Delays in seeking medical care are one explanation for the "Christmas effect."
For years, clinicians in the United States have noted the uptick in deaths from heart-related events over the Christmas holidays, but there were explanations besides the season, such as bad weather or colds and flu.
Researchers from the University of Melbourne wanted to isolate the effect of the holiday itself, apart from the weather, and they’ve found that Christmas is, in fact, rough on the heart.
In results published Thursday in the Journal of the American Heart Association, they find that a generation’s worth of data from New Zealand show that cardiac events spiked 4.2% during the week of Christmas, and that the victims were younger (average age 76.8 years) than the typical patient at other times of the year. This compares with studies in the United States, which have found an increase of about 5% in the week between Christmas and New Year’s Day.
The data covered the period from 1988 to 2013.
Explanations for the rise include increased stress, such as seeing family members or holiday travel, eating rich foods, or consuming larger-than-normal amounts of alcohol.
Researchers also note that if symptoms arise, a patient might be away from home and reluctant to seek medical attention—and if one does, there might be fewer staff available. The study found that those who died were about a year younger on average than would be expected that time of year, which would “add weight” to the thinking that a delay in medical care is a factor.
“We observed a clear Christmas holiday effect in the New Zealand population for persons suffering a cardiac death outside of a hospital setting, replicating the effect observed in US data,” the authors reported. “By virtue of studying data from a Southern Hemisphere location, we have been able to clarify the likely causes contributing to a Christmas holiday effect; however, we are not able to make a definitive statement about the cause of the effect.”
Knight J, Schilling C, Barnett A, Jackson R, Clarke P. Revisiting the “Christmas effect” in the Southern hemisphere [published online December 22, 2016]. J Am Heart Assoc. doi: https://doi.org/10.1161/JAHA.116.005098.