[Mortality and birthdays]

Death has a preference for birthdays-an analysis of death time series

PURPOSE

To examine the relation between the day of death and the day of birth. To determine whether the "death postponement" hypothesis or the "anniversary reaction" hypothesis is more appropriate.

METHODS

We analyzed data from the Swiss mortality statistics 1969-2008. Deaths below the age of 1 were excluded from the analysis. Time series of frequencies of deaths were based on differences between the day of death and the day of birth. We applied autoregressive integrated moving average modeling with intervention effects both in straight and reverse time series.

RESULTS

The overall death excess on the day of birth was 13.8%, mainly because of cardiovascular and cerebrovascular diseases (more in women than in men) as well as suicides and accidents (in particular, falls in men). Unexpectedly, we also found an excess of deaths in cancers. An (negative) aftereffect was found in cancers, and (positive) anticipatory effects were found in falls in men.

CONCLUSIONS

In general, birthdays do not evoke a postponement mechanism but appear to end up in a lethal way more frequently than expected ("anniversary reaction").

Mortality salience of birthdays on day of death in the Major Leagues

The authors assessed the relationship of mortality salience, as represented by birthdays, on the day of death. Preliminary studies considered the role of possible artifacts such as seasonality of birth and death, and time units for evaluation. On the basis of terror management theory's concept of "mortality salience," the authors hypothesized that famous people, in this case Major League Baseball (MLB) players, would be more likely to die on or after their birthdays than would be expected by chance (the "birthday blues"), and that the greater their fame, as represented by induction into the Baseball Hall of Fame, the greater the concentration of deaths shortly after birthdays. The results supported the hypothesis. Theoretical underpinnings of these results and practical implications were discussed.

Heaping in anniversary reaction studies: a cautionary note

Several studies have reported evidence that death is often associated with significant ceremonial events like holidays and birthdays, a phenomenon variously called the "anniversary reaction," "holiday effect," "birthday blues," etc. This article, using data from the social security death index (SSDI), shows how evidence for this phenomenon can arise from an artifact in death records called "death heaping" in which certain dates, usually the 1st or the 15th, are systematically entered for missing data. In this study, each calendar birthday for the year 2003 in the SSDI was paired with either the 14th or 15th calendar day of death. For each pairing, there were more deaths for the 15th than the 14th. A second analysis compared the correspondence between dying on the same day of the month as one's birthday for the first 28 days of the month. A significantly greater number of birth-death combinations occurred for the 1st and 15th day of the month. These results suggest that studies of "anniversary reactions" should conduct preliminary evaluations to consider the possibility that statistically significant relationships do not arise from "death heaping."