Infant abusive head trauma in a military cohort.

OBJECTIVE Evaluate the rate of, and risk factors for, abusive head trauma (AHT) among infants born to military families and compare with civilian population rates. METHODS Electronic International Classification of Diseases data from the US Department of Defense (DoD) Birth and Infant Health Registry were used to identify infants born to military families from 1998 through 2005 (N = 676 827) who met the study definition for AHT. DoD Family Advocacy Program data were used to identify infants with substantiated reports of abuse. Rates within the military were compared with civilian population rates by applying an alternate AHT case definition used in a civilian study. RESULTS Applying the study definition, the estimated rate of substantiated military AHT was 34.0 cases in the first year of life per 100 000 live births. Using the alternate case definition, the estimated AHT rate was 25.6 cases per 100 000 live births. Infant risk factors for AHT included male sex, premature birth, and a diagnosed major birth defect. Parental risk factors included young maternal age (<21 years), lower sponsor rank or pay grade, and current maternal military service. CONCLUSIONS This is the first large database study of AHT with the ability to link investigative results to cases. Overall rates of AHT were consistent with civilian populations when using the same case definition codes. Infants most at risk, warranting special attention from military family support programs, include infants with parents in lower military pay grades, infants with military mothers, and infants born premature or with birth defects.