Classification tree used to define cut-offs for component score and identify profiles of risk of death in the derivation cohort across the four PIRO components.

<p>Each node split decision in the tree was chosen from the possible cut-offs for all components, maximizing the within-node homogeneity.</p

Scores attributed to the selected variables regarding each of the four components of PIRO.

<p>P score – Predisposition score, I score – Insult/Infection score, R score – Host Response score, O score – Organ dysfunction score, ATB – antibiotic therapy, CAI – community-acquired infection, HCAI – healthcare-associated infection, HAI – hospital acquired infection, SOFA – Sepsis-related Organ Failure Assessment.</p

Area under the receiver operating characteristics curve (95% Confidence Interval) of predicted probabilities by hospital mortality of each PIRO component, the combined PIRO model and SAPS II, in the derivation and in the validation cohorts.

<p>Area under the receiver operating characteristics curve (95% Confidence Interval) of predicted probabilities by hospital mortality of each PIRO component, the combined PIRO model and SAPS II, in the derivation and in the validation cohorts.</p

Different stages of PIRO obtained according to the different combinations of Predisposition (P1, P2, P3), Insult (I1, I2), Response (R1, R2) and Organ dysfunction scores (O1, O2).

<p>The numbers represent the mortality rate for each state, e.g., the state P₁I₁R₂O₂ had a mortality of 19% in the derivation cohort and 14% in the derivation cohort. Only states with more than 5 patients were considered. The dashes (−) indicate that there was not enough patients in the respective state to evaluate mortality.</p

Demographic and clinical characteristics of patients in the derivation and validation cohorts.

<p>SD – standard deviation, IQR – interquartile range. SOFA – Sepsis-related Organ Failure Assessment</p>*<p>Independent samples <i>t-</i>test,</p>#<p>Pearson Cui-square Test;</p>&<p>Independent samples median test.</p

Decision tree for surgery.

<p>Decision tree for surgery.</p

Performance of risk matrix in derivation and validation cohort for disabling disease and reoperation (% [CI 95%]).

<p>Performance of risk matrix in derivation and validation cohort for disabling disease and reoperation (% [CI 95%]).</p

Decision rules and proportion and confidence intervals of outcomes observed.

<p>Decision rules and proportion and confidence intervals of outcomes observed.</p

Decision tree for reoperation.

<p>Decision tree for reoperation.</p

Baseline characteristics and comparison between the derivation and the validation cohorts.

<p>Baseline characteristics and comparison between the derivation and the validation cohorts.</p