Bias

Definition

Bias is a systematic error that leads to an incorrect estimate of the association between exposure and disease. It can occur during study design, data collection, analysis, or interpretation.

5 Must Know Facts For Your Next Test

1. Bias can distort findings and affect the validity of epidemiological studies.
2. Selection bias occurs when participants selected for a study are not representative of the target population.
3. Information bias arises from misclassification or measurement errors in data collection.
4. Confounding bias occurs when an outside factor is related to both exposure and outcome, skewing results.
5. Reducing bias involves careful study design, proper data collection methods, and statistical adjustments.

Review Questions

• What are three common types of bias encountered in epidemiological studies?
• How does information bias differ from selection bias?
• What strategies can be used to minimize the impact of bias in a study?

Related terms

Confounding Variable: An extraneous variable that correlates with both the dependent variable and independent variable.

Random Error: Variability in data that arises due to chance rather than systematic errors.

Epidemiology:

The study of how often diseases occur in different groups of people and why.