Epidemiologists conduct investigations to better understand how disease is distributed in the population and what determines who gets sick and who does not.
Name 2 types of studies conducted by Epidemiologists.

Describe each type and give an example of when these type of investigations/studies are used

Describe in your own works Criteria of Causation and how it relates to exposure and a suspected risk factor

Sample paper


With the recent complication and complexity of infections and diseases, research in the medical field is increasingly becoming important for a nation.  Notably, most countries encourage and support epidemiology considering that it helps with the study and analysis of the distribution and the factors that influence the health standards of a defined population. It is worth noting that all epidemiological studies depend on a particular population within a particular period.  The most common studies undertaken by Epidemiologists include cohort study, which examines the outcome or the effect of a particular health issue to a population and case-control studies that analyzes the causes of a health issue (Thrusfield, Michael, Christley, & Robert, 2018). The most fundamental distinction is between studies of diseases widely referred to as incidences and the studies of diseases known as prevalence.


The cohort study examines the “what will happen to me?” of the investigation of an incidence.  Therefore, Epidemiologists follow a group of healthy individuals with different level of exposure to evaluate what will happen to their health over time. On the other hand, case-control study helps to examine the “why me?” part of the examination (Morandi, 2016). This study helps with the investigation of individuals before exposure to a particular health condition and those without it to infer their vulnerability. This examination gives them an opportunity to design and implement control measures. Given the nature of the infection and outcomes, it is correct to state that an observed statistical association between causation or a risk factor and disease does not lead to the establishment of a causal relationship (Morandi, 2016). Notably, the absence of an association does not imply the absence of a causal relationship.


Morandi, S. (2016). Descriptive and epidemiological studies. Oxford Medicine Online. doi:10.1093/med/9780198788065.003.0004

Thrusfield, Michael, Christley, & Robert. (2018). Veterinary Epidemiology. Blackwell Pub.

Related: Energy and Food Webs