The impact of cannabis access laws on opioid prescribing

Measuring the Impact of Medical Cannabis Law Adoption on Employer-Sponsored Health Insurance Costs: A Difference-in-Difference Analysis, 2003-2022

INTRODUCTION

Recent studies suggest that medical cannabis laws may contribute to a relative reduction in health insurance costs within the individual health insurance markets at the state level. We investigated the effects of adopting a medical cannabis law on the cost of employer-sponsored health insurance in the United States.

METHODS

We analyzed state-level data from the Medical Expenditure Panel Survey-Insurance Component (MEPS-IC) Private Sector spanning from 2003 to 2022. The outcomes included log-transformed average total premium costs per employee for single, employee-plus-one, and family coverage plans. We utilized the Sun and Abraham (J Econometr 225(2):175-199, 2021) difference-in-difference (DiD) method, looking at the overall DiD and event-study DiD. Models were adjusted for various state-level demographics and dichotomous policy variables, including whether a state later adopted recreational cannabis, as well as time and unit fixed effects and population weights.

RESULTS

For states that adopted a medical cannabis law, there was a significant decrease in the log average total premium per employee for single (-0.034, standard error [SE] 0.009 (-$238)) and employee-plus-one (-0.025, SE 0.009 (-$348)) coverage plans per year considering the first 10 years of policy change compared with states without such laws. Looking at the last 5 years of policy change, we saw increases in effect size and statistical significance. In-time placebo testing suggested model robustness. Under a hypothetical scenario where all 50 states adopted medical cannabis in 2022, we estimated that employers and employees could collectively save billions on healthcare coverage, potentially reducing healthcare expenditure's contribution to GDP by 0.65% in 2022.

CONCLUSION

Adoption of a medical cannabis law may contribute to decreases in healthcare costs. This phenomenon is likely a secondary effect and suggests positive externalities outside of medical cannabis patients.

Medical Marijuana Legalization in Oklahoma: Effects on Neonatal Exposure to Opiates

OBJECTIVE

The U.S. opioid epidemic has been characterized by increases in opioid misuse, overdose deaths, and neonatal opioid withdrawal syndrome. Research suggests that marijuana legalization has contributed to decreased use of opiates, although many studies had methodological weaknesses and failed to address the pregnant population. Implementation of medical cannabis laws has the potential to reduce maternal opioid use and, therefore, neonatal exposure to the drugs. This study aimed to examine the association between Oklahoma's implementation of state medical marijuana laws and the neonatal exposure to opioids.

STUDY DESIGN

Electronic medical records at two sites (Oklahoma City and Lawton) were searched for results of cord, urine, and meconium screens to detect amphetamines, barbiturates, benzodiazepines, cocaine, ethanol, opiates, phencyclidine, and tetrahydrocannabinol (THC). Two study periods were compared: 19 months before Oklahoma's medical marijuana law took effect and 19 months after legalization began.

RESULTS

A total of 16,804 babies were born alive at the two sites during the study period. The rate of positive THC tests per 1,000 liveborn infants significantly increased from 16.2 per 1,000 during the prelaw period to 22.2 per 1,000 during the postlaw period (p = 0.004). Neonatal opioid exposure incidence showed a nonsignificant decrease from 7.6 positive tests per 1,000 liveborn infants to 6.8 per 1,000 from prelaw to postlaw period (p = 0.542). The number of positive tests for THC and concomitant use of opioids doubled from the prelaw period (n = 4) to postlaw (n = 9), but there were too few cases for statistical significance. Infants at the more rural site had significantly higher rates for amphetamines, benzodiazepines, and THC, with a trend toward higher rates for opiates.

CONCLUSION

Marijuana legalization was related to significant increases in positive test rates for THC, but no significant change/association was noted for neonatal exposure to opioids.

KEY POINTS

· Prior studies have not examined neonatal exposure to opioids following marijuana legalization.. · Oklahoma's new law led to higher neonatal marijuana exposure.. · Legalization of medical marijuana did not change Oklahoma's neonatal opioid positivity rate..

United States marijuana legalization and opioid mortality trends before and during the first year of the COVID-19 pandemic

BACKGROUND

To determine if marijuana legalization was associated with reduced opioid mortality.

STUDY DESIGN

The United States (US) opioid mortality trend during the 2010-2019 decade was compared in states and District of Columbia (jurisdictions) that had implemented marijuana legalization with states that had not. Acceleration of opioid mortality during 2020, the first year of the coronavirus disease 2019 (COVID-19) pandemic, was also compared in recreational and medicinal-only legalizing jurisdictions.

METHODS

Joinpoint methodology was applied to the Centers for Disease Control and Prevention WONDER data. Trends in legalizing jurisdictions were cumulative aggregates.

RESULTS

The overall opioid and fentanyl death rates and the percentage of opioid deaths due to fentanyl increased more during 2010-2019 in jurisdictions that legalized marijuana than in those that did not (pairwise comparison p = 0.007, 0.05, and 0.006, respectively). By 2019, the all-opioid and fentanyl death rates were 44 and 50 percent greater in the legalizing than in the nonlegalizing jurisdictions, respectively. When the COVID-19 pandemic hit in 2020, jurisdictions that implemented recreational marijuana legalization before 2019 had significantly greater increases in both overall opioid and fentanyl death rates than jurisdictions with medicinal-only legalization. For all-opioids, the mean (95 percent confidence interval) 2019-to-2020 increases were 46.5 percent (36.6, 56.3 percent) and 29.1 percent (20.2, 37.9 percent), respectively (p = 0.02). For fentanyl, they were 115.6 percent (80.2, 151.6 percent) and 55.4 percent (31.6, 79.2 percent), respectively (p = 0.01).

CONCLUSIONS

During the past decade, marijuana legalization in the US was associated at the jurisdiction level with a greater acceleration in opioid death rate. An even greater increase in opioid mortality occurred in recreational-legalizing jurisdictions with the onset of the COVID-19 pandemic. Marijuana legalization is correlated with worsening of the US opioid epidemic.

Recreational and Medical Cannabis Legalization and Opioid Prescriptions and Mortality

Importance

While some have argued that cannabis legalization has helped to reduce opioid-related morbidity and mortality in the US, evidence has been mixed. Moreover, existing studies did not account for biases that could arise when policy effects vary over time or across states or when multiple policies are assessed at the same time, as in the case of recreational and medical cannabis legalization.

Objective

To quantify changes in opioid prescriptions and opioid overdose deaths associated with recreational and medical cannabis legalization in the US.

Design, Setting, and Participants

This quasiexperimental, generalized difference-in-differences analysis used annual state-level data between January 2006 and December 2020 to compare states that legalized recreational or medical cannabis vs those that did not.

Intervention

Recreational and medical cannabis law implementation (proxied by recreational and medical cannabis dispensary openings) between 2006 and 2020 across US states.

Main Outcomes and Measures

Opioid prescription rates per 100 persons and opioid overdose deaths per 100 000 population based on data from the US Centers for Disease Control and Prevention.

Results

Between 2006 and 2020, 13 states legalized recreational cannabis and 23 states legalized medical cannabis. There was no statistically significant association of recreational or medical cannabis laws with opioid prescriptions or overall opioid overdose mortality across the 15-year study period, although the results also suggested a potential reduction in synthetic opioid deaths associated with recreational cannabis laws (4.9 fewer deaths per 100 000 population; 95% CI, -9.49 to -0.30; P = .04). Sensitivity analyses excluding state economic indicators, accounting for additional opioid laws and using alternative ways to code treatment dates yielded substantively similar results, suggesting the absence of statistically significant associations between cannabis laws and the outcomes of interest during the full study period.

Conclusions and Relevance

The results of this study suggest that, after accounting for biases due to possible heterogeneous effects and simultaneous assessment of recreational and medical cannabis legalization, the implementation of recreational or medical cannabis laws was not associated with opioid prescriptions or opioid mortality, with the exception of a possible reduction in synthetic opioid deaths associated with recreational cannabis law implementation.

Health, safety, and socioeconomic impacts of cannabis liberalization laws: An evidence and gap map

Background

Globally, cannabis laws and regulations are rapidly changing. Countries are increasingly permitting access to cannabis under various decriminalization, medicalization, and legalization laws. With strong economic, public health, and social justice incentives driving these domestic cannabis policy reforms, liberalization trends are bound to continue. However, despite a large and growing body of interdisciplinary research addressing the policy-relevant health, safety, and socioeconomic consequences of cannabis liberalization, there is a lack of robust primary and systematic research that comprehensively investigates the consequences of these reforms.

Objectives

This evidence and gap map (EGM) summarizes the empirical evidence on cannabis liberalization policies. Primary objectives were to develop a conceptual framework linking cannabis liberalization policies to relevant outcomes, descriptively summarize the empirical evidence, and identify areas of evidence concentration and gaps.

Search Methods

We comprehensively searched for eligible English-language empirical studies published across 23 academic databases and 11 gray literature sources through August 2020. Additions to the pool of potentially eligible studies from supplemental sources were made through November 2020.

Selection Criteria

The conceptual framework for this EGM draws upon a legal epidemiological perspective highlighting the causal effects of law and policy on population-level outcomes. Eligible interventions include policies that create or expand access to a legal or decriminalized supply of cannabis: comprehensive medical cannabis laws (MCLs), limited medical cannabidiol laws (CBDLs), recreational cannabis laws (RCLs), industrial hemp laws (IHLs), and decriminalization of cultivations laws (DCLs). Eligible outcomes include intermediate responses (i.e., attitudes/behaviors and markets/environments) and longer-term consequences (health, safety, and socioeconomic outcomes) of these laws.

Data Collection and Analysis

Both dual screening and dual data extraction were performed with third person deconfliction. Primary studies were appraised using the Maryland Scientific Methods Scale and systematic reviews were assessed using AMSTAR 2.

Main Results

The EGM includes 447 studies, comprising 438 primary studies and nine systematic reviews. Most research derives from the United States, with little research from other countries. By far, most cannabis liberalization research focuses on the effects of MCLs and RCLs. Studies targeting other laws-including CBDLs, IHLs, and DCLs-are relatively rare. Of the 113 distinct outcomes we documented, cannabis use was the single most frequently investigated. More than half these outcomes were addressed by three or fewer studies, highlighting substantial evidence gaps in the literature. The systematic evidence base is relatively small, comprising just seven completed reviews on cannabis use (3), opioid-related harms (3), and alcohol-related outcomes (1). Moreover, we have limited confidence in the reviews, as five were appraised as minimal quality and two as low quality.

Authors’ Conclusions

More primary and systematic research is needed to better understand the effects of cannabis liberalization laws on longer-term-and arguably more salient-health, safety, and socioeconomic outcomes. Since most research concerns MCLs and RCLs, there is a critical need for research on the societal impacts of industrial hemp production, medical CBD products, and decriminalized cannabis cultivation. Future research should also prioritize understanding the heterogeneous effects of these laws given differences in specific provisions and implementation across jurisdictions.

Adult Medical Cannabinoid Use and Changes in Prescription Controlled Substance Use

Introduction: Nonopioid-based strategies for managing chronic noncancer pain are needed to help reduce overdose deaths. Although lab studies and population-level data suggest that cannabinoids could provide opioid-sparing effects, among medical cannabis participants they may also impact overdose risk by modifying other controlled substance use such as sedative hypnotics. However, no study has combined observational data at the individual level to empirically address interactions between the use of cannabinoids and prescribed controlled substances. Methods: Electronic health records, including prescription drug monitoring program data, from a large multisite medical cannabis program in New York State were abstracted for all participants with noncancer pain and recently prescribed noncannabinoid controlled substances who completed a new intake visit from April 15, 2018-April 14, 2019 and who remained actively in treatment for >180 days. Participants were partitioned into two samples: those with recent opioid use and those with active opioid use and co-use of sedative hypnotics. A patient-month level analysis assessed total average equivalent milligrams by class of drug (i.e., cannabinoid distinguishing tetrahydrocannabinol [THC] vs. cannabidiol [CBD], opioids, and sedative-hypnotics) received as a time-varying outcome measure across each 30-day "month" period postintake for at least 6 months for all participants. Results: Sample 1 of 285 opioid users were 61.1 years of age (±13.5), 57.5% female, and using an average of 49.7 (±98.5) morphine equivalents daily at intake. Unadjusted analyses found a modest decline in morphine equivalents to 43.9 mg (±94.1 mg) from 49.7 (±98.5) in month 1 (p=0.047) while receiving relatively low doses of THC (2.93 mg/day) and CBD (2.15 mg/day). Sample 2 of 95 opioid and sedative-hypnotic users were 60.9 years of age (±13.1), 63.2% female, and using an average of 86.6 (±136.2) morphine equivalents daily, and an average of 4.3 (±5.6) lorazepam equivalents. Unadjusted analyses did not find significant changes in either morphine equivalents (p=0.81) or lorazepam equivalents (p=0.980), and patients similarly received relatively low doses of THC (2.32 mg/day) and CBD (2.24 mg/day). Conclusions: Findings demonstrated minimal to no change in either opioids or sedative hypnotics over the 6 months of medical cannabis use but may be limited by low retention rates, external generalizability, and an inability to account for nonprescribed substance use.

Medical cannabis laws lower individual market health insurance premiums

BACKGROUND

To evaluate the impact of medical cannabis laws (MCLs) on health insurance premiums. We study whether cannabis legalization significantly impacts aggregate health insurer premiums in the individual market. Increases in utilization could have spillover effects to patients in the form of higher health insurance premiums.

METHODS

We use 2010-2021 state-level U.S. private health insurer financial data from the National Association of Insurance Commissioners. We examined changes to individual market health insurance premiums after the implementation of medical cannabis laws. We employed a robust difference-in-differences estimator that accounted for variation in policy timing to exploit temporal and geographic variation in state-level medical cannabis legalization.

RESULTS

Seven years after the implementation of Medical Cannabis laws, we observe lower health insurer premiums in the individual market. Starting seven years post-MCL implementation, we find a reduction of $-1662.7 (95% confidence interval [CI -2650.1, -605.7]) for states which implemented MCLs compared to the control group, a reduction of -$1541.8 (95% confidence interval [CI 2602.1, -481.4]) in year 8, and a reduction of $-1625.8, (95% confidence interval [CI -2694.2, -557.5]) in year 9. Due to the nature of insurance pooling and community rating, these savings are appreciated by cannabis users and non-users alike in states that have implemented MCLs.

CONCLUSIONS

The implementation of MCLs lowers individual-market health insurance premiums. Health insurance spending, including premiums, comprises between 16% and 34% of household budgets in the United States. As healthcare costs continue to rise, our findings suggest that households that obtain their health insurance on the individual (i.e., not employer sponsored) market in states with MCLs appreciate significantly lower premiums.

Effects of U.S. State Medical Cannabis Laws on Treatment of Chronic Noncancer Pain

BACKGROUND

State medical cannabis laws may lead patients with chronic noncancer pain to substitute cannabis in place of prescription opioid or clinical guideline-concordant nonopioid prescription pain medications or procedures.

OBJECTIVE

To assess effects of state medical cannabis laws on receipt of prescription opioids, nonopioid prescription pain medications, and procedures for chronic noncancer pain.

DESIGN

Using data from 12 states that implemented medical cannabis laws and 17 comparison states, augmented synthetic control analyses estimated laws' effects on receipt of chronic noncancer pain treatment, relative to predicted treatment receipt in the absence of the law.

SETTING

United States, 2010 to 2022.

PARTICIPANTS

583 820 commercially insured adults with chronic noncancer pain.

MEASUREMENTS

Proportion of patients receiving any opioid prescription, nonopioid prescription pain medication, or procedure for chronic noncancer pain; volume of each treatment type; and mean days' supply and mean morphine milligram equivalents per day of prescribed opioids, per patient in a given month.

RESULTS

In a given month during the first 3 years of law implementation, medical cannabis laws led to an average difference of 0.05 percentage points (95% CI, -0.12 to 0.21 percentage points), 0.05 percentage points (CI, -0.13 to 0.23 percentage points), and -0.17 percentage points (CI, -0.42 to 0.08 percentage points) in the proportion of patients receiving any opioid prescription, any nonopioid prescription pain medication, or any chronic pain procedure, respectively, relative to what we predict would have happened in that month had the law not been implemented.

LIMITATIONS

This study used a strong nonexperimental design but relies on untestable assumptions involving parallel counterfactual trends. Statistical power is limited by the finite number of states. Results may not generalize to noncommercially insured populations.

CONCLUSION

This study did not identify important effects of medical cannabis laws on receipt of opioid or nonopioid pain treatment among patients with chronic noncancer pain.

PRIMARY FUNDING SOURCE

National Institute on Drug Abuse.

Recreational cannabis and opioid distribution

Twenty-one U.S. states have passed recreational cannabis laws as of November 2022. Cannabis may be a substitute for prescription opioids in the treatment of chronic pain. Previous studies have assessed recreational cannabis laws' effects on opioid prescriptions financed by specific private or public payers or dispensed to a unique endpoint. Our study adds to the literature in three important ways: by (1) examining these laws' impacts on prescription opioid dispensing across all payers and endpoints, (2) adjusting for important opioid-related policies such as opioid prescribing limits, and (3) modeling opioids separately by type. We implement two-way fixed-effects regressions and leverage variation from eleven U.S. states that adopted a recreational cannabis law (RCL) between 2010 and 2019. We find that RCLs lead to a reduction in codeine dispensed at retail pharmacies. Among prescription opioids, codeine is particularly likely to be used non-medically. Thus, the finding that RCLs appear to reduce codeine dispensing is potentially promising from a public health perspective.

Marijuana legalization and opioid deaths

Many states have legalized marijuana over the last two decades, initially for medical purposes and more recently for recreational consumption. Despite prior research, it remains unclear how these policies are related to rates of opioid-involved overdose deaths, which have trended rapidly upwards over time. We examine this question in two ways. First, we replicate and extend previous investigations to show that the prior empirical results are frequently fragile to the choice of specifications and time periods, and probably provide an overly optimistic assessment of the effects of marijuana legalization on opioid deaths. Second, we present new estimates suggesting that legal medical marijuana, particularly when available through retail dispensaries, is associated with higher opioid mortality. The results for recreational marijuana, while less reliable, also indicate that retail sales may be correlated with greater death rates relative to the counterfactual of no legal cannabis. A likely mechanism for these effects is the emergence of illicit fentanyl, which has increased the riskiness of even small positive effects of cannabis legalization on the consumption of opioids.

Recreational marijuana laws and the misuse of prescription opioids: Evidence from National Survey on Drug Use and Health microdata

Several studies have concluded that legalizing medical marijuana can reduce deaths from opioid overdoses. Drawing on micro data from the National Survey on Drug Use and Health, a survey uniquely suited to assessing patterns of substance use, we examine the relationship between recreational marijuana laws (RMLs) and the misuse of prescription opioids. Using a standard difference-in-differences (DD) regression model, we find that RML adoption reduces the likelihood of frequently misusing prescription opioids such as OxyContin, Percocet, and Vicodin. However, using a two-stage procedure designed to account for staggered treatment and dynamic effects, the DD estimate of relationship between RML adoption and the likelihood of frequently misusing prescription opioids becomes positive. Although event study estimates suggest that RML adoption leads to a decrease in the frequency of prescription opioid abuse, this effect appears to dissipate after only 2 or 3 years.

The clouded debate: A systematic review of comparative longitudinal studies examining the impact of recreational cannabis legalization on key public health outcomes

Background

Ineffective cannabis regulatory frameworks such as prohibition have sparked interest in alternative solutions to reduce individual and societal harms. While it has been suggested that the recreational legalization process has yielded early successes, the relatively recent implementation of the novel policies has provided a modest time frame for a truly thorough establishment and assessment of key population-level indicators. The following systematic review focuses on identifying the downstream public health sequelae of cannabis legalization policies, including parameters such as cannabis consumption rates, hospitalization rates, vehicular accidents and fatalities, criminal activity, and suicidal behaviors, as well as other substance use trends.

Methods

An exhaustive search of the MEDLINE and Google Scholar databases were performed to identify high-quality (1) longitudinal studies, which (2) compared key public health outcomes between regions which had and had not implemented recreational cannabis legalization (RML) policies, (3) using distinct databases and/or time frames. Thirty-two original research articles were retained for review.

Results

Adult past-month cannabis consumption (26+ years) seems to have significantly increased following RML, whereas young adult (18-26 years) and adolescent (12-17 years) populations do not show a significant rise in past-month cannabis use. RML shows preliminary trends in increasing service use (such as hospitalizations, emergency department visits, or poisonings) or vehicular traffic fatalities. Preliminary evidence suggests that RML is related to potential increases in serious/violent crimes, and heterogeneous effects on suicidal behaviors. While the research does not illustrate that RML is linked to changing consumptions patterns of cigarette, stimulant, or opioid use, alcohol use may be on the rise, and opioid prescribing patterns are shown to be significantly correlated with RML.

Conclusion

The current data supports the notion that RML is correlated with altered cannabis consumption in adults, potentially increased criminal activity, and a decline in opioid quantities and prescriptions provided to patients. Future work should address additional knowledge gaps for vulnerable populations, such as individuals with mental health problems or persons consuming cannabis frequently/at higher THC doses. The effects of varying legalization models should also be evaluated for their potentially differing impacts on population-level outcomes.

Association of a Positive Drug Screening for Cannabis With Mortality and Hospital Visits Among Veterans Affairs Enrollees Prescribed Opioids

IMPORTANCE

Cannabis has been proposed as a therapeutic with potential opioid-sparing properties in chronic pain, and its use could theoretically be associated with decreased amounts of opioids used and decreased risk of mortality among individuals prescribed opioids.

OBJECTIVE

To examine the risks associated with cannabis use among adults prescribed opioid analgesic medications.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was conducted among individuals aged 18 years and older who had urine drug screening in 2014 to 2019 and received any prescription opioid in the prior 90 days or long-term opioid therapy (LTOT), defined as more than 84 days of the prior 90 days, through the Veterans Affairs health system. Data were analyzed from November 2020 through March 2022.

EXPOSURES

Biologically verified cannabis use from a urine drug screen.

MAIN OUTCOMES AND MEASURES

The main outcomes were 90-day and 180-day all-cause mortality. A composite outcome of all-cause emergency department (ED) visits, all-cause hospitalization, or all-cause mortality was a secondary outcome. Weights based on the propensity score were used to reduce confounding, and hazard ratios [HRs] were estimated using Cox proportional hazards regression models. Analyses were conducted among the overall sample of patients who received any prescription opioid in the prior 90 days and were repeated among those who received LTOT. Analyses were repeated among adults aged 65 years and older.

RESULTS

Among 297 620 adults treated with opioids, 30 514 individuals used cannabis (mean [SE] age, 57.8 [10.5] years; 28 784 [94.3%] men) and 267 106 adults did not (mean [SE] age, 62.3 [12.3] years; P < .001; 247 684 [92.7%] men; P < .001). Among all patients, cannabis use was not associated with increased all-cause mortality at 90 days (HR, 1.07; 95% CI, 0.92-1.22) or 180 days (HR, 1.00; 95% CI, 0.90-1.10) but was associated with an increased hazard of the composite outcome at 90 days (HR, 1.05; 95% CI, 1.01-1.07) and 180 days (HR, 1.04; 95% CI, 1.01-1.06). Among 181 096 adults receiving LTOT, cannabis use was not associated with increased risk of all-cause mortality at 90 or 180 days but was associated with an increased hazard of the composite outcome at 90 days (HR, 1.05; 95% CI, 1.02-1.09) and 180 days (HR, 1.05; 95% CI, 1.02-1.09). Among 77 791 adults aged 65 years and older receiving LTOT, cannabis use was associated with increased 90-day mortality (HR, 1.55; 95% CI, 1.17-2.04).

CONCLUSIONS AND RELEVANCE

This study found that cannabis use among adults receiving opioid analgesic medications was not associated with any change in mortality risk but was associated with a small increased risk of adverse outcomes and that short-term risks were higher among older adults receiving LTOT.

Association of Recreational Cannabis Legalization With Alcohol Use Among Adults in the US, 2010 to 2019

Importance

In the US, cannabis use has nearly doubled during the past decade, in part because states have implemented recreational cannabis laws (RCLs). However, it is unclear how legalization of adult-use cannabis may affect alcohol consumption.

Objective

To estimate the association between implementation of state RCLs and alcohol use among adults in the US.

Design, Settings, and Participants

This was a cross-sectional study of 4.2 million individuals who responded to the Behavioral Risk Factor Surveillance System in 2010 to 2019. A difference-in-differences approach with demographic and policy controls was used to estimate the association between RCLs and alcohol use, overall and by age, sex, race and ethnicity, and educational level. Data analyses were performed from June 2021 to March 2022.

Exposures

States with RCLs, as reported by the RAND-University of Southern California Schaeffer Opioid Policy Tools and Information Center.

Main Outcomes and Measures

Past-month alcohol use, binge drinking, and heavy drinking.

Results

Of 4.2 million respondents (median age group, 50-64 years; 2 476 984 [51.7%] women; 2 978 467 [58.3%] non-Hispanic White individuals) in 2010 through 2019, 321 921 individuals lived in state-years with recreational cannabis laws. Recreational cannabis laws were associated with a 0.9 percentage point (95% CI, 0.1-1.7; P = .02) increase in any alcohol drinking but were not significantly associated with binge or heavy drinking. Increases in any alcohol use were primarily among younger adults (18-24 years) and men, as well as among non-Hispanic White respondents and those without any college education. A 1.4 percentage point increase (95% CI, 0.4-2.3; P = .006) in binge drinking was also observed among men, although this association diminished over time.

Conclusions and Relevance

This cross-sectional study and difference-in-differences analysis found that recreational cannabis laws in the US may be associated with increased alcohol use, primarily among younger adults and men.

Medical cannabis and automobile accidents: Evidence from auto insurance

While many states have legalized medical cannabis, many unintended consequences remain under-studied. We focus on one potential detriment-the effect of cannabis legalization on automobile safety. We examine this relationship through auto insurance premiums. Employing a modern difference-in-differences framework and zip code-level premium data from 2014 to 2019, we find that premiums declined, on average, by $22 per year following medical cannabis legalization. The effect is more substantial in areas near a dispensary and in areas with a higher prevalence of drunk driving before legalization. We estimate that existing legalization has reduced health expenditures related to auto accidents by almost $820 million per year with the potential for a further $350 million reduction if legalized nationally.

Trends in Alcohol, Cigarette, E-Cigarette, and Nonprescribed Pain Reliever Use Among Young Adults in Washington State After Legalization of Nonmedical Cannabis

PURPOSE

Liberalization of cannabis laws may be accompanied by changes in the use of substances other than cannabis and changes in associations of cannabis use with other types of substance use. This study assessed (1) trends in alcohol, nicotine, and nonprescribed pain reliever use and (2) changes in associations of cannabis use with these other substances among young adults in Washington State after nonmedical cannabis legalization.

METHODS

Regression models stratified by age (18-20 vs. 21-25) were used to analyze six annual waves of cross-sectional survey data from a statewide sample from 2014 through 2019 (N = 12,694).

RESULTS

Prevalence of past-month alcohol use, heavy episodic drinking (HED), and cigarette use and prevalence of past-year pain reliever misuse decreased, while the prevalence of past-month e-cigarette use increased since 2016 (the first year assessed). Across years and age groups, the prevalence of substance use other than cannabis was higher among occasional and frequent cannabis users compared to cannabis nonusers. However, associations between both occasional (1-19 days in the prior month) and frequent (20+ days) cannabis use and pain reliever misuse and between frequent cannabis use and HED weakened over time among individuals ages 21-25.

DISCUSSION

Contrary to concerns about spillover effects, implementation of legalized nonmedical cannabis coincided with decreases in alcohol and cigarette use and pain reliever misuse. The weakening association of cannabis use with the use of other substances among individuals ages 21-25 requires further research but may suggest increased importance of cannabis-specific prevention and treatment efforts.

Societal Costs and Outcomes of Medical and Recreational Marijuana Policies in the United States: A Systematic Review

Significant support exists in the United States for legalization of marijuana/cannabis. As of 2021, 36 states and four territories approved the legalization of medical cannabis via medical marijuana laws (MMLs), and 15 states and District of Columbia (DC) have adopted recreational marijuana laws (RMLs). We performed structured and systematic searches of articles published from 2010 through September 2021. We assess the literature pertaining to adolescent marijuana use; opioid use and opioid-related outcomes; alcohol use; tobacco use; illicit and other drug use; marijuana growing and cultivation; employment, earnings, and other workplace outcomes; academic achievement and performance; criminal activity; perceived harmfulness; traffic and road safety; and suicide and sexual activity. Overall, 113 articles satisfied our inclusion criteria. Except for opioids, studies on use of other substances (illicit drugs, tobacco, and alcohol) were inconclusive. MMLs and RMLs do not generate negative outcomes in the labor market, lead to greater criminal activity, or reduce traffic and road safety.

Association between fatal opioid overdose and state medical cannabis laws in US national survey data, 2000-2011

AIMS

Most information on the relationship between medical cannabis laws (MCL) and the risk for opioid overdose fatality has been based on studies with ecological designs. To contribute additional information, we used a novel case-control design and individual-level data from national surveys to assess whether state medical cannabis laws were associated with reduced risk of fatal opioid overdose between 2000-2011.

METHODS

Data from participants surveyed in the National Health Interview Survey (NHIS) between 1986-2011 were included. For those sampled between 1986-2009, detailed mortality follow-up data were available from the National Death Index up to 12/31/2011. Opioid overdose decedents (n = 791) were classified as cases. Between 2000-2011, all cases arising in a given year were matched to adult controls who were surveyed the same year and eligible for mortality follow-up (n = 723,920). The distribution of exposure to state MCL was contrasted between cases and controls, providing an approximation of the rate ratio of fatal opioid overdose associated with MCLs. Due to a NHIS sample redesign, we stratified analysis using timeframes before and after 2005.

RESULTS

Overall, compared to controls, cases were more likely to be male, middle-aged, non-Hispanic White, separated/divorced; less educated, and have a family income below the poverty threshold. No overall association between state MCLs and the rate of opioid overdose was observed between 2000-2005 (aOR = 1.22, 95% CI: 0.83-1.79) or between 2006-2011 (aOR = 0.87, 95% CI: 0.60-1.25). No significant difference between sampling timeframes was observed (ratio of aOR's = 0.71, 95% CI: 0.49-1.01).

CONCLUSIONS

We found no overall protective relationship between state MCLs and opioid overdose. Future research with more recent mortality data and more refined cannabis policy classifications would be useful. The importance of the study is two-fold. First, the findings provide an additional source of information countering claims of a protective effect of MCLs on opioid overdoses, suggesting that other solutions to the opioid overdose crisis are needed. Second, the study offers a potentially useful design to answer important population-level public health questions.

The effect of medical cannabis laws on pharmaceutical marketing to physicians

Although cannabis is federally prohibited, a majority of U.S. states have implemented medical cannabis laws (MCLs). As more individuals consider the drug for medical treatment, they potentially substitute away from prescription drugs. Therefore, an MCL signals competitor entry. This paper exploits geographic and temporal variation in MCLs to examine the strategic response in direct-to-physician marketing by pharmaceutical firms as cannabis enters the market. Using office detailing records from 2014-2018 aggregated to the county level, we find weak evidence of a relatively small and delayed response in substitute prescription drug- and opioid-related detailing. While these effects on detailing dollars are more pronounced among smaller pharmaceutical firms, the magnitudes are economically small and likely muted at aggregate levels by the small percent of doctors that actively recommend cannabis for medical treatment.

The Endocannabinoid System: A Potential Target for the Treatment of Various Diseases

The Endocannabinoid System (ECS) is primarily responsible for maintaining homeostasis, a balance in internal environment (temperature, mood, and immune system) and energy input and output in living, biological systems. In addition to regulating physiological processes, the ECS directly influences anxiety, feeding behaviour/appetite, emotional behaviour, depression, nervous functions, neurogenesis, neuroprotection, reward, cognition, learning, memory, pain sensation, fertility, pregnancy, and pre-and post-natal development. The ECS is also involved in several pathophysiological diseases such as cancer, cardiovascular diseases, and neurodegenerative diseases. In recent years, genetic and pharmacological manipulation of the ECS has gained significant interest in medicine, research, and drug discovery and development. The distribution of the components of the ECS system throughout the body, and the physiological/pathophysiological role of the ECS-signalling pathways in many diseases, all offer promising opportunities for the development of novel cannabinergic, cannabimimetic, and cannabinoid-based therapeutic drugs that genetically or pharmacologically modulate the ECS via inhibition of metabolic pathways and/or agonism or antagonism of the receptors of the ECS. This modulation results in the differential expression/activity of the components of the ECS that may be beneficial in the treatment of a number of diseases. This manuscript in-depth review will investigate the potential of the ECS in the treatment of various diseases, and to put forth the suggestion that many of these secondary metabolites of Cannabis sativa L. (hereafter referred to as "C. sativa L." or "medical cannabis"), may also have potential as lead compounds in the development of cannabinoid-based pharmaceuticals for a variety of diseases.

Treating pain related to Ehlers-Danlos syndrome with medical cannabis

We present the case of an 18-year-old woman who suffered from complications of Ehlers-Danlos syndrome (EDS). Her pain was poorly controlled despite being on a myriad of analgesic medications at the time. On initiating cannabinoid-based treatment, her pain was drastically reduced, immediately enhancing the patient's quality of life. As the patient continued to self-administer, she was able to eliminate her opioid requirement. Considering the recent legalisation, we underline the need for physicians to be educated regarding the use of cannabinoids. In this case, specifically for chronic pain stemming from hypermobile EDS. Furthermore, we review the various impediments preventing ease of access to this potentially beneficial treatment.

Opioid Prescribing in Canada following the Legalization of Cannabis: A Clinical and Economic Time-Series Analysis

PURPOSE

On 17 October 2018 recreational cannabis became legal in Canada, thereby increasing access and reducing the stigma associated with its use for pain management. This study assessed total opioid prescribing volumes and expenditures prior to and following cannabis legalization.

METHODS

National monthly claims data for public and private payers were obtained from January 2016 to June 2019. The drugs evaluated consisted of morphine, codeine, fentanyl, hydrocodone, hydromorphone, meperidine, oxycodone, tramadol, and the non-opioids gabapentin and pregabalin. All opioid volumes were converted to a mean morphine equivalent dose (MED)/claim, which is analogous to a prescription from a physician. Gabapentin and pregabalin claims data were analyzed separately from the opioids. Time-series regression modelling was undertaken with dependent variables being mean MED/claim and total monthly spending. The slopes of the time-series curves were then compared pre- versus post-cannabis legalization.

RESULTS

Over the 42-month period, the mean MED/claim declined within public plans (p < 0.001). However, the decline in MED/claim was 5.4 times greater in the period following legalization (22.3 mg/claim post vs. 4.1 mg/claim pre). Total monthly opioid spending was also reduced to a greater extent post legalization ($Can267,000 vs. $Can95,000 per month). The findings were similar for private drug plans; however, the absolute drop in opioid use was more pronounced (76.9 vs. 30.8 mg/claim). Over the 42-month period, gabapentin and pregabalin usage also declined.

CONCLUSIONS

Our findings support the hypothesis that easier access to cannabis for pain may reduce opioid use for both public and private drug plans.

Opioid use in medical cannabis authorization adult patients from 2013 to 2018: Alberta, Canada

BACKGROUND

The opioid overdose epidemic in Canada and the United States has become a public health crisis - with exponential increases in opioid-related morbidity and mortality. Recently, there has been an increasing body of evidence focusing on the opioid-sparing effects of medical cannabis use (reduction of opioid use and reliance), and medical cannabis as a potential alternative treatment for chronic pain. The objective of this study is to assess the effect of medical cannabis authorization on opioid use (oral morphine equivalent; OME) between 2013 and 2018 in Alberta, Canada.

METHODS

All adult patients defined as chronic opioid users who were authorized medical cannabis by their health care provider in Alberta, Canada from 2013 to 2018 were propensity score matched to non-authorized chronic opioid using controls. A total of 5373 medical cannabis patients were matched to controls, who were all chronic opioid users. The change in the weekly average OME of opioid drugs for medical cannabis patients relative to controls was measured. Interrupted time series (ITS) analyses was used to assess the trend change in OME during the 26 weeks (6 months) before and 52 weeks (1 year) after the authorization of medical cannabis among adult chronic opioid users.

RESULTS

Average age was 52 years and 54% were female. Patients on low dose opioids (< 50 OME) had an increase in their weekly OME per week (absolute increase of 112.1 OME, 95% CI: 104.1 to 120.3); whereas higher dose users (OME > 100), showed a significant decrease over 6 months (- 435.5, 95% CI: - 596.8 to - 274.2) compared to controls.

CONCLUSIONS

This short-term study found that medical cannabis authorization showed intermediate effects on opioid use, which was dependent on initial opioid use. Greater observations of changes in OME appear to be in those patients who were on a high dosage of opioids (OME > 100); however, continued surveillance of patients utilizing both opioids and medical cannabis is warranted by clinicians to understand the long-term potential benefits and any harms of ongoing use.

The impact of medical and recreational marijuana laws on opioid prescribing in employer-sponsored health insurance

Using data from Truven Health MarketScan Commercial Claims and Encounters Database between 2009 and 2015, we studied the effects of medical and recreational marijuana laws on opioid prescribing in employer-sponsored health insurance. We used a differences-in-differences (DD) approach and found that the implementation of medical marijuana laws (MMLs) and recreational marijuana laws (RMLs) reduced morphine milligram equivalents per enrollee by 7% and 13%, respectively. The reduction associated with MMLs was predominately in people aged 55-64, whereas the reduction associated with RMLs was largely in people aged 35-44 and aged 45-54. Our findings suggest that both MMLs and RMLs have the potential to reduce opioid prescribing in the privately insured population, especially for the middle-aged population.

Biopsychosocial factors and health outcomes associated with cannabis, opioids and benzodiazepines use among older veterans

Background: Older Veterans may experience injuries that result in chronic pain and mental health conditions. Given the increasing availability of medical cannabis, it is important to examine if it serves as a viable or undesirable form of care relative to existing approaches.Objectives: We compared cannabis, prescription opioids, and benzodiazepines use between older Veteran and non-Veterans, and identified outcomes of cannabis use among Veterans. Because of the physical and mental conditions experienced by older Veterans we expected Veterans to report higher use of opioids and benzodiazepines compared to non-Veterans.Methods: We collected surveys from individuals aged 60 and older enrolled in the Illinois Medical Cannabis Patient Program and conducted logistic regression to identify factors associated with cannabis, opioids and benzodiazepines use between Veterans (N = 514, 90.2% male) and Non-Veterans (N = 2758, 41.1% male) across biopsychosocial factors.Results: Both groups reported similar levels of pain, quality of life, social satisfaction, and sleep quality. Veterans were more likely to use cannabis for mental health conditions (p = <.001) while they reported lower use for pain-related conditions (p = <.001) than non-Veterans. Veterans were less likely to use opioids (p = .013) and benzodiazepines (p < .01) compared to non-Veterans. Veterans also reported desirable health outcomes of cannabis use for pain, sleep quality, health conditions, and quality of life.Conclusions: Our work provides insights for clinicians and policy makers to consider whether cannabis can be a viable option to reduce or replace opioid and benzodiazepine use by older Veterans with chronic physical and mental health conditions.

Demand curve analysis of marijuana use among persons living with HIV

BACKGROUND

Despite medicalization and legalization of marijuana use, factors influencing demand for marijuana among persons living with HIV (PLWH) are incompletely understood. This knowledge gap undermines effective clinical management and policies. This study used demand curve simulation methods to address these issues.

METHODS

Marijuana-using PLWH (N = 119) completed experimental tasks to simulate amount of marijuana purchasing/use across different costs (money or time), and likelihood of reselling marijuana or marijuana therapeutic-use registration card in relation to profits. Additional simulations assessed purchasing of marijuana relative to other drug and non-drug goods.

RESULTS

Simulated marijuana use decreased as money and time costs increased. Consumption was greater for participants with more severe Cannabis Use Disorder (CUD) and anxiety, intermediate pain levels, and past 90-day opioid use. Whereas few participants chose to sell their registration card, marijuana resale (diversion) steeply increased with profit. Likelihood of seeking marijuana therapeutic-use certification decreased in relation to registration card money cost, having to visit more physicians to get a signature, and delay to receiving the card, and increased with duration of certification. Participants who reported recent opioid use were more likely to seek certification. Consumption of several commodities assessed was independent of marijuana.

CONCLUSIONS

Simulated marijuana use was related to participants' clinical profile (CUD, anxiety and pain symptoms, recent opioid use), and unrelated to purchasing other goods. Likelihood of seeking marijuana therapeutic-use registration was affected by several types of costs and recent opioid use. Participants were unlikely to divert registration cards. We discuss clinical and policy implications of these findings.

Choosing Between a Rock and the Pot Place

In the evolving field of medicinal cannabis, there are many questions and concerns broached by patients to which health care providers cannot respond with anything other than anecdotal evidence. Many simple knowledge gaps persist due to barriers to high-quality research at the institutional and state levels: barriers that, in turn, stem from the federal designation of cannabis as an illegal substance. These perspectives of a California-based pain physician on the approach to the cannabis-curious pain patient highlight the necessity of a change in the classification of cannabis to streamline research as to the benefits and risks of this now ubiquitous substance.

Marijuana legalization and disability claiming

We study the effect of recent legalization of recreational marijuana use laws (RMLs) in the United States on new applications and allowances for Social Security Disability Insurance and Supplemental Security Income over the period 2001-2019. We combine administrative caseload data from the Social Security Administration with state policy changes using two-way fixed-effects methods. We find that RML adoption increases applications for both benefits. However, there is no change in allowances post-RML. We provide suggestive evidence that the observed changes in applications post-RML are driven by increases in marijuana misuse and selective migration, and decreases in unemployment.

Do-It-Yourself medicine? The impact of light cannabis liberalization on prescription drugs

Governments worldwide are increasingly concerned about the booming use of CBD (cannabidiol) products. However, we know little about the impact of their liberalization. We study a unique case of unintended liberalization of a CBD-based product (light cannabis) that occurred in Italy in 2017. Using unique and high-frequency data on prescription drug sales and by exploiting the staggered local availability of the new product in each Italian province, we document a significant substitution effect between light cannabis and anxiolytics, sedatives, opioids, anti-depressants and anti-psychotics. Results are informative for regulators and suggest that bans on light cannabis use would disregard the needs of patients to seek effective reliefs of their symptoms.

E-cigarette or vaping product use-associated lung injury (EVALI) features and recognition in the emergency department

Since August 2019, the pulmonary disease termed e-cigarette or vaping product-use associated lung injury (EVALI), has resulted in 2758 hospitalizations and 64 deaths in the United States. EVALI is considered in patients who have vaped or dabbed within 90 days of symptom onset, and have abnormal lung imaging in the absence of any pulmonary infection. The majority of EVALI patients are otherwise healthy adolescents and young adults. The leading etiology of EVALI is contamination of delta-9-tetrahydrocannabinoid (THC) e-liquids with vitamin E acetate. Although the exact pathophysiology of vitamin E acetate-induced lung injury is unknown, vitamin E acetate may lead to pulmonary lipid accumulation and/or interfere with surfactant functioning. EVALI symptoms are vague but consist of a constellation of constitutional, pulmonary, and gastrointestinal symptoms. Patients often present multiple times to healthcare facilities as their clinical condition worsens with a considerable mortality risk. The diagnosis of EVALI hinges on obtaining history leading to the recognition of vaping/dabbing. Physicians need to be persistent, but nonjudgmental, in obtaining vaping histories, especially in THC-prohibited states. Radiographical findings of nonspecific bilateral ground-glass infiltrates are best detected on computed tomography. Management for EVALI requires a multidisciplinary approach focused on supportive respiratory care and ruling-out infectious causes. Corticosteroids may be of benefit. Most patients who are hypoxic, have comorbidities, or lack appropriate follow-up within 24-48 hours should be admitted for monitoring. Patients may benefit from substance abuse counseling and should be instructed to avoid vaping. As the outbreak continues, cases should be reported to local health departments and poison control centers.

So near yet so far: why won't the UK prescribe medical cannabis?

Although cannabis-based products for medicinal use are now legal in the UK, it is still challenging for patients to gain access, and only very few National Health Service prescriptions have been written to date. This paper attempts to make sense of why the UK lags behind so many other countries which also have legalised medical cannabis. From consulting with parents and patients, prescribers, pharmacists and decision-makers it seems that there are a series of distinct barriers to prescribing that need to be overcome in order to improve patient access to medical cannabis in the UK. These include concerns about the perceived lack of scientific evidence. To alleviate these concerns, we highlight the importance of patient-centred approaches including patient-reported outcomes, pharmacoepidemiology and n=1 trials, which can contribute to the development of the evidence base for medical cannabis. We hope that this paper will help policymakers and prescribers understand the challenges to prescribing and so help them develop approaches to overcome the current situation which is detrimental to patients.

Impact of a physician-targeted letter on opioid prescribing

We study the effect of a physician-targeted nudge letter on opioid prescribing. In May 2017, the Social Insurance Institution of Finland sent a personal information letter to all physicians who had issued a prescription containing at least 100 tablets of paracetamol-codeine combination to a new patient. The aim of the letter was to draw the physicians' attention to their prescribing practices and to decrease the size of the first codeine prescription. Using individual level register data and a difference-in-differences strategy, we estimate that the letter decreased the average number of tablets purchased by new patients by 12.5 percent and the probability of a first purchase being at least 100 tablets by six percentage points. We also find that these effects were larger among consistent high prescribers. However, we do not find similar effects on other mild or strong opioids.

Prescription Opioid Distribution after the Legalization of Recreational Marijuana in Colorado

There have been dynamic changes in prescription opioid use in the US but the state level policy factors contributing to these are incompletely understood. We examined the association between the legalization of recreational marijuana and prescription opioid distribution in Colorado. Utah and Maryland, two states that had not legalized recreational marijuana, were selected for comparison. Prescription data reported to the Drug Enforcement Administration for nine opioids used for pain (e.g., fentanyl, morphine, hydrocodone, hydromorphone, oxycodone, oxymorphone) and two primarily for opioid use disorder (OUD, methadone and buprenorphine) from 2007 to 2017 were evaluated. Analysis of the interval pre (2007-2012) versus post (2013-2017) marijuana legalization revealed statistically significant decreases for Colorado (P < 0.05) and Maryland (P < 0.01), but not Utah, for pain medications. There was a larger reduction from 2012 to 2017 in Colorado (-31.5%) than the other states (-14.2% to -23.5%). Colorado had a significantly greater decrease in codeine and oxymorphone than the comparison states. The most prevalent opioids by morphine equivalents were oxycodone and methadone. Due to rapid and pronounced changes in prescription opioid distribution over the past decade, additional study with more states is needed to determine whether cannabis policy was associated with reductions in opioids used for chronic pain.