RESUMO
OBJECTIVE: Influenza can exacerbate asthma, particularly in children. The effectiveness of influenza vaccine in preventing influenza-related asthma exacerbations, however, is not known. We evaluated influenza vaccine effectiveness in protecting children against influenza-related asthma exacerbations. STUDY DESIGN: We conducted a population-based retrospective cohort study with medical and vaccination records in 4 large health maintenance organizations in the United States during the 1993-1994, 1994-1995, and 1995-1996 influenza seasons. We studied children with asthma who were 1 through 6 years of age and who were identified by search of computerized databases of medical encounters and pharmacy dispensings. Main outcome measures were exacerbations of asthma evaluated in the emergency department or hospital. RESULTS: Unadjusted rates of asthma exacerbations were higher after influenza vaccination than before vaccination. After adjustment was done for asthma severity by means of a self-control method, however, the incidence rate ratios of asthma exacerbations after vaccination were 0.78 (95% CI: 0.55 to 1.10), 0.59 (0.43 to 0.81), and 0.65 (0.52 to 0.80) compared with the period before vaccination during the 3 influenza seasons. CONCLUSIONS: After controlling for asthma severity, we found that influenza vaccination protects against acute asthma exacerbations in children.
Assuntos
Asma/prevenção & controle , Asma/virologia , Imunização , Influenza Humana/prevenção & controle , Doença Aguda , Asma/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Influenza Humana/complicações , Masculino , Análise de Regressão , Estudos Retrospectivos , Risco , Índice de Gravidade de Doença , Estados Unidos/epidemiologiaRESUMO
Decision analysis was used to evaluate the probable health benefits, complications, and costs of six management strategies for febrile children at risk for occult bacteremia. The strategy that combined blood culture with empiric oral antibiotic treatment for all patients was predicted to prevent the highest number of major infections and to have the lowest cost per major infection prevented. The strategy that combined a leukocyte count and blood culture for all patients, followed by empiric antibiotic treatment for those with leukocyte count greater than or equal to 10,000/mm3, had almost equal cost and clinical effectiveness and avoided many antibiotic complications. Culture of blood specimens from all patients and no empiric treatment constituted the third most clinically effective intervention but was the least cost-effective in this model. Giving a 2-day oral course of amoxicillin without testing had the lowest average cost per febrile patient but was the least clinically effective intervention. However, the low degree of effectiveness of empiric treatment alone was based on the assumption that oral amoxicillin therapy was only 20% effective in preventing major infections after bacteremia. At higher estimates of effectiveness, treatment alone became a more viable strategy. We conclude that approaches which combine blood culture with empiric antibiotic treatment are the most clinically effective and the most cost-effective strategies for children at risk for occult bacteremia.