Final Code Tree

2. Final Code Tree Pneumoperitoneum or Free Intraperitoneal Air N Y IIIB Ascites or Portal Venous Gas Y N Ventilator or Vassopressors or Neutropenia at Day of Dx Pneumatosis Intestinalis or Thicken bowel wall or Air/fluid levels Y N Y N IIB IIIA IIA Grossly Bloody Stool Y N IB IA

3. Training N=429 Testing N=158 Staging s Score @ Diagnosis

4. Training N=429 Testing N=158 Staging s Score @ Diagnosis

5. LD1 1 freeipair 2.2000022019 2 pneumo 1.4023280789 3 portvenous 1.3417965936 phval -1.2116904385 venton 0.6258134537 feedintol 0.5587447893 abdcolor 0.5046600489 abddistend 0.3848253781 abdileus -0.3783655073 thickbowel -0.3742092256 air 0.2852206988 pintestin 0.1950671434 phsite -0.1793325231 dilatebowel -0.1766555924 caprefill -0.1676547616 thrombocyto 0.1669202262 bloodstool 0.1589296601 abdpain 0.1007602275 o2desat 0.0806709600 neutropenia 0.0463782983 neutcount 0.0378945014 apneic 0.0318267688 wbccell -0.0301628294 bandsperc 0.0190156007 bicarb -0.0103911553 acidosis 0.0062104076 vasson -0.0039799850 neutperc 0.0029960484 platcount -0.0003824272

6. A B Training Testing ROC AUC 0.906 NEC S Training 0.892 NEC M Testing Density True positive rate False positive rate NEC score

7. Testing Training M N = 3 N = 2 NEC S N = 65 N = 28 NEC score M N = 120 N = 49 S N = 65 N = 37 M N = 135 N = 36 NEC S N = 7 N = 3 Patient ID after sorting by NEC score

8. ROC AUC Testing Training # of clinical parameters

9. ROC AUC Testing Training # of clinical parameters

10. A B Training Testing ROC AUC 0.879 NEC S Training 0.898 NEC M Testing Density True positive rate False positive rate NEC score

11. Testing Training M N = 3 N = 2 NEC S N = 69 N = 32 NEC score M N = 188 N = 59 S N = 65 N = 34 M N = 67 N = 26 NEC S N = 3 N = 2 Patient ID after sorting by NEC score

12. ROC AUC Testing Training # of clinical parameters

13. A B Training Testing ROC AUC 0.871 NEC S Training 0.913 NEC M Testing Density True positive rate False positive rate NEC score

14. Testing Training M N = 3 N = 2 NEC S N = 68 N = 26 NEC score M N = 213 N = 65 S N = 67 N = 42 M N = 42 N = 20 NEC S N = 2 N = 0 Patient ID after sorting by NEC score

15. ROC AUC Testing Training # of clinical parameters

16. A B Training Testing ROC AUC 0.826 NEC S Training 0.912 NEC M Testing Density True positive rate False positive rate NEC score

17. Testing Training M N = 3 N = 2 NEC S N = 61 N = 31 NEC score M N = 250 N = 75 S N = 76 N = 37 M N = 5 N = 10 NEC S N = 0 N = 0 Patient ID after sorting by NEC score

18. PAM algorithm for the selection of discriminating features for NEC M and S

19. LD1 phval -2.2055309424 portvenous 1.3076542171 abdcolor 0.8216953121 venton 0.6891401925 thickbowel -0.6109360776 abdileus -0.5729964064 dilatebowel -0.5152799841 feedintol 0.3770836348 neutropenia 0.3508775855 abddistend 0.2990016172 abdpain 0.2874041759 phsite -0.2781764664 caprefill -0.2621917372 acidosis -0.1458238909 vasson 0.0757143616 o2desat -0.0748033015 pintestin -0.0557930985 thrombocyto -0.0537699567 apneic 0.0470925295 neutcount 0.0305651695 bloodstool 0.0294566441 bicarb -0.0293781813 bandsperc 0.0260929163 wbccell -0.0154507234 neutperc 0.0062913956 air 0.0056508200 platcount -0.0006709353

20. ROC AUC Testing Training # of clinical parameters

21. A B Training Testing ROC AUC 0.876 NEC S Training 0.888 NEC M Testing Density True positive rate False positive rate NEC score

22. Testing Training M N = 1 N = 1 NEC S N = 20 N = 12 NEC score M N = 203 S N = 115 N = 69 N = 56 M N = 54 N = 17 NEC S N = 2 N = 0 Patient ID after sorting by NEC score

25. - Log10 (Speaman Correlation P Value) 1 2 3 4 5 6 7 8 9 10 11 Clinical parameters

28. Final Code Tree Pneumoperitoneum or Free Intraperitoneal Air N Y IIIB Ascites or Portal Venous Gas Y N Ventilator or Vassopressors or Neutropenia at Day of Dx Pneumatosis Intestinalis or Thicken bowel wall or Air/fluid levels Y N Y N IIB IIIA IIA Grossly Bloody Stool Y N IB IA