We only get odds ratio from a case–control study, which is an inferior measure of strength of association as compared to relative risk.Tags: Essay About Triangle Shirtwaist FireSport Classification EssayApush Essay Questions Civil WarSimple Essay On How I Spent My Summer VacationPro Gun Control EssayEssays And ReviewsBusiness Plan FarmingCompare And Contrast Thesis Builder
They have pointed the way to a number of important discoveries and advances.
The case–control study design is often used in the study of rare diseases or as a preliminary study where little is known about the association between the risk factor and disease of interest.
Numbers of cases and controls do not have to be equal.
In many situations, it is much easier to recruit controls than to find cases.
All efforts should be made to avoid sources of bias such as the loss of individuals to follow up during the study.
Prospective studies usually have fewer potential sources of bias and confounding than retrospective studies.A retrospective study, on the other hand, looks backwards and examines exposures to suspected risk or protection factors in relation to an outcome that is established at the start of the study.Many valuable case-control studies, such as Lane and Claypon's 1926 investigation of risk factors for breast cancer, were retrospective investigations.Case-Control Study A case-control study is a retrospective study that looks back in time to find the relative risk between a specific exposure (e.g. The goal is figure out the relationship between risk factors and disease or outcome and estimate the odds of an individual getting a disease or experiencing an event. A control group of people who do not have the disease or who did not experience the event is used for comparison.The case–control study is frequently contrasted with cohort studies, wherein exposed and unexposed subjects are observed until they develop an outcome of interest.Controls can carry the same disease as the experimental group, but of another grade/severity, therefore being different from the outcome of interest.Most sources of error due to confounding and bias are more common in retrospective studies than in prospective studies.For this reason, retrospective investigations are often criticised.The study usually involves taking a cohort of subjects and watching them over a long period.The outcome of interest should be common; otherwise, the number of outcomes observed will be too small to be statistically meaningful (indistinguishable from those that may have arisen by chance).