title: Incidence of venous thromboembolism and bleeding events in patients with lower extremity orthopedic surgery: a retrospective analysis of a Japanese healthcare database.
abstract: BACKGROUND
  Orthopedic surgeries of lower extremities such as total knee arthroplasty (TKA), total hip arthroplasty (THA), and hip fracture surgery (HFS) are widely considered to carry a high risk of developing deep venous thrombosis (DVT) and pulmonary thromboembolism (PTE). Growing attention to epidemiological studies using a healthcare database led us to quantify the risks using a Japanese database to reveal recent medical care for such events.
  
  
  METHODS
  The study comprised 36,947 patients who had undergone orthopedic surgeries of the lower extremities and whose medical information from April 2008 to September 2013 was available. The source population of the database was derived from 100 acute-care hospitals with Diagnosis Procedure Combination. The events were defined by diagnosis, medication, imaging, and laboratory tests.
  
  
  RESULTS
  A breakdown of patients who underwent orthopedic surgeries by type of surgery showed 13.6% for TKA, 10.4% for THA, 56.8% for HFS, 1.5% for rupture of Achilles tendon, and 18.0% for simple fracture of lower extremities. The incidence for DVT, PTE, and bleeding events by type of surgery was 1.3, 0.2, and 1.0% for TKA; 0.9, 0.2, and 1.1% for THA; and 0.4, 0.1, and 1.8% for HFS, respectively. The population for risk factor analysis consisted of patients with similar background factors who underwent TKA, THA, or HFS. The statistically significant risk factors for PTE analyzed by the backward elimination procedure in a multivariate model were female sex, history of venous thromboembolism (VTE), thrombophilia, and varicose veins of lower extremity.
  
  
  CONCLUSIONS
  The incidence of DVT, PTE, and bleeding events and the risk factors for DVT and PTE in patients by type of orthopedic surgeries of lower extremities found in our study are considered to be rational as they reflect evidence from real-world cases.
  
  
  BACKGROUND
  University Hospital Medical Information Network Clinical Trials Registry UMIN000012667.
authors.affiliation: Department of Orthopaedic Surgery, Japan Community Healthcare Organization Osaka Hospital, 4-2-78 Fukushima, Fukushima-ku, Osaka, 553-0003, Japan. fuji-th@umin.ac.jp.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fuji
authors.affiliation: Department of Orthopaedic Surgery, Kinki University Faculty of Medicine, Osaka-Sayama City, Osaka, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Akagi
authors.affiliation: Department of Orthopaedic Surgery, Federation of National Public Service Personnel Mutual Aid Associations, Kumamoto Chuo Hospital, Kumamoto City, Kumamoto, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Abe
authors.affiliation: Medical TOUKEI Corporation, Shinjuku-ku, Tokyo, Japan.
authors.forename: Eisei
authors.initials: E
authors.lastname: Oda
authors.affiliation: Medical Data Vision Co., Ltd., Chiyoda-ku, Tokyo, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Matsubayashi
authors.affiliation: Medical Data Vision Co., Ltd., Chiyoda-ku, Tokyo, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Ota
authors.affiliation: Department of Corporate Planning, Linical Co., Ltd., Osaka City, Osaka, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: EU Biostatistics & Data Management, Daiichi Sankyo Europe GmbH, Munich, Germany.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Matsushita
authors.affiliation: Medical Science Department, Daiichi Sankyo Co., Ltd., Chuo-ku, Tokyo, Japan.
authors.forename: Jumpei
authors.initials: J
authors.lastname: Kaburagi
authors.affiliation: Medical Science Department, Daiichi Sankyo Co., Ltd., Chuo-ku, Tokyo, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Ibusuki
authors.affiliation: Safety and Risk Management Department, Daiichi Sankyo Co., Ltd., Chuo-ku, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takita
authors.affiliation: Medical Science Department, Daiichi Sankyo Co., Ltd., Chuo-ku, Tokyo, Japan.
authors.forename: Mikio
authors.initials: M
authors.lastname: Iwashita
authors.affiliation: Division of Biostatistics, Tohoku University Graduate School of Medicine, Sendai City, Miyagi, Japan.
authors.forename: Takuhiro
authors.initials: T
authors.lastname: Yamaguchi
mesh_terms: D000368:Aged; D005260:Female; D006470:Hemorrhage / Q000453:epidemiology* / Q000209:etiology; D049670:History, 17th Century; D049671:History, 18th Century; D006801:Humans; D007564:Japan / Q000453:epidemiology; D035002:Lower Extremity / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000009:adverse effects*; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D012189:Retrospective Studies; D054556:Venous Thromboembolism / Q000453:epidemiology* / Q000209:etiology
keywords: Healthcare database; Hip fracture surgery; Pulmonary thromboembolism; Total hip arthroplasty; Total knee arthroplasty; Venous thromboembolism