AEAS阅读训练 – Traffic Accidents Claim Curbed

Traffic Accidents Claim Curbed

A year ago I reported on a study about an increase in fatal traffic accidents on April 20th, 4/20—a date considered somewhat of a holiday by marijuana aficionados. That study was in the journal JAMA Internal Medicine. And it used data from the U.S. National Highway Traffic Safety Administration. The researchers looked at fatal accidents on 4/20 between 4:20pm and 11:59pm from 1992 to 2016. And they compared that date’s data with the day one week before and one week after. They found a 12 percent increase in the relative risk of a fatal traffic accident after 4:20 PM on April 20—4:20 PM being the time that a lot of pot smokers like to light up on 4/20.

The paper caught the attention of McGill University epidemiologists Sam Harper and Adam Palayew.

“I should say, at first I thought the paper was intriguing.”Sam Harper, on the phone from Montreal.

“I think the most fundamental difficulty with the JAMA paper was really the large magnitude of the effect size, given what we already know about impaired driving, so…in order to increase the national rate of fatal accidents by something like 12 percent would require either a really large segment, as much as 15 percent of the population, to be driving while high after 4:20pm on 4/20, or really, really incredibly high relative risks of driving after the kind of cannabis consumption that you might have had on 4/20. So I think this was actually a hard case to make substantively.”

Harper and Palayew decided to dig deeper.

“So one way to test this is to see whether this elevated risk persists if you compare 4/20 not just to the same day one week before and after, but, for example, to the same day two weeks before and two weeks after. Or to every other day of the year. And that’s part of what we did. And when we did these sorts of additional tests we found very little evidence of any elevated risk on 4/20.

“And then the last thing we did was we also looked at this question of whether certain days showed persistently high risks year after year. I think that’s another way of trying to assess whether or not something is really robust. So again when we did this we found very little evidence that there is any kind of sustained effect of 4/20. Not even for recent years when I think this has become a more popular event.

“But you know, very well-established holidays like July 4th, weekends around Thanksgiving and Labor Day, these things show very reliable excess risks of fatal crashes basically every year since the data started being collected in 1975.”Harper is careful to say they were not “debunking” the original research.

“That’s not the way I see it, I see it as these guys had an interesting idea, and now what we did was poke a little more deeply, look at it a little bit more carefully, and maybe we find it’s not so robust. And that’s kind of interesting, that’s the way the process should work, I hope.”

交通事故索赔得到控制

一年前,我报道了一项关于4月20日(4月20日)致命交通事故增加的研究。4月20日被大麻爱好者视为假日。这项研究发表在《美国医学会内科杂志》(JAMA Internal Medicine)上。它使用了美国国家公路交通安全管理局的数据。研究人员观察了1992年至2016年4月20日下午4点20分至11点59分之间的致命事故。他们将这一天的数据与一周之前和一周之后的数据进行了比较。他们发现,在4月20日下午4点20分以后发生致命交通事故的相对风险增加了12%。4月20日下午4点20分是许多吸食大麻的人喜欢在4月20日下午4点20分吸烟的时间。这篇论文引起了麦吉尔大学流行病学家Sam Harper和 Adam Palayew的注意。

“我得说,起初我觉得这篇论文很有趣。” Sam Harper在蒙特利尔报道。

“我认为在《美国医学会杂志》的论文最基本的困难非常大的大小影响大小,考虑到我们已经知道酒后驾驶,所以…为了增加国家的致命事故的12%需要一个很大的部分,多达15%的人口,驾车而高4:20pm后4/20,或者是真的,在4月20日吸食大麻之后开车的相对风险非常高。所以我认为这实际上是一个很难做出实质性结论的案例。”

“因此,测试这个的一种方法是,如果你将4/20不只是与一周前和一周后的同一天进行比较,而是与两周前和两周后的同一天进行比较,看看这种高风险是否会持续。或者每隔一天。这就是我们所做的。当我们做这些额外的测试时我们发现很少有证据表明4/20有任何风险升高。

然后我们做的最后一件事是,我们还研究了这个问题,即某些日子是否会年复一年地显示出持续的高风险。我认为这是另一种评估事物是否真的强大的方法。所以当我们这样做的时候我们发现很少有证据表明4/20有任何持续的效果。甚至在最近几年,当我认为这已经成为一个更受欢迎的事件。

“但你知道,像7月4日这样的传统节日,感恩节和劳工节前后的周末,这些都显示出非常可靠的致命撞车风险,基本上自1975年开始收集数据以来,每年都有这种风险。Harper谨慎地表示,他们并没有“揭穿”最初的研究。

“我不这么认为,我认为这些人有一个有趣的想法,现在我们做的是更深入地戳一下,更仔细地看一下,也许我们会发现它不是那么健壮。我希望这是一个有趣的过程。”