Impact of Recreational Cannabis Legalization on Opioid Prescribing and Opioid-Related Hospital Visits in Colorado: an Observational Study.

BACKGROUND: Cannabis may be a substitute for opioids but previous studies have found conflicting results when using data from more recent years. Most studies have examined the relationship using state-level data, missing important sub-state variation in cannabis access. OBJECTIVE: To examine cannabis legalization on opioid use at the county level, using Colorado as a case study. Colorado allowed recreational cannabis stores in January 2014. Local communities could decide whether to allow dispensaries, creating variation in the level of exposure to cannabis outlets. DESIGN: Observational, quasi-experimental design exploiting county-level variation in allowance of recreational dispensaries. SUBJECTS: Colorado residents MEASURES: We use licensing information from the Colorado Department of Revenue to measure county-level exposure to cannabis outlets. We use the state's Prescription Drug Monitoring Program (2013-2018) to construct opioid-prescribing measures of number of 30-day fills and total morphine equivalents, both per county resident per quarter. We construct outcomes of opioid-related inpatient visits (2011-2018) and emergency department visits (2013-2018) with Colorado Hospital Association data. We use linear models in a differences-in-differences framework that accounts for the varying exposure to medical and recreational cannabis over time. There are 2048 county-quarter observations used in the analysis. RESULTS: We find mixed evidence of cannabis exposure on opioid-related outcomes at the county level. We find increasing exposure to recreational cannabis is associated with a statistically significant decrease in number of 30-day fills (coefficient: -117.6, p-value<0.01) and inpatient visits (coefficient: -0.8, p-value: 0.03), but not total MME nor ED visits. Counties with no medical exposure prior to recreational legalization experience greater reductions in the number of 30-day fills and MME than counties with prior medical exposure (p=0.02 for both). CONCLUSIONS: Our mixed findings suggest that further increases in cannabis beyond medical access may not always reduce opioid prescribing or opioid-related hospital visits at a population level.

Do Financial Incentives Affect Utilization for Chronically Ill Medicare Beneficiaries?

OBJECTIVE: The objective of this study was to examine the price sensitivity for provider visits among Medicare Advantage beneficiaries. DATA SOURCES: We used Medicare Advantage encounter data from 2014 to 2017 accessed as part of an evaluation for the Center for Medicare & Medicaid Innovation. STUDY DESIGN: We analyzed the effect of cost-sharing on the utilization of 2 outcome categories: number of visits (specialist and primary care) and the probability of any visit (specialist and primary care). Our main independent variable was the size of the copayment for the visit, which we regressed on the outcomes with several beneficiary-level and plan-level control variables. DATA COLLECTION/EXTRACTION METHODS: We included beneficiaries with at least 1 of 4 specific chronic conditions and matched comparison beneficiaries. We did not require beneficiaries to be continuously enrolled from 2014 to 2017, but we required a full year of data for each year they were observed. This resulted in 371,140 beneficiary-year observations. PRINCIPAL FINDINGS: Copay reductions were associated with increases in utilization, although the changes were small, with elasticities <-0.2. We also found evidence of substitution effects between primary care provider (PCP) and specialist visits, particularly cardiology and endocrinology. When PCP copays declined, visits to these specialists also declined. CONCLUSIONS: We find that individuals with chronic conditions respond to changes in copays, although these responses are small. Reductions in PCP copays lead to reduced use of some specialists, suggesting that lowering PCP copays could be an effective way to reduce the use of specialist care, a desirable outcome if specialists are overused.

Cannabis legalization and cannabis-involved pregnancy hospitalizations in Colorado.

The primary objective of this study was to evaluate the association between presence of recreational cannabis dispensaries and prevalence of cannabis-involved pregnancy hospitalizations in Colorado. This was a retrospective cohort study of pregnancy-related hospitalizations co-coded with cannabis diagnosis codes in the Colorado Hospital Association from January 1, 2011, through December 31, 2018 (recreational cannabis began January 1, 2014). Our primary outcome was cannabis-involved pregnancy hospitalizations per 10 k live births per county. The primary exposure measure was county variation in the number of recreational dispensaries. We controlled for counties' baseline exposure to medical cannabis dispensaries and used Poisson regression to evaluate the association between exposure to recreational cannabis and hospitalizations. During the study period, cannabis-involved pregnancy hospitalizations increased from 429 to 1210. Mean hospitalizations per county (1.7 to 4.7) and per 10 k live births (13.2 to 55.7) increased. Overall, increasing recreational dispensaries were associated with increases in hospitalizations (1.02, CI: 1.00,1.04). When comparing counties with different densities of baseline medical cannabis market, low and high exposure counties had fewer hospitalizations than those counties with no exposure (low: IRR 0.97, CI: 0.96-0.99; high: 0.98, CI: 0.96-0.99). In Colorado, there was more than a two-fold increase in cannabis-involved pregnancy hospitalizations between 2011 and 2018. Counties with no baseline exposure to medical cannabis had a greater increase than other counties, suggesting the recreational market may influence cannabis use among pregnant individuals.

Comparison of hospital claims and poison center data to evaluate health impact of opioids, cannabis and synthetic cannabinoids.

INTRODUCTION: Over the past 10 years, opioids and cannabis have garnered significant attention due to misuse and legalization trends. Different datasets and surveillance mechanisms can lead to different conclusions the due to a variety of factors. The primary objective of this study was to compare and describe trends of opioid, cannabis, and synthetic cannabinoid-related healthcare encounters and poison center (PC) cases in Colorado, a state that has legalized cannabis. METHODS: This was a retrospective study comparing hospital claims data (Colorado Hospital Association (CHA)) and poison center cases to describe opioid, cannabis and synthetic cannabinoid-related healthcare encounters and exposures in Colorado from 2013 to 2017 using related genetic codes and International Statistical Classification of Disease codes. RESULTS: Both datasets observed increases in cannabis related encounters and exposures after recreational cannabis legalization in 2014. CHA reported an increase for cannabis-related ER visits from 14,109 in 2013 to 18,118 in 2017 while PC noted a 74.4% increase in cannabis-related cases (125 to 218). CHA inpatient visits associated with cannabis also increased (8311 in 2013 to 14,659 in 2017). On the other hand, Opioid-related exposures to the PC fell (1092 in 2013 to 971 in 2017) while both Opioid-related ER visits (8580 in 2013 to 12,928 in 2017) and inpatient visits in CHA increased (9084 in 2013 to 13,205). CONCLUSIONS: This study demonstrates the differences in surveillance methodology for concurrent drug abuse epidemics using hospital claims and PC data. Both systems provide incomplete reports, but in combination can provide a more complete picture.

Alignment Between Objective and Subjective Assessments of Health System Performance: Findings From a Mixed-Methods Study.

EXECUTIVE SUMMARY: The article examines whether subjective performance assessments from health system executives match objective performance assessments and qualitatively explores ways to achieve high performance. We interviewed 138 C-suite executives of 24 health systems in California, Minnesota, Washington, and Wisconsin between 2017 and 2019. We used maximum variation sampling to select health systems to achieve diversity in performance on objective measures of clinical performance. Our interviews focused on executives' perceptions of their own health system's performance and factors they thought generally contributed to high performance. In our analysis, we grouped health systems based on objective performance levels (high, medium, and low) used in sampling, compared objective performance ratings with executives' subjective performance assessments, and used thematic analysis to identify reasons for subjective assessment of health system performance and levers of high performance in general. There was poor agreement between objective and subjective performance assessments (kappa = 0.082). Subjective assessments were higher than objective assessments and captured more factors than are typically considered in performance accountability and value-based payment initiatives. Executives whose views were inconsistent with objective performance assessments did not cite clinical care quality per se as the basis for their assessment, focusing instead on market competition, financial performance, and high customer satisfaction and loyalty. Executives who cited clinical quality metrics as the basis of their assessment offered subjective ratings consistent with objective ratings. Executives identified organizational culture, organizational governance, and staff engagement as levers for achieving high performance. Future research should explore the benefits and drawbacks of considering subjective performance assessments in value-based payment initiatives.

Implementation of Medical Homes in Federally Qualified Health Centers.

BACKGROUND: From 2011 through 2014, the Federally Qualified Health Center Advanced Primary Care Practice Demonstration provided care management fees and technical assistance to a nationwide sample of 503 federally qualified health centers to help them achieve the highest (level 3) medical-home recognition by the National Committee for Quality Assurance, a designation that requires the implementation of processes to improve access, continuity, and coordination. METHODS: We examined the achievement of medical-home recognition and used Medicare claims and beneficiary surveys to measure utilization of services, quality of care, patients' experiences, and Medicare expenditures in demonstration sites versus comparison sites. Using difference-in-differences analyses, we compared changes in outcomes in the two groups of sites during a 3-year period. RESULTS: Level 3 medical-home recognition was awarded to 70% of demonstration sites and to 11% of comparison sites. Although the number of visits to federally qualified health centers decreased in the two groups, smaller reductions among demonstration sites than among comparison sites led to a relative increase of 83 visits per 1000 beneficiaries per year at demonstration sites (P<0.001). Similar trends explained the higher performance of demonstration sites with respect to annual eye examinations and nephropathy tests (P<0.001 for both comparisons); there were no significant differences with respect to three other process measures. Demonstration sites had larger increases than comparison sites in emergency department visits (30.3 more per 1000 beneficiaries per year, P<0.001), inpatient admissions (5.7 more per 1000 beneficiaries per year, P=0.02), and Medicare Part B expenditures ($37 more per beneficiary per year, P=0.02). Demonstration-site participation was not associated with relative improvements in most measures of patients' experiences. CONCLUSIONS: Demonstration sites had higher rates of medical-home recognition and smaller decreases in the number of patients' visits to federally qualified health centers than did comparison sites, findings that may reflect better access to primary care relative to comparison sites. Demonstration sites had larger increases in emergency department visits, inpatient admissions, and Medicare Part B expenditures. (Funded by the Centers for Medicare and Medicaid Services.).

The impact of practice guidelines on opioid utilization for injured workers.

BACKGROUND: Opioid use is rising in the US and may cause special problems in workers compensation cases, including addiction and preventing a return to work after an injury. OBJECTIVE: This study evaluates a physician-level intervention to curb opioid usage. An insurer identified patients with out-of-guideline opioid utilization and called the prescribing physician to discuss the patient's treatment protocol. RESEARCH DESIGN: This study uses a differences-in-differences study design with a propensity-score-matched control group. Medical and pharmaceutical claims data from 2005 to 2011 were used for analyses. RESULTS: Following the intervention, the use of opioids increased for the intervention group and there is little impact on medical spending. CONCLUSIONS: Counseling physicians about patients with high opioid utilization may focus more attention on their care, but did not impact short-term outcomes. More robust interventions may be needed to manage opioid use. PERSPECTIVE: While the increasing use of opioids is of growing concern around the world, curbing the utilization of these powerfully addictive narcotics has proved elusive. This study examines a prescribing guidelines intervention designed to reduce the prescription of opioids following an injury. The study finds that there was little change in the opioid utilization after the intervention, suggesting interventions along other parts of the prescribing pathway may be needed.

Identifying barriers to move to better health coverage: preferences for health insurance benefits among the rural poor population in La Guajira, Colombia.

Even though access to health insurance in Colombia has improved since the implementation of the 1993 health reforms (Law 100), universal coverage has not yet been accomplished. There is still a segment of the population under the low-income (subsidized) health insurance policy or without health insurance altogether. The purpose of this research was to identify preferences and behavior regarding health insurance among the subsidized rural population in La Guajira, Colombia, and to understand why that population remains under the subsidized health insurance policy. The field experiment gathered information from 400 households regarding their socioeconomic situation, health conditions, and preferences for health insurance characteristics. Results suggest that the surveyed population gives priority to expanded family coverage, physician and hospital choice, and access to specialists, rather than to attributes associated with co-payments or premiums. That indicates that people value healthcare benefits and family coverage more than health insurance expenses, and policy makers could use these preferences to enroll subsidized population into the contributory regime.

Impact of out-of-pocket spending caps on financial burden of those with group health insurance.

BACKGROUND: The Affordable Care Act (ACA) mandates that all private health insurance include out-of-pocket spending caps. Insurance purchased through the ACA's Health Insurance Marketplace may qualify for income-based caps, whereas group insurance will not have income-based caps. Little is known about how out-of-pocket caps impact individuals' health care financial burden. OBJECTIVE: We aimed to estimate what proportion of non-elderly individuals with group insurance will benefit from out-of-pocket caps, and the effect that various cap levels would have on their financial burden. DESIGN: We applied the expected uniform spending caps, hypothetical reduced uniform spending caps (reduced by one-third), and hypothetical income-based spending caps (similar to the caps on Health Insurance Marketplace plans) to nationally representative data from the Medical Expenditure Panel Survey (MEPS). PARTICIPANTS: Participants were non-elderly individuals (aged < 65 years) with private group health insurance in the 2011 and 2012 MEPS surveys (n =26,666). MAIN MEASURES: (1) The percentage of individuals with reduced family out-of-pocket spending as a result of the various caps; and (2) the percentage of individuals experiencing health care services financial burden (family out-of-pocket spending on health care, not including premiums, greater than 10% of total family income) under each scenario. KEY RESULTS: With the uniform caps, 1.2% of individuals had lower out-of-pocket spending, compared with 3.8% with reduced uniform caps and 2.1% with income-based caps. Uniform caps led to a small reduction in percentage of individuals experiencing financial burden (from 3.3% to 3.1%), with a modestly larger reduction as a result of reduced uniform caps (2.9%) and income-based caps (2.8%). CONCLUSIONS: Mandated uniform out-of-pocket caps for those with group insurance will benefit very few individuals, and will not result in substantial reductions in financial burden.

Low rural health insurance take-up in a universal coverage system: perceptions of health insurance among the uninsured in La Guajira, Colombia.

Despite enacting a universal healthcare system in 1993, many Colombians do not participate. Understanding perceptions of the system could help the government market certain features or adjust benefits in order to increase enrollment. Using La Guajira, Colombia, as a case study, we surveyed uninsured rural households regarding insurance preferences, values and beliefs, and perceptions of available services. Four hundred heads of households responded in La Guajira, Colombia. Respondents reported high levels of long-term uninsurance. Overall, the quality of services in the government-run system is perceived as better than being uninsured, but there appear to be constraints on enrollment. Rural Colombians value more family coverage and better choice of physicians, but offering better benefits may not be enough. Many cited access barriers, so reducing these barriers may also increase enrollment. Further surveys in other parts of Colombia should be undertaken to confirm results.

Modernizing Medicare's Benefit Design and Low-Income Subsidies to Ensure Access and Affordability.

Insurance coverage through the traditional Medicare program is complex, fragmented, and incomplete. Beneficiaries must purchase supplemental private insurance to fill in the gaps. While impoverished beneficiaries may receive supplemental coverage through Medicaid and subsidies for prescription drugs, help is limited for people with incomes above the poverty level. This patchwork quilt leads to confusion for beneficiaries and high administrative costs, while also undermining coverage and care coordination. Most important, Medicare's benefits fail to limit out-of-pocket costs or ensure adequate financial protection, especially for beneficiaries with low incomes and serious health problems. This brief, part of a series about Medicare's past, present, and future, presents options for an integrated benefit for enrollees in traditional Medicare. The new benefit would not only reduce cost burdens but also could potentially strengthen the Medicare program and enhance its role in stimulating and supporting innovations throughout the health care delivery system.

Multiple chronic conditions and life expectancy: a life table analysis.

BACKGROUND: The number of people living with multiple chronic conditions is increasing, but we know little about the impact of multimorbidity on life expectancy. OBJECTIVE: We analyze life expectancy in Medicare beneficiaries by number of chronic conditions. RESEARCH DESIGN: A retrospective cohort study using single-decrement period life tables. SUBJECTS: Medicare fee-for-service beneficiaries (N=1,372,272) aged 67 and older as of January 1, 2008. MEASURES: Our primary outcome measure is life expectancy. We categorize study subjects by sex, race, selected chronic conditions (heart disease, cancer, chronic obstructive pulmonary disease, stroke, and Alzheimer disease), and number of comorbid conditions. Comorbidity was measured as a count of conditions collected by Chronic Conditions Warehouse and the Charlson Comorbidity Index. RESULTS: Life expectancy decreases with each additional chronic condition. A 67-year-old individual with no chronic conditions will live on average 22.6 additional years. A 67-year-old individual with 5 chronic conditions and ≥10 chronic conditions will live 7.7 fewer years and 17.6 fewer years, respectively. The average marginal decline in life expectancy is 1.8 years with each additional chronic condition-ranging from 0.4 fewer years with the first condition to 2.6 fewer years with the sixth condition. These results are consistent by sex and race. We observe differences in life expectancy by selected conditions at 67, but these differences diminish with age and increasing numbers of comorbid conditions. CONCLUSIONS: Social Security and Medicare actuaries should account for the growing number of beneficiaries with multiple chronic conditions when determining population projections and trust fund solvency.

Community characteristics and mortality: the relative strength of association of different community characteristics.

OBJECTIVES: We compared the strength of association between average 5-year county-level mortality rates and area-level measures, including air quality, sociodemographic characteristics, violence, and economic distress. METHODS: . We obtained mortality data from the National Vital Statistics System and linked it to socioeconomic and demographic data from the Census Bureau, air quality data, violent crime statistics, and loan delinquency data. We modeled 5-year average mortality rates (1998-2002) for all-cause, cancer, heart disease, stroke, and respiratory diseases as a function of county-level characteristics using ordinary least squares regression models. We limited analyses to counties with population of 100,000 or greater (n = 458). RESULTS: Demographic and socioeconomic characteristics, particularly the percentage older than 65 years and near poor, were top predictors of all-cause and condition-specific mortality, as were a high concentration of construction and service workers. We found weaker associations for air quality, mortgage delinquencies, and violent crimes. Protective characteristics included the percentage of Hispanics, Asians, and married residents. CONCLUSIONS: Multiple factors influence county-level mortality. Although county demographic and socioeconomic characteristics are important, there are independent, although weaker, associations of other environmental characteristics. Future studies should investigate these factors to better understand community mortality risk.

Assessing the feasibility and likelihood of policy options to lower specialty drug costs.

Specialty drugs are high-cost medications often used to treat complex chronic conditions. Even with insurance coverage, patients may face very high out-of-pocket costs, which in turn may restrict access. While the Inflation Reduction Act of 2022 included policies designed to reduce specialty drug costs, relatively few policies have been enacted during the past decade. In 2022-2023, we conducted a scoping literature review to identify a range of policy options and selected a set of 9 that have been regularly discussed or recently considered to present to an expert stakeholder panel to seek consensus on (1) the feasibility of implementing each policy and (2) its likely impact on drug costs. Experts rated only 1 policy highly on both feasibility and impact: grouping originator biologics and biosimilars under the same Medicare Part B reimbursement code. They rated 3 policies focused on setting payment limits as likely to have positive (downward) impact on costs but of uncertain feasibility. They considered 4 policies as uncertain on both criteria. Experts rated capping monthly out-of-pocket costs as feasible but unlikely to reduce specialty drug costs. Based on these results, we offer 4 recommendations to policymakers considering ways to reduce specialty drug costs.

Economic evaluation of a task-shifting intervention for common mental disorders in India.

OBJECTIVE: To carry out an economic evaluation of a task-shifting intervention for the treatment of depressive and anxiety disorders in primary-care settings in Goa, India. METHODS: Cost-utility and cost-effectiveness analyses based on generalized linear models were performed within a trial set in 24 public and private primary-care facilities. Subjects were randomly assigned to an intervention or a control arm. Eligible subjects in the intervention arm were given psycho-education, case management, interpersonal psychotherapy and/or antidepressants by lay health workers. Subjects in the control arm were treated by physicians. The use of health-care resources, the disability of each subject and degree of psychiatric morbidity, as measured by the Revised Clinical Interview Schedule, were determined at 2, 6 and 12 months. FINDINGS: Complete data, from all three follow-ups, were collected from 1243 (75.4%) and 938 (81.7%) of the subjects enrolled in the study facilities from the public and private sectors, respectively. Within the public facilities, subjects in the intervention arm showed greater improvement in all the health outcomes investigated than those in the control arm. Time costs were also significantly lower in the intervention arm than in the control arm, whereas health system costs in the two arms were similar. Within the private facilities, however, the effectiveness and costs recorded in the two arms were similar. CONCLUSION: Within public primary-care facilities in Goa, the use of lay health workers in the care of subjects with common mental disorders was not only cost-effective but also cost-saving.

Changing Care Settings for Injuries.

Tracking injury rates is important for surveillance purposes but little data exist for injuries outside of emergency department visits. We assess the share and type of injuries reported in urgent care centers (UCCs) compared with other settings. We used FAIR Health claims data from 2016 through the first quarter of 2019 to calculate the percent of claims and most common types of injuries. Of the 197 million injury claims, 62% occurred in office settings and 17% in hospital outpatient departments (HOPDs), 5% in inpatient and in ED settings, and less than 2% in UCCs. Injury claims in UCCs increased 6% from 2016 to 2018, whereas injury claims in EDs declined 24%. Overall, physician offices and HOPDs accounted for the largest share of injury care, but UCCs represented the fastest growing setting to treat injuries.

The Effect of the Medicare Advantage Value-Based Insurance Design Model Test on Utilization in 2017.

In 2015, the Centers for Medicare and Medicaid Services announced the Medicare Advantage (MA) Value-Based Insurance Design (VBID) model test, which allows MA insurers to use flexible benefit design strategies, such as reduced cost-sharing, to encourage beneficiaries with chronic disease to use high-value care. During the first year of implementation (2017), nine MA insurers offered VBID in 45 health plans to a total of 96 053 eligible beneficiaries. We used MA encounter data to estimate the impact of VBID on health services utilization in 2017 using a difference-in-differences research design. We found that VBID increased use of 10 out of 18 targeted services, and led to general increases in primary care visits, specialty care visits, and drug fills across eligible beneficiaries. The model was also associated with increases in ambulatory care sensitive inpatient and emergency department visits, an unanticipated effect that may be temporary. Overall, our findings suggest that VBID successfully increased the use of high-value services among eligible MA beneficiaries, an important first step along the pathway to better chronic disease management, lower spending, and improved beneficiary health.

APCDs can Provide Important Insights for Surveilling the Opioid Epidemic, With Caveats.

State-level all-payer claims databases (APCDs) are a possible new public health surveillance tool, but their reliability is unclear. We compared Colorado's APCD with other state-level databases for use in monitoring the opioid epidemic (Colorado Hospital Association and Colorado's Prescription Drug Monitoring Program database for 2010-2017), using descriptive analyses comparing quarterly counts/rates of opioid-involved inpatient and emergency department visits and counts/rates of 30-day opioid fills between databases. Utilization is lower in the Colorado APCD than the other databases for all outcomes but trends are parallel and consistent between databases. State APCDs hold promise for researchers, but they may be better suited to individual-level analyses or comparisons of providers than for surveillance of public health trends related to addiction.

Projected US savings from biosimilars, 2021-2025.

OBJECTIVES: Biologics account for an increasing share of US prescription drug spending. Biosimilars could lower biologic prices through competition, but barriers to increasing both supply and uptake remain. We projected US biosimilar savings from 2021 to 2025 under different scenarios. STUDY DESIGN: We projected US spending on biologics over a 5-year period under 3 scenarios: (1) a baseline scenario holding quarter 4 (Q4) of 2020 market conditions constant; (2) under main assumptions allowing for biosimilar market growth and entry; and (3) an upper-bound scenario assuming greater biosimilar uptake, more robust price competition, and quicker biosimilar entry. METHODS: We first analyzed 2014-2020 US volume and price data from IQVIA's MIDAS database for biologics already facing biosimilar competition to inform model parameter values. We used these inputs to project biosimilar entry, biosimilar volume shares, biosimilar prices, and reference biologic prices. We calculated 2021-2025 new savings from biosimilar competition vs the Q4 2020 baseline. RESULTS: Estimated biosimilar savings from 2021 to 2025 under our main approach were $38.4 billion, or 5.9% of projected spending on biologics over the same period. Biologics first facing biosimilar competition from 2021 to 2025 accounted for $26.1 billion of savings, with $12.2 billion from evolving market conditions for already-marketed biosimilars. Furthermore, $24.6 billion of savings under our main approach were from downward pressure on reference biologic prices rather than lower biosimilar prices. Savings were substantially higher ($124.5 billion) under the upper-bound scenario. CONCLUSIONS: Biosimilar savings from 2021 to 2025 were $38.4 billion under our main assumptions. Greater savings may be feasible if managed care and other settings increase biosimilar utilization and promote competition.

Impact of cannabis legalization on healthcare utilization for psychosis and schizophrenia in Colorado.

BACKGROUND: Emergency department (ED) visits involving psychosis and schizophrenia have increased at a rate exceeding population growth in the United States over the past decade. Research shows a strong dose-response relationship between chronic use of high-potency cannabis and odds of developing symptoms of psychosis. The aim of this study was to evaluate the impact of cannabis legalization on psychosis and schizophrenia-related ED visits in Colorado. METHODS: Using administrative data from Colorado Hospital Association (CHA) on county-level quarterly ED visits between January 1, 2013, and December 31, 2018, we applied a difference-in-difference analysis to examine how new exposure to recreational cannabis dispensaries after 2014 differentially influenced the rate of ED visits for psychosis and schizophrenia, comparing counties with no prior medical cannabis dispensary exposure to counties with low or high medical dispensary exposure. RESULTS: As recreational dispensaries per 10,000 residents increased, there was no significant association with the rate of schizophrenia ED visits per capita (incidence rate ratio or IRR: 0.95, 95% CI [0.69, 1.30]) while the rate of psychosis visits increased 24% (IRR: 1.24, 95% CI [1.02, 1.49]). Counties with no previous medical dispensaries experienced larger increases in schizophrenia ED visits than counties already exposed to a low level of medical dispensaries, but this effect was not significant. Counties with low baseline medical exposure had lower increases in rates of psychosis visits than counties with high baseline medical exposure (IRR 0.83, 95% CI [0.69, 0.99]). CONCLUSIONS: There was a positive association between the number of cannabis dispensaries and rates of psychosis ED visits across all counties in Colorado. Although it is unclear whether it is access to products, or the types of products that may be driving this association, our findings suggest there is a potential impact on the mental health of the local population that is observed after cannabis legalization.