tumor size
0 = small
1 = large

stage of nodes
0 = early
1 = late

histology
1 = squamous cells
2 = other types of cells

treatment
0 = saline (control)
1 = BCG (experiment)

perfomance status at baseline
0 = good
1 = poor

post-operative infection
0 = no
1 = yes

smoking status at follow-up
1 = smokers
2 = ex-smokers
3 = never smokers

0 = alive (censored)
1 = dead