Risk factors for bronchiolitis-associated deaths among infants in the United States

BACKGROUND.Risk factors for bronchiolitis deaths have not been described on a national level. We examined the epidemiology of and identified risk factors for bronchiolitis-associated deaths among infants in the United States. METHODS.Multiple cause-of-death and linked birth/infant death data for 1996 through 1998 were used to examine bronchiolitis-associated infant deaths. Risk factors were assessed by comparing infants who died with bronchiolitis and surviving infants. RESULTS.During 1996 through 1998 there were 229 bronchiolitis infant deaths, resulting in an average annual infant mortality rate of 2.0 per 100 000 live births. The majority (55%) of infant deaths occurred among infants ages 1 through 3 months. The bronchiolitis mortality rate was highest among infants weighing