摘要：Objectives. We evaluated the use of a statewide immunization information system (IIS) to target influenza vaccine reminders to high-risk children during a pandemic. Methods. We used Michigan’s IIS to identify high-risk children (i.e., those with ≥ 1 chronic condition) aged 6 months to 18 years with no record of pH1N1 vaccination among children currently or previously enrolled in Medicaid (n = 202 133). Reminders were mailed on December 7, 2009. We retrospectively assessed children’s eligibility for evaluation and compared influenza vaccination rates across 3 groups on the basis of their high-risk and reminder status. Results. Of the children sent reminders, 53 516 were ineligible. Of the remaining 148 617 children, vaccination rates were higher among the 142 383 high-risk children receiving reminders than among the 6234 high-risk children with undeliverable reminders and the 142 383 control group children without chronic conditions who were not sent reminders. Conclusions. Midseason reminders to parents of unvaccinated high-risk children with current or past Medicaid enrollment were associated with increased pH1N1 and seasonal influenza vaccination rates. Future initiatives should consider strategies to expand targeting of high-risk groups and improve IIS reporting during pandemic events. Shortly after the onset of the 2009 global pandemic of influenza A (H1N1)pdm09 virus (pH1N1), 1 the Advisory Committee for Immunization Practices released recommendations for vaccination that specifically identified 5 target groups, including persons at higher risk for infection or for severe influenza-related complications because of chronic medical conditions. 2 Although administration of a monovalent pH1N1 vaccine began throughout the United States in October 2009, initial vaccine supplies were very limited in many jurisdictions. As a consequence, numerous state and local health departments requested that providers focus vaccine administration on a smaller subset of the initial target groups, 3 based on subgroups designated by the advisory committee as a priority in the event of a vaccine shortage. 2 Early indications from the Centers for Disease Control and Prevention estimated that more than 1 million cases of pH1N1 influenza had occurred in the United States by August 2009 4 and that pediatric deaths from pH1N1 influenza were more common among children with 1 or more chronic medical conditions (hereinafter referred to as “high-risk children”). 5 Reminder–recall for pH1N1 vaccine represented a potential strategy for reaching parents of high-risk children. It had previously been demonstrated as an effective mechanism for increasing pediatric seasonal influenza vaccination among children with chronic conditions. 6–8 In addition, during the 2009–2010 influenza season, a midseason report from the Advisory Committee for Immunization Practices urged health departments to consider implementing practices shown to increase influenza vaccination coverage, including reminder–recall. 9 The Michigan Department of Community Health (MDCH) used the Michigan Care Improvement Registry (MCIR) to target pH1N1 vaccination reminders to children known to have a high-risk condition. MCIR has a high degree of provider participation with more than 95% of children age 6 years or younger having 2 or more vaccine doses entered. 10 At the time of this reminder effort, all immunization providers in Michigan were required by state law to report school-exclusionary vaccinations administered to children to MCIR. In addition, pH1N1 vaccine providers were required to report to MCIR all pH1N1 doses administered during the pandemic. Although using MCIR to target reminders to high-risk children had been demonstrated on a small scale, 11 the use of such notifications during an influenza pandemic was untested. With that in mind, our objective was to describe the feasibility and utility of this effort. To our knowledge, this is the first assessment of a statewide reminder–recall during an influenza pandemic.
