8.8 Group factor levels together - fct_collapse()
Our question relates to the association between tumour ulceration and death from melanoma.
The outcome measure has three levels as can be seen.
For our purposes here, we will generate a disease-specific mortality variable (status_dss
), by combining “Died - other causes” and “Alive”.
meldata %>%
meldata <- mutate(
status_dss = fct_collapse(
status.factor,"Alive" = c("Alive", "Died - other causes"))
)