This is the method used to determine the cause of health outcomes and disease in the population. In this study, the patient and individuals in the community are examined collectively. The study aims to plan and evaluate strategies used to prevent illness and guidance to manage patients whom the disease has already developed. The problem or events that are investigated by Epidemiology are as follows;
- Environmental exposure such as lead and heavy metals, air pollution, and asthma trigger.
- Infectious diseases such as food-borne, influenza, and pneumonia.
- Injuries caused by a natural surge in domestic violence and increase homicide in the community.
- Non-infectious diseases such as an increase in major birth defects and a wide spread rise in a certain type of cancer.
- Natural disasters such as hurricanes.
How the study is conducted
The study begins with a research question, for example, do people who drink alcohol have a higher risk of heart disease? The appropriate number of people will be collected and examined.
Types of epidemiology study design
The study follows a group of healthy people with different exposure levels and examines what happens to their health over time. In this design, the exposure comes before the disease occurrence which allows possible causation. Despite being expensive and time-consuming, the study could encounter bias since assumptions are made about the study participants.
This design compares prior exposure to proposed risk factors of persons with a certain health condition and those without and determines whether people with the disease have higher or lower exposure. The study encounters higher possibilities of bias but it is cheaper as compared to a prospective cohort. The study also allows the examination of rare diseases without using a larger population.
This study describes the trends or patterns on a geographic level and can be applied to investigate a potential association between community-level of exposure and disease. This study is limited to practicalities because it will not be easy to estimate individual exposure.