Univariate versus Multivariate Analyses

There is often a tension between the results of univariate and multivariate analysis that you need to understand a bit better, yielding questions such as:

• Why do the univariate and multivariate results differ?
• What does it mean when results are significant in univariate analysis, but not in multivariate analysis?
• More importantly, what does it mean when results are significant in multivariate analysis, but not in univariate analysis?
• What does it mean when there are two variables that are each independently associated with the outcome, but are also independently associated with each other?

There are basically three effects in the data that you need to know about to be able to explain why your univariate and multivariate results differ:

• Confounding variables
• Suppressor variables
• Interacting variables

Univariate and Multivariate Results that Concur

When the univariate and multivariate results concur, then we are living...