Nav: Home

Legal marijuana reduces chronic pain, but increases injuries and car accidents

May 15, 2019

The legalization of recreational marijuana is associated with an increase in its abuse, injury due to overdoses, and car accidents, but does not significantly change health care use overall, according to a study by researchers at UC San Francisco.

In a review of more than 28 million hospital records from the two years before and after cannabis was legalized in Colorado, UCSF researchers found that Colorado hospital admissions for cannabis abuse increased after legalization, in comparison to other states. But taking the totality of all hospital admissions and time spent in hospitals into account, there was not an appreciable increase after recreational cannabis was legalized.

The study, appearing online May 15, 2019, in BMJ Open, also found fewer diagnoses of chronic pain after legalization, consistent with a 2017 National Academy of Sciences report that concluded substantial evidence exists that cannabis can reduce chronic pain.

"We need to think carefully about the potential health effects of substantially enhancing the accessibility of cannabis, as has been done now in the majority of states," said senior author Gregory Marcus, MD, MAS, a UCSF Health cardiologist and associate chief of cardiology for research in the UCSF Division of Cardiology.

"This unique transition to legalization provides an extraordinary opportunity to investigate hospitalizations among millions of individuals in the presence of enhanced access," Marcus continued. "Our findings demonstrate several potential harmful effects that are relevant for physicians and policymakers, as well as for individuals considering cannabis use."

According to the 2014 National Survey on Drug Use and Health, more than 117 million Americans, or 44.2 percent of all Americans, have used cannabis in their lifetime, and more than 22 million Americans report having used it within the past 30 days. While its use is a federal crime as a controlled substance, 28 states and the District of Columbia now allow it for treating medical conditions. Nine of those states have legalized it for recreational use.

To understand the potential shifts in health care use resulting from widespread policy changes, Marcus and his colleagues reviewed the records of more than 28 million individuals in Colorado, New York and Oklahoma from the 2010-2014 Healthcare Cost and Utilization Project, which included 16 million hospitalizations. They compared the rates of health care utilization and diagnoses in Colorado two years before and two years after recreational marijuana was legalized in December 2012 to New York, as a geographically distant and urban state, and to Oklahoma, as a geographically close and mainly rural state.

The researchers found that after legalization, Colorado experienced a 10 percent increase in motor vehicle accidents, as well as a 5 percent increase in alcohol abuse and overdoses that resulted in injury or death. At the same time, the state saw a 5 percent decrease in hospital admissions for chronic pain, Marcus said.

"There has been a dearth of rigorous research regarding the actual health effects of cannabis consumption, particularly on the level of public health," said Marcus, holder of the Endowed Professorship of Atrial Fibrillation Research in the UCSF School of Medicine. "These data demonstrate the need to caution strongly against driving while under the influence of any mind-altering substance, such as cannabis, and may suggest that efforts to combat addiction and abuse of other recreational drugs become even more important once cannabis has been legalized."

The study findings may be beneficial in guiding future decisions regarding cannabis policy, the researchers said.

"While it's convenient and often most compelling to simplistically conclude a particular public policy is 'good' or 'bad,' an honest assessment of actual effects is much more complex," Marcus said. "Those effects are very likely variable, depending on each individual's idiosyncratic needs, propensities and circumstances. Using the revenues from recreational cannabis to support this sort of research likely would be a wise investment, both financially and for overall public health."

The researchers could not explain why overall health care utilization remained essentially neutral, but said the harmful effects simply may have been diluted among the much larger number of total hospitalizations. They said it also may be that some beneficial effects, either at the individual or societal level, such as violent crime, counterbalanced the negatives.
-end-
Co-Authors: Lead author Francesca Nesta Delling, Eric Vittinghoff, Mark Pletcher, Jeffrey Olgin, Gregory Nah, Kirstin Aschbacher, Christina Fang, Emily Lee, Shannon Fan and Dhruv Kazi, of UCSF; and Thomas Dewland, of Oregon Health & Science University

Funding: The study was supported by the Agency for Healthcare Research and Quality and Health Care Information Division of the Oklahoma State Department of Health.

Disclosures: The authors report no conflicts of interest.

About UCSF: UC San Francisco (UCSF) is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care. It includes top-ranked graduate schools of dentistry, medicine, nursing and pharmacy; a graduate division with nationally renowned programs in basic, biomedical, translational and population sciences; and a preeminent biomedical research enterprise. It also includes UCSF Health, which comprises three top-ranked hospitals - UCSF Medical Center and UCSF Benioff Children's Hospitals in San Francisco and Oakland - as well as Langley Porter Psychiatric Hospital and Clinics, UCSF Benioff Children's Physicians and the UCSF Faculty Practice. UCSF Health has affiliations with hospitals and health organizations throughout the Bay Area. UCSF faculty also provide all physician care at the public Zuckerberg San Francisco General Hospital and Trauma Center, and the SF VA Medical Center. The UCSF Fresno Medical Education Program is a major branch of the University of California, San Francisco's School of Medicine. Please visit http://www.ucsf.edu/news.

University of California - San Francisco

Related Public Health Articles:

The Lancet Public Health: US modelling study estimates impact of school closures for COVID-19 on US health-care workforce and associated mortality
US policymakers considering physical distancing measures to slow the spread of COVID-19 face a difficult trade-off between closing schools to reduce transmission and new cases, and potential health-care worker absenteeism due to additional childcare needs that could ultimately increase mortality from COVID-19, according to new modelling research published in The Lancet Public Health journal.
The Lancet Public Health: Access to identification documents reflecting gender identity may improve trans mental health
Results from a survey of over 20,000 American trans adults suggest that having access to identification documents which reflect their identified gender helps to improve their mental health and may reduce suicidal thoughts, according to a study published in The Lancet Public Health journal.
The Lancet Public Health: Study estimates mental health impact of welfare reform, Universal Credit, in Great Britain
The 2013 Universal Credit welfare reform appears to have led to an increase in the prevalence of psychological distress among unemployed recipients, according to a nationally representative study following more than 52,000 working-age individuals from England, Wales, and Scotland over nine years between 2009-2018, published as part of an issue of The Lancet Public Health journal on income and health.
BU researchers: Pornography is not a 'public health crisis'
Researchers from the Boston University School of Public Health (BUSPH) have written an editorial in the American Journal of Public Health special February issue arguing against the claim that pornography is a public health crisis, and explaining why such a claim actually endangers the health of the public.
The Lancet Public Health: Ageism linked to poorer health in older people in England
Ageism may be linked with poorer health in older people in England, according to an observational study of over 7,500 people aged over 50 published in The Lancet Public Health journal.
Study: Public transportation use linked to better public health
Promoting robust public transportation systems may come with a bonus for public health -- lower obesity rates.
Bloomberg American Health Initiative releases special public health reports supplement
With US life expectancy now on the decline for two consecutive years, the Bloomberg American Health Initiative is releasing a supplement to Public Health Reports, the scholarly journal of the US Surgeon General.
Data does the heavy lifting: Encouraging new public health approaches to promote the health benefits of muscle-strengthening exercise (MSE)
According to a new study in the American Journal of Preventive Medicine, almost 75 percent of US adults do not comply with public health guidelines recommending two or more muscle-strengthening exercise (MSE) sessions a week, with nearly 60 percent of the population doing no MSE at all.
The Lancet Public Health: Moderate carbohydrate intake may be best for health
Low-carb diets that replace carbohydrates with proteins and fats from plant sources associated with lower risk of mortality compared to those that replace carbohydrates with proteins and fat from animal sources.
Mass. public safety, public health agencies collaborate to address the opioid epidemic
A new study shows that public health and public safety agencies established local, collaborative programs in Massachusetts to connect overdose survivors and their personal networks with addiction treatment, harm reduction, and other community support services following a non-fatal overdose.
More Public Health News and Public Health Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Climate Mindset
In the past few months, human beings have come together to fight a global threat. This hour, TED speakers explore how our response can be the catalyst to fight another global crisis: climate change. Guests include political strategist Tom Rivett-Carnac, diplomat Christiana Figueres, climate justice activist Xiye Bastida, and writer, illustrator, and artist Oliver Jeffers.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Speedy Beet
There are few musical moments more well-worn than the first four notes of Beethoven's Fifth Symphony. But in this short, we find out that Beethoven might have made a last-ditch effort to keep his music from ever feeling familiar, to keep pushing his listeners to a kind of psychological limit. Big thanks to our Brooklyn Philharmonic musicians: Deborah Buck and Suzy Perelman on violin, Arash Amini on cello, and Ah Ling Neu on viola. And check out The First Four Notes, Matthew Guerrieri's book on Beethoven's Fifth. Support Radiolab today at Radiolab.org/donate.