Full Moon and the ER

By Dr. Beth Guerra 

There are nights in the ER where I take a moment to reflect upon the phase of the moon. This usually occurs when I have every exam room full of potential patients and multiple critical animals being carried into the ICU on stretchers hemorrhaging, seizuring, or gasping for breath. Every emergency doctor, human or veterinary, cannot shake the conviction that a full moon coincides with a full, and often crazy, emergency room.

I have several friends that are human ER physicians, and we all swear by this phenomenon. Reflecting back on my years in the ER, I can recall with difficulty the full moon shifts where I wasn’t up to my elbows in critical patients, no matter what clinic I was working at during that time. I even psych myself out driving to work when I happen to glance up and notice the moon is waxing full.

Multiple studies have been done about this correlation, in both human and veterinary medicine, and the bottom line is, there is no correlation. Separate statistical analyses have failed to show any link between a full moon and the caseload in the ER clinic.

One study from the Indian Journal of Medical Science (2004) failed to show any positive relation between full moon days and variables such as number of trauma patients, assaults, or attempted suicides. Another retrospective study in Resuscitation (2003) analyzed ER caseloads for six years and did not find a correlation between the number of ER visits, the phases of the moon, or the signs of the zodiac. A similar study in Journal of Veterinary Emergency and Critical Care (2007) found no correlation between case load and the phase of the moon (or Friday the 13^th), but did note that weekends and holidays were consistently the busiest days of the year.

A literature search revealed that this phenomenon has been studied extensively since the late 1960s and has even delved into variables like number of births, dog bites, drug overdoses, suicide attempts, surgical complications, and cardiac arrest. In each instance, no relationship has been established that can be linked to a full moon.

Even with all this evidence to the contrary, I still approach my full moon shifts with a certain amount of trepidation. I make sure to get as much sleep as possible and eat before I get to work; as every emergency shift worker knows, you may not get another chance. I take a deep breath as I walk in the door and remind myself that it’s just another day, and that no matter how out of control things get, I can’t blame it on the moon.