Epidemiology is the study of how diseases spread and what affects how they spread. The epidemiological method is a method scientists use to study how diseases spread and how it affects people.
In the epidemiological method, scientists look at the health of a large group of people over a period of time. For example, they might look at how often people get sick in a certain area, how often people get certain types of cancer, or how often people take certain medicines.
Scientists look at different factors, like age, gender, where people live, what they eat, and more, to figure out if those things have an effect on the spread of the the disease. They look for patterns, like if the same types of people get sick more often than others. They also look for changes over time, like if more people get sick now than in the past.
By looking at these patterns and understanding how diseases spread, scientists can come up with ways to prevent them from spreading. This can help people stay healthy, and help researchers find treatments for people who do get sick.