Question

Why is the potential for bias a particular problem in case-control studies as opposed to other analytic designs?

Answer 1

BIAS- In research bias occurs when systemic error introduced into sampling or testing by selecting one outcome over others.

CASE-CONTROL STUDY: can be defined as an investigation into a relationship between a given disease and one or more preventive factors, in which persons are selected based on their cases ( who have the disease) and controllers ( who are free from disease) compared together to the factors under study.

BIAS IN CASE CONTROL STUDY: A major characteristic of case- control studies is that data on potential risk factors are collected retrospectively and as a result may give raise to bias. This is a particular problem associated with case-control studies and therefore needs to be carefully considered during the design and while conducting the study. The goal is to select individuals in whom the distribution of exposure status would be the same as that of cases in the absence of an exposure disease association. In order to minimize bias, controls should be selected to be a representative sample of the collection.