Fig. 1

Cox regression analyses, 100-day survival functions in both groups of patients (Gastrointestinal symptoms/signs at debut = red curve vs. No gastrointestinal symptoms/signs at debut = blue curve). Table a shows the survival curves of the two groups, without any adjustment. In table b, the same Cox regression analysis with adjustment for sex, age and CCI (Charlson Comorbidity Index): the red curve intercepts the blue curve in two descending tracts, but curves take different directions after a longer observation time, resulting in two different survival functions