Supplementary Appendix. Surgical cohort definitions based on International Classification of Diseases 9th Revision (ICD-9) procedure codes.
Surgical Cohort Procedure
Code Description
Percutaneous Transluminal
Coronary Angioplasty 00.66 Percutaneous transluminal coronary angioplasty [PTCA]
Coronary Artery Bypass
Graft 36.1X Bypass anastomosis for heart revascularization Heart Valve Procedures 35.XX Operations on valves and septa of heart
Cholecystectomy &
Common Duct Exploration
51.11 Laparoscopic exploration of common bile duct 51.2X Cholecystectomy
51.41 Common duct exploration for removal of calculus 51.42 Common duct exploration for relief of other obstruction 51.51 Exploration of common duct
Colorectal Resection
45.7X Open and other partial excision of large intestine 45.8X Total intra-abdominal colectomy
46.04 Resection of exteriorized segment of large intestine
46.1X Colostomy
46.2X Illeostomy
48.4X Pull-through resection of rectum 48.5X Abdominoperineal resection of rectum 48.6X Other resection of rectum
48.7X Repair of rectum Appendectomy 47.0X Appendectomy
Tubal Ligation 66.2X Bilateral endoscopic destruction or occlusion of fallopian tubes 66.3X Other bilateral destruction or occlusion of fallopian tubes Hysterectomy 68.XX Other incision and excision of uterus
Oophorectomy 65.3X Unilateral Oophorectomy 65.5X Bilateral Oophorectomy Total Hip Arthroplasty 81.51 Total hip replacement Total Knee Arthroplasty 81.54 Total knee replacement
Spinal Fusion
81.0X Spinal fusion 81.3X Refusion of spine
81.62 Fusion or refusion of 2-3 vertebrae 81.63 Fusion or refusion of 4-8 vertebrae 81.64 Fusion or refusion of 9 or more vertebrae
Laminectomy 03.0X Exploration and decompression of spinal canal structures
Fracture/Dislocation of Hip or Femur
*Hip replacement codes when paired with ICD-9 diagnosis codes for hip fracture (820.0X, 820.1X,
820.21, 820.22, 820.31, 820.32, 820.8, 820.9)
00.7X Other hip procedures
00.85 Resurfacing hip, total, acetabulum, and femoral head 00.86 Resurfacing hip, partial, femoral head
00.87 Resurfacing hip, partial acetabulum
78.55 Internal fixation of bone without fracture reduction of femur 79.25 Open reduction of fracture without internal fixation of femur 79.25 Open reduction of fracture with internal fixation of femur 79.55 Open reduction of separated epiphysis of femur
79.65 Debridement of open fracture site of femur 79.85 Open reduction of dislocation of hip 79.95 Unspecified operation on bone injury of hip 81.40 Repair of hip, not elsewhere classified 81.51 Total hip replacement
81.52 Partial hip replacement
81.53 Revision of hip replacement, not otherwise specified
Fracture/Dislocation of 79.26 Open reduction of fracture without internal fixation, tibia and fibula
Lower Extremity
79.27 Open reduction of fracture without internal fixation, tarsals and metatarsals 79.28 Open reduction of fracture without internal fixation, phalanges of foot 79.36 Open reduction of fracture with internal fixation, tibia and fibula 79.37 Open reduction of fracture with internal fixation, tarsals and metatarsals 79.38 Open reduction of fracture with internal fixation, phalanges of foot 79.86 Open reduction of dislocation of knee
79.87 Open reduction of dislocation of ankle 79.88 Open reduction of dislocation of foot and toe
