title: Venous thromboembolic events: How low can you go?
abstract: BACKGROUND
  We evaluated postoperative venous thromboembolism (VTE) chemical prophylaxis adherence to assess the preventability of VTEs.
  
  
  METHODS
  A case-control study was performed using the 2011-2015 ACS-NSQIP single institution database. Cases were identified as patients who experienced postoperative VTE within 30 days following surgery. Controls were matched 2:1 on procedure, age, and BMI. Association between inpatient chemical prophylaxis adherence and postoperative VTE was evaluated with conditional logistic regression.
  
  
  RESULTS
  Seventy-three cases were matched to 145 controls. Complete inpatient VTE chemical prophylaxis adherence did not differ between cases and controls (45.2% vs. 46.2%, p = 1.00). Odds of postoperative VTE increased if a patient's prophylaxis was interrupted (OR 6.34, 95% CI 1.82-22.13). However, 53.7% of instances of interrupted prophylaxis were medically justified by concern for bleeding, spine operation, or for additional upcoming procedure.
  
  
  CONCLUSIONS
  Nearly half of patients who experienced postoperative VTEs received appropriate guideline-driven care. Most interruptions in chemical prophylaxis were justified medically. This further questions the preventability of postoperative VTEs and the utility of this outcome as a valid measure of hospital quality.
authors.affiliation: University of Alabama at Birmingham, Department of Surgery, USA.
authors.forename: Caroline E
authors.initials: CE
authors.lastname: Jones
authors.affiliation: University of Alabama at Birmingham, Department of Surgery, USA.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Hollis
authors.affiliation: University of Alabama at Birmingham, Department of Surgery, USA.
authors.forename: Allison A
authors.initials: AA
authors.lastname: Gullick
authors.affiliation: University of Alabama at Birmingham, Department of Surgery, USA.
authors.forename: Tyler
authors.initials: T
authors.lastname: Wahl
authors.affiliation: University of Alabama at Birmingham, Department of Surgery, USA.
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Richman
authors.affiliation: University of Alabama at Birmingham, Department of Surgery, USA.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Graham
authors.affiliation: University of Alabama at Birmingham, Department of Surgery, USA.
authors.forename: Adam T
authors.initials: AT
authors.lastname: Lucy
authors.affiliation: University of Alabama at Birmingham, Department of Surgery, USA.
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Chu
authors.affiliation: University of Alabama at Birmingham, Department of Surgery, USA. Electronic address: msmorris@uabmc.edu.
authors.forename: Melanie S
authors.initials: MS
authors.lastname: Morris
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use*; D016022:Case-Control Studies; D017984:Enoxaparin / Q000627:therapeutic use; D005260:Female; D019983:Guideline Adherence / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000517:prevention & control*; D017410:Practice Guidelines as Topic; D011785:Quality Assurance, Health Care; D014481:United States; D054556:Venous Thromboembolism / Q000209:etiology / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants; D017984:Enoxaparin
keywords: DVT; NSQIP; Preventability; Thromboembolism; VTE