BACKGROUND:
Annual influenza vaccination is recommended for persons with chronic illness, such as persons with asthma. Adolescents with asthma may not have regular office visits and therefore be at increased risk for not receiving influenza vaccine. Although immunization registries are typically designed to support outreach through reminder / recall notices, targeting persons with chronic illness may not be possible based solely on registry information.

OBJECTIVE:
To assess the influenza vaccine coverage among a statewide cohort of adolescents with persistent asthma.

METHOD:
Medicaid enrollment data and administrative claims data were obtained for children 12-18 years of age in 2001. Children with persistent asthma were classified consistent with HEDIS criteria; influenza vaccination claims were identified by procedure code. Michigan Childhood Immunization Registry (MCIR) records for influenza vaccinations were obtained and merged with Medicaid claims data. Univariate and bivariate analyses were conducted to describe the characteristics associated with receiving influenza vaccination.

RESULT:
There were 4,206 children 12-18 years old enrolled in Medicaid during the study period with persistent asthma; 8.8% of these children had evidence of receiving influenza vaccine. Most influenza vaccination records were found in claims data (86.1%) while substantially fewer were found in MCIR (37.2%); 23.4% of vaccinations were found in both data sources. Significant variations in receipt of influenza vaccine were observed by child's, race, county of residence, health plan, and continuous enrollment in the same plan (p< .001).

CONCLUSION:
It is feasible to merge Medicaid administrative claims with immunization registry records to perform vaccination assessments. These findings indicate that very few Medicaid adolescent enrollees with asthma received an influenza vaccination in 2001. Most influenza vaccinations for this cohort were not found in MCIR, suggesting a potential area for further attention to improve registry completeness.

LEARNING OBJECTIVES:
Participants will learn how Medicaid administrative claims data can be used in conjunction with immunization registry data to perform vaccination coverage assessments.