The Advantages and Disadvantages of Case-Control Studies

Rare Disease Studies

• In the case of rare diseases and those with long periods between exposure and outcome, the case-control study method is the only feasible method for carrying out research. In a case study you need two groups: one that has the disease and one free from the disease but that has had exposure to it. No followup is usually required in case control studies, since this method is pretty straightforward. A comparison of the two cases over a short period of time gives answers to the relevant questions of the study.

Time and Cost Effectiveness

• Case-control studies have relatively fewer subjects as compared to other observational methods. This enables the dedication of more resources to studying each case, so as to effectively answer the relevant questions in the case study. Due to the smaller number of subjects, case-control studies are able to come up with the necessary answers in a shorter period of time, compared to other studies such as cohort and cross-sectional studies. The short period of time taken to carry out case-control studies benefits the researcher in terms of cutting down the costs of operations related to the duration of research.

Information Bias

• The case-control study method is highly susceptible to recall bias as it relies on memory and records to establish the exposure status. Those with the condition are more likely to remember information about the suspected factors than the control group, while some of the study members may give inaccurate accounts all together. It is difficult to validate information given by the sets of people regarding exposures from the past -- and this, combined with all other bias factors, contributes to an increased margin of error in the results.

Sampling Bias

• Researchers should select subjects of case-control study at random, although this is at times very difficult to attain -- since they may fail to diagnose some diseases or give the wrong diagnosis. Residents of the area in question may have isolated cases and, therefore, provide inaccuracy in the findings, as the case subjects and the control group members are not equally exposed to the suspected factors.