摘要：Objectives. secondary enforcement laws (police may issue a safety belt citation only if the vehicle has been stopped for another reason). Methods. We analyzed 2002 Behavioral Risk Factor Surveillance System data from 50 states and the District of Columbia. We performed multivariable, log-linear regression analyses to assess the effect of sociodemographic characteristics and safety belt laws on safety belt use. Analyses were stratified by the type of enforcement permitted by state laws. Results. Reported safety belt use was higher in states that had primary versus secondary enforcement laws, both overall and for each sociodemographic characteristic examined. Safety belt use was 85% in states that had primary enforcement laws and 74% in states that had secondary enforcement laws. Cross-sectional data suggested that primary enforcement laws may have the greatest effect on sociodemographic groups that reported lower levels of safety belt use. Conclusions. Primary enforcement laws are an effective population-based strategy for reducing disparities in safety belt use and may, therefore, reduce disparities in crash-related injuries and fatalities. Motor vehicle crashes kill more than 40000 people in the United States each year and are the leading cause of death among Americans aged 1–34 years. 1 Safety belts are the single most effective way to reduce crash-related deaths; estimates of effectiveness range from 45% to 60%. 2 Although rates of safety belt use in the United States have increased substantially since the first state law was passed in 1984, many motor vehicle occupants continue to travel unrestrained. Published reports have shown that people who are male, young, less educated, have a lower income, and reside in rural areas are less likely than their counterparts to wear safety belts. 3 – 6 There is less consistency in reported safety belt use by race/ethnicity. 3 – 5 , 7 – 8 In the United States, safety belt laws can be classified according to the type of enforcement authorized in the state. Primary laws allow police to stop and ticket a motorist solely for being unbelted. Secondary laws allow police to issue a safety belt citation only if the vehicle has been stopped for another reason (e.g., speeding). Numerous evaluations have shown that primary laws are more effective than secondary laws at increasing safety belt use and reducing traffic fatalities and serious injuries. 9 – 15 A 2004 study used data from the 2002 Behavioral Risk Factor Surveillance System (BRFSS), a survey administered by the Centers for Disease Control and Prevention, to examine the influence of primary enforcement laws at the state level. 16 We extended that analysis by examining the effect of primary enforcement laws by sociodemographic characteristics (i.e., gender, race/ethnicity, age, education, household income, marital status, population density, body mass index [BMI], and driving after drinking). We found very few studies that addressed the effect of type of safety belt law on sociodemographic characteristics, and those that did were limited in scope. 17 – 19 Our study is unique in that the large, nationally representative data set contained information about a variety of demographic, behavioral, and environmental characteristics that are independently associated with safety belt use. We used multivariable analysis to simultaneously explore the effect of safety belt laws and sociodemographic characteristics on the use of safety belts.
