Open AccessMethodology series module 2: Case-control studies
Author(s) -
Maninder Singh Setia
Publication year - 2016
Publication title -
indian journal of dermatology/indian journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.395
H-Index - 36
eISSN - 1998-3611
pISSN - 0019-5154
DOI - 10.4103/0019-5154.177773
Subject(s) - medicine , observational study , recall bias , selection bias , outcome (game theory) , matching (statistics) , research design , clinical study design , cohort study , selection (genetic algorithm) , population , recall , case control study , control (management) , disease , statistics , cognitive psychology , clinical trial , artificial intelligence , pathology , computer science , environmental health , psychology , mathematics , mathematical economics
Case-Control study design is a type of observational study. In this design, participants are selected for the study based on their outcome status. Thus, some participants have the outcome of interest (referred to as cases), whereas others do not have the outcome of interest (referred to as controls). The investigator then assesses the exposure in both these groups. The investigator should define the cases as specifically as possible. Sometimes, definition of a disease may be based on multiple criteria; thus, all these points should be explicitly stated in case definition. An important aspect of selecting a control is that they should be from the same 'study base' as that of the cases. We can select controls from a variety of groups. Some of them are: General population; relatives or friends; and hospital patients. Matching is often used in case-control control studies to ensure that the cases and controls are similar in certain characteristics, and it is a useful technique to increase the efficiency of the study. Case-Control studies can usually be conducted relatively faster and are inexpensive - particularly when compared with cohort studies (prospective). It is useful to study rare outcomes and outcomes with long latent periods. This design is not very useful to study rare exposures. Furthermore, they may also be prone to certain biases - selection bias and recall bias.