relative risk

How to Understand a Risk Ratio of Less than 1

December 26th, 2018 by

When a model has a binary outcome, one common effect size is a risk ratio. As a reminder, a risk ratio is simply a ratio of two probabilities. (The risk ratio is also called relative risk.)

Risk ratios are a bit trickier to interpret when they are less than one. 

A predictor variable with a risk ratio of less than one is often labeled a “protective factor” (at least in Epidemiology). This can be confusing because in our typical understanding of those terms, it makes no sense that a risk be protective.

So how can a RISK be protective? (more…)

Member Training: Those Darn Ratios!

December 1st, 2018 by

Ratios are everywhere in statistics—coefficient of variation, hazard ratio, odds ratio, the list goes on. You see them reported in the literature and in your output.

You comment on them in your reports. You even (kinda) understand them. Or, maybe, not quite?

Please join Elaine Eisenbeisz as she presents an overview of the how and why of various ratios we use often in statistical practice.


The Difference Between Relative Risk and Odds Ratios

July 11th, 2016 by

Relative Risk and Odds Ratios are often confused despite being unique concepts.  Why?

Well, both measure association between a binary outcome variable and a continuous or binary predictor variable. (more…)