Character vector specifying what columns to include. Choices
for each element are "beta", "se", "betaci",
"beta_se", "beta_ci""or", "orci", "or_ci",
"hr", "hrci", "hr_ci"), "z", "t", and
"p".
expand_factors
Logical value for whether to include two blank rows for
factor variables (name of variable and reference group).
variable_labels
Character vector in case you want labels other than
the variable names.
prep_kable
Logical value for whether to prepare for
printing via kable. Right now, it just adds forward
slashes so factor levels are indented, which only applies if there are factor
variables and expand_factors = TRUE.
decimals
Numeric value of vector specifying number of decimal places for
each column.