Objective: Examine impact of provider chart audits and parental outreach in improving immunization coverage among children not up-to-date (NUTD) for immunizations in Philadelphia's immunization information system (IIS).
Methods: We identified 10-month-old children NUTD for age-appropriate immunizations using Philadelphia's IIS. Immunization rates at 10, 13, and 19 months were compared before and after contact with providers and parents.
Results: Of 5 610 children NUTD in the IIS at 10 months and living in areas with populations at risk for underimmunization, provider chart audits indicated that 3 612 (64%) were actually up-to-date (UTD); the majority of these (2 203) received additional age-appropriate immunizations and were also UTD at 19 months. Of 1 998 children truly NUTD at 10 months, half received overdue immunizations by 13 months following contact with parents via telephone, postcards, and home visits, but only 23 percent were UTD for age-appropriate vaccines at 19 months.
Conclusions: Provider chart audits improved IIS data completeness, indicating that providers need to submit more complete and timely data to the IIS. Outreach to parents likely contributed to half of the children NUTD at 10 months receiving overdue immunizations by 13 months. However, most were again NUTD at 19 months, indicating that outreach efforts should be continued through 19 months or until children are brought UTD. Furthermore, in spite of outreach, about half of the NUTD children were not brought UTD by 13 or 19 months. New strategies should be developed to ensure that these children receive recommended vaccinations.