Characteristics of Disease and Some Exposure Considerations

Abstract

Disease entities are not natural, but are typically defined by the medical community. Only in exceptional cases, such as for infectious diseases, are the etiological aspects of a disease included by definition. However, involvement of exposure information in the diagnostic criteria would bias further epidemiologic research on the relation of disorder and exposure.

Subspecification of disease by histopathology or some metabolic pattern (e.g., of debrisoquine or antipyrine) or genetic characteristics (e.g., activated oncogenes or inactivated supressor genes) would help in identifying relationships between disease and exposure. Sometimes, however, broad or merged disease entities might be justified, as in studies of ill-defined neuropsychiatric conditions and solvent exposure.

Regarding etiology, few hints can be obtained from the character of the disease itself; however, more interest should be devoted to peak exposures, latency time aspects, etc., both for cancers and other (e.g., neurologic) disorders. The effects of early and late exposures should be evaluated for possible interaction but they also tend to confound each other; exposures of interest might include occupational and others such as parental and childhood exposures, including thereamong passive smoking.

Since human exposures tend to be complex, combined exposures might be considered by using a simple surrogate measure of exposure, e.g., occupational titles. Finally, the ethical consequences of involving genetic characteristics in epidemiology might be considered, since genetically sensitive individuals could be discriminated against in the labor market and suffer other consequences.