An assessment of child passenger safety levels of service in Michigan

<b>Objective:</b> The purpose of this article was to assess the match between child passenger safety resources (child passenger safety technicians [CPSTs], car seat checks, and child restraint system [CRS] distribution programs) and the child population in Michigan by utilizing geographic information systems approaches and to analyze the impact of Michigan’s CPSTs on child passenger safety behaviors on departure from a seat check. <b>Methods:</b> Data were collected from administrative sources and a survey of CPSTs to determine the number and location of child passenger safety resources and children in Michigan. The main analyses used data from 2014. The child population ≤4 years old per county and per traffic safety region was determined from census data. CPST and car seat check locations were determined from a list from the Michigan Office of Highway Safety Planning (Mi-OHSP) and a survey of CPSTs who coordinate seat checks. Summary sheets from Mi-OHSP served as the data source for CRSs distributed through their occupant protection program. Data from child passenger safety checklists completed with seat checks were obtained from Safe Kids Michigan. Addresses were geocoded using Google Maps Geocoding API and then mapped at the county level using ArcGIS Desktop 10.3.1. Descriptive statistics were calculated and levels of service were determined at the county and regional levels. <b>Results:</b> In 2014, there were 570,929 children ≤4 years old in Michigan and 979 CPSTs who worked at 209 known seat check locations. An average of 6,854 seats was checked per year through Safe Kids Michigan Coalitions. All but 3 regions met an intermediate service level for seat check locations by offering one or more per 5,000 children ≤4 years old. There was at least one CPST in 80 of 83 counties (median 5; interquartile range, 2, 10.5). Assuming that an average Michigan CPST provides 10 h of service each year, all but 2 regions reached an intermediate service level of at least one technician hour per 90 children ≤4 years old. Fewer regions reached a basic level of service for the number of seat checks. Almost half (49.5%) of Safe Kids Michigan seat checks resulted in a change in child passenger safety behaviors. <b>Conclusions:</b> Child passenger safety resources in Michigan are not evenly distributed yet most regions and counties meet intermediate levels of service. Reallocating resources to areas that are providing basic levels of service could help reduce disparities in child passenger safety behaviors.

**研究目标：** 本研究旨在借助地理信息系统（Geographic Information Systems, GIS）方法，评估密歇根州儿童乘车安全资源（儿童乘车安全技术员（Child Passenger Safety Technicians, CPSTs）、汽车安全座椅检查及儿童约束系统（Child Restraint System, CRS）发放项目）与当地儿童人口的匹配程度，并分析密歇根州CPSTs在座椅检查实施阶段对儿童乘车安全行为的影响。
**研究方法：** 本研究从行政数据源及针对CPSTs的问卷调查中收集数据，以确定密歇根州儿童乘车安全资源的数量、位置以及当地儿童人口规模，核心分析采用2014年的数据集。从人口普查数据中提取各郡及各交通安全区域内≤4岁儿童的人口数据；从密歇根州公路安全规划办公室（Michigan Office of Highway Safety Planning, Mi-OHSP）的清单及负责协调座椅检查的CPSTs调查问卷中，获取CPST及汽车安全座椅检查点的位置信息；Mi-OHSP提供的汇总表作为其乘员保护项目下发放的CRS的数据源；从密歇根州安全儿童组织（Safe Kids Michigan）获取座椅检查配套使用的儿童乘车安全检查表数据。借助谷歌地图地理编码API（Google Maps Geocoding API）对地址进行地理编码，随后使用ArcGIS Desktop 10.3.1在郡级层面进行制图。计算描述性统计量，并确定郡级及区域级的服务水平。
**研究结果：** 2014年，密歇根州共有570929名≤4岁儿童，以及979名供职于209个已知座椅检查点的CPSTs。密歇根州安全儿童联盟年均完成约6854次座椅检查。除3个区域外，其余所有区域均达到座椅检查点的中级服务水平，即每5000名≤4岁儿童配备至少1个座椅检查点。83个郡中有80个郡至少设有1名CPST（中位数为5，四分位距为2~10.5）。假设密歇根州每名CPST年均提供10小时服务，那么除2个区域外，其余所有区域均达到中级服务水平，即每90名≤4岁儿童至少可获得1小时技术员服务。在座椅检查次数方面，达到基础服务水平的区域较少。近半数（49.5%）密歇根州安全儿童组织的座椅检查可促使儿童乘车安全行为发生改变。
**研究结论：** 密歇根州的儿童乘车安全资源分布并不均衡，但多数区域及郡级单位已达到中级服务水平。将资源重新分配至仅达到基础服务水平的区域，有助于缩小儿童乘车安全行为方面的差距。