Unit 6 DB I John

According to research, epidemiology is a study or research dealing with determinants and distributions of diseases and their frequency within human populations and subsequently its application in disease control (Porta 2008). Research in epidemiology includes a number of study designs, which include both observational and experimental studies. Choosing a given mode of research over the other heavily depends on a given number of particular research questions and concerns involving efficiency and validity (Checkoway 2004). One such method is the experimental method of researching, which investigate the role that a given agent or factor in the treatment and prevention of diseases. Nevertheless, it is evident that such researches are infeasible due the problems concerning participant’s enrollment. Another disadvantage of using the experimental method is that it is costly and more often than not does include certain thorny issues. In this method, the people who have the disease of interest or even its control become the sample of the larger population.

The main characteristic of experimental research method is that it does research on the treatments and preventions for given diseases (Steenland 2007). In such cases, the researcher does actively manipulate recipient groups under the study. On the other hand, observational study researches on preventions, treatments, and causes of a given disease whereby the investigator does observe the course of nature. Cohort does typically examine a number of exposures in relation to a given ailment. As such, the researcher classifies subjects depending on their exposure levels and thereafter by the occurrence of diseases (Morabia 2008). Another research method is case control, which is to some extent identical to cohort only that this there is comparison of exposure histories. Cross-sectional research deals with relationship existing between the disease prevalence and exposure. Lastly is the ecological design, it also investigates the relationship between exposure and prevalence however at population level rather than cross-sectional’s individual level.

Commonly case control design is the inferior alternative method to cohort mode of study. In this method, basis of selecting subjects is on those having the disease and those that do not suffer from the ailment (Rothman 2008). People having the ailments have the classification of cases while those not ailing are the controls. Thereafter, there is obtaining and comparison of the histories of exposure of both the controls and cases. This outlook is very different from the cohort and experimental studies whereby the key to comparison is the incidence occurring between the unexposed and the exposed. Overall, traditionally case control is an inferior mode of study in comparison to other forms of study such as experimental and cohort methods (McNeil 2000).

In the recent past, there is the view that case-control research is a reverse cohort design. However, modern view is supplanting those observation by maintain that it is an efficient way of learning the relationship between disease and its exposure (Pigeot 2005). Population controls have one advantage making them preferred to other designs of researching. This is the manner of indentifying population controls, researchers have the assurance that controls emanate from the same populations from which the cases come. Accordingly, investigators have the confidence that it is possible to compare cases to controls. However, they also have disadvantages that make them not so attracting to researchers. The first demerit in comparison to other forms of research is that they are expensive and end up consuming a lot of time. Overall, the most preferred method is experimental method (Friis 2010).

References

Porta, M. S. (2008). A dictionary of epidemiology. Oxford; Oxford university press.

Checkoway, H. (2004). Research methods in occupational epidemiology. Oxford; Oxford university press.

Steenland, K. (2007). Case studies in occupational epidemiology. Oxford University Press.

Morabia, A. (2004). A history of epidemiologic methods and concepts. New York, Birkhäuser Press.

Rothman, K. J. (2008). Modern epidemiology. London; Lippincott Williams & Wilkins Publishers.

McNeil, D. (2000). Epidemiological research methods. Hoboken; John Wiley and Sons. Pigeot, I. (2005). Handbook of epidemiology. New York; Birkhäuser Press.

Friis, R. H. (2010). Epidemiology 101. New York; Jones & Bartlett Learning.