Child passenger fatality: Child restraint system usage and contributing factors among the youngest passengers from 2011–2015

Abstract

Objective:

Motor-vehicle crashes (MVC) remain a leading cause of preventable injury and death for children aged 0–3 in the United States. Despite advancement in legislation and public awareness there is continued evidence of inappropriate child restraint system (CRS) use among the youngest passengers. The current study focuses on appropriate CRS use from 2011–2015 using data from the Fatality Analysis Reporting System (FARS) for children aged 0–3.

Methods:

Child-, driver-, vehicle-, and trip-related characteristics were investigated within a sample of 648 children from 625 crashes over 5-years in which a child aged 0–3 was fatally injured while unrestrained or wearing an identified CRS type. Multivariable log-binomial regression was used to obtain relative risk.

Results:

Only 48% of the fatally injured children were appropriately restrained in a CRS. Premature transition to a booster seat and seat belt was evident. The largest proportion of rear-facing restraint use was reported in < 1 year olds (40%), with less reported in 1 (11%) and 2 year olds (2%) and no usage in 3 year olds. Younger children were more likely to be in an appropriate CRS, while Black children, driver not restrained in a lap-shoulder belt configuration, and riding in a pickup truck were less likely to be restrained appropriately.

Conclusions:

Evidence of inappropriate CRS use supports the use of more stringent legislation and parental interventions to communicate best practice recommendations and educate caregivers regarding appropriate child restraint methods.

Practical Applications:

Public health campaigns focused on increasing appropriate restraint use in children are of great importance as optimally restrained children are less likely to sustain injuries, or require crash-related hospitalization compared to unrestrained children. Researchers and practitioners may find these surveillance findings essential when developing education and interventions targeting child-parent dyads at the greatest risk for a MVC-related fatality.

1. INTRODUCTION

As pediatric fatalities resulting from motor-vehicle crashes (MVCs) have continued to decline in the United States (U.S.), MVCs continue to remain one of the leading causes of injury and death for children ages 0–3 (Centers for Disease Control and Prevention - National Center for Injury Prevention and Control, 2015; National Center for Statistics and Analysis, 2017a). Contributing causes of these fatalities include failure to use a child restraint system (CRS), such as child safety seats (CSSs) and booster seats, and inappropriate use, such as premature transition and installation errors (Durbin, 2011; Jones, Hoffman, Gallardo, Gilbert, & Carlson, 2017; National Center for Statistics and Analysis, 2017a; Winston, Durbin, Kallan, & Moll, 2000). In 2016, it was estimated that 21% of children ages 4 and younger who were fatally injured in a MVC were unrestrained (National Center for Statistics and Analysis, 2017b). Despite substantial increases in CRS usage and declines in injury and death associated with non-restraint, in part due to legislative efforts, CRS usage for children aged 0–3 is still under 100% (Boyle & Lampkin, 2009; Durbin, 2011; Hoffman, Gallardo, & Carlson, 2016; National Center for Statistics and Analysis, 2017b; Weatherwax, Coddington, Ahmed, & Richards, 2016). Consistency in the instances of CRS misuse and unrestrained children across studies is disconcerting, as optimally restrained children are less likely to sustain injuries or require crash-related hospitalization compared to unrestrained children (Chen, Durbin, Elliott, Kallan, & Winston, 2005; Hafner et al., 2017; Hoffman et al., 2016; Jones et al., 2017; Lee, Farrell, & Mannix, 2015; Sauber-Schatz, Thomas, & Cook, 2015).

Appropriate use of CRSs and the associated life-saving benefits are recognized by associations such as the National Highway Traffic Safety Administration (NHTSA) and the American Academy of Pediatrics (AAP) (Durbin, 2011; National Highway Traffic Safety Administration [NHTSA], 2018a). NHTSA recommends that children should remain rear-facing for added safety benefits, as long as the child does not exceed the maximum manufacturer stated height and weight limit of the CRS with the minimum age being 1-year-old. After outgrowing a rear-facing CRS the child should be transitioned to a forward-facing CRS with a harness until the child exceeds the maximum manufacturer stated height and weight (National Highway Traffic Safety Administration [NHTSA], 2018a). Recently, the added safety benefits for rear-facing past 1 year of age have been challenged due to lack of statistical power, but more research is needed (McMurry et al., 2018). Furthermore, current research investigating appropriate CRS usage is warranted for policy and intervention development given the variability in child passenger safety legislation across U.S. states. Over half of U.S. states, as of 2017, did not specify rear-facing CRSs for children aged 1 year or younger within their child safety law, and only nine specified rear-facing restraint past 1 year of age (Chen et al., 2005; Insurance Institute for Highway Safety [IIHS], 2017; Weatherwax et al., 2016; Wolf et al., 2017). The current study aims to extend and update the literature on appropriate CRS use and unrestrained child passengers in MVC-related fatalities, focusing on the youngest vehicle passengers using the Fatality Analysis Reporting System (FARS) fatality data from 2011–2015.

2. METHODS

2.1. Data Resources

2.1.1. Data Source

The data for this cross-sectional study were obtained from the FARS database for child fatalities that occurred in 2011–2015. The FARS is a census of all MVCs in the United States, maintained by NHTSA since 1975, including all public roadway crashes that result in at least one fatality within 30 days (NHTSA, 2016). The FARS records person-, vehicle-, and trip-related characteristics, including the age of the occupant, restraint use of the occupant, vehicle body classification, and the date on which the crash occurred. Several data elements, such as race and ethnicity, are only recorded for persons who sustained fatal injuries. These elements are reviewed and coded by trained FARS analysts.

2.1.2. Study Population

The study population of children aged 0–3 years old were passenger vehicle occupants who had sustained fatal injuries from a crash (N = 1088). As this study focused on appropriate CRS use in passenger vehicles, children with missing or unknown/not reported restraint use (n = 72), in addition to children who were fatally injured in unknown vehicle types, ATVs, motorcycles, or commercial and public transport (n = 21), were not included in the sample. After excluding these observations there were 995 fatally injured children. Lastly, as the FARS database contains specified CRS types (i.e., rear-facing, forward-facing CSS, or booster seat) and a generic CRS usage (i.e., either booster seat or car seat not specified), generic cases were further excluded as booster seat usage could not be distinguished from car seat usage (n = 347). Therefore, the sample of fatalities with a specified CRS type was comprised of 648 children, 625 vehicles, and 625 crashes.

2.2. Variable Definitions

2.2.1. Independent variables

Child characteristics included child age, sex, and race. Age was grouped into four discrete categories: less than 12 months (0-year-old), 12–23 months (1-year-old), 24–35 months (2-years-old), and 35–47 months (3-years-old). Child sex was categorized as male and female and race as White, Black, and other (including Native American/Alaska Native, Asiatic races, and multi-racial due to small cell size).

Driver characteristics included driver age, sex, restraint use, and alcohol use. Driver age was grouped into three discrete categories: 24-years-old and younger, 25 through 39-years-old, and 40 years and older, similar to age categorizations used in previous literature (see Hoffman et al., 2016; Macy, Cunningham, Resnicow, & Freed, 2014). Driver restraint use was categorized into appropriate restraint use (use of a lap-shoulder belt configuration; NHTSA, 2018b) or other restraint use (other restraint types such as shoulder-belt only, lap-belt only, or no restraint use). Driver alcohol use was categorized as either yes or no based on police reports determining driver alcohol involvement.

Vehicle characteristics included vehicle type and model year. Vehicle type was categorized according to the NHTSA definitions, which standardizes motor-vehicle classification by size, weight, and work status (at work or not at work) of the driver (NHTSA, 2016). The sample was limited to MVCs that occurred in four-wheeled passenger cars, including pickup trucks, vans, passenger cars, and sport utility vehicles (SUVs). Vehicle model year was categorized into before 2005, 2005–2009, and after 2009.

Trip characteristics included time of day, day of the week, year, and posted speed limit. Time of day and day of week were categorized based on the NHTSA operational definitions (NHTSA, 2016). Time of day consisted of daytime (i.e., 6:00 am-5:59 pm) and nighttime (i.e., 6:00 p.m.−5:59 am). Day of the week consisted of weekends (i.e., 6:00 p.m. Friday through 5:59 a.m. Monday) and weekdays (i.e., 6:00 a.m. Monday through 5:59 p.m. Friday). Year referred to the year when the crash occurred and posted speed limit referred to the speed limit in miles per hour (mph) of the section of road on which the vehicle was immediately traveling on before the critical event that contributed to the crash. Speed limit was categorized into less than 55 mph and 55 mph or greater. Crashes that occurred on roadways with no statutory limit or on non-traffic areas (e.g., driveway or parking lot) were grouped into the less than 55 mph category.

2.2.2. Outcome variable

For the purposes of this study, a composite variable was derived from the NHTSA CRS recommendations (NHTSA, 2018a) and available information in the FARS database (i.e., restraint use, misuse of restraint, and seating position). Based on this transformation, a child who was appropriately restrained met all the following criteria: was in a CRS (i.e., rear- or forward-facing), no indications of restraint misuse, and seated in the rear seat of the vehicle. Conversely, a child who was not appropriately restrained was: in the incorrect restraint system (i.e., a child of any age restrained in a lap-shoulder belt, a child less than 1-year-old not rear-facing), in a misused CRS, or seated in the front row of the vehicle. Weight and height information were not included in the operational definition as this information is not available in the FARS database.

2.3. Statistical Analyses

Contingency tables were constructed for the descriptive analysis. CRS type by age percentages were assessed for premature transition from rear-facing CRS for children less than 1-year-old and lap-shoulder belt usage for all ages. Using the SAS GENMOD procedure, a multivariable log-binomial regression model was fit to the data. As the study outcome was relatively common (total number of children properly restrained was greater than 10%), a log-binomial model with generalized estimating equation was utilized over logistic regression to estimate crude and adjusted relative risk (cRR and aRR, respectively) and 95% confidence intervals (CI). This model allowed us to adjust for clusters of children who were passengers in the same vehicle.

Appropriate CRS usage was regressed individually on each study variable to obtain cRRs and p-values. All variables that met the statistical threshold of p < 0.2 were included in the multivariable model. The available sample size for the multivariable model (n = 528 fatalities, m = 508 clusters) was less than the total (N = 648 fatalities, M = 625 clusters) due to missing data (61 missing for race, 41 missing for driver restraint, 23 missing for speed limit, and 1 missing for model year). Data analyses were performed using SAS Enterprise Guide version 7.11 (SAS Institute Inc., 2015).

3. RESULTS

Characteristics of children (aged 0–3) who were fatally injured are presented in Table 1. Of the fatally injured children, approximately 23% were aged 0, 1, and 2 years old, with a slightly higher amount being 3 year olds (30%). Over half of the children were male (53%), and over half were of White race (67%), and the majority (83%) were seated in the second row of the vehicle. Overall, most drivers were aged 25–39, female, and using the appropriate restraint configuration. For most crashes police-reported alcohol use was absent and the driver was not fatally injured. Of the 625 vehicles in the sample, most were passenger cars, or manufactured in 2004 or earlier. Regarding trip characteristics, most crashes occurred within posted speed limits of 55 mph or greater (66%), during daytime hours (59%), or on weekdays (60%). Each year (2011–2015) contributed to approximately 20% of fatally injured child passengers, with 2012 having the highest (24%).

Table 1:

Characteristics of fatally injured child passengers 0–3 years old, United States, 2011–2015

Characteristic	Total Crash Population, n (%)
Child (N=648)
Age (years)
<1	149 (23.0)
1	153 (23.6)
2	152 (23.5)
3	194 (29.9)
Sex
Male	341 (52.6)
Female	307 (47.4)
Race
White	391 (66.6)
Black	133 (22.7)
Other	63 (10.7)
Unknown	61
Seat Position
Front Row	74 (11.9)
Second Row	510 (82.3)
Third Row	19 (3.1)
Other	17 (2.7)
Unknown	28
Driver (N=625)
Age
≤ 24 Years Old	218 (34.9)
25–39 Years Old	316 (50.6)
≥ 40 Years Old	91 (14.6)
Sex
Female	360 (57.6)
Male	265 (42.4)
Restraint use
Appropriatea	402 (68.6)
Otherb	184 (31.4)
Unknown	39
Alcohol use
Yes	97 (15.5)
No	528 (84.5)
Fatally Injured
Yes	166 (26.6)
No	457 (73.4)
Unknown	2
Vehicle (N=625)
Vehicle Type
Passenger car	345 (55.2)
Pickup truck	60 (9.6)
Van	50 (8.0)
SUV	170 (27.2)
Vehicle Age
> 2009	61 (09.8)
2005–2009	145 (23.2)
< 2005	418 (67.0)
Unknown	1
Crash (N=625)
Crash Time
6:00AM - 5:59 PM	369 (59.0)
6:00PM - 5:59 AM	256 (41.0)
Speed limit
< 55 mph	205 (34.0)
≥ 55 mph	398 (66.0)
Unknown	22
Weekend
Yes	251 (40.2)
No	374 (59.8)
Year
2011	117 (18.7)
2012	152 (24.3)
2013	118 (18.9)
2014	106 (17.0)
2015	132 (21.1)

mph = miles per hour.

^aAppropriate restraint use includes ‘shoulder-lap belt configuration’.

^bOther restraint use includes ‘lap-belt only’, ‘shoulder-belt only’, and ‘no use of restraint’.

When assessing a raw count of fatalities by restraint use (Table 2), more children were reported in forward-facing CRSs when compared to rear-facing. In assessing premature CRS transition, it was revealed that only 40% of children less than 1-year-old were reported in a rear-facing CRS. Premature transition was further evident when investigating forward-facing CRS usage, as 13% of children less than 1-year-old were in forward-facing CRS. As seen in Table 3, 0.7% of 1 year olds, 9.9% of 2 year olds, and 14.9% of 3 year olds were reported as being in a booster seat. Use of any seat belt type (lap-shoulder belt, shoulder-belt only, and lap-belt only) and no restraint use were evident across all ages, with the highest percentage observed in 3 year olds (53%). For example, 4.7% of children less than 1-year-old, 1.3% of 1 year olds, 7.9% of 2 year olds, and 9.3% of 3 year olds were restrained with a lap-shoulder belt.

Table 2.

Rates of restraint type by child age among fatally injured child passengers 0–3 years old, United States, 2011–2015

	Rear-facing CRS	Forward-facing CRS	Booster Seat	Seatbelta	Otherb	Total
	n (row %)
Age (years)
< 1	59 (39.6)	20 (13.4)	0 (0.0)	7 (4.7)	63 (42.3)	149
1	16 (10.5)	67 (43.8)	1 (0.7)	2 (1.3)	67 (43.8)	153
2	3 (2.0)	56 (36.8)	15 (9.9)	12 (7.9)	66 (43.4)	152
3	0 (0.0)	44 (22.7)	29 (14.9)	18 (9.3)	103 (53.1)	194
Total	78 (12.0)	187 (28.9)	45 (6.9)	39 (6.0)	299 (46.1)	648

^aIncludes ‘Lap-shoulder Belt’.

^bIncludes ‘Lap-belt Only’, ‘Shoulder-belt Only’, and ‘No Restraint Use’.

CRS = child restraint system.

Table 3.

Multivariable analysis of appropriate CRS use among fatally injured child passengers 0–3 years old, United States, 2011–2015

Characteristic	Total	Appropriate CRS use±, %	Risk Ratio
			Crude	95% CI	Adjusted	95% CI
Sample (N)	528	48.3%
Child
Age (years)
<1	121	38.0	1.62	(1.15, 2.28)	1.72	(1.21, 2.45)
1	126	42.9	1.92	(1.42, 2.59)	1.90	(1.36, 2.66)
2	117	32.5	1.32	(0.96, 1.81)	1.54	(1.07, 2.23)
3	164	20.7	1.00	(Reference)	1.00	(Reference)
Race
White	354	37.9	1.00	(Reference)	1.00	(Reference)
Black	122	21.3	0.62	(0.44, 0.87)	0.57	(0.39, 0.81)
Other	52	23.1	0.61	(0.38, 0.98)	0.73	(0.47, 1.15)
Driver
Restraint use
Appropriatea	368	38.6	1.00	(Refer ence)	1.00	(Reference)
Otherb	160	18.8	0.45	(0.32, 0.63)	0.66	(0.47, 0.91)
Alcohol use
Yes	82	19.5	0.55	(0.36, 0.85)	0.69	(0.44, 1.10)
No	446	35.0	1.00	(Reference)	1.00	(Reference)
Vehicle
Type
Passenger car	293	38.6	1.00	(Reference)	1.00	(Reference)
Pickup truck	50	14.0	0.36	(0.18, 0.69)	0.44	(0.22, 0.87)
Van	40	27.5	0.90	(0.59, 1.35)	0.77	(0.48, 1.24)
SUV	41	28.3	0.68	(0.51, 0.92)	0.92	(0.61, 1.07)
Model Year
> 2009	54	46.3	1.00	(Refer ence)	1.00	(Reference)
2005–2009	121	42.1	0.93	(0.66, 1.31)	0.93	(0.66, 1.32)
< 2005	353	27.2	0.60	(0.43, 0.82)	0.71	(0.51, 0.99)
Crash
Speed limit
< 55 mph	167	26.3	0.65	(0.49, 0.87)	0.78	(0.60, 1.01)
≥55 mph	361	35.5	1.00	(Reference)	1.00	(Reference)

mph = miles per hour, CRS = child restraint system.

^*Relative risk was estimated using log binomial model with generalized estimating equation.

^±Child was in a CRS, children in a rear- or forward-facing CRS, no indication of restraint misuse, and the child was seated in the rear seat of the vehicle.

^aIncludes ‘Lap-Shoulder Belt’.

^bIncludes ‘Lap-Belt only’, ‘Shoulder-belt only’, and ‘No Restraint Use’.

Bolded results indicate a significance of p<0.05.

As seen in Table 3, of the 528 children analyzed, only 48% were appropriately restrained. Several factors were associated with appropriate CRS use. Age and race were the only statistically significant child-level factors. Younger children were more likely to be appropriately restrained than older children. Compared to 3-year-olds, children who were less than 1-year-old, 1-year-old, and 2-years-old were 1.72 (95% CI = 1.21, 2.45), 1.90 (95% CI = 1.36, 2.66), and 1.54 (95% CI = 1.07, 2.23) times more likely to be appropriately restrained, respectively. Compared to White children, Black children were 0.57 times (95% CI = 0.39, 0.81) less likely to be appropriately restrained.

Investigation of driver-level factors revealed that drivers restrained with a shoulder-belt only, lap-belt only, or that were unrestrained were 0.66 times less likely to appropriately restrain child passengers than drivers who had used the appropriate lap-shoulder belt configuration (95% CI = 0.47, 0.91). Further, the crude analysis showed police reported alcohol use was associated with a lower likelihood of appropriate CRS use, which was not statistically significant after adjustment for other factors (aRR: 0.69, 95% = 0.44, 1.10). No significant association was found for driver age or sex.

Vehicle type was significantly associated with appropriate CRS usage. Children transported in pickup trucks were 0.44 times (95% CI = 0.22, 0.87) less likely to be appropriately restrained than children transported in passenger cars. Regarding vehicle model year, vehicles manufactured prior to 2005 were 0.71 times (95% CI: 0.51, 0.99) less likely to contain an appropriately restrained child passenger when compared to vehicles manufactured after 2009. For trip-level factors, posted speed limit was also marginally statistically significant after adjustment (95% CI = 0.60, 1.01), with children being less likely to be appropriately restrained when the speed limit was less than 55 mph compared to greater than 55 mph. No significant association was found for any other trip-level factors.

4. DISCUSSION

Child restraint systems (CRS) have been shown to reduce injuries and fatalities when used appropriately (Durbin, 2011; Wolf et al., 2017). Legislative efforts and best-practice recommendations, which support and promote appropriate CRS usage, have improved over the last few decades, but further work is needed regarding legislation and compliance (Durbin, 2011; Weatherwax et al., 2016). The current study investigated MVC-related fatalities from 2011–2015 utilizing fatality data from the FARS database. Multivariable analysis revealed that approximately less than half of children (0–3 years old) who were fatally injured in a MVC were appropriately restrained in a CRS. Furthermore, premature transition and inappropriate use of CRS was evident for all investigated ages. Risk factors were assessed at multiple levels (child, driver, vehicle, and trip). Black children and children of older age were less likely to be appropriately restrained. Other significant factors associated with a decreased likelihood of appropriate restraint included lack of driver restraint or use of a seat belt other than the lap-shoulder configuration and being a pickup truck occupant. Similarities and differences regarding child-, driver-, crash-, and trip-level factors were found when compared to previous findings among various pediatric age ranges (Agran, Anderson, & Winn, 1998; Arbogast, Jermakian, Kallan, & Durbin, 2009; Bachman et al., 2016; Benedetti, Klinich, Manary, & Flannagan, 2017; Chen et al., 2005; Hoffman et al., 2016; Johnston, Rivara, & Soderberg, 1994; Lee et al., 2015; Macy et al., 2014; Simpson, Moll, Kassam-Adams, Miller, & Winston, 2002; Williams, 1998; Zonfrillo, Ferguson, & Walker, 2015).

When assessing child-level factors, evidence of racial disparities was consistent with Lee et al. (2015) who also found Black children were less likely to be appropriately restrained in comparison to White children. Furthermore, racial differences in child passenger safety, including rear-facing CRS use and CRS misuse, have been observed as early as newborn infant discharge (Hoffman et al., 2016; Jones et al., 2017; Macy et al., 2014). In particular, Macy et al. (2014) found after adjusting for sociodemographic variables and parental restraint use, White parents had almost four times greater odds of reporting appropriate CRS usage compared to non-White parents. Non-White parents also showed higher proportions of premature CRS transition (Macy et al., 2014).

Regarding age, the literature consistently shows that children age 0–3 exhibit higher percentages of appropriate CRS use in comparison to older child occupants (Bachman et al., 2016; Chen et al., 2005; Lee et al., 2015). Whereas most studies collapse ages 0–3 into one category, Chen et al. (2005) found that children aged 1–3 were more likely to be appropriately restrained compared to children less than 1-year-old. The current analyses compared restraint across ages of the youngest passengers, providing greater insight on variations in appropriate CRS usage within this age range. While usage of appropriate restraint systems in the current sample are similar across age categories, 1-year-olds showed the highest percentage of appropriate CRS use compared to 3-year-olds who showed the lowest percentage.

After adjustment for other multivariable factors, the only driver-level factor significantly associated with appropriate CRS use was driver restraint use, as found in previous studies (Agran et al., 1998; Williams, 1998). Although police-reported alcohol use was not significantly associated with appropriate restraint after adjustment, the effect mimics a previous investigation utilizing FARS with children aged 0–9, which showed a significant association between higher CRS rates and no reported alcohol use (Agran et al., 1998). Whereas child and driver level factors are routinely assessed with restraint use in the literature, fewer studies have examined vehicle characteristics and rates of appropriate CRS usage. Specifically, Lee et al. (2015) found the highest levels of child restraint for fatalities involving passenger cars and vans compared to pickup trucks and SUVs, with pickup trucks having the highest proportions of unrestrained child passengers. The current findings also found the same association for pickup trucks. Furthermore, we also found support for the relationship between model year and appropriate CRS usage (Bachman et al., 2016), as older model years had a lower likelihood of containing an appropriately restrained child passenger compared to newer vehicle models.

The current investigation of crash-level factors did not support previously reported associations between nighttime crashes and decreased likelihood of appropriate restraint and increased likelihood of non-restraint (Chen et al., 2005; Lee et al., 2015). Lack of significant association could be attributed to the differences in the operational definition of appropriate CRS usage and the narrow age-range of the current study. Furthermore, the current findings regarding posted speed limit also aligned with findings from Chen et al. (2005), which found no statistical significant association between posted speed limit and appropriate restraint use. While these crash-level factors were not statistically significant in the current study, more research is needed on the impact of situational trip influences as they may further explain patterns of pediatric non-restraint. Parents in other studies have reported situational influences for supporting and opting out of using booster seats and relying on seat belts based on specific trip characteristics, such as travelling short distances (Simpson et al., 2002; Zonfrillo et al., 2015).

4.1. Premature CRS transition among the youngest passengers

Premature transition from the appropriate CRS is often reported and investigated for child passengers, ages 4 and older, but is evident even in the youngest child passengers (aged 0–3) (Bachman et al., 2016; Jones et al., 2017; Vesentini & Willems, 2007; Winston et al., 2000). In an observational study of pediatric restraint use in a metropolitan city, Bachman et al. (2016) also found that younger children had a greater likelihood of being faced incorrectly. The current findings were similar as premature transition was evident at all investigated ages, including but not limited to premature transition from rear-facing to forward-facing and to a lap-shoulder belt. Surprisingly, lap-shoulder belt usage, an unacceptable method of restraint for all children within the sample age range regardless of weight or height, was reported among the youngest passengers. This is alarming as research has shown a lower risk of death for children aged 0–3 when using a CRS compared to seat belt usage (Rice & Anderson, 2009). While the current analyses could not separate the proportion of other belt usage and no restraint, 52% of the current sample was restrained with some form of seat belt or unrestrained, neither of which are recommended for this occupant age range.

4.2. Limitations

Three notable limitations should be considered when interpreting the current results. All interpretations were framed from a restraint type perspective as the FARS database does not contain the child’s weight or height at the time of the crash. Whereas other studies have also taken this approach (Chen et al., 2005; Lee et al., 2015), a previous telephone survey conducted with caregivers revealed that parents reporting their child being too tall, their child’s feet touching the seat, and their child being too heavy were primary reasons for transitioning their children to a forward-facing CRS before 2 years old (Jones et al., 2017). Lack of weight and height data may result in biased measures of appropriate use and premature transition, as the child may have been transitioned to the appropriate restraint system for exceeding the manufacturer height and weight limits. Finding an appropriate CRS may be less of an issue as more manufacturers have expanded height and weight limits (American Academy of Pediatrics, 2017; Durbin, 2011).

The second limitation involves the large proportion of child fatalities coded as generic CRS use. Whereas this is a limitation to the FARs database, approximately 30–40% of each age category was listed in FARS as generic use. Previous CRS studies have not analyzed crashes with ‘unknown restraint’ (Chen et al., 2005; Lee et al., 2015), therefore only investigating crashes with confirmed CRS type or lack thereof. While police report and surveillance methodology can also be further improved, the FARs database is uniform across states, and quality and consistency checks are vital features of the database.

Lastly, as the FARS database is designed to capture fatalities within 30 days of a MVC, the sample may not be fully representative of the general population. These crashes may overestimate high-risk restraint behaviors. Despite this limitation, a previous study found 95% of sampled families at newborn discharge misused infant CSSs (Hoffman et al., 2016). Whereas the bias is still present, our sample of children does represent those at highest risk for a MVC-related fatality.

5. CONCLUSIONS

Investigation of CRS usage among the youngest and historically most restrained child passengers revealed evidence of premature transition, as children aged 0–3 were being restrained with booster seats and seat belts, suggesting room for improvement. Public health efforts should be directed toward legislative efforts and parental interventions to communicate best practice recommendations and CRS education.

6. PRACTICAL APPLICATIONS

Public health campaigns targeted toward increasing the appropriate use of CRSs in children aged 0–3 are of great importance as optimally restrained children are less likely to sustain injuries or require crash-related hospitalization compared to unrestrained children (Chen et al., 2005; Hafner et al., 2017; Hoffman et al., 2016; Jones et al., 2017; Lee et al., 2015). These findings revealed that a small proportion of fatally injured children aged 0–3 were appropriately restrained, as over 50% of the sample fell under the inappropriate category. This public health problem may be overshadowed by the high percentage of restraint use among children within the age range, but being restrained does not guarantee nor supersede whether the restraint mechanism is appropriate. Researchers and practitioners may find these surveillance findings essential when developing education and interventions targeting child-parent dyads at the greatest risk for a MVC-related fatality in the United States.

HIGHLIGHTS.

• Child-, driver-, vehicle-, and trip-related characteristics were investigated within a study sample from the Fatality Analysis Reporting System (FARS) from 2011–2015 in which a child aged 0–3 years was fatally injured.

• Only 48% of the 528 children were appropriately restrained in a CRS based on age.

• Significant factors associated with a decreased likelihood of appropriate included children of older age and black race, lack of driver restraint or use of a seat belt other than the lap-shoulder configuration, and being a pickup truck occupant.

AUTHOR VITAE

Grace Lee is a medical student at The Ohio State University College of Medicine. Ms. Lee graduated cum laude from University of California San Diego, where she earned a B.S. in human biology with a minor in psychology and a M.S. in biology.

Caitlin N. Pope is a Postdoctoral Research Scientist at the Center for Injury Research and Policy at The Research Institute at Nationwide Children’s Hospital. She earned her B.A. and M.A. in psychology from the University of North Carolina Wilmington and Ph.D. in lifespan developmental psychology from the University of Alabama at Birmingham. Dr. Pope’s research focuses on understanding the cognitive and psychosocial mechanisms behind risky health behaviors, such as distracted driving, and safe mobility across the lifespan.

Ann Nwosu is a Biostatistician at the Center for Injury Research and Policy at The Research Institute at Nationwide Children’s Hospital. She graduated cum laude from Indiana University in Bloomington with a B.A. in sociology and a minor in Spanish. Ms. Nwosu earned her M.S. in public health with a specialization in biostatistics from the Ohio State University.

Lara B. McKenzie is a Principal Investigator in the Center for Injury Research and Policy and an Associate Professor in the Department of Pediatrics in the College of Medicine and in the Division of Epidemiology in the College of Public Health at the Ohio State University. She earned her MA in Psychology from the Catholic University of America and her PhD in social and behavioral science and public health from the Bloomberg School of Public Health. Dr. McKenzie’s research focuses on adoption of safety behaviors to prevent or reduce the consequences of injury to children in and around the home.

Motao Zhu is a Principal Investigator in the Center for Injury Research and Policy and an Associate Professor in the Department of Pediatrics in the College of Medicine and in the Division of Epidemiology in the College of Public Health at the Ohio State University. He earned his MD from Peking University and his PhD in epidemiology from the State University of New York at Albany. Dr. Zhu’s research focuses on travel behaviors and transportation injuries.