Confounding variable

How it is used

Also called a confounder. Researchers identify, measure and adjust for confounders, either through study design (randomisation, matching) or in the analysis (adding them to a regression). Unmeasured confounding is a common limitation of observational studies.

Example sentences

1. Age is a likely confounding variable: older people both exercise less and have more health problems.

2. We adjusted for income, education and smoking as potential confounding variables.

Common collocations

• adjust for confounding variables
• potential confounder
• unmeasured confounding
• control for confounders

Related terms

• control forTo remove or account for the influence of a variable in an analysis, usually by including it in a model, so that the effect of interest is not mixed up with it.
• causationA relationship in which a change in one variable directly produces a change in another, as opposed to the two simply moving together.
• independent variableThe variable that a researcher changes, controls or uses to explain changes in another variable; in an experiment it is the factor being manipulated.
• random assignmentPlacing participants into the groups of an experiment by chance, for example with computer-generated random numbers, so that the groups are similar at the start.
• biasA systematic error that pushes results in one direction, so that estimates are consistently too high or too low rather than just randomly off.

This word in other fields

The same English word can have a different meaning in another field:

• confounding variable · Psychology

More terms: Data and Variables

• variable
• categorical variable
• continuous variable
• dependent variable
• observation
• missing data