Purpose of the Study. To measure the burden of influenza among children with asthma and other medical conditions, many of whom do not receive influenza vaccination.
Study Population. Study participants included black and white children aged <15 years who were enrolled in the Tennessee Medicaid program from 1973–1993. Three high-risk patient categories were established including asthma, other lung disease, and other chronic disease. The second data set included ongoing prospective virus surveillance system at Vanderbilt University, which permits precise definition of the influenza season on an annual basis.
Methods. A retrospective cohort analysis was used to determine the rates of hospitalization for acute cardiopulmonary disease, outpatient visits, and antibiotic courses throughout the year. Annual differences between event rates when influenza virus was circulating and event rates during winter months when there was no influenza in the community were used to calculate influenza-attributable morbidity.
Results. Influenza accounted for an average of 19, 8, and 2 excess hospitalizations for cardiopulmonary disease yearly per 1000 high-risk children aged <1 year, 1 to <3 years, and 3 to <15 years, respectively. For every 1000 children, an estimated 120 to 200 outpatient visits and 65 to 140 antibiotic courses were attributed to influenza annually. Specifically in the group of asthmatic children <15 years, an estimated 10% to 20% had an additional outpatient visit during an average influenza season, and approximately 14% of these children received an additional antibiotic prescription.
Conclusions. Children <15 years with asthma and other chronic medical conditions experience substantial morbidity requiring inpatient and outpatient care during the influenza season. The hospitalization rates in this study are comparable to rates in adult high-risk populations for whom influenza vaccination is recommended. More effective targeting of this population for annual influenza immunization is warranted.
Reviewer’s Comments. Despite an increase in published medical evidence supporting the benefits of immunizing children with chronic lung diseases, particularly asthma, the rates of actual vaccination remain low. For example, in the United States, it is estimated that only up to 25% of children with moderate to severe asthma receive the influenza vaccine. In an average year, up to 30% of children will be infected with influenza, and this disease may cause substantial morbidity in children with and without chronic illnesses such as asthma. Current vaccine coverage rates for influenza among children with asthma remain unacceptable and creative strategies to utilize this preventive therapy, especially in patients with asthma, will continue to be a challenge that health care providers need to resolve.
- Copyright © 2002 by the American Academy of Pediatrics