The epidemiology of hysterical conversion

Abstract

Abstract Clinical epidemiology is the study of illness in populations. One of its aims is to estimate the magnitude of the problem posed by a particular disorder—usually defined according to the disorder’s frequency and severity in the population. It may also provide clues as to the cause by identifying the characteristics—such as age, sex, socio-economic status, or exposure to risk factors—of those who have the disorder, or by highlighting variations in occurrence over time or between places. The third value of epidemiology is that it can assist in planning treatment trials , successful design of which relies on accurate knowledge of rates of occurrence (to plan recruitment) and of natural history (to estimate sample size).