Outcomes and factors associated with infant abusive head trauma in the US

OBJECT Head trauma is the leading cause of death in abused children, particularly prior to the age of 2 years. An awareness of factors associated with this condition as well as with a higher risk of mortality is important to improve outcomes and prevent the occurrence of these events. The objective of this study was to evaluate outcomes and factors associated with poor outcomes in infants with diagnosed abusive head trauma (AHT). Patient characteristics, socioeconomic factors, and secondary conditions such as retinal bleeding, contusion, and fractures were considered. METHODS Data were obtained from the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality. From the Kids' Inpatient Database (KID) sample, the authors identified infants no older than 23 months who had been diagnosed with AHT in 2000, 2003, 2006, and 2009. All statistical analyses were conducted in SAS 9.2. Descriptive statistics were provided, and multivariate logistic regression models were applied to evaluate factors associated with mortality and nonroutine discharge. RESULTS A total of 5195 infants were analyzed in this study. Most infants (85.5%) had ages ranging between 0 and 11 months and were male (61.6%). Overall mortality was 10.8%, with a rate of 9.8% in the 0- to 11-month-old cohort and 16.5% in the 12- to 23-month-olds (p = 0.0003). The overall nonroutine discharge rate of 25.6% increased significantly from 23.3% to 39.0% with increasing age (0-11 vs 12-23 months of age, p < 0.0001). Assuming a multivariate model that adjusted for multiple confounders, the authors found that older infants (12-23 vs 0-11 months, OR 1.81, 95% CI 1.18-2.77) with a secondary diagnosis of retinal bleeding (OR 2.85, 95% CI 2.02-4.00) or shaken baby syndrome (OR 2.09, 95% CI 1.48-2.94) had an increased risk of mortality; these factors were similarly associated with an increased odds of a nonroutine discharge. A higher income ($30,001-$35,000 vs $1-$24,999) was associated with a reduction in the odds of mortality (OR 0.46, 95% CI 0.29-0.72). In the subset of cases (1695 [32.6%]) that specified the perpetrator involved in infant injury, the authors found that the father, stepfather, or boyfriend was most frequently reported (67.4%). A trend for a higher AHT incidence was documented in the early ages (peak at 2 months) compared with older ages. CONCLUSIONS Despite the higher incidence of AHT among infants during the earlier months of life, higher mortality was documented in the 12- to 23-month-olds. Retinal bleeding and shaken baby syndrome were secondary diagnoses associated with higher mortality and nonroutine discharge. Males (67.4%) were overwhelmingly documented as the perpetrators involved in the injury of these infants.