All-cause mortality around the anniversary of a sibling’s death: findings from Swedish National Register Data

ICON member and PhD candidate Sandra Rogne published a time-stratified case-crossover study together with Alessandra Grotta, Can Liu, Lisa Berg, Jan Saarela, Ichiro Kawachi, Ayako Hiyoshi and Mikael Rostila. The study examines whether mortality risk increases around the anniversary of a sibling’s death.

About the study

The death of a family member can have consequences for both physical and mental health. Previous research has shown that anniversaries of significant losses may trigger stress and grief reactions, with increases in psychological, somatic and behavioural problems reported around these dates. While such anniversary reactions have been studied following the death of parents and children, less is known about their effects following the death of an adult sibling.

Using Swedish national register data from 1990 to 2016, the researchers conducted a time-stratified case-crossover study including 12,789 adults who had experienced the death of a sibling and subsequently died themselves. Each individual served as their own control, allowing the researchers to compare mortality around the anniversary with mortality on comparable days. The analyses also examined whether patterns differed according to the sex and age of the bereaved individual, the sex of the deceased sibling, sibling birth order and whether at least one parent was still alive.

Overall, the anniversary of a sibling’s death was not associated with an increased mortality risk. Among women, mortality risk was lower on the anniversary itself, while women who had lost a younger or same-age sibling also showed a lower risk in the period from one day before through the anniversary. In contrast, men who had experienced sibling loss before age 50 had an elevated mortality risk during the 12 days leading up to and including the anniversary, potentially indicating an anticipatory anniversary reaction. However, some of these associations were not statistically significant in sensitivity analyses, and the authors emphasise that the sex- and age-specific findings require further investigation.

Highlights

“Overall, mortality did not increase around the anniversary of a sibling’s death, suggesting that anniversary reactions following sibling loss may differ from those observed after the death of a parent or child”.

Publication details

Rogne, S., Grotta, A., Liu, C., Berg, L., Saarela, J., Kawachi, I., Hiyoshi, A., & Rostila, M. (2026). All-cause mortality around the anniversary of a sibling’s death: Findings from Swedish National Register Data. American Journal of Epidemiology, 195(3), 824–831.

Read more: https://doi.org/10.1093/aje/kwaf213

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