Cannabis Legalization Linked to Drop in Opioid-Related Emergency Room Visits
States that legalize recreational cannabis appear to experience a short-term dip in opioid-related emergency department visits, according to a new study published in Health Economics.
In the new analysis, led by scientists at the University of Pittsburgh Graduate School of Public Health, the researchers found that the number of opioid-related visits to hospital emergency rooms in each state dipped for around six months after its legalization went into effect. This trend was particularly significant among the male demographic and in all adults between 25-44 years old.
Although these emergency department visits returned to baseline levels after this initial period, the public health experts behind the study believe that their finding still represents a positive step forward in tackling the US opioid epidemic, especially when combined with other public health measures, such as the expanding access to opioid misuse treatment centers.
Emergency department visits fall by around 8 percent after legalization
The researchers used information from the Healthcare Cost and Utilization Project (HCUP) Fast Stats database for this analysis, which included data on the number of opioid-related emergency department visits per 100,000 population reported by each state in quarterly intervals. These visits recorded inpatient admissions as well as simple treat-and-release visits for all manner of opioid-related reasoning, such as poisonings, opioid-induced psychosis, and symptoms of withdrawal.
These data were then combined with information on state-level recreational and medical cannabis legalization implementation dates, other opioid-related state policies (as taken from the RAND-USC Schaeffer Opioid Policy Tools and Information Center), and socioeconomic characteristics data from the American Communities Survey to create an event study model.
Together, the researchers looked at data from 29 different states that reported complete quarterly information to the Fast Stats database from 2011 to 2017. Four of the states that were included in the dataset – California, Maine, Massachusetts, and Nevada – legalized recreational cannabis in this period. The other 25 states were used as controls, with additional robustness checks done to ensure that no general trends observed were being driven by a single state.
The researchers found that, on average, opioid-related emergency department visits fell by around 7.6 percent in the six months following the implementation of recreational cannabis laws. This dip was predominantly driven by reductions in admissions from the male demographic, and to a slightly lesser extent, adults between 25-44 years old. This finding makes sense, the researchers say, as these demographics also account for the majority of cannabis users.
Visits gradually return to baseline levels post-legalization, but do not continue to rise
After around two quarters, this observed reduction in emergency department visits dissipated and returned to baseline levels – but importantly, these visits did not appear to increase past the baseline.
“This isn’t trivial—a decline in opioid-related emergency department visits, even if only for six months, is a welcome public health development,” said lead author Coleman Drake, Ph.D., assistant professor in the University of Pittsburgh’s Department of Health Policy and Management, in a statement. “But that being said, while cannabis liberalization may offer some help in curbing the opioid epidemic, it’s likely not a panacea.”
The new analysis is somewhat limited by the original datasets not distinguishing between the different types of opioids (e.g. heroin, fentanyl, etc.) that were the cause of these visits, nor the different diagnoses being presented (e.g. opioid use disorder, overdose, extreme withdrawal). As a result, it is impossible for the researchers to identify a causal link between this decrease in visits and legalization.
This new analysis also excludes four other states which legalized recreational cannabis during the target timeframe – Alaska, Colorado, Oregon, and Washington – as a result of inconsistently reported Fast Stats data from quarter-to-quarter. As a result, the analysis is missing data from states which have had legalized recreational cannabis for a much longer period of time, and possibly additional long-term trends that might exist.
Still, the discovery of this temporary dip in emergency department visits indicates signs of promise to the researchers.
“We can’t definitively conclude from the data why these laws are associated with a temporary downturn in opioid-related emergency department visits but, based on our findings and previous literature, we suspect that people who use opioids for pain relief are substituting with cannabis, at least temporarily,” Drake said.
“Cannabis can provide pain relief for persons using opioids, but cannabis ultimately is not a treatment for opioid use disorder. Still, this is good news for state policymakers. States can fight the opioid epidemic by expanding access to opioid use disorder treatment and by decreasing opioid use with recreational cannabis laws. These policies aren’t mutually exclusive; rather, they’re both a step in the right direction.”
Cannabis and the US opioid crisis
The United States Department of Health and Human Services officially declared the nation’s opioid crisis a public health emergency in 2017. From 42,000 drug overdose deaths in 2016, the issue has accelerated to now more than 81,000 drug overdose deaths between June 2019 and May 2020 – the highest number of overdose deaths ever recorded in a 12-month period according to the Centers for Disease Control and Prevention (CDC). While the number of drug overdose deaths was already increasing, the CDC believes that these latest numbers also reflect an acceleration directly linked to the advent of the COVID-19 pandemic.
These drug overdose deaths are largely driven by the use of synthetic opioids such as fentanyl, and the contamination of other illicit drugs (primarily cocaine) with illicitly manufactured fentanyl or heroin. As such, addressing problems with opioid misuse and addiction has the potential to save potentially tens of thousands of lives each year.
In light of this opioid crisis, researchers from around the world are now beginning to investigate whether cannabis might hold some benefits for those struggling with opioid misuse disorder.
In one recent study from scientists in Vancouver, it was discovered that people who inject opioids are significantly less likely to overdose if they are also using cannabis to treat an underlying pain condition. Those who used cannabis in the study were also less likely to report daily heroin use. In most cases, this opioid use was never completely substituted by cannabis use. However, the researchers behind the study believe that these results indicate that improving access to legal and safe cannabis could lead to a meaningful reduction in the overdose risk associated with opioid use.
Notably, it has also been observed that counties in the US with higher numbers of legal cannabis dispensaries tend to record lower levels of opioid-related overdose deaths relative to other areas – though the nature of this study meant it was unable to determine cause and effect.