Epidemiology, Prevalence and Incidence

Original Editor - Your name will be added here if you created the original content for this page.

Top Contributors - Rachael Lowe, Lucinda hampton, Kim Jackson, Simisola Ajeyalemi, Samuel Adedigba, Tony Lowe, Amanda Ager and Jess Bell  

Epidemiology[edit | edit source]

Many definitions have been proposed, but the following definition captures the underlying principles of epidemiology:

Epidemiology is the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems[1]

It is the study of how often diseases occur in different groups of people and why, and is used to plan and evaluate strategies to prevent illness and as a guide to the management of patients in whom disease has already developed.[2]  Epidemiology is often described as the basic science of public health[3]

The CDC[3] break this definition down into the important principles of epidemiology:

Study - a scientific discipline with sound methods of scientific inquiry at its foundation. Various methods can be used to carry out epidemiological investigations: surveillance and descriptive studies can be used to study distribution; analytical studies are used to study determinants.[4]

Distribution - the frequency (number of health events in a population and it's relationship of that number to the size of the population) and pattern (the occurrence of health-related events by time, place, and person) of health events in a population.

Determinants - the causes and other factors that influence the occurrence of disease and other health-related events.

Health-related states or events - these may include communicable and non-communicable diseases, chronic diseases, injuries, birth defects, maternal-child health, occupational health, and environmental health. More recently studies have included behaviours related to health and well-being and genetic markers of disease risk.

Specified populations - the epidemiologist is concerned about the collective health of the people in a community or population[3]. A key feature of epidemiology is the measurement of disease outcomes in relation to a population at risk.[2] Implicit in any epidemiological investigation is the notion of a target population about which conclusions are to be drawn and ore often observations can only be made on a study sample, which is selected in some way from the target population.[2]

Application - Epidemiology is not just “the study of” health in a population; it also involves applying the knowledge gained by the studies to community-based practice.

Epidemiology is the study (scientific, systematic, data-driven) of the distribution (frequency, pattern) and determinants (causes, risk factors) of health-related states and events (not just diseases) in specified populations (patient is community, individuals viewed collectively), and the application of (since epidemiology is a discipline within public health) this study to the control of health problems.[3]

Prevalence[edit | edit source]

Incidence[edit | edit source]

References[edit | edit source]

  1. Last JM, editor. Dictionary of epidemiology. 4th ed. New York: Oxford University Press; 2001. p. 61.
  2. 2.0 2.1 2.2 The BMJ. What is Epidemiology. Chapter 1 in: Epidemiology for the uninitiated. http://www.bmj.com/about-bmj/resources-readers/publications/epidemiology-uninitiated/1-what-epidemiology (accessed 28 August 2017)
  3. 3.0 3.1 3.2 3.3 Introduction to Epidemiology. Lesson 1 in: Centers for Disease Control and Prevention. Principles of Epidemiology in Public Health Practice, An Introduction to Applied Epidemiology and Biostatistics. https://www.cdc.gov/OPHSS/CSELS/DSEPD/SS1978/Lesson1/Section1.html (accessed 28 August 2017)
  4. World Health Organisation. Epidemiology. http://www.who.int/topics/epidemiology/en/ (accessed 28 August 2017)