Researchers at the University of Michigan C.S. Mott Children's Hospital say many children with asthma - who are at an increased risk for influenza-related complications - aren't getting immunized against the flu, even when they visit their doctor during flu season.
In this month's issue of the Archives of Pediatric and Adolescent Medicine, the researchers report that among unvaccinated children with asthma who were enrolled in Michigan Medicaid, 73 percent had at least one office visit during flu season. During the course of two flu seasons, 40 percent of these children had the opportunity to become vaccinated, but were not.
"Our findings confirm concerns about low influenza immunization rates among children with asthma," says study lead author Kevin Dombkowski, DrPH, M.S., member of the Child Health Evaluation Research (CHEAR) Unit in the Division of General Pediatrics, and research assistant professor in the Department of Pediatrics and Communicable Diseases at the U-M Medical School.
"After studying this group of children over the course of two flu seasons, we found that only 17 percent were vaccinated during the first season, and 22 percent were vaccinated the following flu season. In all, fewer than 10 percent of these children were vaccinated both seasons. The national goal is for 60 percent or more of them to receive the flu vaccine every season."
Despite vaccination recommendations, many high-risk children, including those with asthma, do not receive an annual flu shot. Even during seasons with vaccine shortages, these high-risk individuals are prioritized to receive the available doses.
Prior studies have found that missed opportunities - medical visits where a vaccine-eligible child is seen by a health care professional, but not immunized - occur frequently and, if eliminated, could greatly improve vaccination rates.
To better gauge the potential for improving and maintaining vaccination rates for children with asthma, Dombkowski and his colleagues felt it was important to understand the degree to which missed opportunities for flu vaccination occur among these children.
The CHEAR study analyzed 4,358 children with asthma, ages 5 to 15, who were enrolled in the Michigan Medicaid program.
For the 2001-2002 and 2002-2003 flu seasons, the researchers measured the children's outpatient office visits, rate of flu vaccinations, and missed opportunities for immunization.
About 77 percent of the children had at least one office visit, and nearly 65 percent had two visits during the 2001-2002 flu season.
During that time period, only 17 percent received a flu shot. Among the unvaccinated children in the group, about 70 percent missed at least one opportunity to be vaccinated.
Likewise, 22 percent were vaccinated for the 2002-2003 season, while about 70 percent who had the opportunity to be vaccinated, were not. Overall, the majority of children in the study - 71 percent - were not vaccinated for either flu season.
"If we were able to prevent even a small percentage of these missed opportunities, we could substantially increase the overall influenza vaccination rate among these children," says Dombkowski. "And if we were able to completely eliminate these missed opportunities, we would see a 77 percent influenza vaccination rate for this group."
Studies have shown that two of the greatest barriers to vaccinating high-risk children are physicians' failure to recommend the vaccine and parents' lack of knowledge about their child's risk for serious complications.
In order to increase vaccination rates, Dombkowski stresses that there need to be interventions aimed at improving physician and parent awareness about the importance of annual vaccinations for children with asthma. Such interventions could include physician-focused reminder systems that prompt health care professionals to recommend influenza vaccination at a medical visit, he says.
"Reminder systems are among the most effective mechanisms to improve vaccination rates and can be built into immunization registries," says Dombkowski, who points to his current work with the Michigan Department of Community Health to a pilot physician-reminder system for influenza vaccination this fall in Michigan's statewide immunization registry.