Impact of State Immunization Registry on Immunization Rates of Sixth Grade Students

Background:  Beginning with the 2010-2011 school year Indiana law requires accredited schools to enter immunization records for kindergarten, first and sixth grade students into the state immunization registry (CHIRP). In previous years, schools submitted summary reports on a paper form. These summary reports were used to calculate the immunization rates for the state’s 93 counties. The registry automatically calculates the appropriate interval between doses of vaccines that are given as part of a series.

Objectives:  To determine if the new requirement to enter immunization records into the registry would impact school immunization rates.

Methods:  Data were analyzed from the 2009-2010 school year. To simplify the analysis, only the records relating to sixth grade were analyzed. For the 2009-2010 school year some schools submitted the required information both on a paper form and through CHIRP.  For the purpose of this analysis, only schools that submitted a paper sixth grade reporting form and had 50% or more of their sixth grade students entered into CHIRP were analyzed. This left 122 schools to be analyzed. Paired t tests and ANOVA were conducted using PASW Statistics 18.0.  A p value less than 0.05 was statistically significant.

Results:  For these 122 schools, the paper forms indicated that 98.1% of sixth grade students met school immunization entrance requirements. According to CHIRP, 82.2% of these same students met all entrance requirements. For each vaccine examined, there was a statistically significant difference in the number of students who were compliant with state law. The difference in the number students with exemptions was not significant.

Conclusions:  The use of the state’s immunization registry will have a large effect on the reported immunization rates of Indiana’s school children. It appears that the reported immunization rate will be much lower this school year compared to the 2009-2010 school year.