Evidence-appraisal glossary
Covariate adjustment
Covariate adjustment is the statistical practice of accounting for other variables in an analysis so that the estimated effect of the factor of interest is separated from their influence.
Also called: adjusted analysis, multivariable adjustment.
By including covariates such as age, sex, or disease severity in a regression model, researchers try to compare like with like and reduce confounding. Adjustment can only address variables that were measured, recorded accurately, and modeled correctly, so residual confounding often remains; adjusting for a variable on the causal pathway or for a common effect of two variables can actually introduce bias rather than remove it.
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This is a plain-language methodology definition for reading research. It is general education, not medical advice.