From a poster describing a study in cancer patients. This is from a table in the poster, which describes the characteristics of the patients (Age groups, Sex ect.) You can see what percentage of the total patient sample belonged to this or that subgroup.

enter image description here

What is the meaning of this (ref)? I don't get it.

I can't get the full text of the paper, it's behind a paywall.

1 Answer 1


The authors are fitting a regression model. It is common in regression with factors as predictors to consider one level of the factor as a "reference" level. Every other variable in the model expresses some difference relative to that reference level.

Ultimately the choice of reference doesn't matter that much for the model, as long as appropriate comparisons are made, but it does help you understand how the numbers in the paper combine to get a result for a particular population.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.