

Objective: This prospective study examines coverage levels for immunization of two-year-old children in a large private pediatric practice, and delineates the frequency of missed opportunities for vaccination.

Methods: A private single-specialty group pediatric practice in a suburban locale. Methods: With the aid of our office billing computer, 218 children between the ages of 21 and 24 months who had ever received medical care in our practice were identified. A manual chart review was performed to identify those children no longer receiving care from us. Of the 189 patients remaining, the immunization records in the patients' charts were compared to the State of Delaware immunization registry to identify those who had not received the full panel of recommended vaccines. Those charts were examined to identify reasons for underimmunization. No patient recall was performed. The charts of underimmunized children were reexamined five months later to determine how many had become fully immunized.

Results: On initial review, 86 percent of 21-24 month old children in our practice had received all recommended vaccines. Only 15 percent of the underimmunized children had had a missed opportunity for vaccination in the initial chart review. About half of the underimmunized patients received their missing vaccines over the next five months, yielding an eventual immunization rate of 94 percent. Only two of the 11 children still underimmunized by the end of the study (aged 26 to 29 months) had appeared for an 18 month or a 24 month well child visit; only four of the 11 had had a missed opportunity to receive immunizations during the five month study period. A subsequent chart review showed that 90 percent of our patients were up-to-date at 24 months of age.

Conclusions: Achievement of a 90 percent immunization rate for two year old children is possible in a large private practice. Most underimmunized children in our practice had failed to appear for recommended well visits; a minority experienced missed opportunities for immunization.