#EMConf: Case Control Study
-Compare two groups of patients – one with disease (case), one without the disease (control).
-Looks for prior exposure/risk factor.
-Measures the odds ratio – odds that the disease group (case) was exposed to a risk factor.
-Example: Lung cancer group (case) and healthy group (control). “Patients with lung cancer had a higher odds of smoking than those without lung cancer.”
-Different from cohort study which looks at a group with exposure, group without exposure to see if the exposure increased likelihood of disease (relative risk). “Smokers had a higher risk of developing lung cancer.”
-Easy and fast to collect data since all retrospective.
-Able to examine rare diseases or diseases with long course in short amount of time.
-If low prevalence, odds ratio = relative risk.
-Cannot determine disease incidence