Accid. Anal. & F’rev. Vol. 23. No. 1. pp. 19-28. Printed in Great Britain.
MOTOR
OMII-4575/91 s3.a) + .lm 8 1991 Pergamon Press plc
1991
VEHICLE DEATHS IN CHILDREN: GEOGRAPHIC VARIATIONS
SUSAN P. BAKER, ANNA WALLER,
AND
JEAN LANGLOIS
The Johns Hopkins University, Injury Prevention Center, Baltimore, Maryland 21205. U.S.A. (Received
10 August 1989; in revised form 23 March 1990)
Abstruet-Motor vehicle-related injury is the leading cause of death in children ages O-14 years in the United States. Using data from the National Center for Health Statistics and the Fatal Accident Reporting System, specific types of motor vehicle injury death in children were examined for the years 1980-1985 (using NCHS data) and 1985-1986 (using FARS data). Death rates were calculated for each specific category of motor vehicle injury for each state and were then mapped to determine patterns of geographic variation. In general, nontraffic pedestrian death rates and death rates for crashes involving light trucks and/or rollovers were higher in the West, and rates of pedestrian deaths in traffic were highest in the South. Some of the likely contributing factors and possible interventions are discussed.
State-by-state mapping of injury rates can reveal major regional variations. These variations are important because identifying states with the highest rates of a specific injury cause of death may suggest likely contributing factors which can then be targeted for intervention. For example, a previous study of motor vehicle mortality rates for all ages by county found a pronounced inverse correlation with population density (Baker, Whitfield, and O’Neill 1987). The highest death rates were seen in the western half of the United States and in counties with the lowest population per square mile. Many factors were thought to contribute to this pattern including differences in road characteristics, travel speeds, types of vehicles, and available trauma services. Similarly, analysis of drowning rates for children less than 5 years of age revealed high rates in California, Florida, and the southwest (Baker, Whitfield, and O’Neill 1988). Since toddlers are especially likely to drown in swimming pools, this kind of data can encourage areas with high death rates to explore such measures as childproof fencing requirements for home swimming pools. Especially low injury rates in a state or region may also Suggest protective factors that should be considered by other states and regions. Death rates (per million miles of travel) from collisions with utility poles are low in states where utility lines tend to be buried or located far from travel lanes (Baker, O’Neill, and Karpf 1984), a lesson that might be useful if applied in the northeast. The study presented here examines geographic variations at the state level of childhood motor vehicle-related mortality. Injury prevention efforts are usually administered at the state or local level, and state-specific data are often needed in order to motivate agencies and obtain needed funding for prevention programs. Information about injuries to children is especially valuable because of societal willingness to protect children from hazards that may be accepted in the case of adult injuries. Recently, Colorado parents whose children were killed when they plunged over embankments are working for the installation of guardrails in appropriate areas. Clearly, many measures that reduce injuries to children will also reduce injuries to older road users. This is especially true of “pre-event” measures that reduce the risk of crashes. This research expands on data presented in the monograph Childhood injury Morr&y: Stare-by-State Mortality Facts (Baker and Waller 1989) by focusing on motor vehicle related-mortality only and by supplementing detailed analysis of National Center for Health Statistics (NCHS) data with analysis of Fatal Accident Reporting System (FARS) data.
19
20
S. P.
BAKER et al.
DEFINITIONS The analysis of NCHS data defined cause of injury on the basis of the “E codes”, the External Causes of Injury in the International Classification of Diseases. Brief descriptions of the motor vehicle-related causes follow. Motor vehicle occupant deaths (E810-819, .O, .l, .9) are those that occur in traffic and involve children who are passengers (or, occasionally, drivers) in cars or trucks. The category includes falls from vehicles and children killed when riding on the outside of the vehicles, for example in the back of pickup trucks. For the 1-14 year age group as a whole, motor vehicle occupant fatalities outrank all other injuries and diseases as the leading cause of death. Pedestrian traffic deaths (E810-819, .7) refer to children who are struck and killed on public roads when not in or on a motor vehicle or bicycle. Although most children are on foot, the category also includes any children on roller skates or skateboards. Pedestrian injuries are a universal and serious problem, due to failure to separate pedestrian and vehicular traffic. Pedestrian nontraffic deaths (E820-825, .7) occur off public roads, for example, in driveways and parking lots. These deaths are most common in rural areas, especially in western states. Many are miscoded as pedestrian traffic deaths. Motorcyclist deaths (E810-825, .2, .3) include all children categorized as occupants (riders) of motorcycles, regardless of whether the injury occurred on public or private property. Two-thirds of the fatally injured children are listed as the driver of the motorcycle. Most deaths involve head injuries sustained in collisions with other motor vehicles. Bicyclist deaths (E810-825, .6) include any child on a vehicle that is operated solely by pedals and, therefore, exclude children riding motorized bicycles. The analyses presented here are limited to deaths resulting from collisions with motor vehicles, because these represent 95% of all bicyclist deaths in childhood. The overwhelming majority of fatal injuries to bicyclists are head injuries. The analyses of FARS data defined rollover crushes as those in which either the first harmful event or any subsequent harmful event was a rollover. Light trucks were identified from the “Model” variable in FARS and include light duty and standard pickup trucks, truck-based utility vehicles, and truck-based station wagons, vans, van-based station wagons, and van derivatives.
METHODS
Deaths of children age O-14 were analyzed using the two data bases. Deaths of motor vehicle occupants, pedestrians (in traffic and not in traffic, separately), bicyclists, and motorcyclists were studied for the six-year period, 1980-1985, using mortality tapes from the National Center for Health Statistics (NCHS). Death rates for states were calculated using the average annual numbers of deaths of residents ages O-14 (the numerator) and the number of residents based on United States Census Bureau estimates for the same age group (the denominator). Analyses of NCHS data were supplemented with analyses of data from the Fatal Accident Reporting System (FARS) for 1985-1986. State-specific death rates for rollover crashes and light trucks were based on the numbers of deaths in crashes that occurred in each state, again using the U.S. Census Bureau estimates of the number of residents as the denominator. (Numerator definitions differed because NCHS records do not identify the state in which the injury occurred, and FARS records do not include the state of residence. Use of crash location rather than state of residence in the numerator results in similar maps, since children typically are killed in crashes that occur in their home state.) Class boundaries for each map were selected at points that distinguish among states with high, medium, or low death rates but do not reflect confidence limits.
Motor vehicle deaths in children
21
RESULTS
In 1985, 1,610 children ages O-14 were killed as motor vehicle occupants according to NCHS. FARS reported 1,670 motor vehicle occupant deaths in this age group for 1985 (4% more than NCHS). NCHS reported that 1,161 children died as pedestrians, 353 as bicyclists, 187 as pedestrians, but not in traffic, and 98 as motorcyclists in 1985. Motor vehicle occupants
Occupant deaths are the leading category of death for the 1-14 age group as a whole, exceeding any other cause of injury or disease. (For children less than one year old, perinatal deaths are the largest category overall [i.e. including noninjury deaths], and homicide is the leading cause of fatal injury [Waller, Baker, and Szocka 19891.) The occupant death rate was higher among infants than in older age groups (Fig. 1). Previous analysis by single year of age shows that beginning at about age 13, occupant death rates are higher than they are for infants (Baker, O’Neill, and Karpf 1984). Rates of motor vehicle occupant death were generally highest in the south, southwest, and mountain states (Fig. 2), with the highest rates in Idaho, New Mexico, and Wyoming. However, Utah’s rate was less than half the rate for these three nearby states, and was significantly lower than the U.S. rate (2.4 vs. 3.2 per 100,000 children, p < 0.01). Rollover crashes. Based on FARS data, this subset comprises about 24% of all occupant deaths in the O-14 age group. These crashes were examined separately because of the dramatic geographic pattern noted for all ages combined (Baker et al. 1984) and because of concern expressed by parents whose children had been killed in rollover crashes in Colorado. Of the ten states with the highest rates, ail but Alabama were in the west, primarily the mountain states (Fig. 3). As for motor vehicle occupant deaths in general, occupant restraint use by children exerts a critical effect on these rates. Light trucks. Deaths in crashes of light trucks comprised about 23% of all childhood occupant deaths (FARS data). With the exception of West Virginia, states with high death rates were in the western half of the U.S. (Fig. 4). Crash circumstances (rollover vs. nonrollover) were analyzed in relation to vehicle type (Table 1). Light trucks were overinvolved in rollover crashes (p < 0.001). The relationship between light trucks and rollover crashes was present for most individual states with large enough numbers for separate analysis. During 1985 and 1986,65 of the 226 children riding in unenclosed or exterior portions of light trucks were killed. Of these, 25 died following falls from the vehicles. (When deaths are coded as “falls,” the first significant event was not an impact with an object
AGE
0
2
4
6
DEATH RATE/lOO,OOO
n OCCUPANT q PEDESTRIAN,
q PEDESTRIAN, NON-TRAFFIC
MOTORCYCLE Fig. I. Motor vehicle-related
TRAFFIC
m BICYCLE 0 OTHER
injury death rates by age and category. U.S., 1980-1985
6
22
S. P.
BAKER
et al.
Fig. 2. Motor vehicle occupant death rates, ages O-14, U.S., 1980-1985.
or another vehicle. Since FARS data are based on police-reported events, it is probable that some fatal falls from vehicles do not appear in this data base.) The 226 children coded as being in an unenclosed part of a light truck (such as the back of a pickup truck) involved in a fatality were studied separately, to differentiate them from occupants of “other exterior portions,” which could include a child on a vehicle hood or running board; 94 (42%) were coded as ejected, compared with 18% (646/3657) of those occupying other positions of light trucks.
Fig. 3. Motor vehicle occupant death rates in rollovers. ages O-14, U.S., 1985-1986.
Motor vehicle deaths in children
1.~a.s/100.
l!E!l
0.el.afloo.
0-0.w100.
23
ooo/rm
4
ooo/ra ooo/ra
Fig. 4. Motor vehicle occupant death rates in light trucks, ages O-14, U.S.. 1985-1986.
Among the occupants of light trucks, 43% of the children coded as ejected were fatalities, compared to 16% of those not ejected. (Note: these percentages are not true fatality rates, as the population of crashes is limited to those in which at least one person was killed.) Pedestrians
The pedestrian death rate was highest at age 5-9, and was even higher than the occupant death rate in this age group. With the exception of Alaska, the states with the highest rates were all in the southern half of the U.S. and those with the lowest rates were all in the northern half (Fig. 5). Pedestrians, nontraffic
Pedestrian deaths in nontraffic situations comprised 17% of all motor vehicle related deaths in the l-4 year age group (Fig. 1) and were rare at other ages. One-year-old children had the highest rate. The highest death rates were observed in the western half of the country (Fig. 6). Other research has shown that for all ages combined, the nontraffic pedestrian death rate is five times as high in remote rural areas as in large cities (Baker et al. 1984). Table I. Rollover crashes in relation to vehicle type, fatally injured children ages O-14. United States, 1985-1986
S. P.
24
Fig. 5. Pedestrian-Traffic
BAKER et al.
death rates, ages O-14, U.S., 1980-1985.
Bicyclists Bicyclist death rates were high among children age 5 or older. In the lo-14 year age group, they were almost as common as pedestrian deaths (Fig. 1). There appeared to be no particular geographic pattern. Motorcyclists Motorcyclist deaths were uncommon in children less than 10 years old. Although no states license children less than 15 years of age as motorcycle operators, 68% of the motorcyclists killed were identified by FARS as the operator of the motorcycle. In general, the lowest motorcyclist death rates were found in the eastern and northeastern states (Fig. 7).
DISCUSSION
Death rates in childhood from all injury causes combined show a clear pattern of being highest throughout the south and in the Rocky Mountain states (Wailer et al. 1989). Motor vehicle-related deaths accounted for 37% of all injury deaths to children in the years 1980-1985 and have a strong influence on the overall pattern of geographic variation in overall injury death rates. It is important to look at the subcategories of motor vehicle-related deaths, if we are to develop adequate prevention strategies, Injury prevention measures for motor vehicle occupants are very different from those for pedestrians. Bicyclists and motorcyclists need protection measures different from either occupants or pedestrians. By further examining subsets of motor vehicle occupant fatalities (rollover and pickup truck fatalities, for example) more specific ideas for prevention efforts might be generated. Alcohol is a major and well-known contributing factor to motor vehicle occupant deaths. Its importance in deaths of child occupants was shown in North Carolina, where it is related to 26% of child passenger deaths (Margolis, Ketch, and Lacey 1986). The influence of societal norms is suggested by the very low death rate of children as motor vehicle occupants in Utah (See Fig. 2), where a large proportion of the residents abstain from alcohol use. (A similar geographic pattern is seen for all ages [Baker et al. 19841.)
Motor vehicle deaths in children
Fig. 6. Pedestrian-Nontraffic
25
death rates, ages O-14. U.S., 1980-1985
Prevention of motor vehicle occupant fatalities among children must include expanded use of occupant restraints. Existing child restraint laws exempt many children based on age, relationship to driver, the type of vehicle, and other factors (Teret et al. 1986). Since adult seat belt use laws cover front-seat occupants only, children, who frequently ride in the back seat, are excluded from protection under these laws as well. In addition to their own injury risk, unrestrained rear-seat occupants may increase the
Fig. 7. Motorcyclist death rates, ages O-14. U.S., 1980-1985.
26
S. P.
BAKER et al.
severity of injury to front-seat occupants. Closing these existing gaps in protection should be a priority for everyone working to prevent childhood injury death. Requiring restraint use for older children in both the front and back seat of all passenger vehicles, at all times, would go a long way towards preventing childhood motor vehicle occupant deaths and has a potential carryover effect in preventing the numerous and costly deaths and injuries in teenagers and young adults (Rice et al. 1989). Prevention of pedestrian deaths in traffic must focus on environmental designs that separate children from moving vehicles. Rivara and Barber (1985) emphasize that, at least in an urban setting, traffic engineering modifications seem to be the most practical solution. Small children cannot be relied upon to be safe pedestrians, especially if their playground is the street, but a simple training program (the “Willy Whistle” campaign) in three cities was associated with a 20% reduction in dart-out injuries to child pedestrians and should be tried elsewhere (Blomberg et al. 1983). The high death rates in many relatively rural southern states underscore the need for states to analyze their pedestrian injuries in relation to circumstances and specific locations, since preventive measures will differ between urban and rural locations. (Developing countries, where a large proportion of children killed in traffic are pedestrians, may share with southern states some of the factors that contribute to high rates of pedestrian injury and death, as well as potential remedies for such factors.) Nontraffic pedestrian deaths are particularly important in children under five years of age. As the map in Fig. 6 illustrates, the lowest rates are seen in states where a large proportion of the population lives in urban areas. The rate in remote rural areas is five times the rate in large cities (Baker et al. 1984). A study of such deaths in Washington state (Brison, Wicklund, and Mueller 1988) found a predominance of l- to 2-year-old children, typically backed over in the home driveway. Certain types of vehicles (i.e. light trucks and vans) figured prominently in these deaths, and the greater use of such vehicles in many western states probably contributes to high death rates. It should be determined whether vehicle design changes that increase visibility might be effectivesomewhat comparable to the addition of loud signals that automatically warn people when a heavy truck is backing up. Circular driveways that eliminate the need for backing up have been promoted in at least one Indian community and may be feasible in other rural areas. The most effective way known to prevent deaths to bicyclists and motorcyicists is the use of protective helmets every time the cycle is ridden. Head injuries are the leading cause of death among cyclists, and bicycle helmets have recently been shown to reduce the risk of head injury by 85% (Thompson, Rivara. and Thompson 1989). As in the case of nontraffic pedestrian deaths, bicyclist deaths (especially when no motor vehicle is involved) have a higher than ususal chance of not being reported to police. Children are even less likely to wear bicycle helmets than adults; it appears that people who pay for their own bicycles often buy themselves a helmet-parents, on the other hand, tend to buy their child only the bicycle, perhaps not recognizing the importance of protecting their children from head injury. In Victoria. Australia, an intensive campaign that included carefully designed educational components and rebates for people who purchased helmets increased helmet use by primary school children from 5% to 39% in a two-year period (Wood and Milne 1988). Death in rollover crashes is not unique to children. It should be noted, however, that (1) rollover crashes account for almost one-fourth of motor vehicle occupant deaths in the under 15 age group, (2) mortality shows a pronounced geographic pattern, and (3) states can prevent many crashes through provision of adequate guardrails in locations where vehicles would be apt to overturn if they left the road or shoulder. In the mountain states there are many locations where vehicles leaving the paved road are likely to plunge down a steep enbankment; some Indian Health Service Community Injury Control Programs are currently identifying and attempting to rectify such problems in and near Indian reservations (Dauphinais and Fulgham 1989). Some problems point to the need for intervention at the federal level. For example,
Motor vehicle deaths in children
27
other research has shown that many overturns occur in utility vehicles that have a high center of gravity in relation to the width of the wheelbase; the high rollover rates for certain vehicles point to the need for NHTSA to address the problem through its vehicle standards (Robertson 1989). No attempt was made to adjust for the number of pickup trucks and other light trucks in each state. This is important to note because the variation in death rates among states undoubtedly reflects differences in the proportion of registered vehicles that are light trucks. However, if a large number of children are dying as occupants of pickup trucks, it is especially important for the state to examine its child restraint laws. For example, in New Mexico (where pickup trucks are extremely popular and common) 24 children were killed as occupants of light trucks in 1985, accounting for 6% of all light truck fatalities to children O-14 years of age in the entire U.S. that year and 60% of all motor vehicle occupant deaths among New Mexican children. New Mexico now requires children in the occupant compartment of pickup trucks to be restrained, but allows children to ride unrestrained in the back of pickup trucks-where it is now illegal to carry a dog! Several states exclude passengers of pickup trucks from their passenger protection laws (Wells, Williams, and Fields 1989). The transportation of children in pickup trucks produces unique problems, since many have only two seating positions equipped with seat belts. The development of a safety harness for use in the back of a pickup truck and of inexpensive enclosures for truck beds should be explored. States should include pickup trucks and vans in their passenger protection legislation so that parents are required to protect child passengers with restraint systems, and should prohibit children from riding in the unenclosed back of trucks. In summary, states have many opportunities to reduce motor vehicle-related deaths, which are the largest source of mortality in children and adolescents. Geographic patterns in the major differences among states in childhood death rates for various categories of motor vehicle deaths have only recently been recognized (Waller et al. 1989). We hope that each state will examine the data describing its injury problems in detail (some of which is provided in Baker and Waller 1989), identify major sources of child mortality, and take steps to prevent needless death and injury. Review by states of FARS data and local police data will contribute potentially valuable details, ranging from non-use of restraint systems to defective highway design. Acknowledgements-This research was supported by the Centers for Disease Control, USPHS, through grant #R49/CCR302486-02 to the Johns Hopkins Injury Prevention Center and by the Insurance Institute for Highway Safety. The findings, opinions, and conclusions expressed are those of the authors and do not necessarily reflect the views of the sponsors. REFERENCES Baker, S. P.; O’Neill, B.; Karpf, R. S. The Injury Fact Book. Lexington, MA; Lexington Books; 1984. Baker, S. P.; Wailer, A. E. Childhood Injury Mortality: State-by-State Mortality Facts. Baltimore, MD: The Johns Hopkins Injury Prevention Center; 1989. Baker, S. P.; Whitfield, R. A.; O’Neill, B. Geographic variations in mortality from motor vehicle crashes. N. Eng. J. Med. 316: 1384-1387; 1987. Baker, S. P.; Whitfield, R.; O’Neill. B. County mapping of injury mortality. J. Trauma 28: 741-745; 1988. Blomberg, R. D.; Preusser, D.; Hale, A.; Lead, W. Experimental field test of proposed pedestrian safety measures. Vol. 2. Washington, DC: National Highway Traffic Safety Administration; 1983. Brison, R. J.; Wicklund, K.; Mueller, B. A. Fatal pedestrian injuries to young children: A different pattern of injury. Am. J. Public Health 78: 793-795; 1988. Dauphinais, R.; Fulgham, R. Study of fatal rollover crashes in the Navajo area. Window Rock, AZ: Navajo Area Indian Health Service; 1989. Margolis, L. H.; Ketch, J.; Lacey, J. H. Children in alcohol-related motor vehicle crashes. Pediatrics 77: 870872; 1986. Rice, D. P.; MacKenzie, E. J.; and associates. Cost of injury-United States: A report to Congress, 1989. San Francisco, CA: Institute for Health and Aging, University of California; 1989. Rivara, F. P.; Barber, M. Demographic analysis of childhood pedestrian injuries. Pediatrics 76: 375-381; 1985. Robertson, L. S. Risk of fatal rollover in utility vehicles relative to static stability. Am. J. Public Health 79: 300-303; 1989. Teret, S. P.; Jones, A. S.; Williams, A. F.; Wells, J. K. Child restraint laws: An analysis of gaps in coverage. Am. J. Public Health 76: 31-34; 1986.
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Thompson. R. S.: Rivara. F. P.; Thompson, D. C. A case-control study of the effectiveness of bicycle safety helmets. N. Ene. J. Med. 320: 1361-1367; 1989. Waller, A. E.; Bakir, S. P.; Szocka, A. Childhood injury deaths: National analysis and geographic variations. Am. J. Public Health 79: 310-315; 1989. Wells. J. K.; Williams, A. F.; Fields, M. Coverage gaps in seat belt use laws. Am. J. Public Health 79: 332333; 1989. Wood. T.; Milne. P. Head injuries to pedal cyclists and the promotion of helmet use in Victoria, Australia. Accid. Anal. Prev. 20: 177-185; 1988.
MOTOR
OMII-4575/91 s3.a) + .lm 8 1991 Pergamon Press plc
1991
VEHICLE DEATHS IN CHILDREN: GEOGRAPHIC VARIATIONS
SUSAN P. BAKER, ANNA WALLER,
AND
JEAN LANGLOIS
The Johns Hopkins University, Injury Prevention Center, Baltimore, Maryland 21205. U.S.A. (Received
10 August 1989; in revised form 23 March 1990)
Abstruet-Motor vehicle-related injury is the leading cause of death in children ages O-14 years in the United States. Using data from the National Center for Health Statistics and the Fatal Accident Reporting System, specific types of motor vehicle injury death in children were examined for the years 1980-1985 (using NCHS data) and 1985-1986 (using FARS data). Death rates were calculated for each specific category of motor vehicle injury for each state and were then mapped to determine patterns of geographic variation. In general, nontraffic pedestrian death rates and death rates for crashes involving light trucks and/or rollovers were higher in the West, and rates of pedestrian deaths in traffic were highest in the South. Some of the likely contributing factors and possible interventions are discussed.
State-by-state mapping of injury rates can reveal major regional variations. These variations are important because identifying states with the highest rates of a specific injury cause of death may suggest likely contributing factors which can then be targeted for intervention. For example, a previous study of motor vehicle mortality rates for all ages by county found a pronounced inverse correlation with population density (Baker, Whitfield, and O’Neill 1987). The highest death rates were seen in the western half of the United States and in counties with the lowest population per square mile. Many factors were thought to contribute to this pattern including differences in road characteristics, travel speeds, types of vehicles, and available trauma services. Similarly, analysis of drowning rates for children less than 5 years of age revealed high rates in California, Florida, and the southwest (Baker, Whitfield, and O’Neill 1988). Since toddlers are especially likely to drown in swimming pools, this kind of data can encourage areas with high death rates to explore such measures as childproof fencing requirements for home swimming pools. Especially low injury rates in a state or region may also Suggest protective factors that should be considered by other states and regions. Death rates (per million miles of travel) from collisions with utility poles are low in states where utility lines tend to be buried or located far from travel lanes (Baker, O’Neill, and Karpf 1984), a lesson that might be useful if applied in the northeast. The study presented here examines geographic variations at the state level of childhood motor vehicle-related mortality. Injury prevention efforts are usually administered at the state or local level, and state-specific data are often needed in order to motivate agencies and obtain needed funding for prevention programs. Information about injuries to children is especially valuable because of societal willingness to protect children from hazards that may be accepted in the case of adult injuries. Recently, Colorado parents whose children were killed when they plunged over embankments are working for the installation of guardrails in appropriate areas. Clearly, many measures that reduce injuries to children will also reduce injuries to older road users. This is especially true of “pre-event” measures that reduce the risk of crashes. This research expands on data presented in the monograph Childhood injury Morr&y: Stare-by-State Mortality Facts (Baker and Waller 1989) by focusing on motor vehicle related-mortality only and by supplementing detailed analysis of National Center for Health Statistics (NCHS) data with analysis of Fatal Accident Reporting System (FARS) data.
19
20
S. P.
BAKER et al.
DEFINITIONS The analysis of NCHS data defined cause of injury on the basis of the “E codes”, the External Causes of Injury in the International Classification of Diseases. Brief descriptions of the motor vehicle-related causes follow. Motor vehicle occupant deaths (E810-819, .O, .l, .9) are those that occur in traffic and involve children who are passengers (or, occasionally, drivers) in cars or trucks. The category includes falls from vehicles and children killed when riding on the outside of the vehicles, for example in the back of pickup trucks. For the 1-14 year age group as a whole, motor vehicle occupant fatalities outrank all other injuries and diseases as the leading cause of death. Pedestrian traffic deaths (E810-819, .7) refer to children who are struck and killed on public roads when not in or on a motor vehicle or bicycle. Although most children are on foot, the category also includes any children on roller skates or skateboards. Pedestrian injuries are a universal and serious problem, due to failure to separate pedestrian and vehicular traffic. Pedestrian nontraffic deaths (E820-825, .7) occur off public roads, for example, in driveways and parking lots. These deaths are most common in rural areas, especially in western states. Many are miscoded as pedestrian traffic deaths. Motorcyclist deaths (E810-825, .2, .3) include all children categorized as occupants (riders) of motorcycles, regardless of whether the injury occurred on public or private property. Two-thirds of the fatally injured children are listed as the driver of the motorcycle. Most deaths involve head injuries sustained in collisions with other motor vehicles. Bicyclist deaths (E810-825, .6) include any child on a vehicle that is operated solely by pedals and, therefore, exclude children riding motorized bicycles. The analyses presented here are limited to deaths resulting from collisions with motor vehicles, because these represent 95% of all bicyclist deaths in childhood. The overwhelming majority of fatal injuries to bicyclists are head injuries. The analyses of FARS data defined rollover crushes as those in which either the first harmful event or any subsequent harmful event was a rollover. Light trucks were identified from the “Model” variable in FARS and include light duty and standard pickup trucks, truck-based utility vehicles, and truck-based station wagons, vans, van-based station wagons, and van derivatives.
METHODS
Deaths of children age O-14 were analyzed using the two data bases. Deaths of motor vehicle occupants, pedestrians (in traffic and not in traffic, separately), bicyclists, and motorcyclists were studied for the six-year period, 1980-1985, using mortality tapes from the National Center for Health Statistics (NCHS). Death rates for states were calculated using the average annual numbers of deaths of residents ages O-14 (the numerator) and the number of residents based on United States Census Bureau estimates for the same age group (the denominator). Analyses of NCHS data were supplemented with analyses of data from the Fatal Accident Reporting System (FARS) for 1985-1986. State-specific death rates for rollover crashes and light trucks were based on the numbers of deaths in crashes that occurred in each state, again using the U.S. Census Bureau estimates of the number of residents as the denominator. (Numerator definitions differed because NCHS records do not identify the state in which the injury occurred, and FARS records do not include the state of residence. Use of crash location rather than state of residence in the numerator results in similar maps, since children typically are killed in crashes that occur in their home state.) Class boundaries for each map were selected at points that distinguish among states with high, medium, or low death rates but do not reflect confidence limits.
Motor vehicle deaths in children
21
RESULTS
In 1985, 1,610 children ages O-14 were killed as motor vehicle occupants according to NCHS. FARS reported 1,670 motor vehicle occupant deaths in this age group for 1985 (4% more than NCHS). NCHS reported that 1,161 children died as pedestrians, 353 as bicyclists, 187 as pedestrians, but not in traffic, and 98 as motorcyclists in 1985. Motor vehicle occupants
Occupant deaths are the leading category of death for the 1-14 age group as a whole, exceeding any other cause of injury or disease. (For children less than one year old, perinatal deaths are the largest category overall [i.e. including noninjury deaths], and homicide is the leading cause of fatal injury [Waller, Baker, and Szocka 19891.) The occupant death rate was higher among infants than in older age groups (Fig. 1). Previous analysis by single year of age shows that beginning at about age 13, occupant death rates are higher than they are for infants (Baker, O’Neill, and Karpf 1984). Rates of motor vehicle occupant death were generally highest in the south, southwest, and mountain states (Fig. 2), with the highest rates in Idaho, New Mexico, and Wyoming. However, Utah’s rate was less than half the rate for these three nearby states, and was significantly lower than the U.S. rate (2.4 vs. 3.2 per 100,000 children, p < 0.01). Rollover crashes. Based on FARS data, this subset comprises about 24% of all occupant deaths in the O-14 age group. These crashes were examined separately because of the dramatic geographic pattern noted for all ages combined (Baker et al. 1984) and because of concern expressed by parents whose children had been killed in rollover crashes in Colorado. Of the ten states with the highest rates, ail but Alabama were in the west, primarily the mountain states (Fig. 3). As for motor vehicle occupant deaths in general, occupant restraint use by children exerts a critical effect on these rates. Light trucks. Deaths in crashes of light trucks comprised about 23% of all childhood occupant deaths (FARS data). With the exception of West Virginia, states with high death rates were in the western half of the U.S. (Fig. 4). Crash circumstances (rollover vs. nonrollover) were analyzed in relation to vehicle type (Table 1). Light trucks were overinvolved in rollover crashes (p < 0.001). The relationship between light trucks and rollover crashes was present for most individual states with large enough numbers for separate analysis. During 1985 and 1986,65 of the 226 children riding in unenclosed or exterior portions of light trucks were killed. Of these, 25 died following falls from the vehicles. (When deaths are coded as “falls,” the first significant event was not an impact with an object
AGE
0
2
4
6
DEATH RATE/lOO,OOO
n OCCUPANT q PEDESTRIAN,
q PEDESTRIAN, NON-TRAFFIC
MOTORCYCLE Fig. I. Motor vehicle-related
TRAFFIC
m BICYCLE 0 OTHER
injury death rates by age and category. U.S., 1980-1985
6
22
S. P.
BAKER
et al.
Fig. 2. Motor vehicle occupant death rates, ages O-14, U.S., 1980-1985.
or another vehicle. Since FARS data are based on police-reported events, it is probable that some fatal falls from vehicles do not appear in this data base.) The 226 children coded as being in an unenclosed part of a light truck (such as the back of a pickup truck) involved in a fatality were studied separately, to differentiate them from occupants of “other exterior portions,” which could include a child on a vehicle hood or running board; 94 (42%) were coded as ejected, compared with 18% (646/3657) of those occupying other positions of light trucks.
Fig. 3. Motor vehicle occupant death rates in rollovers. ages O-14, U.S., 1985-1986.
Motor vehicle deaths in children
1.~a.s/100.
l!E!l
0.el.afloo.
0-0.w100.
23
ooo/rm
4
ooo/ra ooo/ra
Fig. 4. Motor vehicle occupant death rates in light trucks, ages O-14, U.S.. 1985-1986.
Among the occupants of light trucks, 43% of the children coded as ejected were fatalities, compared to 16% of those not ejected. (Note: these percentages are not true fatality rates, as the population of crashes is limited to those in which at least one person was killed.) Pedestrians
The pedestrian death rate was highest at age 5-9, and was even higher than the occupant death rate in this age group. With the exception of Alaska, the states with the highest rates were all in the southern half of the U.S. and those with the lowest rates were all in the northern half (Fig. 5). Pedestrians, nontraffic
Pedestrian deaths in nontraffic situations comprised 17% of all motor vehicle related deaths in the l-4 year age group (Fig. 1) and were rare at other ages. One-year-old children had the highest rate. The highest death rates were observed in the western half of the country (Fig. 6). Other research has shown that for all ages combined, the nontraffic pedestrian death rate is five times as high in remote rural areas as in large cities (Baker et al. 1984). Table I. Rollover crashes in relation to vehicle type, fatally injured children ages O-14. United States, 1985-1986
S. P.
24
Fig. 5. Pedestrian-Traffic
BAKER et al.
death rates, ages O-14, U.S., 1980-1985.
Bicyclists Bicyclist death rates were high among children age 5 or older. In the lo-14 year age group, they were almost as common as pedestrian deaths (Fig. 1). There appeared to be no particular geographic pattern. Motorcyclists Motorcyclist deaths were uncommon in children less than 10 years old. Although no states license children less than 15 years of age as motorcycle operators, 68% of the motorcyclists killed were identified by FARS as the operator of the motorcycle. In general, the lowest motorcyclist death rates were found in the eastern and northeastern states (Fig. 7).
DISCUSSION
Death rates in childhood from all injury causes combined show a clear pattern of being highest throughout the south and in the Rocky Mountain states (Wailer et al. 1989). Motor vehicle-related deaths accounted for 37% of all injury deaths to children in the years 1980-1985 and have a strong influence on the overall pattern of geographic variation in overall injury death rates. It is important to look at the subcategories of motor vehicle-related deaths, if we are to develop adequate prevention strategies, Injury prevention measures for motor vehicle occupants are very different from those for pedestrians. Bicyclists and motorcyclists need protection measures different from either occupants or pedestrians. By further examining subsets of motor vehicle occupant fatalities (rollover and pickup truck fatalities, for example) more specific ideas for prevention efforts might be generated. Alcohol is a major and well-known contributing factor to motor vehicle occupant deaths. Its importance in deaths of child occupants was shown in North Carolina, where it is related to 26% of child passenger deaths (Margolis, Ketch, and Lacey 1986). The influence of societal norms is suggested by the very low death rate of children as motor vehicle occupants in Utah (See Fig. 2), where a large proportion of the residents abstain from alcohol use. (A similar geographic pattern is seen for all ages [Baker et al. 19841.)
Motor vehicle deaths in children
Fig. 6. Pedestrian-Nontraffic
25
death rates, ages O-14. U.S., 1980-1985
Prevention of motor vehicle occupant fatalities among children must include expanded use of occupant restraints. Existing child restraint laws exempt many children based on age, relationship to driver, the type of vehicle, and other factors (Teret et al. 1986). Since adult seat belt use laws cover front-seat occupants only, children, who frequently ride in the back seat, are excluded from protection under these laws as well. In addition to their own injury risk, unrestrained rear-seat occupants may increase the
Fig. 7. Motorcyclist death rates, ages O-14. U.S., 1980-1985.
26
S. P.
BAKER et al.
severity of injury to front-seat occupants. Closing these existing gaps in protection should be a priority for everyone working to prevent childhood injury death. Requiring restraint use for older children in both the front and back seat of all passenger vehicles, at all times, would go a long way towards preventing childhood motor vehicle occupant deaths and has a potential carryover effect in preventing the numerous and costly deaths and injuries in teenagers and young adults (Rice et al. 1989). Prevention of pedestrian deaths in traffic must focus on environmental designs that separate children from moving vehicles. Rivara and Barber (1985) emphasize that, at least in an urban setting, traffic engineering modifications seem to be the most practical solution. Small children cannot be relied upon to be safe pedestrians, especially if their playground is the street, but a simple training program (the “Willy Whistle” campaign) in three cities was associated with a 20% reduction in dart-out injuries to child pedestrians and should be tried elsewhere (Blomberg et al. 1983). The high death rates in many relatively rural southern states underscore the need for states to analyze their pedestrian injuries in relation to circumstances and specific locations, since preventive measures will differ between urban and rural locations. (Developing countries, where a large proportion of children killed in traffic are pedestrians, may share with southern states some of the factors that contribute to high rates of pedestrian injury and death, as well as potential remedies for such factors.) Nontraffic pedestrian deaths are particularly important in children under five years of age. As the map in Fig. 6 illustrates, the lowest rates are seen in states where a large proportion of the population lives in urban areas. The rate in remote rural areas is five times the rate in large cities (Baker et al. 1984). A study of such deaths in Washington state (Brison, Wicklund, and Mueller 1988) found a predominance of l- to 2-year-old children, typically backed over in the home driveway. Certain types of vehicles (i.e. light trucks and vans) figured prominently in these deaths, and the greater use of such vehicles in many western states probably contributes to high death rates. It should be determined whether vehicle design changes that increase visibility might be effectivesomewhat comparable to the addition of loud signals that automatically warn people when a heavy truck is backing up. Circular driveways that eliminate the need for backing up have been promoted in at least one Indian community and may be feasible in other rural areas. The most effective way known to prevent deaths to bicyclists and motorcyicists is the use of protective helmets every time the cycle is ridden. Head injuries are the leading cause of death among cyclists, and bicycle helmets have recently been shown to reduce the risk of head injury by 85% (Thompson, Rivara. and Thompson 1989). As in the case of nontraffic pedestrian deaths, bicyclist deaths (especially when no motor vehicle is involved) have a higher than ususal chance of not being reported to police. Children are even less likely to wear bicycle helmets than adults; it appears that people who pay for their own bicycles often buy themselves a helmet-parents, on the other hand, tend to buy their child only the bicycle, perhaps not recognizing the importance of protecting their children from head injury. In Victoria. Australia, an intensive campaign that included carefully designed educational components and rebates for people who purchased helmets increased helmet use by primary school children from 5% to 39% in a two-year period (Wood and Milne 1988). Death in rollover crashes is not unique to children. It should be noted, however, that (1) rollover crashes account for almost one-fourth of motor vehicle occupant deaths in the under 15 age group, (2) mortality shows a pronounced geographic pattern, and (3) states can prevent many crashes through provision of adequate guardrails in locations where vehicles would be apt to overturn if they left the road or shoulder. In the mountain states there are many locations where vehicles leaving the paved road are likely to plunge down a steep enbankment; some Indian Health Service Community Injury Control Programs are currently identifying and attempting to rectify such problems in and near Indian reservations (Dauphinais and Fulgham 1989). Some problems point to the need for intervention at the federal level. For example,
Motor vehicle deaths in children
27
other research has shown that many overturns occur in utility vehicles that have a high center of gravity in relation to the width of the wheelbase; the high rollover rates for certain vehicles point to the need for NHTSA to address the problem through its vehicle standards (Robertson 1989). No attempt was made to adjust for the number of pickup trucks and other light trucks in each state. This is important to note because the variation in death rates among states undoubtedly reflects differences in the proportion of registered vehicles that are light trucks. However, if a large number of children are dying as occupants of pickup trucks, it is especially important for the state to examine its child restraint laws. For example, in New Mexico (where pickup trucks are extremely popular and common) 24 children were killed as occupants of light trucks in 1985, accounting for 6% of all light truck fatalities to children O-14 years of age in the entire U.S. that year and 60% of all motor vehicle occupant deaths among New Mexican children. New Mexico now requires children in the occupant compartment of pickup trucks to be restrained, but allows children to ride unrestrained in the back of pickup trucks-where it is now illegal to carry a dog! Several states exclude passengers of pickup trucks from their passenger protection laws (Wells, Williams, and Fields 1989). The transportation of children in pickup trucks produces unique problems, since many have only two seating positions equipped with seat belts. The development of a safety harness for use in the back of a pickup truck and of inexpensive enclosures for truck beds should be explored. States should include pickup trucks and vans in their passenger protection legislation so that parents are required to protect child passengers with restraint systems, and should prohibit children from riding in the unenclosed back of trucks. In summary, states have many opportunities to reduce motor vehicle-related deaths, which are the largest source of mortality in children and adolescents. Geographic patterns in the major differences among states in childhood death rates for various categories of motor vehicle deaths have only recently been recognized (Waller et al. 1989). We hope that each state will examine the data describing its injury problems in detail (some of which is provided in Baker and Waller 1989), identify major sources of child mortality, and take steps to prevent needless death and injury. Review by states of FARS data and local police data will contribute potentially valuable details, ranging from non-use of restraint systems to defective highway design. Acknowledgements-This research was supported by the Centers for Disease Control, USPHS, through grant #R49/CCR302486-02 to the Johns Hopkins Injury Prevention Center and by the Insurance Institute for Highway Safety. The findings, opinions, and conclusions expressed are those of the authors and do not necessarily reflect the views of the sponsors. REFERENCES Baker, S. P.; O’Neill, B.; Karpf, R. S. The Injury Fact Book. Lexington, MA; Lexington Books; 1984. Baker, S. P.; Wailer, A. E. Childhood Injury Mortality: State-by-State Mortality Facts. Baltimore, MD: The Johns Hopkins Injury Prevention Center; 1989. Baker, S. P.; Whitfield, R. A.; O’Neill, B. Geographic variations in mortality from motor vehicle crashes. N. Eng. J. Med. 316: 1384-1387; 1987. Baker, S. P.; Whitfield, R.; O’Neill. B. County mapping of injury mortality. J. Trauma 28: 741-745; 1988. Blomberg, R. D.; Preusser, D.; Hale, A.; Lead, W. Experimental field test of proposed pedestrian safety measures. Vol. 2. Washington, DC: National Highway Traffic Safety Administration; 1983. Brison, R. J.; Wicklund, K.; Mueller, B. A. Fatal pedestrian injuries to young children: A different pattern of injury. Am. J. Public Health 78: 793-795; 1988. Dauphinais, R.; Fulgham, R. Study of fatal rollover crashes in the Navajo area. Window Rock, AZ: Navajo Area Indian Health Service; 1989. Margolis, L. H.; Ketch, J.; Lacey, J. H. Children in alcohol-related motor vehicle crashes. Pediatrics 77: 870872; 1986. Rice, D. P.; MacKenzie, E. J.; and associates. Cost of injury-United States: A report to Congress, 1989. San Francisco, CA: Institute for Health and Aging, University of California; 1989. Rivara, F. P.; Barber, M. Demographic analysis of childhood pedestrian injuries. Pediatrics 76: 375-381; 1985. Robertson, L. S. Risk of fatal rollover in utility vehicles relative to static stability. Am. J. Public Health 79: 300-303; 1989. Teret, S. P.; Jones, A. S.; Williams, A. F.; Wells, J. K. Child restraint laws: An analysis of gaps in coverage. Am. J. Public Health 76: 31-34; 1986.
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Thompson. R. S.: Rivara. F. P.; Thompson, D. C. A case-control study of the effectiveness of bicycle safety helmets. N. Ene. J. Med. 320: 1361-1367; 1989. Waller, A. E.; Bakir, S. P.; Szocka, A. Childhood injury deaths: National analysis and geographic variations. Am. J. Public Health 79: 310-315; 1989. Wells. J. K.; Williams, A. F.; Fields, M. Coverage gaps in seat belt use laws. Am. J. Public Health 79: 332333; 1989. Wood. T.; Milne. P. Head injuries to pedal cyclists and the promotion of helmet use in Victoria, Australia. Accid. Anal. Prev. 20: 177-185; 1988.
