American Board of Surgery Qualifying Exam (ABS QE) Practice Test

What does confounding bias result from?

1. Factors related to both exposure and outcome not on the causal path

2. Keen awareness of group assignments during assessment

3. Non-impartial information gathering methods

4. Early detection of disease leading to apparent longer survival

The correct answer is: Factors related to both exposure and outcome not on the causal path

Confounding bias arises when an external factor is related to both the exposure and the outcome being studied but is not part of the causal pathway between them. This additional variable can obscure the true relationship between the primary exposure and the outcome, leading researchers to draw incorrect conclusions about cause and effect. For instance, if a study is examining the impact of a new medication on heart disease but does not account for age as a confounding variable, the analysis may falsely attribute the effects of age-related heart risks to the medication, skewing results. Recognizing and controlling for confounders is crucial in research design and analysis to ensure that results accurately reflect the true relationships involved. The other options describe biases or issues that can affect the validity of a study but do not specifically pertain to confounding bias. Recognizing these distinctions is important for understanding the complexities of research methodology.