California Center for Population Research

The causes and consequences of early and mid-life disease and disability in past populations are important research topics because of their contemporary as well as historical implications. Contemporary epidemiological conditions, of course, have changed as fundamentally as demographic behavior from the past. However the biological consequences of earlier illnesses for later mortality and morbidity persist today, and in spite of their importance for human biology as well as health policy, remain poorly understood. Better understanding of these relationships requires individual-level longitudinal data on health and other conditions in early and mid life linked to later health outcomes including timing of death. Such data are relatively rare, and are especially uncommon for non-Western populations. Chinese household and population registers from the Qing Dynasty (1644-1911) record information on adolescent and adult disease and disability for several million males that can be linked to their later health and mortality outcomes. This paper uses such sources to make a very preliminary examination of the causes and consequences of early and mid-life disabilities for one distinct subpopulation especially in terms of later mortality. Our study population consists of 84,973 adult men who lived in northeast China between 1749 and 1909, 9,436 of whom were registered as disabled and 3,643 of whom had a specific recorded disability or disease. Because these registers record individuals and families over time, they allow for application of event history methods to examine the determinants of disability, as well as its consequences. Because they organize these largely rural individuals by household and village, they allow for examination of the role of family and community characteristics to determine health and disability status, and to modulate the effects of health and disability status on mortality. Because they record these non-Western populations in their entirety, they allow us to distinguish the effects of different social and institutional conditions as well as different disease environments.