Too small for a seatbelt: predictors of booster seat use by child passengers.

OBJECTIVES Motor vehicle injury is the leading cause of injury death for children 4 to 8 years of age. Although booster seat use in this age group substantially reduces the risk of injury, most children are currently restrained by seatbelts designed for adults. The objective of this study was to measure booster seat use directly, determine factors predictive of proper child restraint, and assess parental reasons for booster use and nonuse. METHODS We conducted a cross-sectional, observational study in Seattle, Washington, Spokane, Washington, and Portland, Oregon, from February to April 2000. Drivers were surveyed in their vehicles after picking up children from schools and child care centers. Trained observers recorded child age, weight, and height and directly observed restraint use. Observed restraint use was compared with the recommended restraint method based on the child's weight and age. Data were analyzed using multivariate logistic regression, adjusted for clustering by car and site. RESULTS We observed 2880 children traveling in cars, 1539 of whom were eligible for booster seat use. Eighty-eight percent of drivers agreed to respond to our survey. Only 16.5% of children for whom a booster seat was recommended were properly restrained, compared with 80% of younger children for whom a child safety seat was recommended and 55% of children for whom an adult seatbelt was recommended. Relative to a 4-year-old booster-eligible child, a 6-year-old was only half as likely to use a booster seat (odds ratio [OR]: 0.47; 95% confidence interval [CI]: 0.31-0.71) and an 8-year-old almost never used a booster seat (OR: 0.04; 95% CI: 0.01-0.19). Booster use was more common when the driver wore a seatbelt (OR: 3.1; 95% CI: 1.8-5.4). Parents whose children were using booster seat cited "safety" (61%) and "child comfort and visibility" (12%) as their primary concerns. When a child was not using a booster seat, parents most often believed that their child was "too big for a car seat" (56%), reported that the seat was in another vehicle (9%), or stated that they "had not heard" of booster seats (8%). CONCLUSIONS Many parents still incorrectly believe that children are safe in a seatbelt and have outgrown the need for a car seat. These results demonstrate the need for public education campaigns to educate parents about booster seat use.