Electronic Appendix s1

ELECTRONIC APPENDIX

TABLE OF CONTENTS

I. List of Participating Hospitals II. Acknowledgements III. Matching Results IV. Complication Definitions V. Payment and Cost Algorithms VI. Surgical Outcome Results Table 3A (with full display of p-values) ELECTRONIC APPENDIX I. List of Study Hospitals Hospital Name City and State 1 Advocate Good Samaritan Hospital Downers Grove, IL 2 Advocate Lutheran General Hospital Park Ridge, IL 3 Baptist Health System San Antonio, TX 4 Baylor All Saints Medical Center Dallas, TX 5 Baylor Medical Center at Garland Dallas, TX 6 Baylor Medical Center at Grapevine Dallas, TX 7 Baylor Medical Center at Irving Dallas, TX 8 Baylor Medical Center at Plano Dallas, TX 9 Baylor University Medical Center Dallas, TX 10 Blessing Hospital Quincy, IL 11 Carle Foundation Hospital Urbana, IL 12 Central Dupage Hospital Winfield, IL 13 Christus Spohn Hospital Christi, TX 14 Christus St. Michael Health System Texarkana, TX 15 Covenant Health System Lubbock, TX 16 Good Shepherd Medical Center Longview, TX 17 Harris Methodist Fort Worth Ft. Worth, TX 18 Harris Methodist HEB Bedford, TX 19 Huntington Hospital Great Neck, NY 20 Kaleida Health Buffalo, NY 21 Lake Forest Hospital Lake Forest, IL 22 Las Palmas Medical Center El Paso, TX 23 Loyola University Medical Center Maywood, IL 24 Memorial Sloan-Kettering Cancer Center New York, NY 25 Methodist Medical Center of Illinois Peoria, IL 26 New York Hospital Queens Flushing, NY 27 NorthShore Long Island Jewish Medical Center Great Neck, NY 28 NorthShore University Hospital Great Neck, NY 29 Northwestern Memorial Hospital Chicago, IL 30 NYU Langone Medical Center New York, NY 31 Passavant Area Hospital Jacksonville, IL 32 Proctor Hospital Peoria, IL 33 Providence Health Center Waco, TX 34 Riverside Medical Center Kankakee, IL 35 Rockford Memorial Rockford, IL 36 Seton Medical Center Austin Austin, TX 37 Sherman Hospital Elgin, IL 38 SID Peterson Hospital Kerrville, TX 39 Southwest Texas Methodist San Antonio, TX 40 St James Olympia Fields Olympia Fields, IL 41 St Joseph Regional Health System Bryan, TX 42 St. Anthony's Memorial Hospital Effingham, IL 43 St. Elizabeth Hospital Beaumont, TX 44 St. John's Hospital Springfield, IL 45 Texas Orthopedic Hospital Houston, TX 46 Trinity Medical Center Rock Island, IL 47 Unity Hospital Rochester, NY

II. Acknowledgements

We wish to thank the following persons for their assistance in collecting data for this study.

Kenneth J. Abrams, MD, MBA David Amar, MD Jane Byrnes, RN Karen Carroll, RN MS APRN-BC Janet Cottrell, RN, MS BJ Dalton, RN, BSN Kristin Duncan, RN, BSN, MBA Neil Fleming, PhD, CQE Nancy Franklin, LVN Lisa Galati Burke, PAC Lisa Gayre, RHIA Melissa Green Geraldine Koster, RN Susann F. Land, MD, MBA Jill Lapaglia RN, MNSc Lori Loya, RN, BSN Rachel Magsalin, MD Paige Metz, RN Susan Mitchell, BSN, CPHQ Reed Panos, MD Martha J. Radford, MD, FACC, FAHA Jane Redmond, RN Scott Robins, MD Joye Roole, RN, ONC Judith Rosenblum, RN Meri Beth Schwendeman, RN Laura A. Sheppard, RN, BSN, CCS Ljuba Stojiljkovic, MD, PhD John V. White, MD III. Matching Results III.A. Combined Limited Match Matched All Non- Non- DIFFAV* DIFFAV Obese Obese Obese Before After N= 2,045 N= 2,045 N=9,177 Matching Matching Variable (%) (%) (%) (SD) P-value (SD) P-value BMI (Body Mass Index) mean 39.74 26.14 25.72 3.6 <0.00001 3.5 <0.0001 Weight (kg) mean 108.20 73.78 73.64 2.29 <0.00001 2.28 <0.0001 Height (cm) 164.85 167.68 168.83 -0.38 <0.00001 -0.27 <0.0001 Limited Match Variables Age (years) 71.54 71.43 73.15 -0.4 <0.00001 0.03 0.52072 Sex Male (%) 33.40 33.55 44.94 -0.24 <0.00001 0 0.94716 Race: White (%) 90.66 91.30 92.22 -0.06 0.02192 -0.02 0.51255 Black (%) 6.85 6.50 4.25 0.11 <0.00001 0.01 0.70706 Other (%) 2.49 2.20 3.53 -0.06 0.01719 0.02 0.60579 Procedure: Hip (%) 25.33 25.33 25.91 -0.01 0.59558 0 1.00000 Total hip replacement 23.23 23.18 22.84 0.01 0.70533 0 1.00000 Partial hip replacement 0.24 0.24 0.69 -0.06 0.01730 0 1.00000 Revision of hip 1.86 1.91 2.39 -0.04 0.16452 0 1.00000 Knee (%) 50.27 50.27 29.28 0.44 <0.00001 0 1.00000 Total Knee Replacement 48.51 48.70 28.40 0.42 <0.00001 0 0.92523 Revision of Knee 1.76 1.56 0.88 0.08 0.0010 0.02 0.71401 Colectomy for cancer (%) 10.42 10.42 17.26 -0.2 <0.00001 0 1.00000 Left colectomy for cancer 3.37 3.23 5.06 -0.08 0.00102 0.01 0.86112 Right colectomy for cancer 6.65 6.80 11.09 -0.16 <0.00001 -0.01 0.90065 Total other colectomy for cancer 0.39 0.39 1.11 -0.08 0.00171 0 1.00000 Colectomy not for cancer (%) 4.84 4.84 8.72 -0.15 <0.00001 0 1.00000 Left colectomy not for cancer 3.91 3.96 6.90 -0.13 <0.00001 0 1.00000 Right colectomy not for cancer 0.39 0.44 0.82 -0.05 0.04473 -0.01 1.00000 Total other colectomy not for cancer 0.54 0.44 1.00 -0.05 0.05326 0.01 0.82337 Thoracotomy (%) 9.14 9.14 18.83 -0.28 <0.00001 0 1.00000 Pneumonectomy 0.24 0.24 0.70 -0.07 0.01766 0 1.00000 Lobectomy 5.43 5.43 12.04 -0.24 <0.00001 0 1.00000 Wedge Resection 3.42 3.47 5.95 -0.12 <0.00001 0 1.00000 Other Thoracotomy 0.05 0.00 0.14 -0.03 0.48849 0.02 1.00000 Thoracotomy with dx of cancer 8.46 8.41 16.93 -0.26 <0.00001 0 1.00000 Closed Thoracotomy 1.76 1.71 4.01 -0.13 <0.00001 0 1.00000 30-day mortality (probability) 0.0110 0.0109 0.0203 -0.48 <0.00001 0.01 0.68446 Propensity to be Obese (probability) 0.2124 0.2122 0.1320 0.74 <0.00001 0 0.43333 *The difference of the group means in units of standard deviations. III. Matching Results III.A. Limited Match (continued) Matched All DIFFAV DIFFAV Non- Non- Before After Obese Obese Obese Matching Matching Variable (%) (%) (%) (SD) P-value (SD) P-value Additional Variables for Complete Match Diabetes: No Diabetes (%) 0.6122 0.8132 0.7922 -0.4 <0.00001 -0.45 <0.00001 Diabetes w/o Meds (%) 0.1203 0.0797 0.0807 0.13 <0.00001 0.14 0.00002 Diabetes with Meds (%) 0.2675 0.1071 0.1271 0.36 <0.00001 0.41 <0.00001 Transfer-In (%) 0.44 0.24 0.46 0.0 1.00000 0.03 0.42314 Admission from ER (%) 4.50 4.50 7.60 -0.13 <0.00001 0.0 1.00000 APACHE score (mean) 23.88 22.95 24.70 -0.11 0.00009 0.13 <0.00001 Missing APACHE score (%) 0.20 0.24 0.15 0.01 0.55501 -0.01 1.00000 Hx Asthma (%) 11.39 6.85 6.98 0.15 <0.00001 0.16 <0.00001 Hx Chronic Lung Disease (%) 19.66 18.88 26.30 -0.16 <0.00001 0.02 0.55206 Hx CollagenVascular Disease (%) 4.79 6.70 5.72 -0.04 0.09811 -0.09 0.01053 Hx Dementia (%) 1.86 3.23 4.08 -0.13 <0.00001 -0.08 0.00704 Hx Hypothyroidism (%) 20.59 17.36 16.60 0.1 0.00002 0.08 0.00951 Hx Hepatic Abnormalities (%) 3.47 4.79 5.98 -0.12 <0.00001 -0.06 0.04080 Hx Renal Dysfunction (%) 4.65 2.25 3.65 0.05 0.03566 0.12 0.00003 Hx Renal Failure (%) 3.77 1.86 2.89 0.05 0.03917 0.11 0.00029 Hx Smoking (%) 7.87 9.54 11.89 -0.13 <0.00001 -0.06 0.06705 Hx Weight Loss (%) 1.47 2.89 4.53 -0.18 <0.00001 -0.08 0.00250 Hx Stroke (%) 3.91 4.11 5.49 -0.07 0.00347 -0.01 0.81111 Hx Paraplegia (%) 0.49 0.49 0.76 -0.03 0.24338 0 1.00000 Hx Hypertension (%) 85.57 71.44 72.13 0.33 <0.00001 0.35 <0.00001 Hx Congestive Heart Failure (%) 15.40 8.26 10.30 0.15 <0.00001 0.21 <0.00001 Hx Myocardial Infarction (%) 5.43 4.60 6.22 -0.03 0.18339 0.04 0.25150 Hx Arrhythmia (%) 20.73 17.80 22.44 -0.04 0.09901 0.07 0.01929 Hx Angina (%) 3.18 3.67 3.73 -0.03 0.23977 -0.03 0.43903 Hx Valvular Heart Disease (%) 11.54 10.46 13.61 -0.06 0.01274 0.03 0.29401 Hx Sleep Apnea (%) 1.91 0.29 0.27 0.16 <0.00001 0.16 <0.00001 Hx Alcoholism (%) 0.39 0.49 1.14 -0.09 0.00127 -0.01 0.81412 Hx Cancer (%) 29.44 31.05 46.08 -0.35 <0.00001 -0.03 0.27599 Hx Hemophilia/Cogenital Coagulopathy (%) 2.89 3.18 3.40 -0.03 0.27357 -0.02 0.64857 Hx Post Inflammatory Pulmonary Fibrosis (%) 3.77 4.16 6.30 -0.12 <0.00001 -0.02 0.57479 Hx Thrombocytopenia (%) 0.78 0.88 0.87 -0.01 0.79101 -0.01 0.86360 Hx Seizures 0.10 0.20 0.44 -0.07 0.02499 -0.02 0.68727 Hx Electrolyte and Fluid Abnormality (%) 4.65 5.23 5.82 -0.05 0.03805 -0.03 0.42737 Hx Coagulopathy (%) 0.24 0.24 0.26 0 1.00000 0 1.00000 Hx Unstable Angina (%) 0.88 0.93 1.16 -0.03 0.34871 0 1.00000 III.B. Combined Complete Match Matched Non- All Non- DIFFAV DIFFAV Obese Obese Obese Before After N = 2,045 N = 2,045 N = 9,177 Matching Matching Variable (%) (%) (%) (SD) P-value (SD) P-value BMI (Body Mass Index) mean 39.74 26.30 25.72 3.6 <0.00001 3.45 <0.00001 Weight (kg) mean 108.20 74.43 73.64 2.29 <0.00001 2.23 <0.00001 Height (cm) 164.85 167.91 168.83 -0.38 <0.00001 -0.29 <0.00001 Limited Matching Variables Age (years) 71.54 71.51 73.15 -0.4 <0.00001 0.01 0.99594 Sex Male (%) 33.40 34.91 44.94 -0.24 <0.00001 -0.03 0.32259 Race: White (%) 90.66 91.83 92.22 -0.06 0.02195 -0.04 0.20312 Black (%) 6.85 5.62 4.25 0.11 <0.00001 0.05 0.12049 Other (%) 2.49 2.54 3.53 -0.06 0.01718 0.00 1.00000 Procedure: Hip (%) 25.33 25.33 25.91 -0.01 0.59557 0.00 1.00000 Total hip replacement 23.23 23.52 22.84 0.01 0.72704 -0.01 0.85344 Partial hip replacement 0.24 0.15 0.69 -0.06 0.01730 0.01 0.72629 Revision of hip 1.86 1.66 2.39 -0.04 0.16453 0.01 0.72158 Knee (%) 50.27 50.27 29.28 0.44 <0.00001 0.00 1.00000 Total knee replacement 48.51 48.90 28.40 0.42 <0.00001 -0.01 0.82667 Revision of knee 1.76 1.37 0.88 0.08 0.0010 0.03 0.37796 Colectomy for cancer (%) 10.42 10.42 17.26 -0.2 <0.00001 0.00 1.00000 Left colectomy for cancer 3.37 3.28 5.06 -0.08 0.00102 0.00 0.93054 Right colectomy for cancer 6.65 6.70 11.09 -0.16 <0.00001 0.00 1.00000 Total other colectomy for cancer 0.39 0.44 1.11 -0.08 0.0017 -0.01 1.00000 Colectomy not for cancer (%) 4.84 4.84 8.72 -0.15 <0.00001 0.00 1.00000 Left colectomy not for cancer 3.91 4.01 6.90 -0.13 <0.00001 0.00 0.93613 Right colectomy not for cancer 0.39 0.49 0.82 -0.05 0.04473 -0.01 0.81412 Total other colectomy not for cancer 0.54 0.34 1.00 -0.05 0.05328 0.02 0.47970 Thoracotomy (%) 9.14 9.14 18.83 -0.28 <0.00001 0.00 1.00000 Pneumonectomy 0.24 0.15 0.70 -0.07 0.01767 0.01 0.72629 Lobectomy 5.43 5.77 12.04 -0.24 <0.00001 -0.01 0.68330 Wedge resection 3.42 3.23 5.95 -0.12 <0.00001 0.01 0.79371 Other thoracotomy 0.05 0.00 0.14 -0.03 0.48851 0.02 1.00000 Thoracotomy with dx of cancer 8.46 8.85 16.93 -0.26 <0.00001 -0.01 0.69712 Closed thoracotomy 1.76 1.52 4.01 -0.13 <0.00001 0.01 0.62253 30-day mortality (probability) 0.0114 0.0105 0.0185 -0.22 <0.00001 0.03 0.67332 Propensity to be obese (probability) 0.2454 0.235 0.1222 0.93 <0.00001 0.08 0.28524 III.B. Complete Match (continued) Matched DIFFAV DIFFAV Non- All Non- Before After Obese Obese Obese Matching Matching Variable (%) (%) (%) (SD) P-value (SD) P-value Additional Variables for Complete Match Diabetes: No Diabetes (%) 61.22 60.73 79.22 -0.40 <0.00001 0.01 0.77297 Diabetes w/o Meds (%) 12.03 12.13 8.07 0.13 <0.00001 0.00 0.96173 Diabetes with Meds (%) 26.75 27.14 12.71 0.36 <0.00001 -0.01 0.80514 Transfer-In (%) 0.44 0.24 0.46 0.00 1.00000 0.03 0.42314 Admission from ER (%) 4.50 3.96 7.60 -0.13 <0.00001 0.02 0.43730 APACHE score (mean) 23.88 23.81 24.70 -0.11 0.00010 0.01 0.40112 Missing APACHE score 0.002 0.002 0.002 0.01 0.55517 0.00 1.00000 Hx Asthma (%) 11.39 9.88 6.98 0.15 <0.00001 0.05 0.12804 Hx Chronic Lung Disease (%) 19.66 18.88 26.30 -0.16 <0.00001 0.02 0.55206 Hx CollagenVascular Disease (%) 4.79 3.81 5.72 -0.04 0.09808 0.04 0.14299 Hx Dementia (%) 1.86 1.17 4.08 -0.13 <0.00001 0.04 0.09541 Hx Hypothyroidism (%) 20.59 18.44 16.60 0.10 0.00002 0.06 0.08972 Hx Hepatic Abnormalities (%) 3.47 3.13 5.98 -0.12 <0.00001 0.02 0.59964 Hx Renal Dysfunction (%) 4.65 4.55 3.65 0.05 0.04127 0.00 0.94050 Hx Renal Failure (%) 3.77 3.47 2.89 0.05 0.03925 0.02 0.67561 Hx Smoking (%) 7.87 7.19 11.89 -0.13 <0.00001 0.02 0.44116 Hx Weight Loss (%) 1.47 1.27 4.53 -0.18 <0.00001 0.01 0.68683 Hx Stroke (%) 3.91 3.37 5.49 -0.07 0.00294 0.03 0.40404 Hx Paraplegia (%) 0.49 0.39 0.76 -0.03 0.24343 0.01 0.81412 Hx Hypertension (%) 85.57 85.87 72.13 0.33 <0.00001 -0.01 0.82319 Hx Congestive Heart Failure (%) 15.40 14.77 10.30 0.15 <0.00001 0.02 0.60012 Hx Myocardial Infarction (%) 5.43 5.48 6.22 -0.03 0.18338 0.00 1.00000 Hx Arrhythmia (%) 20.73 21.52 22.44 -0.04 0.09325 -0.02 0.56558 Hx Angina (%) 3.18 2.74 3.73 -0.03 0.23973 0.02 0.46048 Hx Valvular Heart Disease (%) 11.54 11.25 13.61 -0.06 0.01275 0.01 0.80566 Hx Sleep Apnea (%) 1.91 0.24 0.27 0.16 <0.00001 0.16 <0.00001 Hx Alcoholism (%) 0.39 0.24 1.14 -0.09 0.00127 0.02 0.58044 Hx Cancer (%) 29.44 28.61 46.08 -0.35 <0.00001 0.02 0.58149 Hx Hemophilia/Cogenital Coagulopathy (%) 2.89 2.20 3.40 -0.03 0.27364 0.04 0.19638 Hx Post Inflammatory Pulmonary Fibrosis (%) 3.77 3.13 6.30 -0.12 <0.00001 0.03 0.30372 Hx Thrombocytopenia (%) 0.78 0.64 0.87 -0.01 0.79101 0.02 0.71008 Hx Seizures 0.10 0.05 0.44 -0.07 0.0250 0.01 1.00000 Hx Electrolyte and Fluid Abnormality (%) 4.65 5.18 5.82 -0.05 0.03806 -0.02 0.46955 Hx Coagulopathy (%) 0.24 0.20 0.26 0.00 1.00000 0.01 1.00000 Hx Unstable Angina (%) 0.88 0.64 1.16 -0.03 0.34875 0.02 0.47143 IV. OBSOS Complication Groups

OBSOS Complication Group Original Complication Category* 1. WOUND INFECTION Deep Wound Infection 2. SEPSIS Sepsis Disseminated Intravascular Coagulation 3. RESPIRATORY Pneumonia, Aspiration Pneumonia, Other Pneumothorax Respiratory Compromise Bronchospasm 4. VENOUS THROMBOEMBOLISM Pulmonary Embolism Deep Vein Thrombosis 5. CENTRAL NEUROLOGICAL Cerebral Vascular Accident/Stroke EVENTS Transient Ischemic Attack Coma Seizure Psychosis Nervous System Complications 6. CARDIAC EVENTS Cardiac Event Cardiac Emergency Congestive Heart Failure 7. HYPOTENSION/SHOCK Hypotension, Hypovolemia, And Shock 8. URINARY TRACT INFECTIO Urinary Tract Infection 9. PYELONEPHRITIS Pyelonephritis 10. RENAL DYSFUNCTION Renal Dysfunction (Acute Renal Failure) 11. INTERNAL ORGAN DAMAGE Internal Organ Damage Perforation Peritonitis Intestinal Obstruction Return To Surgery 12. BLEEDING (SURGICAL OR GI) Gastrointestinal Bleed/Blood Loss 13. DECUBITUS ULCER Decubitis Ulcer 14. ORTHOPEDIC COMPLICATIONS Orthopedic Complication Necrosis Of Bone Osteomyelitis

*For complete listing of ICD9 diagnosis/procedure and CPT procedure codes, please see complication definitions at http://stokes.chop.edu/programs/cor/outcomes.php V. Payment and Cost Algorithms

V.A. Exclusions for Non-Acute Care 1. Inpatient Hospital (Part A) File a. Exclude claim for hospitalizations in non-acute settings using 6-digit Medicare hospital ID (hospital identified as other than “Short-term (General and Specialty) Hospital” or “Critical Access Hospital”) i. Exclude if the 3rd position of the ID is not equal to “0” or if the 3rd and 4th positions are not equal to “13” ii. Exclude if if 4th, 5th, or 6th position in identifier is not a number b. Exclude claim if DRG = 462 (Rehabilitation) 2. Outpatient File a. Exclude claim for encounters in non-acute settings using 6-digit Medicare hospital ID (hospital identified as other than “Short-term (General and Specialty) Hospital” or “Critical Access Hospital”) i. Exclude if the 3rd position of the ID is not equal to “0” or if the 3rd and 4th positions are not equal to “13” ii. Exclude if 4th, 5th, or 6th position in identifier is not a number b. Exclude claim if principal diagnosis = V57 or subterms (Care involving use of rehabilitation procedures) 3. Physician/Carrier (Part B) File a. Exclude any claim if the from and through dates fall on or between the admission and discharge dates of a non-acute hospitalization (as defined above) or between the from and through dates of a claim for outpatient care in a non-acute hospital b. Exclude claim if no line item place of service codes from the following list appear: 11 = Office 15 = Mobile Unit 20 = Urgent Care Facility 21 = Inpatient hospital 22 = Outpatient hospital 23 = Emergency room - hospital 24 = Ambulatory surgical center 41 = Ambulance - land 42 = Ambulance - air or water 50 = Federally qualified health centers 65 End stage renal disease treatment 71 = State or local public health clinic facility 81 Independent laboratory c. Exclude claim if principal diagnosis = V57 or subterms (Care involving use of rehabilitation procedures)

V.B. Cost Estimate, Method 1 – Resource Utilization-Based Cost Accounting 1. Facility and Accommodation Costs: a. Accommodations: i. Determine number of inpatient critical care and non-critical care days from revenue centers in the Inpatient file. ii. Multiply number of critical care/non-critical care days by average daily cost for each type (adjust to 2008 values using CPI-M, hospital component - CCM: 3913.15; Non-CCM: 1282.51) Non-Critical Care Revenue Centers Critical Care Revenue Centers 0100-0101 All inclusive rate-room and board 0200-0209 Intensive care 0110-0119 Private medical or general 0210-0213, 0219 Coronary care 0120-0129 Semi-private 2 bed (medical or general) 0130-0139 Semi-private 3 and 4 beds 0140-0149 Private (deluxe) 0150-0159 Room & Board ward (medical or general) 0160, 0164, 0167 Other Room & Board b. Operating Room Time Cost (index admission only) i. Determine operating room time using “best anesthesia chart time,” if available; If best anesthesia time missing, use claim anesthesia time from Physician/Carrier (Part B) file; if both best chart time and claim time missing, assign each patient median best anesthesia time by procedure ii. Multiply anesthesia time by mean of OR time cost range and inflate to 2008 dollars ($18.03/minute) b. Emergency Room Visit Fixed Costs (post-discharge only) i. For post-discharge Part B records only, separate records into line items and locate place of service code 23 (“Emergency Room – Hospital”) ii. Treat each unique ER date as separate visit, sum visits per patient c. Multiply by average ER visit cost, inflated to 2008 dollars ($415.39) 2. Service Costs: (Note: Office visits, Home Care, SNF, and non-ER Outpatient use only section 2 methods) a. Separate line items from Part B (each includes patient ID, CPT code, units count, place of service) b. Anesthesia - if first two digits of CPT code are 00 or 01, code indicates anesthesia billing i. Apply standard CMS base units (2008 list) to each CPT code; if applicable, anesthesia modifier AD reduces base units to 3 per procedure for medical supervision ii. Since time units count reflects anesthesia time in minutes divided by 1.5, divide reported time by 10 to determine number of 15-minute anesthesia time units iii. Add base and time units for each line item, multiply by $20.03 (un- weighted mean of locality conversion factors, number needs to be revised once national CF available); If applicable, anesthesia modifier QK reduces total AVUs by 50% of allowed rate for medical direction of multiple procedures iv. Sum anesthesia line item costs by patient c. Other Services - apply method to all non-anesthesia Part B line items i. Merge line item CPT with AMA CPT/RVU list (2008 file) to determine RVU for each ii. Using place of service codes, determine whether facility or non-facility RVU is appropriate – for this cost estimate, treat outpatient hospitals as “non-facility” sites of care to adjust for facility component of service costs iii. Multiply RVUs by line item service count (=1 in 99% of non-anesthesia cases) iv. Multiply total RVUs by conversion factor ($38.09 in 2008) v. Sum line item costs by patient 3. Summary Equation: Resource Cost = (Inpatient CCM days*3913.15) + (Inpatient Non-CCM days*1282.51) + (Operating Room Time*18.03) + (Number of ER visits*415.39) + (Anesthesia Units*20.03) + (RVUs*38.09) V.D. Cost Estimate, Method 2 – Cost-to-Charge Ratios 1. Charge Sources: a. Inpatient Hospital Charges: extract total charge for each inpatient bill, index admission and any readmission beginning within 30 days of index admission b. Outpatient Hospital Charges (beginning after discharge, within 30 days of admission): i. Where available, extract total charge from line item with revenue center 0001 ii. If total charge line item absent, sum line items for entire bill and report as total 2. Cost-to-Charge Ratios Source: a. Total hospital costs from HCRIS Cost Report worksheet C, column 5, line 101 b. Total hospital charges from worksheet C, column 6 (inpatient) and column 7 (outpatient), line 101 c. Divide total costs by total charges for each year’s cost-charge ratio d. If there are multiple top-level reports for a single provider in a single year, take average of ratios 3. Merging Charges with Appropriate Cost-Charge Ratio: a. Multiplying the cost-to-charge ratio by charges to generate cost estimate. Attempt to apply the cost-charge ratio from the matching provider-year to each bill b. If the bill has no matching provider-year cost-charge ratio, the 6-digit Medicare provider code may refer to a hospital sub-unit (e.g. rehabilitation or psychiatric unit). These subunit distinctions are not given separate cost reports and must be matched to the “parent provider.” For these bills, the provider ID code includes a letter in the 3rd position; replace the letter with ‘0’ (short-term general and specialty hospital indicator) and attempt to match the bill to available cost-reports again c. If a hospital lacks a cost-charge ratio for the year of admission/encounter, but has valid cost reports for other OBSOS study years, use the average of available cost- charge ratios for that hospital d. For hospitals with no valid cost-charge ratios for the OBSOS study years, use the annual mean of all 47 OBSOS study hospitals 4. Physician Services: For physician service component, calculate costs in the same manner as indicated in “resource-based” cost method described above. The only exception is that bills using outpatient place of service codes should receive the correct “non-facility” RVU, since this costing method accounts for the facility costs of outpatient care through charges 5. Summary Equation: Cost-to-Charge Ratio Cost = (Inpatient Charges*Hospital CCR) + (Outpatient Charges*Hospital CCR) + (Anesthesia Units*20.03) + (RVUs*38.09) VI. Table 3A. Surgical Outcome Results (with full display of p-values) Non-Obese P-value, Non-Obese P-value, Complete Match Complete Limited Match Limited Outcome Measures OR† and 95% CI Match OR OR† and 95% CI Match OR Death 30-day 1.50 (0.73, 3.19) 0.31050 1.16 (0.60, 2.26) 0.75522 Death 180-day 1.04 (0.69, 1.58) 0.91961 0.95 (0.64, 1.40) 0.84819 Complications 30-day Wound Infection 1.64 (1.21, 2.21)d 0.00094 1.59 (1.18, 2.16)c 0.00184 Sepsis 1.81 (1.14, 2.90)b 0.00967 1.9 (1.21, 3.04)c 0.00417 Respiratory 1.44 (1.19, 1.75)e 0.00017 1.44 (1.19, 1.75)e 0.00012 Venous Thromboembolism 1.47 (1.09, 2.00)a 0.01050 1.23 (0.92, 1.64) 0.16023 Central Neurological Events 1.06 (0.78, 1.44) 0.76247 0.87 (0.65, 1.16) 0.35559 Cardiac Events 1.32 (1.04, 1.67)a 0.02098 1.69 (1.35, 2.14)f <0.00001 Hypotension/Shock 1.38 (1.07, 1.80)a 0.01311 1.27 (0.99, 1.63) 0.05901 Urinary Tract Infection 1.55 (1.24, 1.94)e 0.00010 1.85 (1.46, 2.35)f <0.00001 Pyelonephritis 2.00 (0.54, 9.07) 0.38770 8.00 (1.07, 355)a 0.03910 Renal Dysfunction 2.05 (1.39, 3.05)e 0.00015 2.67 (1.77, 4.11)f <0.00001 Internal Organ Damage 1.25 (0.95, 1.64) 0.11097 1.16 (0.90, 1.49) 0.26148 Bleeding (surgical or GI) 0.91 (0.79, 1.05) 0.19765 0.97 (0.84, 1.13) 0.71037 Decubitis Ulcer 1.23 (0.67, 2.26) 0.56817 1.59 (0.83, 3.10) 0.17417 Orthopedic Complications 0.92 (0.66, 1.29) 0.68521 0.99 (0.70, 1.39) 1.00000 Length of Stay (days) Ratio†† 1.12f Ratio†† 1.15f (Obese to (Obese to Non-Obese) 95% CI < 0.00001 Non-Obese) 95% CI < 0.00001 (1.08, 1.17) (1.11. 1.21) Readmission or Death 7-day 1.56 (1.08,2.27)a 0.01196 1.67 (1.13,2.50)a 0.01041 30-day 1.38 (1.08,1.77)b 0.00952 1.53 (1.20,1.96)d 0.00054

Ratio†† Cost Ratio Ratio†† Cost Ratio (Obese to minus (Obese to minus Costs and Payments, In- Non-Ob.) PMT Ratio Non-Ob.) PMT Ratio hospital or Within 30 Days Complete Complete Limited Limited 1.10f 0.06f 1.10 f 0.06 f Costs ($) (Estimated using cost-to- (1.07,1.12) (0.04,0.08) (1.08,1.13) (0.04,0.08) charge ratios) P < 0.00001 P < 0.00001 P < 0.00001 P < 0.00001 1.10f 0.08f 1.11f 0.08 f Costs ($) (Estimated using resources) (1.08,1.13) (0.05,0.10) (1.09,1.14) (0.06,0.10) P < 0.00001 P < 0.00001 P < 0.00001 P < 0.00001 1.03f 1.03 f Medicare Payments ------(PMT)* (1.02,1.05) (1.02,1.05) ($) P < 0.00002 P < 0.00001

† OR: Odds ratio comparing obese to non-obese; ††H-L: Hodges-Lehmann Estimator P-values compare obese to non-obese.