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Over 40% of deceased drivers in vehicle crashes test positive for THC: Study

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Re: Over 40% of deceased drivers in vehicle crashes test positive for THC: Study

#291

Post by SecretDreams »

iLoveOncall wrote: post #194
SecretDreams wrote: post #61

Earlier quoted context omitted.

Yes, it would be useful. When controlling for variables, you normally want to compare against a baseline. If 40% of the whole population has THC in them, we'd need a control population (maybe from earlier when thc was less prominent) to see if per capita deaths has meaningfully increased. I'd do the same study, tangentially, for tech workers to see if productivity has changed when controlling for other variables.

No it wouldn't. That would be true if you looked at a variable which is not influenced by driving, like the percentage that wear red jumpers, but one would hope that not everyone is reckless enough to be highly intoxicated and drive. This is again THC apologizism, nobody would even begin to suggest this if we were talking about alcohol.

> This is again THC apologizism, nobody would even begin to suggest this if we were talking about alcohol.

This is literally how safe legal limits were derived.

Re: Over 40% of deceased drivers in vehicle crashes test positive for THC: Study

#292

Post by notatoad »

Someone wrote: post #87

> In a review of 246 deceased drivers, 41.9% tested positive for active THC in their blood, with an average level of 30.7 ng/mL — far exceeding most state impairment limits. That could mean they all had levels far exceeding most state impairment limits, but it also could mean most of them had trace levels, while a few had levels way above 30.7 ng/mL. So, it says fairly little. Also (FTA) “Researchers analyzed coroner…

>focusing on 246 deceased drivers who were tested for THC following a fatal crash”. That means there could be selection bias at play.

that wording definitely sets off warning alarms for selection bias. but it looks like there were approximately 350 traffic deaths in montgomery county during that period [1]. that probably about lines up with 246 drivers dying during that period, so it seems likely they tested all or almost all deceased drivers.

[1] https://dam.assets.ohio.gov/image/upload/statepatrol.ohio.go...

Re: Over 40% of deceased drivers in vehicle crashes test positive for THC: Study

#293

Post by [deleted] »

metadope wrote: post #226
Youden wrote: post #114

Earlier quoted context omitted.

There was a larger discussion in a previous thread on this topic: https://news.ycombinator.com/item?id=45494730 Since then, [0] has been published and I think it's worth at least a skim. Since it's quite recent the introduction summarizes some of the most recent research. The things that jump out at me are: - [0]: Habitual users with baseline concentrations above legal limits perform just as well as habitual users wi…

> the number of drivers in accidents with THC in their blood is going up because the number of people with THC in their blood is going up This. In just the short time since legalization, recreational use in my immediate vicinity (a small Ohio village, one stop light) has decidedly, undeniably increased. I offer only an anecdotal observation, but my evening walks around town are now accompanied by a dank potpourri of…

[deleted]

Re: Over 40% of deceased drivers in vehicle crashes test positive for THC: Study

#294

Post by SecretDreams »

hattmall wrote: post #277
graeme wrote: post #244

Earlier quoted context omitted.

If the population of dead drivers with over the limit THC is 40%, and this dramatically exceeds the population average, that would strongly suggest the THC level IS an indicator of either: 1. Impairment from THC, or 2. Worse than average driving and risk management skills in those who use the drug

It's seat belts. People who die in wrecks are overwhelmingly not wearing seat belts. I would think marijuana users as a group probably have average seat belt usage, but people who don't wear seat belts probably have much higher than average marijuanna usage. Roughy 92% of people wear seat belts. But that 8% of people that don't wear setbelts makes up 50% or more of all fatalities. From my personal experience it seems…

The seat belts comment is so apt. We should be looking at the full population of drivers involved in accidents, not just those that went through a windshield.

Restraints play such a pivotal role in crash safety, but not wearing them isn't a meaningful indicator of impairment status.

Re: Over 40% of deceased drivers in vehicle crashes test positive for THC: Study

#295

Post by LorenPechtel »

mattmaroon wrote: post #254
jeremyjh wrote: post #245

Earlier quoted context omitted.

Doesn't that support the hypothesis that high THC levels are dangerously impairing people's driving?

Not necessarily, they could both be a comorbidity of some other factor (bad decision making causes both, for instance) but it certainly doesn’t refute it.

That was my first thought on reading it. Dope is for dopes!

Re: Over 40% of deceased drivers in vehicle crashes test positive for THC: Study

#296

Post by henearkr »

hattmall wrote: post #277
graeme wrote: post #244

Earlier quoted context omitted.

If the population of dead drivers with over the limit THC is 40%, and this dramatically exceeds the population average, that would strongly suggest the THC level IS an indicator of either: 1. Impairment from THC, or 2. Worse than average driving and risk management skills in those who use the drug

It's seat belts. People who die in wrecks are overwhelmingly not wearing seat belts. I would think marijuana users as a group probably have average seat belt usage, but people who don't wear seat belts probably have much higher than average marijuanna usage. Roughy 92% of people wear seat belts. But that 8% of people that don't wear setbelts makes up 50% or more of all fatalities. From my personal experience it seems…

I can't make sense of it mathematically. A statistical distribution fitting these characteristics does not exist.

If non-weeders have an average seat belt wearing, and if weeders also have an average seat belt wearing, then the proportion of weeders inside of the seat belt non-wearing class is just equal to the proportion of weeders inside the whole population.

Re: Over 40% of deceased drivers in vehicle crashes test positive for THC: Study

#297

Post by LorenPechtel »

VanTheBrand wrote: post #278
Aurornis wrote: post #179

Earlier quoted context omitted.

One helpful data point is that only about 20% of people over age 12 report any THC use at all in the prior year. Some surveys have even lower numbers, around 1 in 8, but let’s take the highest number for the sake of this comparison. So the median THC level is 0%. Having 40% of people register high enough levels of THC to pass an impairment threshold is a remarkably high number no matter how you look at it.

I think there is definable a connection between cannabis use and auto accidents. It slows your reaction time and that’s a known factor with accidents. That said, substance use data is notoriously underreported[1] in surveys. So that 20% data point is not very helpful. Also 12-15 year olds are bringing that number down in your data and also can’t drive making it even less useful for comparison. [1] https://www.science…

And substance use impairment is overreported. If the driver was impaired it's counted even if the impairment has no bearing on the accident. A drunk hits a red light runner--it's called alcohol even if he had no hope of avoiding it.

My understanding of stoned drivers is they tend to be too conservative--waiting for the stop sign to turn green etc. If that's accurate it could also mean stoned drivers are worse at avoiding the mistakes of others.

Re: Over 40% of deceased drivers in vehicle crashes test positive for THC: Study

#298

Post by LorenPechtel »

carlmr wrote: post #128
macNchz wrote: post #91

Earlier quoted context omitted.

It’s a very widespread problem, I think, and probably has a complex mix of causes, but my perception as a NYC runner, cyclist, and driver is that there’s a fairly small percentage of extremely antisocial drivers who we allow to behave badly with relative impunity, which itself moves the Overton window of driving behavior towards aggression/chaos, so to speak. Very frequently when there is a newsmaking incident in whi…

>it turns out that they got dozens of speed camera tickets per year To me the answer is quite simple for any of these. Treat repeated small infractions like bigger and bigger infractions. E.g. double the cost every iteration if it happens within a specific time frame. Ok, you speed once? $100. Twice $200. Thrice $400. And so on. We only reset if you don’t reoffend for any speeding in 5 years. If you want to speed 20…

I'm in favor of escalating punishment, but it doesn't reset, it decays. Say 3 years with not tickets and it goes down one level.

Re: Over 40% of deceased drivers in vehicle crashes test positive for THC: Study

#299

Post by BiteCode_dev »

macNchz wrote: post #225
BiteCode_dev wrote: post #156

Earlier quoted context omitted.

For these reasons, many countries have adopted a point-based system for driving licences. E.G: in France you have 12 points, driving over the speed limit is a fine, but also removes up to 6 points depending on the speed. If you go down to 0 points, your licence is suspended. If you stay without a fine for long enough, you get back points. Some countries have fines that depend on how much you make. Some countries will…

New York actually does have a points system, but since they're tied to the driver's license rather than the car itself, you only get them if you're actually pulled over, not from cameras. Within NYC there's a fair amount of camera enforcement, but comparatively very little by the police directly, so drivers whose licenses might otherwise be suspended via points are still driving around. The mechanisms for keeping peo…

France gets around that by assuming it's the car's owner's fault. If you were not driving the car during the infraction, the person driving the car must fill out a form saying he or she did and take the hit voluntarily.

If the car's owner is a company, the company must declare a default conductor for this purpose.

Re: Over 40% of deceased drivers in vehicle crashes test positive for THC: Study

#300

Post by avereveard »

Youden wrote: post #114
tokai wrote: post #13

An issue with having the legal limit at ~2-5ng/ml is that it makes habitual users be over the limit if they have smoked recently or not.[0] Making the prohibition seem unserious to some, not about safety but about punitive control, and in turn making it matter less if you smoke and drive as you are taking the risk of getting into trouble in any case. The impairments of driving under the influence of alcohol have been…

There was a larger discussion in a previous thread on this topic: https://news.ycombinator.com/item?id=45494730 Since then, [0] has been published and I think it's worth at least a skim. Since it's quite recent the introduction summarizes some of the most recent research. The things that jump out at me are: - [0]: Habitual users with baseline concentrations above legal limits perform just as well as habitual users wi…

If that's the conclusion you'd also expect 40% of the population using it.
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