Table 5 Results of the bootstrap analysis for the variable selection in the models

Hgb (g/dl) at baseline and localisation

26.56

-

ASA class

9.90

-

Residual tumour classification

19.78

-

 TNM

16.32

-

 LODDS

17.76

3.19

 Complications during admission

6.27

-

 Invasion: vascular, perineural, lymphatic

3.41

1.82

 Diagnosis tests performed within the first year of follow-up

-

22.61

 Any complication due to the treatment within the 2 year follow-up

-

9.46

 Age at baseline & Radiotherapy treatment within the 2 year follow-up

-

12.60

Colostomy closure within the 2-year follow-up period

-

9.65

 Medical complications within the 2-year follow-up period

-

10.27

 Tumour recurrence within the 2-year follow-up period

-

14.50

 Readmissions within the 2-year follow-up period

-

15.89