Supplemental Table 1. ICD-9 diagnosis codes for Emergency General Surgery used to create study population – grouped by category. ICD-9 Primary Diagnosis Codes for "Emergency General Surgery" ICD-9 423 456 510 512 512 518 530 530 008 153 154 209 235 455 555 562 564 564 565 566 569 569 569 569 569 578 4th Digit 3 0 Any 0,1 8 1,2,3 4 8 4 0-4,6-9 0,1 1 2,5 Any Any 1 7 9 1 0,1,2,3 4 5 6 1 1 5th Digit Any 2 5 Any 1,2,3 1,2 Any DESCRIPTION CATEGORY Cardiac Tamponade Esophageal Varices With Bleeding Empyema with or without Mention Of Fistula Spontaneous Tension or Iatrogenic Pneumothorax Spontaneous Pneumothorax Acute or Chronic Respiratory Failure Following Trauma and Surgery Perforation Of Esophagus Esophageal Hemorrhage Intestinal Infection Due To Clostridium Difficile Malignant Neoplasm of Colon Malignant Neoplasm Of Rectosigmoid Junction and Rectum Malignant carcinoid tumors of the appendix, large intestine, and rectum Neoplasm Of Uncertain Behavior, Stomach, Intestines, Rectum or unspecified digestive organs Hemorrhoids (internal and external) Regional Enteritis Diverticula Of Colon with diverticulitis and/or hemorrhage Megacolon, Other Than Hirschsprung's Unspecified Functional Disorder Of Intestine Anal fistual Anal and Rectal Abscess Anorectal Polyps, Prolapse, Stenosis, or Hemorrhage Ulcer or pain of Anus And Rectum Abscess Of Intestine Colostomy And Enterostomy Complications Rectal Prolapse Blood In Stool Cardiothoracic Cardiothoracic Cardiothoracic Cardiothoracic Cardiothoracic Cardiothoracic Cardiothoracic Cardiothoracic Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal 596 619 V55 567 567 567 567 568 568 789 235 570 572 574 575 576 577 550 551 552 553 560 519 596 V55 V90 785 675 680 681 682 1 1 2,3,4 2 3 8 9 0 8 0,3,4,6 3 0 Any Any Any 0,2 Any Any Any Any Any 0 6 0 1,2,3,8 ,9 5 Any Any Any Any Intestinovesical Fistula Digestive-Genital Tract Fistula, Female Attention To Ileostomy, colostomy or other Artificial Opening of the Digestive Tract Peritonitis or peritoneal abscess Retroperitoneal infections Other Specified Peritonitis Unspecified Peritonitis Peritoneal Adhesions (Postoperative) (Postinfection) Hemoperitoneum (Nontraumatic) Abdominal Pain, Mass, Rigidity or Tenderness Neoplasm of uncertain behavior of liver and biliary passages Acute and subacute Necrosis Of Liver Abscess Of Liver Calculus Of Gallbladder or Bile duct with Acute Cholecystitis other cholecystitis Other Disorders of the Gallbladder Other Disorders of the Biliary Tract Acute Pancreatitis, Cyst or Pseudocyst of the Pancreas Inguinal Hernia Other Hernias of the Abdominal Cavity with Gangrene Other Hernias of the Abdominal Cavity with Obstruction without Gangrene Other Hernias of the Abdominal Cavity without Obstruction or Gangrene Intestinal Obstruction without mention of Hernia Tracheostomy Complications Rupture Of Bladder, Nontraumatic Attention To Tracheostomy Colorectal Colorectal Colorectal General Abdominal General Abdominal General Abdominal General Abdominal General Abdominal General Abdominal General Abdominal Hepato-panc-biliary Hepato-panc-biliary Hepato-panc-biliary Hepato-panc-biliary Hepato-panc-biliary Hepato-panc-biliary Hepato-panc-biliary Hernias Hernias Hernias Hernias Intestinal Obstruction Other Other Other Any Retained foreign bodies Other 0,2,9 Any Any Any Shock unspecified, septic, Hypovolemic, NOS Infections of the Breast and Nipples associated with Childbirth Carbuncles And Furuncles Cellulitis and abscess of Fingers and Toes Other Cellulitis and Abscess Resuscitation Soft Tissue Soft Tissue Soft Tissue Soft Tissue 1,2,9 Any 9 1 Any Any Any Any Any Any Any Any Any 685 686 705 707 709 728 728 729 729 729 729 729 785 V58 V58 152 153 209 531 532 533 534 535 536 537 537 540 541 542 543 560 562 Any 8,9 8 Any 4 8 8 3 4 6 7 9 4 3 4 Any 5 0 Any Any Any Any Any 4 0,3,4 8 Any Any Any Any Any 0 3 Any 6 8 0 Any 1,2 Any 1,3,9 Any Any Any Any Any 1 0,1,2,9 3,4 Any 1,2,3 Pilonidal Cyst Other Local Infections Of Skin And Subcutaneous Tissue Hidradenitis Chronic Ulcers of Skin, including Pressure Ulcers Foreign Body Granuloma Of Skin And Subcutaneous Tissue Necrotizing Fasciitis Rhabdomyolysis Panniculitis, Unspecified Site Unspecified Fasciitis Residual Foreign Body In Soft Tissue Nontraumatic Compartment Syndrome Seroma or Hematoma Of Soft Tissue Gangrene Attention to Dressings or Sutures Encounter For Planned Post-Operative Wound Closure Malignant Neoplasm Of Ileum Malignant Neoplasm Of Appendix Vermiformis Malignant Carcinoid Tumor Of The Small Intestine Gastric Ulcer, Acute or Chronic Duodenal Ulcer, Acute or Chronic Peptic Ulcer, Acute or Chronic Gastro jejunal Ulcer, Acute or Chronic Gastritis or duodenitis, With Hemorrhage Gastrostomy Complications Other Obstruction Of Duodenum Angiodysplasia or Dieulafoy lesion of Stomach, with Hemorrhage Acute Appendicitis Appendicitis, Unqualified Other Appendicitis Other And Unspecified Diseases Of Appendix Intestinal obstruction without mention of hernia Diverticula Of Small Intestine with diverticulitis and/or hemorrhage Soft Tissue Soft Tissue Soft Tissue Soft Tissue Soft Tissue Soft Tissue Soft Tissue Soft Tissue Soft Tissue Soft Tissue Soft Tissue Soft Tissue Soft Tissue Soft Tissue Soft Tissue Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract 568 578 578 617 751 V55 441 444 451 557 8 0 9 5 0 1 3 2 Any 0,9 Any 1,2 Any Intestinal Fistula, Ulceration, Perforation, or Dieulafoy lesion Hematemesis Hemorrhage Of Gastrointestinal Tract, Unspecified Endometriosis Of Intestine Meckel's Diverticulum Attention To Gastrostomy Abdominal Aneurysm, Ruptured Arterial Embolism And Thrombosis Of Lower Extremity and Upper Extremity Phlebitis And Thrombophlebitis Acute or Unspecified Vascular Insufficiency Of Intestine Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Upper GI Tract Vascular Vascular Vascular Vascular