You've probably been warned about avoiding black cats, walking under ladders, or breaking mirrors — especially today.
According to Western superstition, this is one of the unluckiest days of the year. But does Friday the 13th actually increase your chances of having an accident, or ending up in hospital?
If you ask medical staff, you might be surprised by what they have to say.
"There's superstition in emergency departments and just kind of in medicine in general," Dr Bruce Lo told ABC podcast Sum Of All Parts.
Dr Lo, an associate professor at Eastern Virginia Medical School, spent years working in a busy emergency department surrounded by colleagues who were convinced of the connection.
And it's not just Dr Lo's team that seems to suffer from a not-entirely-ironic sense of the supernatural. Australian nurses say the same medical folklore applies to hospitals here.
"We often want an answer to why our days are so crazy, and a lot of it comes down to some really weird superstitions," said Alana, a paediatrics nurse from Melbourne.
Putting it to the test
So what does the scientific literature have to say?
"There's a lot of papers on the full moon and the effects in the medical field, including the emergency department," Dr Lo said.
Unable to find much on Friday the 13th, Dr Lo and his colleagues decided to look into it.
"We said, 'You know what, there's not a whole lot out there. Why don't we look to see what the answer is within our health system, in terms of what we see in the emergency department?'" Dr Lo said.
They totted up admission rates and visits on 13 (get it?) Friday-the-13ths over a seven year period — comparing each example to the Fridays that came before and after it.
And they evaluated 13 (yes, 13) conditions including heart attacks, car accidents and appendectomies, as well as total ED volumes.
"What we found was it really didn't make a difference," Dr Lo said.
Of the 13 categories, just one was found to have an increased risk associated with Friday the 13th: penetrating trauma. Make of that what you will.
"There was a slight increase in risk [of penetrating trauma] on Friday the 13th … but for everything else, for the most part, it really made no difference at all," he said.
There are a handful of academic papers, Dr Lo added, which show a slight increase in risk for car accidents or hospital visits on Friday the 13th and full moons, but "by far and away" the literature pointed toward all of it being superstition.
"They basically all say the same thing, which is it makes no difference. There really is no validity in terms of those particular dates or scenarios," Dr Lo said.
Full moon feelings
Despite what the scientific literature says, full moons remain notorious amongst nurses for being extremely busy shifts.
"It usually starts with a really, really crazy period on the ward, and it will just be manic," Alana said. The patients will be unsettled … you're continually trying to get on top of all your tasks and you can't, patients might be needing to go to surgery and they're all delayed, or they come back and they're sicker than you thought they would be. You're just so busy."
Kristian, a nurse in the emergency department at the same hospital, said there's "definitely a correlation" between full moons and the number of psychiatric patients admitted.
"You know you're going to be busier than usual. The acuity's going to be higher, and you expect a lot more mental health."
Both nurses agreed that working on the night of full moon is "probably one of the least favorite shifts of all nurses" because "things are just nuts".
"It's really hard to word … it's just a feeling that everyone feels on the ward," Alana said.
The Q word myth
Meanwhile, there's a perfectly mundane word that both nurses and Dr Lo say medical professionals do their utmost to avoid when on the hospital floor.
"You're not allowed to say the word 'quiet' on the ward. We say the Q word," Alana said. "Because if you ever dare say that it's quiet, the ward will just turn upside down and back to front, and go absolutely crazy."
The "q word" superstition is so well recognized that a study was conducted in 2010 to see if there was any evidence that the mention of this word actually influenced the number of visits to an emergency department.
"For a team of scientists to actually study dropping the 'q word' in a ward is enough to show that even they are curious about these random superstitions in hospitals," Alana said.
The study, however, found no correlation between attendance rates and mentions of the words 'quiet' or 'busy', and concluded that the belief was "unfounded".
Despite there being "no scientific basis" behind most of these beliefs, Dr Lo said people in the medical profession (and beyond) would continue to believe what they wanted to believe.
"I think it's just human nature and how we like to associate things. And it's a part of our culture," Dr Lo said.
As humans, he said, we tend to remember the more difficult or challenging days and forget the unremarkable ones.
"There's that human bias that goes along with it. And I think there's something fun about just saying, 'Gosh, it's the full moon', or 'It's Friday the 13th', or 'It's some sort of weird jinx that was placed on us that caused us to have a particularly busy shift or some particularly difficult patients'."
Alana and Kristian both agreed that their superstitions are likely to be somewhat self-fulfilling prophecies — but were nonetheless fun to believe.
"It almost gives you a bit of a release, when you think, 'I've had a crazy day, my job's nuts'," Alana said. "Being a nurse is one of the busiest professions I think I've been in, and to have that feeling that 'it's going to be OK because it's just a full moon' kind of brings you back to work the next week. It brings a little light to some of the crazy moments on the ward."
News Source: ABC News AU
Image Source: ABC News AU