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