Effect of missed opportunities on influenza vaccination rates among children with asthma

Objectives: To assess rates of influenza vaccination among children with asthma; document the frequency, timing, and patterns of missed opportunities to vaccinate during successive influenza seasons; and project potential influenza vaccination rates that could be achieved by reducing or eliminating missed opportunities. Setting: Michigan Medicaid program during the 2001-2002 and 2002-2003 influenza seasons. Design: Retrospective cohort analysis of administrative claims. Participants: We evaluated the claims of 4358 children aged 5 to 18 years with persistent asthma who were continuously enrolled in Medicaid. Main Outcome Measures: Influenza vaccinations and missed opportunities assessed using procedure and diagnosis codes. Results: During the 2001-2002 season, 16.7% of children with asthma received an influenza vaccination; during 2002-2003, 21.8% received the vaccine (9.5% vaccinated in both seasons). However, 76.5% of children had at least 1 office visit during the 2001-2002 influenza season (75.3% during 2002-2003). Among children without influenza vaccination, 72.9% had at least 1 missed opportunity for vaccination during the 2001-2002 season and 69.3% during 2002-2003. The most common outcome was having at least 1 missed opportunity (39.6%) in each of 2 successive influenza seasons. Eliminating missed opportunities prior to the historical peak of influenza season would have increased the influenza vaccination rate among this population of children to 76%. Conclusions: Missed opportunities for influenza vaccination among children with asthma are common and are often repeated from one influenza season to the next. Future studies should assess how interventions could be aimed at patients and health care professionals to improve awareness of the need for annual influenza vaccination.