# Trends in Cannabis Urine Drug Screen Testing in Colorado’s Largest Health System > **Author:** Benjamin Caplan, MD (ABFM Board Certified, MA Lic. #240562, NPI: 1962722637) > **Publisher:** CED Clinic (https://cedclinic.com) > **Canonical URL:** https://cedclinic.com/cannabis-urine-drug-screen-trends-colorado-health-system/ > **Published:** 2026-04-27T08:02:47-04:00 | **Last Modified / Clinically Audited:** 2026-09-28T16:03:13-04:00 > **Clinical Summary:** Explore cannabis urine drug screen trends in Colorado's largest health system, highlighting demographic factors and testing patterns over time. --- CED Clinical Relevance  #71Notable Clinical Interest  Emerging findings or policy developments worth monitoring closely. 🔬 Evidence Watch  |  CED Clinic Journal Journal of [cannabis research](https://cedclinic.com/pediatric-cannabis-certification-care-children/) Study Type Cohort Population Human participants Why This Matters This item covers developments relevant to [cannabis medicine](https://cedclinic.com/essential-oils-industrial-hemp-antimicrobial-benefits/) and [clinical practice](https://cedclinic.com/cannabis-reproductive-health-women-clinical-evidence/). Clinicians monitoring evidence in this area should review the source material. Clinical Summary Colorado was the first state in the United States to legalize [recreational cannabis](https://cedclinic.com/tennessee-medical-cannabis-program-debate-2026/), which provides a unique opportunity to evaluate cannabis urine drug screen (UDS) testing trends in a large healthcare system in response to that policy. This study examined how testing rates and positivity evolved over time and whether testing patterns varied by demographic factors. In this retrospective cohort study, we analyzed all University of Colorado Health visits from 2008 to 2022 using electronic medical record data. We assessed group comparisons with Chi-squared tests and t-tests and demographic predictors of UDS testing using multivariable log binomial models. From 2008 to 2022, the positivity rate for cannabis among UDSs rose from 14% in 2008 to 30% in 2015, then plateaued. The proportion of visits with cannabis testing declined from 0.25% to 0.04%. Younger patients, males, and individuals identifying as Black, Hispanic, or American Indian were more likely to be tested than their counterpart Dr. Caplan’s Take “This is a development worth tracking. The clinical implications will become clearer as more evidence accumulates.” Clinical Perspective 🧠 Clinicians should review this item in the context of their current practice and patient population. 💬 Join the Conversation Have a question about how this applies to your situation? [Ask Dr. Caplan →](https://benjamincaplan.com/ask-dr-caplan) Want to discuss this topic with other patients and caregivers? [Join the forum discussion →](https://cedclinic.com/interact/discussion-forums/forum/cannabis-industry/) Have thoughts on this? Share it: [X Share on X](https://twitter.com/intent/tweet?text=Just%20read%20this%20on%20CEDclinic.com%3A%20Trends%20in%20cannabis%20urine%20drug%20screen%20testing%20in%20Colorado%E2%80%99s%20largest%20health%20system%3A%20a%20retrospective%20co...%20%40drcaplan&url=https%3A%2F%2Fcedclinic.com%2Ftrends-in-cannabis-urine-drug-screen-testing-in-colorado-s-largest-health-s%2F)[in Share on LinkedIn](https://www.linkedin.com/sharing/share-offsite/?url=https%3A%2F%2Fcedclinic.com%2Ftrends-in-cannabis-urine-drug-screen-testing-in-colorado-s-largest-health-s%2F)[🦅 Share on BlueSky](https://bsky.app/intent/compose?text=Just%20read%20this%3A%20Trends%20in%20cannabis%20urine%20drug%20screen%20testing%20in%20Colorado%E2%80%99s%20largest%20health%20system%3A%20a%20retrospective%20co...%20via%20%40drcaplan.bsky.social%20https%3A%2F%2Fcedclinic.com%2Ftrends-in-cannabis-urine-drug-screen-testing-in-colorado-s-largest-health-s%2F)[📷 Follow on Instagram](https://www.instagram.com/drbenjamincaplan)[📝 Read more on Substack](https://doctorapprovedcannabis.substack.com/)[🔔 Subscribe via RSS](https://cedclinic.com/feed/) 📰 Source: [https://pubmed.ncbi.nlm.nih.gov/41772740/](https://pubmed.ncbi.nlm.nih.gov/41772740/) Table of Contents - [FAQ](#FAQ)[Why did researchers study cannabis drug testing in Colorado?](#Why_did_researchers_study_cannabis_drug_testing_in_Colorado) - [How was the Colorado urine drug screen study conducted?](#How_was_the_Colorado_urine_drug_screen_study_conducted) - [How often did cannabis urine tests come back positive over time?](#How_often_did_cannabis_urine_tests_come_back_positive_over_time) - [Did the health system test more or fewer patients for cannabis?](#Did_the_health_system_test_more_or_fewer_patients_for_cannabis) - [Which patients were more likely to be tested for cannabis?](#Which_patients_were_more_likely_to_be_tested_for_cannabis) - [Related](#Related) ## FAQ ### Why did researchers study cannabis drug testing in Colorado? Colorado was the first U.S. state to legalize [recreational cannabis](https://cedclinic.com/tennessee-medical-cannabis-program-debate-2026/), which offered a unique chance to see how urine drug screen testing in a large health system changed in response to that policy. The study examined how testing rates and positivity evolved over time and whether testing patterns varied by demographic factors. ### How was the Colorado urine drug screen study conducted? It was a retrospective cohort study that analyzed electronic medical record data from all University of Colorado Health visits from 2008 to 2022. Researchers compared groups using Chi-squared tests and t-tests and used multivariable log binomial models to identify demographic predictors of testing. It was published in the Journal of [Cannabis Research](https://cedclinic.com/pediatric-cannabis-certification-care-children/). ### How often did cannabis urine tests come back positive over time? The share of urine drug screens positive for cannabis rose from 14% in 2008 to 30% in 2015 and then plateaued. This is the positivity rate among the urine drug screens that were actually performed, not the rate of cannabis use among all patients seen in the health system. ### Did the health system test more or fewer patients for cannabis? Fewer. The proportion of visits that included cannabis testing declined from 0.25% to 0.04% over the study period. So while a higher share of the tests that were done came back positive, cannabis testing itself became much less common across University of Colorado Health visits. ### Which patients were more likely to be tested for cannabis? Younger patients, males, and individuals identifying as Black, Hispanic or American Indian were more likely to be tested than their counterparts. These demographic patterns were identified using multivariable log binomial models of predictors of urine drug screen testing. 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[Read More](https://cedclinic.com/new-clinical-insights-on-cannabis-and-patient-outcomes/) [What Cannabis Does to Your Brain in the First 24 Hours – Verywell Health](https://cedclinic.com/cannabis-brain-effects-evidence-first-24-hours/) Learn about the immediate effects of cannabis on the brain within the first 24 hours after use. [Discover More](https://cedclinic.com/cannabis-brain-effects-evidence-first-24-hours/) [New Research Suggests Cannabinoids Like CBD and CBG May Help Improve Fatty Liver](https://cedclinic.com/cannabinoids-fatty-liver-clinical-relevance/) Review emerging research on how cannabinoids such as CBD and CBG could support [liver health](https://cedclinic.com/cannabinoid-receptor-type-1-antagonist-obesity-steatohepatitis/). [Learn More](https://cedclinic.com/cannabinoids-fatty-liver-clinical-relevance/) ### Related --- ### Verification & Medical Governance - **Lead Clinical Author:** Benjamin Caplan, MD - **Credentials:** Board Certified in Family Medicine (ABFM), Founder & CMO CED Clinic & CED Foundation, Author of *The Doctor-Approved Cannabis Handbook* (Penguin Random House). - **Clinical Scale:** 350,000+ lifetime evaluations overseen; 81,008-patient Real-World Evidence Registry (`~/.ced_rwe_vault.db`); 125,000+ peer-reviewed study literature observatory (`http://localhost:8768/api/explorer/terminal`). - **License Verification:** Commonwealth of Massachusetts License #240562 (https://checkahealthlicense.mass.gov/). - **NPI Registry:** 1962722637 (https://npiregistry.cms.hhs.gov/provider-view/1962722637). - **Ethics & Data Privacy:** Clinical registry observations adhere strictly to HIPAA Safe Harbor de-identification (45 CFR § 164.514(b)) and criteria for secondary research exemption under 45 CFR § 46.104(d)(4).