When one child is treated for a severe injury, the risk of injury to other children in the family is nearly doubled within the first month after the injury, with risk peaking within the first 6 to 10 days, according to a study that was supported in part by the Agency for Healthcare Research and Quality (HS10724). For some undetermined reason, the increased risk does not occur among siblings 4 years or younger, and it is more pronounced in families with two children as opposed to larger families.
The instantaneous elevation in risk may reflect family stress that predates the first child's injury. Alternatively, family disruption resulting from the family's response to the initial injury may increase injury risk for other siblings, explains Brian Johnston, M.D., M.P.H., of the University of Washington.
Dr. Johnston and his colleagues tracked medically treated unintentional injuries among 16,335 children (0 to 15 years of age) enrolled in a health maintenance organization between 1995 and 1997. They compared the risk of sibling injury after minor and more severe injury of a child (within the prior 6 months) with the injury risk of children without an injured sibling, after adjustment for age, sex, sibling group size, and noninjury health care use.
Overall, 5,851 children had a total of 8,973 injuries. Injury incidence was 44 percent higher among children with a recently injured sibling compared with children who did not have an injured sibling (319 vs. 235 injuries per 1,000 child-years). When only serious injuries were considered, the adjusted relative risk (ARR) of sibling injury was nearly doubled (ARR 1.95). Injury risk peaked 6 to 10 days after exposure (ARR 6.30) and returned to baseline by 30 days after the initial injury. Overall, the difference in injury risk between sibling groups in which one member had been injured in the previous 6 months and those with no recent injury varied from 3.7 percent to 27 percent, depending on the severity of the injuries considered and the size of the sibling group.
More details are in "Transient elevation in risk of injury in siblings following injury encounters," by Dr. Johnston, David C. Grossman, M.D., M.P.H., and Robert S. Thompson, M.D., in the January 2003 Journal of Pediatrics 142, pp. 79-83.