Modeling improvements in booster seat use: a discrete choice conjoint experiment

Automobile crashes are the leading cause of death in children aged 1–14 years. Many children, however, are not properly restrained in safety seats that reduce serious injury and death. This study used a discrete choice conjoint experiment to study factors influencing the decision to use booster seats. Parents of 1714 children aged 4–9 years from nine Canadian provinces completed choice tasks presenting experimentally varied combinations of 15 4-level booster seat promotion attributes. Latent class analysis yielded three segments of parents. The choices of the Benefit Sensitive segment (50%) were most sensitive to the injury prevention benefits of booster seats. The choices of parents in the Context Sensitive segment (33.5%) were more likely to be influenced by installation complexity, oppositional behavior, and the prospect that their child may be teased for riding in booster seats. Parents in the High Risk segment (16.5%) were younger, less educated, and less knowledgeable about vehicle safety legislation. They anticipated fewer benefits, expected more barriers and were less likely to use booster seats. Simulations suggest that consistent enforcement coupled with advertising focusing on injury prevention and the use of booster seats by other parents would increase adoption.     

Seat belt misuse among children transported in belt-positioning booster seats

Objective

Observe and report seat belt use among children transported in belt-positioning booster seats.

Design

We conducted a cross-sectional, observational survey of children transported in motor vehicles between 2006 and 2007. While drivers completed a survey reporting the child's age, weight and gender, and the driver's age, gender, race, income, education, and relationship to the child; a child passenger safety technician recorded vehicle seating location, restraint type, and use of the car safety seat harness or seat belt as appropriate for the child.

Setting

Twenty-five fast food restaurants and discount department stores throughout Indiana.

Participants

A convenience sample of drivers transporting children younger than 16 years.

Main exposure

Seat belt use among children transported in belt-positioning booster seats.

Outcome measure

Seat belt misuse.

Results

Overall, 1446 drivers participated, 2287 children were observed with 564 children in belt-positioning booster seats. At least one seat belt misuse was observed for 64.8% of the children transported. Common misuses were the shoulder belt being placed over the booster seat armrest (35.8%); shoulder belt not at mid-shoulder position (28.5%), seat belt was too loose (24.5%), and the shoulder belt was either behind the child's back (9.1%) or under their arm (10.0%).

Conclusion

There is a high frequency of seat belt misuses among children transported in booster seats. Advice to parents on appropriate car seat selection, and encouragement to parents to supervise seat belt use may decrease misuse.     

Use of booster seats by Michigan children 4-8 years of age

This study reports the results of a statewide survey of restraint use by 4–8-year-old children in Michigan conducted between July 13 and 29, 2004. In this study, 3420 4–8-year-old children were observed traveling in passenger cars, vans/minivans, sport-utility vehicles, and pickup trucks. Restraint use was estimated for children traveling in all vehicles combined, as well as for each vehicle type separately. Children's restraint use was also calculated by the sex, age, and belt use of the driver. Separate estimates were also made of the restraint use of 4–8-year-old children by the combination of sex and belt use of the driver. Overall, 8.6 ± 5.9% of 4–8-year-old children were seated in a booster seat, 48.8 ± 10.3% were wearing a safety belt, 5.1 ± 3.4% were seated in a child safety seat, and the remaining 37.5 ± 11.5% were traveling completely unrestrained. When examining the rates by vehicle type, booster seat use was highest among children riding in sport-utility vehicles and lowest for those in pickup trucks. Surprisingly, children riding in passenger cars were more likely to be completely unrestrained than those in any other type of vehicle. While the sex of the driver did not seem to influence the restraint use of target-aged children, the driver's age did seem to have an effect. Booster seat use was quite low (0.6%) for children traveling with a driver over the age of 60, compared to 7.0 and 9.1% for those riding with drivers 16–29 and 30–59 years of age, respectively. The safety belt use of the driver also had a substantial influence on children's restraint use. Irrespective of driver sex, children riding with belted drivers were traveling in booster seats about 10% of the time, while those riding with unbelted drivers were only in booster seats 1–2% of the time.     

Psychosocial factors related to parental restraint of pre-school children in motor vehicles

While the use of safety restraints effectively reduces the risk of death or injury in accidents, many children still travel unrestrained in motor vehicles. Compulsory seat belt legislation in Australia increased rates of adult use dramatically, but did not have the same impact with children. In order to understand why levels of children's restraint use remain low, it is necessary to investigate parental factors related to use and non-use of restraints. This study assessed the rates of safety restraint use of parents and their pre-school children, and the sociodemographic, attitudinal and belief characteristics of parents which relate to children's restraint use, using the Health Belief Model as a basis for investigation. Restraint use for adults was substantially higher than for pre-school children. Children were more likely to be restrained if their parents were wearing seat belts, were married, were of high socioeconomic status, did not smoke, engaged in certain other preventive health behaviors on their children's behalf, traveled longer distances to pre-school and provided child seats for their children. In terms of the Health Belief Model, parents of restrained and unrestrained children differed in their evaluation of the "costs" and "benefits" of using restraints for their children, and in health locus of control. Parents of unrestrained children perceived the "costs" of restraint use, in terms of nuisance value, installation difficulty and financial cost, to be high. They were also less likely to believe that they could play a significant role in preventing injury to their children. Implications of these findings for safety restraint campaigns are discussed.     

Grandparents and child passenger safety

Purpose

This study compares child passenger safety (CPS) practices of grandparents versus parents and determines grandparents’ opinions on car safety seats (CSS), barriers to use, and ways to transport grandchildren safely.

Methods

Observational surveys were conducted on a convenience sample of drivers transporting children younger than sixteen years at 25 locations by certified child passenger safety technicians observing children in motor vehicles and recorded use of child passenger restraints. The drivers were surveyed on their knowledge, attitudes, beliefs, and practices regarding CPS. Data from drivers identifying themselves as grandparents were analyzed; also, three grandparent focus groups provided opinions on CPS practices.

Results

During the study 1758 parents transporting 2713 children and 284 grandparents transporting 391 grandchildren were included. While most drivers were restrained and used child occupant restraints, almost 25% of parents and grandparents chose the incorrect seat to transport the child, and greater than 68% had at least one harness error. Grandparents were more likely to have looser lower anchor straps or seat belts and have children younger than thirteen years in the front seat.The focus group-grandparents had a favorable attitude toward CSS. Grandparents acknowledged the need for CSS but opined that CSS were difficult to use. Physical barriers included arthritis, back pain, mobility, decreased strength, and vision problems.

Conclusions

Grandparents and parents were equally likely to use CSS and choose correct seats. Compared to parents, grandparents were more likely to travel with their grandchildren with CSS installed with looser harnesses or an installed CSS with looser seat belt or lower anchors. Additionally, grandparents were more likely to have a child younger than thirteen years in the front seat. The use of community resources such as permanent fitting stations could help grandparents improve a grandchild's travel safety.     

Factors associated with the premature graduation of children into seatbelts

This study investigated the factors associated with the premature graduation into seatbelts for Australian children aged 4-11 years. From 699 child restraint use questionnaires, 195 children were identified as meeting the booster seat height-weight criteria (height: 100-145 cm and weight: 14-26 kg). Of these children, 44% were correctly traveling in a booster seat, while 56% had been moved prematurely into a seatbelt. A multivariable logistic regression model showed that there were a number of key predictors associated with the premature graduation to seatbelts. For example, children who were moved prematurely into a seatbelt were more likely to be older, have other children travelling in the vehicle and have younger parents compared to children appropriately restrained in a booster seat. In addition, there was a significant interaction between vehicle type and parent's household income. Based on the findings of this study, a number of recommendations are made for strategies to enhance appropriate restraint use for this age group, as well as for future research.     

Attitudes of commercial motor vehicle drivers towards safety belts

Despite the fact that Hawaii has one of the highest seat belt use rates for passenger vehicles in the United States, and has had a mandatory seat belt use law since the 1980s, studies have shown that commercial motor vehicles (CMV) seat belt use rates are low. To better understand this phenomenon, a comprehensive survey of commercial vehicle drivers was conducted in Hawaii to ascertain attitudes and self-reported behaviors regarding seat belt use. A total of 791 drivers responded to a written questionnaire implemented at weigh stations and distributed to various trucking firms and transport centers. Approximately 67% reported that they use seat belts “always” when driving a CMV (commercial motor vehicle), yet when asked how often do other CMV drivers use seat belts, only 31% responded “always.” Interestingly, 86% of these same drivers reported that they use seat belts “always” when driving a personal vehicle. The major reason cited for non-use of belts was “frequent stops/inconvenience” (29%), and “not safety conscious” (23%). Notably, the self-reported use of safety belts is highest among operators of vans (88% said “always”), followed by buses (87% said “always”) and lowest among truck drivers (only 60% said “always”). In this paper, some of the differences between self-reported users and non-users are explored and a multivariate logit model was developed to predict the odds of belt use as a function of various factors.     

Discrepancies between knowledge and practice of childhood motor vehicle occupant safety in Nova Scotia—A population-based study

Objectives

To determine discrepancies between knowledge and practice of childhood motor vehicle restraints (CMVRs) and vehicle seating position amongst parents within the province of Nova Scotia.

Design

Random telephone survey.

Setting

The Canadian province of Nova Scotia.

Subjects

Four hundred and twenty-six households with at least one child under the age of 12 years, totaling 723 children.

Main outcome measures

The proportion of parents whose children who should be in a specific stage of CMVR and sitting in the rear seat of the vehicle, and who demonstrate correct knowledge of that restraint system and seating position, yet do not use that restraint system/seating position for their child (demonstrate practice discrepant from their knowledge).

Results

Awareness of what restraint system to use is good (>80%). However, knowledge of when it is safe to graduate to the next stage is low (30–55%), most marked for when to use a seatbelt alone. Awareness of the importance of sitting in the rear seat of a vehicle was universal. Discrepancies between knowledge and practice were most marked with booster seats and rear-seating of older children. Factors influencing incorrect practice (prematurely graduated to a higher-level restraint system than what is appropriate for age and weight) included lower household income, caregiver education level, and knowledge of when to graduate from forward-facing car seats and booster seats. Incorrect practice was also more commonly observed amongst children of weight and/or age approaching (but not yet reaching) recommended graduation parameters of the appropriate CMVR.

Conclusions

Discrepancies between knowledge and practice are evident through all stages of CMVRs, but most marked with booster seats. The roles of lower socioeconomic status and gaps in CMVR legislation, in influencing discrepant practice, must be acknowledged and suggest the need for targeted education concurrent with development of comprehensive all-stages CMVR policies.     

The effect of seating location on the injury of properly restrained children in child safety seats

Properly restrained child passengers in the National Automotive Sampling System (NASS), General Estimates System (GES), were studied for the effect of seating position on the risk of injury. The analysis focused on children seated in a child safety seat in a rear seat location. A multiple logistic regression model was used to assess whether the center rear seat is a safer seating position than either of the outboard rear seats. Standard errors for the odds ratios (ORs) of injury for several correlates of injury including seating position were obtained using a jackknife procedure. This analysis of the data showed that the center rear seat is not a safer seating position than either of the outboard rear seats in terms of odds of injury (left seat OR = 0.88, 95% CI = 0.73-1.03; right seat OR = 1.03, 95% CI = 0.85-1.20). These results do not agree with those of previous studies that suggested the center rear seat is the safest position for parents to place a child safety seat.     

Personal,temporal and spatial characteristics of seriously injured crash-involved seat belt non-users in Hawaii

The characteristics of crash-involved seat belt non-users in a high use state (Hawaii) are examined in order to better design enforcement and education programs. Using police crash report data over a 10-year period (1986-1995), we compare belted and unbelted drivers and front seat occupants, who were seriously injured in crashes, in terms of personal (age, gender, alcohol involvement, etc.) and crash characteristics (time, location, roadway factors, etc.). A logistic regression model combined with the spline method is used to analyze and categorize the salient differences between users and non-users. We find that unbelted occupants are more likely to be male, younger, unlicensed, intoxicated and driving pickup trucks versus other vehicles. Moreover, non-users are more likely than users to be involved in speed-related crashes in rural areas during the nighttime. Passengers are 70 times more likely to be unbelted if the driver is also unbelted than passengers of vehicles with belted drivers. While our general findings are similar to other seat belt studies, the contribution of this paper is in terms of a deeper understanding of the relative importance of various factors associated with non-use among seriously injured occupants as well as demonstrating a powerful methodology for analyzing safety problems entailing the categorization of various groups. While the former has implication for seat belt enforcement and education programs, the latter is relevant to a host of other research questions.     

Premature graduation of children in child restraint systems: an observational study

This study investigated the use and misuse of child restraint systems (CRS) in Flanders (Belgium). Observations were conducted at a random sample of primary school and recreation areas. In total 1376 children were observed. A logistic regression model was constructed in order to determine the variables involved. The parameter-estimates of this model have shown that children are more often restrained when the driver buckles up, the ride takes less than 1h, the children are younger, the children sit in the front seat of the car, a recreational area is the destination of the trip and there are less than five children in the car. Also premature graduation to CRS was analysed. More than half of the children are not appropriately restrained, according to their age, weight or height. Improper shoulder belt use (putting the shoulder belt behind the back or under the arm) was observed in 8.99% of the children being restrained with high back booster seats, in 32.73% of the children being restrained with backless booster seats and finally in 19.07% of the children being restrained with seat belts. The risk of incorrectly using the shoulder belt increases when children are prematurely graduated in a CRS. The results are discussed in the light of other studies on this matter.     

Vehicle child restraint usage for Pacific children aged 6 weeks to 4 years: Findings from the Pacific Islands Families study

Child restraint systems (CRSs) for vehicles are designed to provide protection and prevent or reduce child mortality and morbidity in road traffic accidents. Overall, 90% of children under 5 years of age in New Zealand currently use CRSs. There is considerable regional variability in CRS usage, but little information exists on its ethnic variations or determinants. “Increasing the level of restraint use” is explicitly stated as one of the 13 priorities within the New Zealand Ministry of Transport's new road safety strategy. As such, understanding CRS prevalence, patterns and associates within different communities is essential in realising this priority. Utilising a large birth cohort of Pacific children (n = 1376 mothers), this study aimed to report the prevalence of maternal self-reported car seat usage at the 6 weeks, 1-year, and 2 years postpartum measurement waves; car/booster seat usage at the 4 years postpartum measurement wave; and to identify important associates using generalised estimating equation (GEE) models. Car seats were not used by 161 (11.8%) Pacific children at the 6 weeks measurement wave, 71 (5.8%) at 1-year, and 44 (3.8%) at 2 years, while car/booster seats were not used by 139 (13.3%) at the 4 years wave. Multivariable GEE model results revealed that mothers with no formal education, high parity, who smoked tobacco, lower household income, who lacked English language proficiency, and had multiple births were all at higher odds of failing to use car seat/booster seats. Despite differential attrition being noted in mothers over time, a sensitivity analysis using multiple imputation methods yielded similar findings. Targeted initiatives and education programs focusing on these higher risk groups, in particular, is needed to increase uptake and use of CRS thereby decreasing Pacific children's exposure to injury risk. As New Zealand has a large and increasing proportion of Pacific, Maori and Asian people, there is a continuing need to understand cultural factors in traffic safety. Only when culturally appropriate initiatives and education programs have been developed and disseminated that meet the needs of New Zealand's different communities is the national priority likely to be realised.     

Accessory child safety harnesses: Do the risks outweigh the benefits?

Accessory child safety harnesses are available in some countries as alternative restraints for young children or as an accessory restraint used with booster seats. Their use, in Australia at least, is becoming more common. There have been concerns that the risk of misuse of these restraints outweighs any potential benefit this system might have over a retractable lap-shoulder belt system used with a booster seat. However to date there is no evidence to confirm or deny this. This study used laboratory simulated frontal crash tests to examine the performance of accessory child safety harness systems compared to the lap-shoulder belt when used alone and when used with two common designs of Australian booster seat. The performance of the child safety harness system when misused was also investigated. The results demonstrate that the correctly used child safety harness system performed no better than the lap-shoulder system, and in fact allows for a greater risk of submarining. Furthermore, one common form of child safety harness misuse, where the harness is over-tightened causing the lap belt to be positioned high over the abdomen, allowed extremely undesirable dummy motion. This involved gross submarining and direct contact between the harness system and the dummy's neck. These findings suggest that the risks associated with accessory child safety harness systems most likely outweigh any potential benefits, in frontal impacts at least.     

Impacts of culture on driver knowledge and safety device usage among Hispanic farm workers

This study examines Hispanic migrant farm workers' driving behaviors and knowledge of the laws. These laborers worked and drove in California's agricultural region up to 8 months a year. Results are based on 167 face-to-face interviews conducted in Spanish at five labor camps and 126 observations conducted at these same camps in California. Most drivers were male licensed drivers (79%), who learned to drive at ages 8-14 in Mexico (42%). Those licensed in Mexico versus the US received more citations and unlicensed drivers were rated with poor driving skills. Drivers reported 'always' using seat belts (86%), yet admitted not buckling up within the previous 2 months. Observational data showed that only 37% used belts and 55% of drivers riding alone were belted. Reasons for non-use reflected cultural and economic issues and lack of effective media safety campaigns for this group. Most (75%) drivers with children (< 4 years) said they used child safety seats and others with 1+ children (< 4 years) used no safety seats (20%) or only one seat (53%). Observations showed that regardless of the number of riders aged 0-4, the number of car seats never exceeded one. In 66% of the cars where a single child was carried and where two children were carried, no car seats were used. In all of these cases there were other passengers and drivers who were not belted.     

Children at risk: predictors of car safety seat misuse in Ontario

When used correctly, child safety seats can reduce the risk of death and serious injury by 54% in toddlers and 71% in infants [National Highway Traffic Safety Administration (NHTSA), 2001. Traffic Safety Facts 2001. Children (DOT HS 809 471), U.S. Department of Transportation, Washington, DC]. The purpose of this study was to identify factors that predict correct use of car safety seats. The study was conducted in a large urban area in Southwestern Ontario and a small urban and rural area in Northern Ontario. Participants were 1263 caregivers who completed a self-report survey on their knowledge and use of car safety seats for their children (N=2199). Logistic regression analysis revealed that female caregivers, caregivers with higher levels of education, and caregivers who reported that finding information about the correct use of child safety seats was "difficult" were more likely to report correctly using car safety seats. The results also showed that children aged 7 months to 8 years old had substantially lower odds of being in the correct car safety seat compared to children aged 6 months or younger, or children aged 9 years or older. The high risk nature of misuse of child seats for infants and younger children may be an important cue to action for health professionals to develop comprehensive prevention strategies.     

Factors influencing the use of infant car restraints

Over a six-week period 100 mothers in Dunedin, New Zealand obtained General Motors infant car seats from a rental scheme. In interviews conducted in the maternity hospital, before the seats had been used, the mother's perceptions of the comfort and ease of use of the seat were recorded. All mothers rated the seats as very safe. From details of 2,830 car trips undertaken by these mothers while their infants were 0-3 months old and from a further 687 journeys by 85 of those mothers when their infants were 4-6 months old we found that an infant car seat was used for only 72% of journeys with the younger infant compared to 91% of journeys with the older infant. Those mothers who had rated the seat--before ever using it--as appearing uncomfortable or difficult to use were less likely to make use of it. The seat was least likely to be used when the mother was going out for more than two hours in the evening for some purpose that involved only a short car journey.     

An investigation of factors reducing seat belt use amongst Spanish drivers and passengers on urban roads

Seat belt use on Spain's highways is more than 80%, while on the urban roads this figure is around 50%. As there was little information available to explain the difference in seat belt use rates, the main aim of this study was to investigate why there is a lower rate of seat belt use on urban roads. A number of perceptions, beliefs and expectancies about seat belt use were examined to identify variables that discriminated between seat belt users and non-users on urban roads. The subjects were 398 undergraduate students (aged 17-47) studying at the University of Girona, Spain. On the urban roads reported discomfort from using the seat belt was higher, while perceptions of risk (for non-users), safety perceptions (for those using a seat belt), beliefs about the seriousness of a crash or the effectiveness of the seat belt were all lower than on the highway. Perceptions of safety, discomfort, and social influence predicted seat belt use on urban roads. Concern about being fined for not using a seat belt did not predict seat belt use. The results of this research suggest that in order to increase seat belt use on urban roads, the issue of discomfort must be addressed. In addition, prevention campaigns should include information about the effectiveness of the seat belt in preventing/reducing injuries or deaths on urban roads. The results also highlight the importance of social influence for determining seat belt use/non-use and the potential role social influence could play in increasing seat belt usage.     

Knowledge and practice of childhood motor vehicle restraint use in Nova Scotia: Phase II

Objective

To examine changes to knowledge and practice of childhood motor vehicle restraint (CMVR) use in Nova Scotia after the implementation of stricter car seat and new booster seat (BS) legislation in 2007.

Methods

A random telephone survey of households (at least one child <12 years) was performed in 2004 and 2010. Logistic regression determined variables independently associated with correct knowledge and/or practice of CMVR use.

Results

Families were surveyed in the pre- (N = 426 families, 728 children) and post- (N = 453 families, 723 children) legislative periods. Reported appropriate use of forward-facing car seats (FFCSs) and BSs increased significantly (74–92% and 58–95%, respectively). After adjusting for covariates, the post-law period remained a significant predictor of increased knowledge of when to graduate to a BS or a seat belt alone (SB) (OR:1.4(95% CI:1.0–2.0) and 1.9(1.4–2.7), respectively), which was significantly associated with correct use. The strongest independent predictor of the correct use of FFCSs and BSs was the post-law period (OR:14(3.0–68) and 43(17–114), respectively). With regards to rear-facing car seats (RFCSs), new legislation and associated social marketing on graduating from a rear-facing car seat was not associated with increases in correct practice.

Conclusions

Legislation, combined with social marketing at the time of introduction, is an effective means to educate parents on when to graduate from a FFCS and the importance of BSs while also influencing parents to use them, though not for RFCS graduation. The known protective effect of BSs dictates the need for all regions in Canada to adopt comprehensive BS legislation.