Early-Life Disease Exposure and Its Heterogeneous Effects on Mortality Throughout Life: Sweden, 1905-2016.

Exposure to infectious diseases in early life has been linked to increased mortality risk in later life in high-disease settings, such as eighteenth- and nineteenth-century Europe. Less is known about the long-term effects of early-life disease exposure in milder disease environments. This study estimates heterogeneous effects from disease exposure in infancy on later-life mortality in twentieth-century Sweden, by socioeconomic status at birth and sex. Using historical population data for southern Sweden, we study 11,515 individuals who were born in 1905-1929 from age 1 until age 85. We measure exposure to disease using the local post-early neonatal mortality rate in the first 12 months after birth and apply flexible parametric survival models. For females, we find a negative effect on life expectancy (scarring) at ages 1-85 following high disease exposure in infancy, particularly for those born to unskilled workers. For males, we find no negative effect on later-life survival, likely because stronger mortality selection in infancy outweighs scarring. Thus, even as the incidence of infectious diseases declined at the start of the twentieth century, early-life disease exposure generated long-lasting negative but heterogeneous population health effects.

Early-Life Assets in Oldest-Old Age: Evidence From Primary Care Reform in Early Twentieth Century Sweden.

Do early-life effects of investments in public health persist to the oldest-old ages? This article answers this question by using the primary care reform in rural Sweden that between 1890 and 1917 led to the establishment of local health districts, together with openings of hospitals and recruitments of medical personnel, as a natural experiment in early-life environmental conditions. The initiatives undertaken within these districts targeted control of infectious diseases, including various isolation and disinfection measures. This study applies a difference-in-differences method combined with propensity score matching to register-based individual-level data for Sweden from 1968 to 2012 and to multisource, purposely collected data on the reform implementation. Providing pioneering evidence for such a distal relationship (ages 78-95), this study finds that treatment through primary care in the year of birth leads to a significant reduction in all-cause mortality (4 % to 6%) and mortality from cardiovascular diseases (5 % to 6 %) and to an increase in average incomes (2 % to 3 %). The effects are universal and somewhat stronger among individuals from poor socioeconomic backgrounds and at higher baseline levels of disease burden.