Identifying High-risk Areas for Child Safety Seat Misuse: A Geographic Information Systems Approach


Child safety seats and seat belts have been proven effective for reducing the risk of severe injuries and death. However not all children are restrained according to recommendations and there are concerning race and age-based disparities in child passenger restraint use in the United States (U.S.).
Aim 1: To determine geographic census block groups of low and high levels (hot spots) of participation in the C.S. Mott Children’s Hospital and Greater Grand Rapids Buckle Up programs and compare hot spots to non-hot spots for program participation in regard to socio-demographic measures (e.g., race/ethnicity, poverty rates, child age).
Aim 2: To identify hot spot geographic areas for child safety seat misuse and compare hot spots to non-hot spots for child safety seat misuse in regard to socio-demographic measures (e.g., race/ethnicity, poverty rates, child age).

Background: Motor vehicle collisions (MVCs) remain the leading cause of death in early childhood in the United States. Seat belts and child safety seats greatly reduce the risk of severe injuries and death associated with MVCs. However not all children are restrained according to recommendations and child safety seat misuse is common. Socioeconomic factors contribute to misuse. Child passenger safety technicians educate families and address misuse through child safety seat inspections. Little is known about child safety seat inspection program participation rates or the populations being served by these programs. Objectives: To determine program participation rates and child safety seat misuse rates within the census block groups serviced by the child safety seat inspection programs coordinated by the Safe Kids Coalitions of Huron Valley and Greater Grand Rapids. Data Sources: We completed retrospective analyses of data collected during 4,529 child safety seat inspections conducted through the two Safe Kids Coalitions from January 2011 to June 2013. Socioeconomic characteristics of census block groups were obtained from the 2010 U.S. Census and the American Community Survey. Methods: Participant home addresses were geocoded. Addresses that mapped to the same location were considered households. Households were mapped to census block group. Program participation rates and misuse rates were calculated for each census block group. Census block group socioeconomic characteristics 2 were used in the absence of individual demographic characteristics. Maps were generated to demonstrate the geographic variation in program participation. Census block groups with high participation rates (>90th percentile) were compared with census block groups with lower participation rates on the socioeconomic characteristics of the census block groups in the two areas using chi-square tests. Misuse rates were compared across the socioeconomic characteristics of the census block groups in the two areas using linear regression. Results: Huron Valley participants came from 799 households located within 401 census block groups. Greater Grand Rapids participants came from 2,004 households located within 503 census block groups. Overall, median child safety seat inspection program participation rate per household with children per census block group was 0.10 (IQR: 0.06, 0.21) in the Huron Valley area and 0.20 (IQR: 0.14, 0.49) in the Greater Grand Rapids area. In both areas, census block groups with high participation rates generally had lower median household income, higher percentage of families below the poverty level, higher percentage of households with no vehicle, higher percentage of rental properties and higher percentage of nonwhite and Hispanic residents than census block groups with low participation rates. While geographic differences were observed in child safety seat inspection program participation rates, misuse was more evenly distributed. Conclusions: This pilot study demonstrates the utilization of child safety seat inspection programs through Safe Kids Huron Valley and Greater Grand Rapids was geographically uneven but these programs appeared to be reaching families in census block groups expected to have the greatest need for child passenger safety resources due to poverty or minority race/ethnicity. Surprisingly, misuse rates were high across households participating in these programs regardless of the socioeconomic characteristics of the census block groups from which they came.