The effect of cannabis legalisation on Emergency Care 

By John Pickering 27/02/2016

Medical cannabis application guidelines are to be reviewed, announced Associate Health Minister Peter Dunne this week. Co-incidently a paper was published* in the Annals of Emergency Medicine on the effect on Emergency Care of legalising medical marijuana use in Colorado. Alas, this article is behind a paywall.  It does not have a lot of detail. However, it is relevant to the New Zealand debate.  Not so much as to any possible change in guidelines on applications made to the minister, but rather to the effect a broader legalisation of marijuana for medical purposes may  have an on our emergency departments. i.e. just one of the many factors which need to be taken into account in the debate.

In 2009 the prosecution of marijuana users and suppliers was halted in the state of Colarado where the use of medical marijuana had been previously legalised and licensed.  Within 2 years the number of registered medical marijuana licences increased 24 times from 5000 to nearly 120,000.  This was not the only effect:

  • The percentage of 18 to 25 year olds reporting marijuana use increased from 35% to 43%
  • The percentage of those aged 26+ perceiving marijuana posed “great risk” dropped from 45% to 31%.

While these numbers may reflect in part the readiness to be “honest” after the law change, the following statistic probably is truly related to increased use:

  • The hospitalisations after marijuana use nearly doubled from 15 per 100,000 hospitalisations to 28 per 100,000 hospitalisations.

As the authors concluded:

“It is clear that marijuana availability and use in Colorado significantly increased after the commercialization of medical marijuana. Providers in states with impending legalization measures should become familiar with the symptoms and management of acute marijuana intoxication, as well as understand the effects on chronic diseases frequently observed in the ED.”

I was fascinated that in a population of 5.4 million there were nearly 120,000 licensed medical marijuana users in Colorado.  That is 1 in 45 people! That strikes me as amazingly high proportion. However, I guess that it all depends on just what medicinal purposes may mean.  The process to get a license (at least now), seems relatively easy involving a few simple forms.  The Physician recommends the number of plants to be grown and ticks a box stating one of eight conditions: Cancer, Glaucoma, HIV or AIDS positive, Cachexia, Severe Nausea, Severe Pain, Persistent muscle spasms, Seizures.  The patient sends in a form too, with $15.

According to the latest statistics on the Colorado medical marijuana registry there are currently 107,000 active patients registered with an average age of 43. 21-40 year olds comprised 43% pf the patients.  93% report severe pain.  Hmmm… it seem Colorado has an epidemic of “severe” pain amongst their young adults.


ps. Before you jump in with comments, recognise that there is a lot of misconception around medical cannabis in New Zealand. Minister Peter Dunne cleared some of them up in a press release in January. (eg did you know that there is already a cannabis product approved for therapeutic use?).

Note: Recreational marijuana became legal in Colorado in 2014.

Disclaimer:  I an not an expert in the field, merely I came across this article because it was published in a journal I access for my other research concerning emergency departments.  If you believe the methods to measure these things, Ann Emerg Med is the top ranked Emergency medicine journal

*Kim, H., & Monte, A. A. (2016). Colorado Cannabis Legalization and Its Effect on Emergency Care. Annals of Emergency Medicine,

Photo: Public Domain, from Wikipedia.

Tagged: cannabis, Emergency Department, Emergency Room, medial marijuana, Peter Dunne

0 Responses to “The effect of cannabis legalisation on Emergency Care ”

  • Well, I’ve been to Venice beach in California and the whole “medical marijuana” thing was a complete farce. More or less, it was a backdoor way to get pot legally. They had tons of places with signs out offering it, with guys outside yelling “the doctor is in the house”. All you needed was valid Ca ID proving you were resident and of age, claim your back was sore or something on the approved list and leave with a “prescription” and your baggie. The system is lax enough to allow that huge amount of licensed people using it, there are doctors obviously doing a booming trade in supplying this with little control.

    No surprise you are seeing use rising and harms coming through the system with this, no drug is innocuous even though there are people making out it’s the wonder drug of the century. I’ve even seen a person come in with a paradoxical reaction after inadvertently (or so they said) ingesting marijuana here in NZ, most people don’t know that instead of reducing nausea and vomiting it can have the effect in some people of causing uncontrollable vomiting. There are also issues with that it is often smoked and so on.

    Marijuana has some therapeutic qualities that can help some patients, and there is Sativex and other pharmaceuticals developed for people with MS and other conditions that help. However, it seems having a licensed medication and simply lobbying to have better access to that and have it funded is anathema to those same people that are pushing for “medical marijuana” or as is a better term “back door legalisation”. Funny thing is that I have no problems looking at using medications of this type nor even considering some form of decriminalisation surrounding personal use, but loathe this push for medical marijuana going on currently which ignores all of that or engaging sensible discussion of benefits/risks of change in favour of emotive stories and really pushing hard for raw plant options.

  • Interesting statistics. I find it very encouraging really. Availability jumped massively but use in the specified age group only went up 8%. Granted that represents a large number of people. I’d be interested to see how usage changed, did the 35% include those who had tried it once or was it just regular users? I suspect the former. So then does the overall increase mean more people tried it or more people became regular users? The later would be concerning.

    And emergency care went up 13 people per 100,000? Is that bad? i’m not familiar with this kind on medical statistic to know the significance. How does this stack up against other emergency care, household accidents, alcohol related injuries etc. Jumping by a factor of 2 is certainly significant. But is an increase of 0.00013% clinically relevant?

  • Interesting comments Michelle & Darcy.
    Darcy … a doubling in ED attendance more likely reflects a doubling in usage than the ~ 23% (8/35) increase self reported use . Having said that, with home grown cannabis and apparently a lot of “first time growers” I wonder if there is potential also for harm through the growing/harvesting process?
    The authors talk about the toxic effects of Marijauna and warn about the long term chronic effects There’s plenty or research about that. This is outside my area of knowledge, so hard to say the clinical significance of 13 more per 100,000 attendances. More details are needed, eg are they 13 at the more serious end of attendances, or more mild end? I’ve only witnessed & been involved in case research concerning synthetic cannabis – in those cases it was really nasty and put people in the ICU with severely damaged kidneys.

  • Thanks for that. It would be good to see all of these questions answered and the statistics put into the wider health context. I’m open to many potential outcomes with regard to access but I often see things presented in a way that most definitely favour one particular view. Hard not to do that even with ostensibly neutral information.