What is a covariate?

A covariate is a variable that is thought to have an effect on both the independent and dependent variables in a study. It is often included in statistical analyses to account for potential confounding factors or to improve the accuracy of results. Covariates can help control for extraneous variables that may influence the relationship between the variables of interest and can help reduce bias in the findings.

In experimental or observational studies, covariates are used to adjust for differences between groups that may affect the outcome being studied. For example, in a study looking at the relationship between education level and income, age could be considered a covariate as it may also influence both variables.

Covariates can be continuous or categorical variables, and they are often included as control variables in regression models to account for their potential impact on the outcome variable. Careful consideration and selection of covariates are important in the design and analysis of research studies to ensure that the relationships observed are valid and reliable.