Statistical Issues in Research I: Overview of Epidemiological Study Design

Clinical Research studies are scientific investigations conducted to prove a hypothesis or answer specific clinical research questions. In the conducting clinical research investigators utilises different study design. The appropriateness of the chosen study design is fundamental for the validity and generalizability of the findings of the research study. Study design is the method used for conduct of a scientific investigation. Each type of study design represents a different approach to gathering information. Study designs can be broadly classified into observational (non-experimental) and Interventional (experimental) study designs. In observational studies, the researcher does not intervene in the study but just observes the occurrence of disease or outcome of interest in people who are already separated into groups. In this review the different type of epidemiological study designed is reviewed with the aim of outlining the characteristics and features of each study design.When and the conditions in which the design are to be used are also highlighted.