Scholars have defined epidemiology

Scholars have defined epidemiology in various ways. Morris (2007) refers to epidemiology
as the “study of health and populations in relation to their environment and
ways of living.” (p. 1165). Frost (1936) considers epidemiology to be “something more
than the total of its established facts . . .” and to include the “. . . orderly arrangement
of facts into chains of inference which extend more or less beyond the bounds of direct
observation.” The most acceptable definition is “the study of the distribution and
determinants of health related status or events in specified populations” (Last, 1988,
p. 159).
Epidemiology is a branch of science that investigates the risk factors responsible
for the causation of diseases through retrospective and prospective observations, a
complete history of disease, and the frequency of occurrence or transmission mechanisms
of disease in populations and explores preventive and therapeutic control measures.
A responsible public health approach does not end at the level of investigation
and planning for the solution of a particular disease. Public health professionals advance
study conclusions and use these data to formulate public health policy and law.