Data frame with the EQ-5D, age, follow-up and grouping columns
names_eq5d
Character vector of column names for the EQ-5D dimensions
name_fu
Character string for the follow-up column
levels_fu
Character vector containing the order of the values in the follow-up column.
If NULL (default value), the levels will be ordered in the order of appearance in df.
name_groupvar
Character string for the grouping column
name_age
Character string for the age column
eq5d_version
Version of the EQ-5D instrument
country
A character string representing the name of the country.
This could be in a 2-letter format, full name or short name, as specified in the country_codes datasets.