KEYWORDS:
CASA, AFIX, registry, assessment

BACKGROUND:
Registries and the Clinic Assessment Software Application (CASA) are a powerful combination for the assessment of immunization practices. However, a key challenge is accurately defining an assessment population that represents the true population.

OBJECTIVE(S):
This study examined the validity of three registry-based assessments for the purpose of understanding which of the three criteria best represent the true population.

METHOD(S):
A chart pull of a clinic’s population between the ages of 1 and 3 years was conducted. CASA analysis provided an up-to-date rate and information on immunization practices. Next, three separate registry-based assessments were run on the same clinic using three different population-defining criteria and processes. Analysis of the three registry-based assessment were compared with the results of the chart pull to determine which most closely resembled the clinic’s population.

RESULT(S):
The population-defining criteria resulting in the assessment most highly correlated (r=.997) with the chart pull was that in which all patients between the ages of 1 and 3 who had ever received at least one immunization were included in the assessment.

CONCLUSIONS(S):
Valid measurements of immunization rates are crucial to improving immunization practices, and faulty definitions of assessment populations provide misleading results. This study finds that registry-based CASA assessments should include all patients between the ages of 1 and 3 years who have had at least one immunization at a clinic. Criteria that restrict this population must be carefully considered lest too many be removed from the assessment.

LEARNING OBJECTIVES:
Participants will understand the following: 1) challenges of defining a population with a registry-based assessment; 2) reasons why assessing everyone who has received at least one immunization at a clinic is the more accurate assessment method; 3) lack of a medical home notably affects the assessment process.