Cardiac and non-cardiac deaths peak during Christmas and New Year’s in part because people delay seeking medical treatment, researchers report in today’s Circulation: Journal of the American Heart Association.
For the study, researchers examined records for 53 million deaths from natural causes over a 26-year period (1973-2001), excluding suicides, homicides and accidents.
They compared the number of deaths during the holiday period, which they defined as Dec. 25 to Jan. 7, to the number of deaths that would be expected at that time of year if deaths from natural causes were unaffected by the holidays.
“We found that there is a general tendency for cardiac and non-cardiac deaths to peak during the winter, but above and beyond this seasonal increase, there are additional increases in cardiac and non-cardiac deaths around Christmas and New Year’s,” said lead author David P. Phillips, Ph.D., professor, department of sociology, University of California at San Diego, La Jolla, Calif.
“These twin mortality spikes are particularly striking if you look at a subset of heart deaths where people are dead on arrival (DOA), die in the emergency department (ED) or die as outpatients.”
In DOA emergency department and outpatient groups, more cardiac deaths occurred on Dec. 25 than on any other day of the year. The second-largest number of deaths was on Dec. 26, and the third-largest number was on Jan. 1. For patients who survived past the emergency department to be hospitalized, there was no obvious double spike at Christmas and New Year’s Day, although there was a general increase during the holiday period and just afterwards.
In the DOA/ED/outpatient group, 4.65 percent more cardiac deaths and 4.99 percent more non-cardiac deaths occurred during the holiday period than would be expected from the season without the holiday effect. For inpatients, the cardiac holiday effect was 1.6 percent more.
The researchers also found that the percentage of holiday deaths is growing proportionately over time. In the latest three years studied, observed holiday mortality was 4.4 percent above what was expected for the winter months. In the earliest three years of the study, holiday mortality was 0.95 percent above expected.
The authors estimated that during the Christmas-New Year holidays, there were about 42,039 more deaths during the 26-year study period than would be expected without the “holiday effect.”
“Of all the things we considered that might elicit the increase in holiday deaths from natural causes, including changes in diet and alcohol consumption and emotional stress, only two explanations were consistent with our data,” Phillips said. “One possibility is that sick people tend to delay seeking medical care during the holidays. Another is that there are often changes in medical staff during the holidays and, as a result, the quality of care might be compromised.”
Phillips’ work is an expansion of a 1999 report by Robert A. Kloner, M.D., Ph.D., who wrote an editorial about Phillips’ report. In his report, Kloner analyzed 12 years of data from Los Angeles County and found about 33 percent more deaths occurred in December and January than in June through September, with deaths peaking on Jan. 1.