Since passing medical marijuana laws, states have seen lower numbers of fatal car crashes involving opioids

September 15, 2016, Columbia University

A study conducted at Columbia University's Mailman School of Public Health found that there were fewer drivers killed in car crashes who tested positive for opioids in states with medical marijuana laws than before the laws went into effect. The study is one of the first to assess the link between state medical marijuana laws and opioid use at the individual level. Findings will be published online in the American Journal of Public Health.

Researchers analyzed 1999-2013 Fatality Analysis Reporting System data from 18 U.S. that tested for alcohol and other drugs in at least 80 percent of drivers who died within one hour of crashing. They looked at opioid positivity among drivers ages 21 to 40 who crashed their cars in states with an operational law compared with drivers crashing in states before those laws went into effect. There was an overall reduction in opioid positivity for most states after implementation of an operational medical marijuana law.

"We would expect the adverse consequences of opioid use to decrease over time in states where medical marijuana use is legal, as individuals substitute marijuana for opioids in the treatment of severe or chronic pain," explained June H. Kim, MPhil, a doctoral student in the Department of Epidemiology at the Mailman School of Public Health, and lead author.

Among the 68,394 deceased drivers, approximately 42 percent were fatally injured in states that had an operational medical , 25 percent died in states before an operational law went into effect, and 33 percent died in states that had never passed a medical marijuana law.

In 1996, California was the first state to pass a voter-initiated medical marijuana law. Since then, 22 additional states and the District of Columbia have enacted their own medical marijuana laws either by voter initiatives or through state legislation.

"The trend may have been particularly strong among the age group surveyed because minimum age requirements restrict access to medical marijuana to patients age 21 and older, and most medical marijuana patients are younger than 45," noted Kim. According to the authors, they would expect to see similar reductions in opioid use among older cohorts if medical marijuana is increasingly embraced by older generations.

"This study is about the possible substitution relationship between marijuana and opioids. The toxicological testing data for fatally injured drivers lend some suggestive evidence that supports the substitution hypothesis in young adults, but not in older adults,"said Guohua Li, MD, DrPH, Mailman School professor of Epidemiology, the founding director of the Center for Injury Epidemiology and Prevention at Columbia, and senior author.

"As states with these laws move toward legalizing marijuana more broadly for recreational purposes, future studies are needed to assess the impact these laws may have on opioid use," noted Kim.

Explore further: Survey: More US adults use marijuana, don't think it's risky (Update)

Related Stories

Survey: More US adults use marijuana, don't think it's risky (Update)

August 31, 2016
Marijuana use is becoming more accepted among U.S. adults as states loosen pot laws, new national survey data shows.

Research shows 25 percent fewer opioid-related deaths in states allowing medical marijuana

August 25, 2014
On average, states allowing the medical use of marijuana have lower rates of deaths resulting from opioid analgesic overdoses than states without such laws. Opioid analgesics, such as OxyContin, Percocet and Vicodin, are ...

Medicinal marijuana – a gateway to increased illegal drug use?

July 6, 2016
Whether medicinal marijuana should be legalised has attracted debate recently. Central to the discussion both in New Zealand and overseas, is how legalising the drug for medicinal purposes will affect the use of non-medical ...

Variation in medical marijuana program regulations impacts enrollment

March 7, 2016
A study published today in Health Affairs found that while 14 of the nation's 24 medical marijuana programs were essentially nonmedical in practice, they enrolled more than 99 percent of overall participants. Fewer than one ...

Canada to allow medical marijuana patients to grow cannabis

August 11, 2016
The Canadian government says medical marijuana patients will be able to grow their own cannabis under new regulations that come into effect later this month.

Up in smoke or bottoms up: How policy could affect substance abuse

January 12, 2015
Half of young drivers who died in car crashes in American states such as California, Hawaii and West Virginia were under the influence of either alcohol or marijuana, or both. This is the story told by the statistics recording ...

Recommended for you

It's not just for kids—even adults appear to benefit from a regular bedtime

September 21, 2018
Sufficient sleep has been proven to help keep the body healthy and the mind sharp. But it's not just an issue of logging at least seven hours of Z's.

Patient-centered visual aid helps physicians discuss risks, treatments with parents

September 21, 2018
A series of illustrations and charts designed as decision aids for parents of children with minor head injuries helped them communicate with emergency medicine physicians and make informed decisions about their child's care, ...

Alcohol responsible for one in 20 deaths worldwide: WHO

September 21, 2018
Alcohol kills three million people worldwide each year—more than AIDS, violence and road accidents combined, the World Health Organization said Friday, adding that men are particularly at risk.

Most nations falling short of UN targets to cut premature deaths from chronic diseases

September 21, 2018
People in the UK, US and China have a higher risk of dying early from conditions like cancer, heart disease and stroke than people in Italy, France, South Korea and Australia.

Smart pills dumb down medical care, experts warn

September 21, 2018
Enthusiasm for an emerging digital health tool, the smart pill, is on the rise but researchers at the University of Illinois at Chicago have published a paper in the American Journal of Bioethics that cautions health care ...

China's doctor shortage prompts rush for AI health care

September 20, 2018
Qu Jianguo, 64, had a futuristic medical visit in Shanghai as he put his wrist through an automated pulse-taking machine and received the result within two minutes on a mobile phone—without a doctor present.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.