BACKGROUND:
Childhood immunization rates are one of the leading health indicators used to assess the health of the nation. Measuring immunization rates at the community-level usually requires conducting surveys or medical record review in provider offices. Public school immunization data (PSID) may be useful to estimate coverage rates at the community-level. We evaluated whether PSID analyzed using CDC’s Clinic Assessment Software Application (CASA) and ArcView GIS could identify geographic areas that are in need of additional resources and interventions.

OBJECTIVE:
To describe the use of PSID, CASA and ArcView GIS as a method for measuring retrospective immunization coverage rates among kindergarteners by community area.

METHOD:
The Chicago Public Schools provided the Chicago Department of Public Health (CDPH) with PSID for kindergartners entering school during four years (2000-2003). PSID consists of demographic information, home address, and immunizations required for school-entry. Using CASA and ArcView GIS, coverage rates were determined for MMR and 4:3:1(4DTP:3IPV:1MMR) by 35 months of age by racial/ethnic group and community of residence.

RESULT:
MMR coverage rates determined from 2003 PSID were similar to 2000 Chicago National Immunization Survey (NIS) estimates (84.6% vs. 87.2+4.6%, respectively). MMR coverage rates determined by race and ethnicity from PSID were similar to NIS estimates (white: 89.5% vs. 92.2+6.4%, respectively; black: 79.0% vs. 83.5+9.4%, respectively; Hispanic: 89.5% vs. 87.5+5.8%, respectively). Comparison of PSID 4:3:1 coverage rates and NIS 4:3:1 estimates revealed similar findings. In each of the four years studied, PSID identified 9 communities that consistently had MMR coverage rates <70%.

CONCLUSION:
PSID, ArcView GIS, and CASA can be used to efficiently and accurately estimate immunization coverage rates at the community-level. PSID can also be used to identify pocket-of-need communities and to monitor the progress/success of interventions.

LEARNING OBJECTIVES:
1. Establishing relationships with public schools in your community area.
2. Identifying pockets-of-need in community areas.
3. Comparing/validating PSID to other forms of immunization coverage data.
4. Monitoring the success of interventions using PSID.