Case-control studies work backwards, first identifying diseased and nondiseased individuals, and then ascertaining the frequency of previous exposures.
- 2.Ideal characteristics for selecting cases:
Use a specific definition of the disease
Select individuals who have incident disease
- 3.Ideal characteristics for selecting controls:
Controls should derive from the same underlying population as the cases
Controls should have the opportunity to be counted as cases if they develop disease
- 4.Case-control studies have certain advantages:
Can be useful for studying rare outcomes and those with long latency periods
Can be useful for evaluating multiple risk factors for a disease
- 5.Case-control studies have certain disadvantages:
Observational design: other factors may be responsible for observed associations
Recall bias may distort associations
Case-control studies can estimate only the relative risk of disease; the incidence and attributable risk cannot be determined from case-control data alone.
The primary measure of effect in a case-control study is the odds ratio.
Odds ratios approximate relative risks when the outcome is rare.
KeywordsDevelopmental Disorder Oxidative Stress Marker Pervasive Developmental Disorder Kidney Dysfunction Specific Definition