Each winter, a strange phenomenon repeats itself as people gather to celebrate the holiday season: Deaths spike.
The surge was particularly extreme in early 2015, when nearly a third more senior citizens died than normal in the first two weeks of the New Year.
Researchers have known for some time that more people die in winter. But even when they adjust for the expected increase, an irrepressible bulge that begins to swell in December persists.
Experts aren’t quite sure what causes it, but it affects nearly every age and disease group. It fells both men and women. And, curiously, after researchers adjust for it, three days emerge as the deadliest for deaths of natural causes: Dec. 25, Dec. 26 and Jan. 1.
“These increases are above and beyond what you would expect for that season,” said David Phillips, a sociology professor at the University of California, San Diego, who has studied the phenomenon. “We did not find equivalent spikes on any other major holiday. There’s something about Christmas and New Year.”
Dr. Phillips examined 57.5 million U.S. death certificates from 1979 through 2004. He compared the actual number of deaths with the expected number and found that over two weeks beginning with Christmas, an excess of 42,325 deaths from natural causes occurred over the 25-year period.
“People have known forever that mortality from a wide variety of causes is higher in the winter, but nobody knew before we did about the spike above that hill, particularly on Dec. 25, Dec. 26 and Jan. 1,” he said.
Although Dr. Phillips appears to be the only researcher who has broken the trend down by day and factors such as demographics and type of disease, the others have documented the overall seasonal effect.
Legacy.com, which hosts obituaries for 1,500 newspapers around the world, noticed it a few years after it launched in 1998.
“If you have people reading literally millions of tributes a year, if it fluctuates by as much as 20% in one part of the year, you need to know that to have correct staffing to handle the volume,” said Stopher Bartol, Legacy’s founder and executive chairman.
Once the company noticed the variation, it used government data to model the trend and verify what it suspected. As Mr. Bartol reported on the company blog: “Yes, it’s true: More people die in January.”
To try and explain the holiday spikes, Dr. Phillips, who focused on deaths from natural causes, examined five major groups of disease, including circulatory ailments; diseases of the respiratory system; cancer; endocrine, nutritional and metabolic disorders; and diseases of the digestive system.
The spikes occurred in all but cancer.
By age, only children appeared to be exempt from the trend. The increases occurred in all settings combined, but were especially acute among patients who died in the emergency room or who were dead on arrival, suggesting, Dr. Phillips said, that overcrowded and understaffed emergency rooms might contribute or that patients delay seeking medical help this time of year until it’s too late. No single cause seems to bear full responsibility, he said, although actuaries at the Reinsurance Group of America believe flu played a part last year, when the U.S., U.K. and Japan reported spikes that were significantly higher than in any of the previous 10 years.
“By about week two of the year, they were 130% of what they have been on average for ages over 65 in the U.S.,” said Peter Banthorpe, the head of actuarial research for RGA Services UK who wrote the report. “In the U.K., we saw the number spike 120% over the average.” 14 other European countries, he said, reported similar increases.
Mr. Banthorpe suspected a strain of influenza not covered by the annual vaccine contributed to the increase, a theory supported in the U.S. by the Centers for Disease Control and Prevention, which recorded the highest rate of flu-associated hospitalizations among people 65 and older since it began tracking the numbers in 2005. That year’s vaccine, the CDC reported, did not protect against the strain of H3N2 flu that was predominant early that year.
Dr. Phillips couldn’t pin down what is responsible for the holiday spikes, but he did rule out several potential contributing factors. For example, stress, winter travel and substance abuse did not explain the increase, he said, nor did the coldness itself.
“We show the effect is slightly smaller in the cold states than in the warm states,” Dr. Phillips said.
More than likely, he concluded, a variety of circumstances, not merely foul weather or the strain of the holidays, are to blame.
“A lot of times researchers wave their arms in the air and say well, it’s cold, people are depressed, they’re stressed.” Dr. Phillips said. “Probably there are several explanations.”
So, to borrow from the Bard, with the wrathful, nipping cold of winter upon us–at least in some parts of the country–perhaps it’s best to take shelter in the warmth of another’s watchful gaze. And, if needed, seek the help of a trusted physician without delay.