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Study breakdown

States that legalized medical marijuana saw reduced opioid use among cancer patients

Cross SectionalStrong evidence
The takeaway

Medical marijuana legalization was associated with lower rates of opioid dispensing and fewer pain-related hospital visits among some adults being treated for newly diagnosed cancer.

Oncologists, pain management specialists, health policy researchers

5.6 percentage point reduction in opioid dispensing among breast cancer patients with prior opioid use

What the researchers found

In a difference-in-differences analysis of 58,195 cancer patients across 34 states, medical marijuana legalization was associated with a 5.6 percentage point reduction in opioid dispensing among breast cancer patients with recent opioid use and a 6.3 percentage point reduction in pain-related hospital events among lung cancer patients.

Why it matters

Published in JAMA Oncology, this study provides large-scale evidence that medical marijuana legalization may offer cancer patients alternatives to opioids for pain management, at a time when opioid prescribing in cancer care has been declining rapidly.

The numbers in context

38,189 breast cancer patients; 12,816 colorectal cancer patients; 7,190 lung cancer patients; 5.6 percentage point reduction in opioid days for breast cancer (P=.001); 6.3 percentage point reduction in pain-related hospital events for lung cancer (P=.03)

How the study worked

Cross-sectional study using 2012-2017 national commercial claims data with a difference-in-differences design. Examined privately insured patients aged 18-64 newly diagnosed with breast, colorectal, or lung cancer across 34 states.

What this study cannot tell us

Limited to privately insured patients aged 18-64, excluding Medicare and Medicaid populations. Cannot confirm patients actually used marijuana. Observational design cannot establish causation.

How to read the evidence

Large-scale difference-in-differences analysis published in a top-tier journal, though observational design limits causal inference.

When this study was published

Published 2023 using 2012-2017 data

The bigger picture

As states continue to expand cannabis legalization, understanding its effects on opioid prescribing patterns in cancer care could inform both policy decisions and clinical pain management strategies.

Questions still open

  • Do these patterns hold for older cancer patients on Medicare? Are patients substituting cannabis for opioids, or are other factors driving the reduction?

Common questions

Did medical marijuana legalization reduce opioid use in cancer patients?
Yes. The study found significant reductions in opioid dispensing among breast cancer patients with prior opioid use (5.6 percentage points) and lung cancer patients without prior opioid use (6.5 percentage points).
Were there fewer pain-related hospital visits?
Among lung cancer patients with recent opioid use, medical marijuana legalization was associated with a 6.3 percentage point reduction in pain-related emergency department visits or hospitalizations.

Read the original research

Medical Marijuana Legalization and Opioid- and Pain-Related Outcomes Among Patients Newly Diagnosed With Cancer Receiving Anticancer Treatment.

JAMA oncology, 9(2), 206-214

Citation

Bao, Yuhua; Zhang, Hao; Bruera, Eduardo; Portenoy, Russell; Rosa, William E; Reid, M Carrington; Wen, Hefei. (2023). Medical Marijuana Legalization and Opioid- and Pain-Related Outcomes Among Patients Newly Diagnosed With Cancer Receiving Anticancer Treatment.. JAMA oncology, 9(2), 206-214. https://doi.org/10.1001/jamaoncol.2022.5623

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