Epidemiology is the study of the distribution of various diseases in the human population and the factors that shape this distribution.

Epidemiological methods, in contrast to experimental ones, focus on human populations, and unlike traditional clinical research, epidemiological investigation pertains to groups and is generally comparative.

The collective and comparative perspective delineates the superiority of epidemiology over case-based clinical research, while the lack of mandatory disease correspondence between humans and various laboratory animals constitutes a point of superiority of epidemiology over experimental research.

This book contains the principles and methods of general epidemiology as well as their applications in etiological research, clinical medicine, and health services.

[Excerpt from the foreword]