Epidemiological Study Epidemiological Study research papers examine the scientific study of the patterns, causes and effects of disease. An epidemiological study is a scientific investigation that compares two groups of people who are alike in all aspects save one factor in which investigators attempt to determine if any factor is responsible for a health effect. Epidemiology is the study of the patterns, and the cause and effect of disease. It is the foundation for public health information through the scientific identification of risk factors. Epidemiological studies are frequently used in public health in order to push for certain diet or behavior changes, where the information is provided to people in order that they can make more informed decisions regarding their own health. Epidemiological Study Designs There are four types of epidemiological studies. Ecological Cross-Sectional Case Control Cohort Case series are the qualitative study of a single individual or small group of patients with the same diagnosis. These are purely descriptive studies. Case control studies are those that select test subjects based on a disease status. The case group, those that have the selected disease, are compared to the control group, those without the disease. Cohort studies look at subjects who are under the risk of exposure to a particular disease. When the study begins, the individuals are disease free, such as smokers and nonsmokers and their development of lung cancer. Finally, an outbreak investigation is the examination of a disease occurrence, which seeks to trace and understand an outbreak of a particular disease.