INFANT INJURY DEATH IN WASHINGTON-STATE, 1981 THROUGH 1990

Objective: To measure annual rates of infant injury death in Washingto n State and identify potential risk factors for infant injury death. M ethods: A population-based case-control study using a linked file-of b irth and death certificates for the years 1981 through 1990. Results: The leading causes of infant injury death, per 100000 live births, wer e intentional injury (9.1); suffocation, choking, or hanging (6.9); mo tor vehicle crashes (4.4); and drowning (3.2). Unintentional injury de ath rates fell steeply during the 1970s but remained steady during the 1980s. Infanticide rates rose during the 1980s. Young maternal age (o dds ratio, 9.0; 95% confidence interval, 4.5 to 17.9, for age < 20 yea rs vs age > 30 years) and higher parity (odds ratio, 5.0; 95% confiden ce interval, 3.1 to 8.3, for parity of two or more vs parity of zero) were associated with infant injury death. There was a twofold increase in the risk of infant injury death if the mother smoked, was black, o r lived in a rural area. Male sex of the infant, late prenatal care, a nd low income were associated only with intentional deaths, while high er parity was more strongly associated with unintentional injury death s. Conclusions: During 1981 through 1990, infant mortality caused by i njuries increased in Washington State. Young maternal age and higher p arity were strongly associated with infant injury death.