Our results found that children with AAT often have worse short-term outcomes when compared with children with noninflicted abdominal trauma. These outcomes include longer hospitalizations, higher charges, and higher mortality rates. The 1 exception was among infants, in whom mortality rates were not significantly different for children with AAT and noninflicted abdominal injury.
These outcomes are similar to those seen in several other studies of children with AAT and abusive head trauma.3,7,8
These studies found longer ICU and overall hospital stays,7
poorer short-term outcomes,7
and higher mortality rates3,8
for children with abusive injury when compared with children with noninflicted injury. Most studies have also found abusive injuries to be more severe,2,3,8
with the exception of the study by Keenan et al.7
In a 10-year retrospective review of abdominal trauma at a children's trauma center, Wood et al2
found that children with abusive injuries had a higher number of injuries and more severe injuries than children with noninflicted injury. Trokel et al,3
examining data from the National Pediatric Trauma Registry, found higher mortality rates for children with AAT compared with those with noninflicted injuries. Both of these studies included only children hospitalized at designated children's trauma centers; therefore, the average injury severity was higher than what would be seen in a sample of all hospitals, such as found in the KID database.
Several reasons could explain the poorer outcomes among abused children. First, children with abusive injuries often present to the hospital with absent or misleading histories, as the caregiver either does not know what happened or does not want others to know. The absence of injury history may increase the likelihood of misdiagnosis and may delay appropriate treatment until the child has more obvious and life-threatening sequelae. The higher number of procedures in the abused children in our sample may reflect the need for more tests to make a diagnosis in the absence of an accurate history, and may partly explain the higher charges. In a review of abdominal trauma hospitalizations, Canty et al9
suggested that absent history could lead to poorer outcomes. However, their data do not support the hypothesis, as 5 of 15 children with abusive injuries (33%) and 29 of 64 children with noninflicted injuries (45%) were diagnosed with abdominal injuries >4 hours after hospital presentation. Unfortunately, testing this hypothesis was not possible with the KID database because data regarding the time between presentation and diagnosis are not available.
Another possibility is that caregivers delay seeking care for children with abusive injuries because they are unaware of the history or they hope that the child will get better and avoid the need for medical care.2,9,10
Canty et al9
suggested this possibility as well. Of 79 children with blunt abdominal trauma in their case series, 8 had delayed presentations for medical care, and 5 of the 8 were children with abusive injuries. Wood et al2
tested this hypothesis and found no significant differences in the proportions of abused and nonabused children with delays in seeking care.
A third possibility is that the types of abdominal injuries seen in abuse are different from injuries seen in noninflicted trauma. Several studies have shown that hollow viscous injury and pancreatic injury are more common in abused children.1,2,11,12
Hollow viscous injuries may present in a delayed fashion with peritonitis. By the time peritonitis develops, the child may be quite ill, require prolonged hospitalization, and have a high risk of mortality. Pancreatitis may present insidiously, causing confusion with other causes of vomiting and abdominal pain in children. By the time the diagnosis is made, the child may be very ill and again require prolonged hospitalization.
A fourth possibility is that there are differences between children with AAT and noninflicted injury in the types and number of extra-abdominal injuries. Although such differences may exist, the lack of any difference in injury severity between the 2 groups suggests that factors other than differences in the type and number of extra-abdominal injuries are more likely to explain differences in outcomes.
Higher charges and longer hospital stays in the children with abusive injuries could also be the result of child protective services involvement. When there are concerns that a child may have been injured by a caregiver or household member, discharge may be delayed to establish a safety plan, remove a suspect from the home, or find foster or kinship care placement.
The finding that there was no difference in mortality among infants with abusive versus noninflicted abdominal trauma was surprising. This lack of difference is primarily explained by a high mortality rate for infants (9.7%) and a low mortality rate for older children (2.7%) with noninflicted injury. In contrast, mortality rates for infants with abusive injury were similar to those for older children (9.6% vs 9.2%). It is possible that because older children are ambulatory and active, they are more likely than younger children to sustain abdominal injuries from falls and contact sports, whereas infants who sustain noninflicted abdominal injuries do so primarily in automobile crashes, with a higher risk of fatality.
Our study does have limitations. First, although the KID database includes 80% of all child hospitalizations, it is not a perfect representation of all US hospitalizations. However, the database does provide a broader sample, with a presumed wider range of severity, than pediatric trauma databases. Another limitation was the absence of data on race for one third of the sample. Although our findings were the same whether race was included or excluded from the models, we were unable to look specifically at outcomes by race.
Strengths of our study should be noted. First, to the best of our knowledge, this is the first study to examine outcomes of AAT among children hospitalized at any acute care hospital, not just trauma centers. This allowed us to include children with injuries that might not have been severe enough to warrant admission to a trauma center. Our large sample size is also a strength, because it allowed us to stratify our data to examine outcomes according to age group.