Introducing epidemiology

Abstract

Although definitions are frequently unenlightening, no text on epidemiology would be complete without its statutory ‘one-liner’. Epidemiology has been defined as ‘the study of the distribution and determinants of the health related states and events in defined populations, and the application of this study to the control of health problems’ (Last, 1987, p. 29). It is a term derived from the Greek (epi=upon; demos=people; logos=science). In contrast with nursing and medicine, epidemiology is concerned with populations rather than individuals. Consequent on this, epidemiologists, to a greater extent than doctors and nurses, are interested in all members of a group, be they ‘healthy’ or ‘sick’. Some of the people which they study would therefore not normally have come to the attention of the health services. Another particular difference between epidemiology and medicine is that the former often wishes to know whether something has occurred, rather more than the mechanism through which it occurred.