The special term univariate indicate that the model should be fitted individually for
every variable included in univariate.
univariate(x)When used within a model formula, produces univariate models for each variable provided.
(character)
a vector of variable names separated by commas.
If provided alongside with pairwise specification, the model
y ~ ARM + univariate(SEX, AGE, RACE) lead to the study and comparison of the models
y ~ ARM
y ~ ARM + SEX
y ~ ARM + AGE
y ~ ARM + RACE