Child Health Evaluative Sciences, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada.
Inj Prev. 2012 Aug;18(4):210-5. doi: 10.1136/injuryprev-2011-040173. Epub 2011 Dec 10.
To determine whether pedestrian countdown signals (PCS) reduce pedestrian-motor vehicle collisions in the city of Toronto, Canada.
A quasi-experimental study design was used to evaluate the effect of PCS on the number of pedestrian-motor vehicle collisions in the city of Toronto, from January 2000 to December 2009. Each intersection acted as its own control. We compared the number of pedestrian-motor vehicle collisions per intersection-month before and after the intervention. Stratified models were used to evaluate effect modification by pedestrian age, injury severity and location (urban vs inner suburbs). Poisson regression analysis with repeated measures (generalised estimating equations) was used to estimate the RR and 95% CI.
The analysis included 9262 pedestrian-motor vehicle collisions at 1965 intersections. The RR of collisions after PCS installation was 1.014 (95% CI 0.958 to 1.073), indicating no statistically significant effect of PCS on collisions. There was no evidence to suggest effect modification between PCS and collisions by age, injury severity or location.
The installation of PCS at 1965 signalised intersections in Toronto did not reduce the number of pedestrian-motor vehicle collisions at these intersections.
确定行人倒计时信号（PCS）是否能减少加拿大多伦多市的行人和机动车碰撞事故。
采用准实验设计，评估了 PCS 对 2000 年 1 月至 2009 年 12 月期间多伦多市行人和机动车碰撞数量的影响。每个交叉路口作为自己的对照。我们比较了干预前后每个路口/月的行人和机动车碰撞数量。采用分层模型评估了行人年龄、伤害严重程度和位置（城市与内郊区）的效应修饰作用。采用广义估计方程的重复测量泊松回归分析来估计 RR 和 95%CI。
分析包括 1965 个交叉路口的 9262 起行人和机动车碰撞事故。PCS 安装后的碰撞 RR 为 1.014（95%CI 0.958 至 1.073），表明 PCS 对碰撞没有统计学上显著的影响。没有证据表明 PCS 与年龄、伤害严重程度或位置之间存在碰撞的修饰作用。
在多伦多的 1965 个信号交叉路口安装 PCS 并没有减少这些路口的行人和机动车碰撞数量。
