Multivariable analysis in cerebrovascular research: practical notes for the clinician.

The term 'multivariate analysis' is often used when one is referring to a multivariable analysis. 'Multivariate', however, implies a statistical analysis with multiple outcomes. In contrast, multivariable analysis is a statistical tool for determining the relative contributions of various factors to a single event or outcome. The purpose of this article is to focus on analyses where multiple predictors are considered. Such an analysis is in contrast to a univariable (or 'simple') analysis, where single predictor variables are considered. We review the basics of multivariable analyses, what assumptions underline them and how they should be interpreted and evaluated.