Bias in Observational Studies
Holly Ann Hill, David G. Kleinbaum · Encyclopedia of Biostatistics · 2005
Abstract We consider three sources of bias affecting observational studies and ways to address them: selection bias, information bias, and confounding. We discuss these sources of bias with respect to cohort and case–control designs. Even if a study is internally valid and not subject to these sources of bias, a judgment must be made whether the results generalize to some other target population.