It’s not uncommon for ED patients to present with acute intoxication. This complicates not only their clinical care, but also the informed consent process.

A recent study set out to determine to what extent acute alcohol intoxication affects capacity to assent, consent, or refuse research participation.1

“We demonstrated that alcohol concentration is predictive of who may be appropriate to participate in the informed consent process,” says Marc L. Martel, MD, the study’s lead author and an emergency physician at Hennepin County Medical Center in Minneapolis. Some key findings include the following:

  • Of 415 patients who completed the University of California, San Diego Brief Assessment of Capacity to Consent screening tool, only 16 answered all 10 questions correctly.
  • Of the 16 patients deemed to possess the capacity, only eight could recall the consent process. “This raises a critical question: If a patient transiently has the capacity, can consent be considered meaningful if the patient cannot recall the encounter?” asks Martel.
  • Mean alcohol concentrations in the capacity group were lower than in those lacking capacity.
  • Of the 287 patients who were interviewed upon sobriety at discharge, 182 patients did not recall completing the questionnaire.

The researchers were aware of the findings of a previous study in 2015.2 That study supported the feasibility of using the same screening tool to assess the capacity of frequent ED users with severe alcohol use disorders to participate in research. Of 19 participants, 16 were deemed capable of providing informed consent. Capacity did not correlate with blood alcohol concentrations. “This finding was contrary to our clinical experience,” says Martel.

Hennepin County Medical Center’s ED has a separate area that is specifically designed and staffed to manage acutely intoxicated patients. “Although tolerance to the effects of ethanol is common in our frequent ED users, we were concerned by the data that would suggest these patients would be considered to have the capacity to consent to the higher standard required to consent to research,” explains Martel.

Researchers enrolled patients who presented to the ED intoxicated and were undifferentiated. In contrast, the 2015 study’s population consisted of individuals with severe alcohol use disorders. “In emergency research, it is unlikely that we will know the patient’s substance use history,” notes Martel. “Our findings can be generalized more so than the 2015 study.”

This supports the concept that emergency research protocols involving time-sensitive treatments in intoxicated patients must be performed using an exception from informed consent (EFIC) under current guidelines, the researchers concluded.

“Although a reliable method to assess the capacity of acutely intoxicated patients would open doors to safely and ethically perform resuscitation or emergency research, the lack of a reliable method strongly suggests that more studies in these patients may need to be considered and qualify for EFIC,” says Martel.


  1. Martel ML, Klein LR, Miner JR, et al. A brief assessment of capacity to consent instrument in acutely intoxicated emergency department patients. Am J Emerg Med 2017 Jun 26. pii: S0735-6757(17)30493-X. doi: 10.1016/j.ajem.2017.06.043. [Epub ahead of print]
  2. McCormack R, Gallagher T, Goldfrank LR, et al. Including frequent emergency department users with severe alcohol use disorders in research: Assessing capacity. Annals Emerg Med 2015: 65(2):172-177.


  • Marc Martel, MD, Department of Emergency Medicine, Hennepin County Medical Center, Minneapolis. Email: