Abstract
OBJECTIVE: To determine if infants hospitalized for any reason before 90 days of age are at increased risk for future serious injury. SETTING: Washington State. METHODS: A population based retrospective cohort study, using data from Washington State birth and death certificates linked to a statewide hospital discharge database for the years 1989 through 1997. Participants included healthy full term infants born in Washington State between 1989 and 1995. A total of 29,466 infants hospitalized <90 days of age (early hospitalization) were compared to 29,750 randomly selected infants not hospitalized early. The primary outcome was an injury resulting in hospitalization or death between 3-24 months. RESULTS: Among infants hospitalized early, 76/10,000 had a subsequent serious injury before age 2, compared with 47/ 10,000 infants without an early hospitalization (relative risk (RR) 1.6; 95% confidence interval (CI) 1.3 to 2.0). In a multivariate model including maternal age and parity, the adjusted RR for serious injury associated with early hospitalization was 1.5 (95% CI 1.2 to 1.8). Infants hospitalized early were three times as likely to be hospitalized between 3-24 months of age for intentional injury compared with infants not hospitalized early (RR 3.3; 95% CI 1.1 to 10.1). CONCLUSIONS: Infants hospitalized in the first three months of life for any reason were 50% more likely to have a subsequent serious injury compared with infants not hospitalized early and were also at increased risk of intentional injury. This identifiable group of infants might be suitable for targeted childhood injury prevention programs including those involving prenatal and postnatal visits.