Epidemiology methods or approaches include:
a. Descriptive Epidemiology
Descriptive epidemiology studies how the disease frequency changes based on the change in epidemiology variables consisting of person, place and time.
Person includes role of age, gender, social class, occupation, income, ethnic group, marital status, family size, family structure and parity.
Place is the knowledge of geographical distribution (e.g, urban and rural, border, etc.) of a disease that is useful for health service plan and can give explanation about disease etiology.
Time studies about the relationship between time and disease. It is the basic requirement in epidemiological analysis, because change of disease based on the time shows the change of etiological factors.
b. Analytic Epidemiology
This study or approach is used to examine the data and information obtained by descriptive epidemiological study.
There are three studies of epidemiology:
1. Case History Study
This study will compare two groups, i.e a group affected by the cause of the disease and a group of people not affected by the disease (control group).
2. Cohort Study
In this study, a group of people are exposed (exposed) on the disease cause (agent). Then, it is taken a group of other people who have the same characteristics with the first group. The second group is called control group. After a predetermined time, the two groups are compared, the difference between two groups is meaningful or not.
3. Experiment Epidemiology
The study is done by conducting experiments to the subject group, and then compared with the control group (which is not subject to the experiment).