Previous studies have shown that young fatherhood is associated with higher later-life mortality. It is unclear whether the association is credible, in the sense that mortality and young fatherhood appear to be associated because both are determined by family-related environmental, socioeconomic and genetic characteristics.
We used a household-based 10% sample drawn from the 1950 Finnish census to estimate all-cause mortality of fathers born during 1940-1950. The fathers were followed from age 45 until death, or the end of age 54. We used a standard Cox model and a sibling fixed-effects Cox model to examine whether the effect of young fatherhood was independent of observed adulthood characteristics and unobserved early-life characteristics shared by brothers.
Men who had their first child before the age of 22 or at ages 22-24 had higher mortality as compared with their brothers who had their first child at the median or mean age of 25-26. Men who had their first child later at ages 30-44 had lower mortality than their brothers who had a first child before the age of 25. The pattern of results from a standard model was similar to that obtained from a fixed-effects sibling model.
The findings suggest a causal effect of young fatherhood on mortality and highlight the need to support young fathers in their family life to improve health behaviours and health.