Bias and confounding are critical issues in epidemiological research that can distort study findings.
- Bias: Systematic errors that can affect the validity of study results. Common types include selection bias (systematic differences in characteristics between those selected for the study and those not) and information bias (errors in the measurement of exposure or outcome).
- Confounding: When the relationship between an exposure and an outcome is influenced by a third variable that is associated with both. Confounding can be addressed through study design (randomization, matching) or statistical methods (stratification, multivariable analysis).
