Injuries

Measurement Issues

As with any public health problem, it is important to have data available from routine surveillance—the systematic, ongoing collection of information about illnesses, injuries, or events. To fully understand the magnitude of the problem, one must consider both the mortality (fatalities) and morbidity (nonfatalities) associated with injury. Mortality is readily assessed using data available from death certificates. Data are coded as to the underlying causes of death and can yield valuable information about factors contributing to the injury. In states having medical examiner systems, these records can provide more detail about the circumstances of death.

The Centers for Disease Control and Prevention report that for every child who dies as a result of an injury, there are an estimated 34 who are injured seriously enough to require hospitalization, and another 1,000 who receive medical care in an outpatient setting. Even more children experience injuries that result in limitations of their activities or cause discomfort but that do not require medical attention. Hospitalized injuries can be examined using hospital discharge data compiled in each state as well as nationally. The standards of reporting, however, are not as stringent as with death statistics. Underlying causes are not uniformly coded in all states, some requiring that this information be included and others reporting on a voluntary basis.

Data about nonhospitalized cases are even less uniformly compiled. There are few statewide and no national reporting systems for emergency department cases. Injuries treated in private doctor's offices, urgent care centers, or by school nurses may or may not be routinely documented, but there are no national record-keeping systems to monitor these events systematically. Consequently, information about injury morbidity is of variable quality.

Types of Injuries

Causes of injury death differ by age and by type of injury, as demonstrated in Table 1. The data presented in these figures reflect only mortality.

In 1998, 18,292 U.S. children died as a result of injuries, for an overall death rate of 23.55 per 100,000 population. Of these fatalities, 12,416 were classified as unintentional, 3,461 as homicide, and 2,061 as suicide. Rates varied by race and gender, with boys (aged zero to nineteen) experiencing an overall death rate of 32.04 per 100,000, compared to 14.63 for girls. As shown in Table 2, racial differences reveal higher rates for minority youth, with Native Americans experiencing the highest rates of unintentional injury and suicide while African Americans' rates for homicide exceed those of other ethnic groups. Some of this difference is attributable to environmental conditions associated with poverty (African Americans and Native Americans) and/or living in rural areas (Native Americans) where risks are high and rapid access to medical care is less readily available.

Injury patterns differ by both age and type of event, as demonstrated in Tables 1 and 3. For all age groups, motor vehicle crashes were a significant cause of fatalities in 1998. The youngest children (infants) are most likely to be fatally injured as a result of suffocation, motor vehicle traffic, and drowning/submersion. For toddlers, the leading causes of injury death are motor vehicle traffic, drowning/submersion, and homicide, while for those in the five to fourteen age group (elementary and middle-school age), most fatal injuries result from motor vehicle traffic, homicide, and drowning/submersion. In contrast, teenagers are fatally injured as a result of motor vehicle crashes, homicide, and suicide.

As shown in Table 3, various causes of injury fatality exhibit differing patterns depending on age. In part, this is a function of different developmental factors that impinge on children's abilities to avoid injury events (e.g., being able to walk without falling, being able to make judgments about avoiding risks, testing authority, having transient depression, acting impulsively). In addition, children have greater or lesser exposures to different risky situations (e.g., crossing streets without a parent, playing sports, riding a tricycle near traffic, being a teenage driver, owning or carrying firearms, working on a construction crew) based on the practices of their parents (e.g., level of supervision provided, drinking and smoking behaviors, disciplinary practices); or because of social, economic, or cultural factors (e.g., access to affordable, high-quality child care; well-constructed homes that are equipped with fire safety devices such as smoke detectors; practices of riding in the back of pickup trucks; use of hazardous products such as firearms, baby walkers, in-line skates, or trampolines.

Morbidity

Morbidity (i.e., nonfatal injury) is both much more common than mortality and presents different patterns of injury. In 1997, 213,000 hospitalizations of children ages zero to fifteen in the United States resulted from injuries, while in 1996 alone an estimated 8.71 million in this age group were treated and released from emergency care. Using 1990s data from North Carolina on unintentional injury for children under age fifteen, Table 4 lists the differences in injury patterns by age group for the leading causes of death, of nonfatal, hospitalized injuries, and estimated incidence of injuries treated in outpatient settings. This demonstrates the importance of considering the range of injury outcomes in establishing priorities and devising preventive strategies.

Furthermore, several child and adolescent injury problems are not easily recognized in the health care system at all, yet have profound effects on injury occurrence and developmental outcomes. One type of event is child abuse and neglect. Reporting through social services systems and national surveys indicates that as many as 1.5 million children a year experience physical or sexual abuse at the hands of an adult caretaker. Likewise, children and adolescents may be sexually assaulted or raped by strangers or experience injuries in dating relationships, similar to domestic violence experienced by adults. National estimates indicate that as many as 1.4 million persons under age eighteen experience sexual assault or rape each year. In addition, it is estimated that 8.8 percent of adolescents may experience violence in their dating relationships, including incidents of hitting, slapping, or being physically hurt.

Other types of circumstances that put teenagers at risk of nonfatal injuries are sports participation and employment. Together, these two categories of injury result in more emergency care for teenagers than any other categories. Sports and occupational injury are the two most common categories. National data suggest that as many as 3.5 million youth under age 14 are injured in sports and recreational activities annually, 775,000 of them requiring emergency care. Seventy-five percent are boys. Similarly, youth who are employed are exposed to a variety of hazards, with as many as half experiencing injuries at work.

Just as development affects whether a child is at risk of experiencing an injury-producing event, so is development affected by being injured. Injuries with the greatest impact in the behavioral and emotional development of the child are head injuries, specifically traumatic brain injuries, and severe burns. Little research has been done on the outcome of other types of injuries in children and adolescents.

Brain Injury

As reported in 1996, more than 100,000 children and adolescents are hospitalized each year with traumatic brain injury (TBI), of which about 88 percent are classified as mild, 7 percent moderate, and 5 percent severe. Although children under five years of age have the lowest rate of TBI, the severity of injury is disproportionately high. Evaluations of neurological and psychological outcomes following pediatric TBI, however, have been focused almost exclusively on school-age children and adolescents. The few studies that have assessed the consequences of mild TBI for infants and/or preschoolers identified lower IQ scores in infants and young children than in older children who suffered a mild TBI. Philip Wrightson, Valerie McGinn, and Dorothy Gronwall (1995) studied pre-schoolers who sustained mild head injuries and reported that deficits in cognitive development, identified at twelve months after injury, were significantly associated with reading ability at age six and a half. It is not clear if mild TBI and concussion result in long-term problems in children given the difficulty in differentiating effects that may be a direct consequence of mild TBI or of learning disabilities or attention deficits in the TBI group, which do not manifest themselves until later in development.

Follow-up studies of severe TBI in school-age children and adolescents identified physical, cognitive (e.g., lower IQ scores), language, and psychological deficits that may be temporary or permanent. The most common language problems are word retrieval difficulties and decreased speed of information processing. Follow-up studies for as long as three years after the TBI reveal persistent neurobehavioral deficits. Acute behavioral problems include emotional outbursts, restlessness, and low tolerance to stimulation.

Cognitive delays have significant effects on social, educational, and vocational prognosis of children following TBI. For example, in a study in which TBI children were compared with age, gender, and grade-matched peers, Kenneth Jaffe and his colleagues found that more severe head injury was associated with lowered neurobehavioral functioning. Developmental deficits include lack of attention and long, heightened distractibility, short-term memory impairment, difficulty with logical thinking and reasoning, slowed reaction time, and impaired spatial or visual motor skills. The duration of post-traumatic amnesia was reported to be the best predictor of these deficits. Severe TBI results in significant neurobehavioral deficits that are persistent after the first year and that are related to the severity of the head injury.

The effects of age at injury on subsequent cognitive development are unclear. In studies examining cognitive, social, academic, and vocational outcomes following severe TBI, some have reported that age at injury was not predictive of long-term outcome. Others identified more severe consequences in children ages zero to six than in older children. Several studies of outcomes following TBI failed to find associations between age at injury and either severity of cognitive consequences and the rate of recovery of neuropsychological, or behavioral disturbance. Several other studies, however, suggest that trauma to the brain may have more severe outcomes and more significant long-term consequences for infants and preschoolers than for older children. A number of findings regarding the language and memory effects of TBI in infants, school-age children, and adolescents are also consistent with the hypothesis that skills in a rapid stage of development at the time of TBI were more adversely affected than already well-established skills.

A study that determined the long-term outcome of severe brain injury in preschoolers revealed that none of the children who were younger than four years old at the time of the severe brain injury were able to live independently or work full-time in adulthood. Other studies also reported abnormalities following TBI in 40 percent of children with minimal or no loss of consciousness.

Injury can have important consequences for family functioning, which in turn adversely affects the family's ability to assist the child in achieving her full potential. Most of these adverse effects are seen in families with children who sustained severe head injury. Several studies have revealed that the level of family functioning before the injury was a better predictor of family functioning at one year after the injury than the severity of the TBI. The researchers inferred that family dysfunction prior to the injury event was likely to continue following the injury. Parental overreaction and family dysfunction were likely to exacerbate the child's emotional reaction to the injury. Poverty can exacerbate these problems and further decrease the level of functioning of children following TBI.

Burns

Burns also produce devastating results for child development. The effects of the injury on the psychological and emotional health of children and the family demonstrate inconsistent findings.

Studies conducted in the 1970s revealed that 50 percent of children showed signs of emotional disturbance several years after their injury. Studies in the 1980s indicated that the prevalence of these symptoms might be much lower and that the level of family and child functioning prior to the injury were the most important predictors of postburn adjustment and coping. A survey of burned children in 1985 found psychosocial maladjustment in 15 percent of the children. For some of the children and families, however, psychological disturbance existed before the injury and might have hindered emotional and even physical recovery afterward. The premise that visible scarring is more damaging than hidden burn scars has not been studied well. Adaptation takes place over a period of years. In the first couple of years after the burn, children have developmental regression, phobias, and various other symptoms. These symptoms progressively resolve in the subsequent years.

Parents are frequently stressed by the child's behavior, depressed over the burn and the child's future, and have feelings of guilt regarding the circumstances leading to the injury. Some research has shown that parental stress clearly differentiated parents of burned children from other parents; children with better psychological adjustment come from families that have higher levels of cohesion, independence, and more open expressiveness. This has important implications for interventions as mothers and burned children can be identified and given special support at the time of the initial care for the child's injury.