Registered nurse Sabrina Moore* says she could always tell when there was a full moon. “That’s the night we would get a code. Or patients would act up, or something strange would happen,” she recounts.
Many registered nurses and other health-care practitioners can either describe their own experience or of one their colleagues’ of what is known as the “full moon phenomena”—when chaotic events seem to happen when the moon is fully lit by the sun.
Despite the anecdotal stories and claims to the contrary, Moore doesn’t truly believe there’s a connection between the phases of the moon and patient behaviour. “I think it’s more of a self-fulfilling prophecy,” says Moore. “Like if you think it’s true then, falsely, you assume it must be.”
Professor Jean-Luc Margot, from the UCLA’s department of physics and astronomy would agree. A few years ago, he made it his mission to tackle the oft-repeated claim of a link between the moon and behavior in health-care settings. After reviewing dozens of studies examining the link between the effect of the moon on hospital admission rates, birth, birth complications, and violent behaviour or mood disorders—Margot found no link whatsoever. “We can say with certainty that none of these areas of human affairs are affected by the moon,” reported Margot.
His study—conclusively showing that the moon does not impact us in unexpected ways—was published in the journal Nursing Research in March 2015.
Given that there are no grounds for this phenomenon, why is it still so common in today’s society and still repeated by health-care professionals? Margot surmises it’s a case of confirmation bias, or a cognitive tendency to reinforce a belief we already hold, or to disregard data that invalidates that belief. On hectic days on shift, when you notice it’s a full moon, your belief is reinforced. On other hectic days that you don’t notice a full moon, you tend to forget your belief.
While the full moon may not influence patient behaviour, it has the potential to affect nursing decision-making, cautions Christy Raymond-Seniuk, PhD, RN a nurse researcher and faculty member at MacEwan University. For example, it could affect observational skills when assessing a patient with a mental illness. Nurses may need to be extra mindful of their own bias towards the effect of the full moon.
“Inquisitiveness is one main aspect of critical thinking,” adds Raymond-Seniuk. “And for that reason, it’s fine that we are drawn to the full moon belief. The problem is when we try to make a personal experience fit into the phenomena instead of asking the questions we should.”
Raymond-Seniuk adds that critical thinking is about constantly asking questions and searching for evidence to support inquiries. In other words, instead of attributing patient behaviour to the full moon, we should be asking, what are the true underlying factors causing such behaviour?
Margot adds, “It’s important to have the attitude and willingness to reconsider our beliefs when faced with data that contradicts them.” In this case, that’s remembering that on the next full moon, it’s actually business as usual.”
*Name has been changed.