Effects of Early-Life Conditions on Adult Mortality: A Review

Citation: Elo, Irma T., Preston, Samuel H. (1992) Effects of Early-Life Conditions on Adult Mortality: A Review. Population Index (RSS)
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Tagged: uw-madison (RSS), wisconsin (RSS), sociology (RSS), demography (RSS), prelim (RSS), qual (RSS), WisconsinDemographyPrelimAugust2009 (RSS), epidemiology (RSS)

Summary

This paper considers the effects of health conditions in childhood on an individual's mortality risks as an adult. It examines epidemiological evidence on some of the major mechanisms expected to create a linkage between childhood and adult mortality and reviews demographic and epidemiologic studies for evidence of the hypothesized linkages. The most precise linkages between child and adult health conditions pertain to specific infectious agents whose long-tern effects have been well documented in clinical and epidemiological studies. The circumstances under which health conditions in childhood can be expected to influence adult mortality include disease processes associated with respiratory TB, hepatitis B and cirrhosis/liver cancer, rheumatic heart disease, and respiratory infections/bronchitis. Other potentially significant links are more speculative. For example, persistent viruses may give rise to many chronic afflictions of adulthood such as diabetes and Alzheimer's diseases, and dietary practices and the burden of infectious diseases in childhood may predispose individuals to death from cardiovascular disorders. Many empirical studies support the notion that childhood conditions play a major role in adult mortality. Apart from population-based cohort studies of respiratory TB, which Elo and Preston believe have firmly established the demographic importance of this mechanism in certain populations, most of the available evidence is circumstantial and not specific to a particular mechanism. Instead, some indicator that can be assumed to be associated with features of the childhood environment is shown to be associated with adult mortality from some cause of death of from all causes. Date of birth is a predictors of mortality in 19th and early 20th century Europe, a relationship that probably owes much to the activity of TB. During the later 20th century in Europe, so much is changing to rapidly that disentangling period and cohort influences becomes very difficult. However, studies of abrupt changes induced by 20th century wars continue to suggest that childhood environments affect subsequent mortality, hinting at what relationships might be in more chronically deprived populations. One's place of birth also appears to be persistently associated with risks of adult death in a wide variety of circumstances. Attempts to identify the features of birthplace that are most closely associated with adult mortality have focused on the prevalence of certain childhood diseases, as indexed by mortality rates. While results of these studies are generally consistent with biomedically informed expectations, the studies suffer from serious design flaws. An individual's height is probably the single best indicator of nutritional and disease environment in childhood. Like data and place of birth, it is a summary measure of many health-related circumstances and events, but it has the advantage of reflecting the experiences of an individual child. Several recent studies demonstrate that people who grew taller as children face substantially reduced death risks as adults, especially from cardiovascular diseases. The effect persists when several other variables are introduced as controls. The research design of studies connecting height and adult mortality have not been very elaborate, however, and the results are intriguing but hardly conclusive. The empirical results reviewed here are nearly always based on data for developed countries, where statistical systems have facilitated inquiry. While this regional focus is regrettable, it seems likely that the biomedical links between childhood and adulthood differ by degree rather than kind between developing and developed countries.