Death of a spouse is at the very top. Death of a close family member is way up there as well, but little data exists as to how this stress affects children who lose a sibling. Now this paper, appearing in JAMA Pediatrics, suggests that the childhood death of a sibling is a major risk factor for all-cause mortality.
Using national data from Denmark and Sweden, the researchers examined over 5 million individuals born between 1973 and 2009. Of those, 55,818 individuals – just over 1% - experienced the death of a sibling during childhood.
Those who did had a higher risk of death for the rest of their lives. The risk of death was increased by about 70%.
These results are pretty stark, but we need to think a bit about mechanism. We may posit that the death of a sibling results in significant psychological and physiologic stress, which may predispose to various disease states down the road. Or, we might see the death of a sibling as a marker of genetic or environmental risks. One wonders, for example, if adopted children would carry the same increased risk. Or perhaps the death of a child affects the manner in which the parents care for the surviving sibling.
We can tease this out a bit by looking at some of the data hidden a bit deeper in the paper. One analysis looks at, broadly, the causes of death in the sibling pairs, categorized as illness-related or due to “external causes” – which is mostly accidents. If shared genetic and environmental risk is a strong player, we’d expect similar causes of death in sibling pairs. And indeed, we see that for children exposed to a sibling who died of a disease, their risk of dying of disease is roughly doubled, while the risk of dying of external causes only goes up by a non-significant 30%. Among those exposed to a sibling who died of external causes, the risk of dying of external causes went up 90%, but only increased 37% for disease-related death.
This tells us that there are likely some background shared risks here that aren’t fully captured in the data. But it also tells us that there is certainly residual risk, likely related to psychological stress.
Across the board, the risk of death was higher within one year of a siblings death. But the risk never went away.
This figure shows higher risks in that first year, regardless of the age of bereavement. The risk decreases with time, but still persists, even 15 years later. These children are, in some sense, haunted.
The take home from all of this is that death of a sibling should be considered a strong risk factor for children’s overall health, for a variety of reasons. Managing the stress and helping these children cope should be considered not just in the months after the loss, but for years or even decades after.