It absolutely would. If 40% of people test positive for THC, then this would mean there is no effect. I find it unlikely 40% of people test positive for THC, but yes, it does matter.

▲

gpm 2 days ago | parent | next [-]

That wouldn't actually mean no effect, you need 40% of people driving to test positive for it to be no effect. It's unlikely the population driving is equivalent to the population at large - for one there's a set of responsible people who won't drive while high. For another weed use isn't randomly distributed through the population but correlated with certain subsets, which probably have a non-average rate of driving just by coincidence.

(Not that it really matters since I don't buy for a second that anywhere near 40% of people/people-driving are high at any given time. I also don't put much faith in numbers in the abstract of a a yet-to-be-published study...)

	▲	meroes 2 days ago \| parent [-]
		There is a case for the two populations to be quite similar. THC in the blood doesn’t mean actively high for habitual users, which would be most users if THC consumption is high. It means recent use, but not clear impairment.

▲

Chris2048 2 days ago | parent | prev | next [-]

> If 40% of people test positive for THC, then this would mean there is no effect

Can you explain what you mean by this?

▲

xienze 2 days ago | parent | prev [-]

The article is not saying 40% of all drivers tested positive, it’s stating that 40% of people who died in a car accident tested positive, at pretty high levels too.

	▲	dragonwriter 2 days ago \| parent \| next [-]
		> It’s stating that 40% of people who died in a car accident tested positive, at pretty high levels too. It doesn't say anything about the distribution, only that the "average" (presumably, the arithmetic mean, a measure particularly sensitive to distortion by outliers) was at a particularly high level.
	▲	leptons 2 days ago \| parent \| prev [-]
		The levels described are actually pretty low. The "legal limit" is so low for THC that anyone who's had THC in the previous days could test positive, even if they aren't "high" at the time of driving. It isn't quite the same as the BAC legal limits for alcohol. And it doesn't account for body weight, tolerance, and other factors that definitely contribute to how a driver reacts no matter how long it's been since they consumed THC. And the study doesn't seem to differentiate between the different types of THC either, some of which are not psychoactive at all and which people use to relieve pain and anxiety. There's quite a lot of people using non-psychoactive THC which wouldn't impair driving.