In both the United States and Canada, car safety for children is of considerable interest and concern. In many areas, laws requiring child restraints in cars passed long before similar laws requiring adults to use seat belts. A study in Canada in 1996 found that "a substantial proportion [of families] use some form of restraint to protect their children as car passengers but a substantial proportion either use the wrong type for the size of the child, or have them improperly installed." The study also found a correlation between restraint use and the presence of certain household hazards. One interesting result revealed that parents who used baby walkers in the home were far less likely to properly restrain their children in the car.

BACKGROUND

Because children under 5 years of age vary in size and physical development, different restraints are recommended--based primarily on a child's weight. For infants and other children weighing less than 20 pounds (9 kg), rear-facing car seats are recommended. For children weighing 20-40 pounds (9-18 kg), forward-facing car seats are recommended. For children weighing more than 40 pounds (18 kg), regular seat belts, with or without a booster seat, are recommended.

To be fully effective, a child restraint must be properly installed and must properly fit the child. Studies have documented improper installation of car seats and other types of misuse. A 1997 study found that 24-60 percent of child restraint devices (excluding seat belts) "failed to pass a standard inspection."

STUDY METHODS

These studies of misuse are often conducted in busy parking lots. The Canadian study used this method, along with "a population-based survey of households with at least one child aged 1-4." M.L. Chipman, W. Koblin, and P. Thomas discussed the results of the study in their article "Hidden Hazards: Inappropriate Occupant Restraint for Children Aged 1-4 Years," published by the Association for the Advancement of Automotive Medicine.

The first portion of the study involved the SAFEKIDS Canada annual check of car seat safety. Trained personnel at three different car seat clinics in Metropolitan Toronto found several "major errors in use," including:

seat in use despite having been in a collision, seat not meeting national standards, seat not appropriate for weight and height of the child, problems in routing the car seat belt, lack of a tether strap, and failure to fasten it securely.

The household-survey portion of the study, conducted in the same municipality, sought to identify household hazards to which children might be subjected and included questions about car ownership and child restraint. Using birth registrations for the calendar years 1992-1995, the researchers selected households at random. The child whose birth registration resulted in the family's being chosen for the study was known as the "index child," to differentiate that child from other children in the family.

Interviewers visited the selected households to administer a questionnaire and obtain information by inspecting the house. They conducted interviews in 570 households. With data entry still occurring, the article included analysis of 203 households. To be considered properly restrained in the car, the index child had to be restrained with the correct device for his or her weight class. If the child's method of restraint did not meet one of four conditions, he or she was considered "inappropriately" restrained. This designation was also used for children who were not restrained at all.

Interviewers gathered other household information "to assess how other factors were associated with appropriate use" of car child-restraint devices. Factors studied included the number of younger children in the family, the level of parental education, the index child's age and gender, parental perception of danger, and the presence of other household hazards.

STUDY RESULTS

Ninety car seats were inspected in the first portion of the study--the actual car inspection or car seat clinic. Of these 90, only two were problem-free. The other 88 suffered from a variety of faults, including improperly tightened or routed seat belts and failure to meet national standards. Seventy percent of all seats examined did not have the tether strap correctly installed.

The average age of the index children in the household interview portion of the study was two-and-a-half years, and the number of boys and girls was roughly equal. Most households (almost 90 percent) had two parents whose average age was in their 30's and early 40's, and who (about 69 percent) had some education beyond high school. Almost 90 percent of households reported owning a motor vehicle. In contrast to the results of car seat clinics, about 69 percent of households reported using a tether strap in front-facing car seats. Nearly 89 percent of households reported using child restraints all the time. Overall, interviewed parents reported that only slightly over half the children (54.6 percent) were "appropriately restrained."

Car ownership was "strongly associated with the appropriate use of seat belts." Researchers speculated that families using borrowed or rented vehicles might find the use of child seats "beyond the parents' control." Parental higher education "was moderately associated with appropriate use." Children who had younger siblings "were just as likely to be appropriately restained [sic] as those without." However, "boys were less likely to be appropriately restrained than girls." The result of the survey's examination of parental perception of safety was surprising. Ironically, those parents who felt their children would sustain severe injury in a crash "had significantly lower use of appropriate restraints."

As a way of indicating "awareness or tolerance of risk," the household survey also assessed the relationship between restraint use and other household safety hazards, notably the use of baby walkers. Results showed that parents who had used a baby walker "were significantly less likely to report appropriate restraint use."

CONCLUSIONS

A number of factors contributed to the differences in results between the two portions of the study. The formal inspection of car seats performed during the car seat clinic was not possible in a home interview situation. In addition, interviewers in the household survey had to rely on information from parents regarding the use of a tether strap. While parents who said that no tether strap was used can be assumed to have given correct information, no assumptions can be made about the accuracy of other parental reports on tether strap use. Speculation about the greater use of appropriate restraint for girls than for boys remains just that--speculation. No information is available on this gender issue.

The fact that parents who used baby walkers were less likely to appropriately restrain their children offered up an interesting theory. Canada has outlawed the sale of new baby walkers, deeming them unsafe. However, second-hand and imported walkers are still used. It is possible that families who use baby walkers "are either less well informed about the hazard or more tolerant of risk. This tolerance may extend to tolerance of other hazards, such as an untethered car seat or other improper restraint."