I would like to find out the most commonly used study designs including their basic characteristics, the types of biases and how to minimize the entrance and effect of these biases into a study?
Some of the most commonly used epidemiological study designs include:
Cohort studies: In medicine , a cohort study is often done to obtain evidence or to try to refute the existence of a possible association between cause and effect; the failure to refute a hypothesis gives it more credibility. The cohort is often identified before the appearance of the disease under investigation. The study groups are observed over a period of time to determine the frequency of new incidence of the studied disease among them. Therefore the cohort cannot be defined as a group of people who have the disease. Longitudinal cohort diseases between exposure and disease strongly help in studying causal associations, though distinguishing true causality usually rquires further corroboration from further experiemental trials.
The advantage of prospective cohort study is the longitudinal observation of the individual through time, and the collection of data at regular intervals, decreasing the chance of recall error. These types of studies can be costly to conduct, are sensitive to attriton and take a long follow-up time to provide useful data. Despite these factors the results that are obtained from long-term cohort studies are better quality to retrospective cross sectional studies. ...
The following solution discusses some examples of the most commonly used study designs . It details their basic characteristics, the types of biases and how to minimize the entrance and effects of these biases into a study.