One in four surgery patients using cannabis and other substances

This large-scale preoperative study of 2,688 elective surgery patients reveals a significant and often-overlooked health concern: over one in four surgical patients (27.6%) report high-risk substance use, with cannabis being the most common at 15.0% prevalence. The research, drawn from real-world screening data at a Midwestern health system between February 2024 and February 2025, found that cannabis use was more prevalent than alcohol (11.1%), nicotine (8.5%), or other drugs (0.4%). Additionally, 6.6% of patients engaged in polysubstance use, combining high-risk consumption of multiple substances—a pattern that could significantly complicate surgical outcomes and anesthesia management.

The study identified important risk factors associated with high-risk substance use before surgery: younger age, male sex, and poor self-reported health were linked to substantially elevated odds of problematic substance patterns. Notably, prevalence varied dramatically across surgical specialties, with neurosurgery patients showing the highest rates (27.1% high-risk use, 11.4% polysubstance use) compared to endocrine surgery (15.1% and 3.3% respectively). These disparities suggest that certain surgical populations may face heightened perioperative risks related to substance use.

The findings carry important clinical implications: many surgical patients using cannabis regularly may not disclose this use to their surgical teams, potentially affecting anesthesia dosing, pain management strategies, and recovery protocols. The researchers advocate for universal preoperative substance use screening to identify at-risk patients and enable targeted interventions—a recommendation that underscores the need for open, non-judgmental conversations between patients and their surgical care teams about all substance use, including cannabis.