title: Effectiveness and safety of different duration of thromboprophylaxis in 16,865 hip replacement patients--a real-word, prospective observational study.
abstract: BACKGROUND
  Clinical trials have provided evidence about efficacy and safety of extended thromboprophylaxis among total hip replacement (THR) patients. There is a lack of evidence on effectiveness and safety of extended treatment in unselected patients from routine clinical practice. We examined the effectiveness and safety of short (1-6 days) and standard (7-27 days) compared with extended (≥28 days) thromboprophylaxis using population-based design.
  
  
  METHODS
  Among all primary THR procedures performed in Denmark from 2010 through 2012 (n=16,865), we calculated adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) for risk of symptomatic venous thromboembolism (VTE) and major bleeding, in addition to net clinical benefit, defined as the number of VTE avoided minus the number of excess bleeding events occurring among patients prescribed short-term and standard versus extended treatment.
  
  
  RESULTS
  The 90-day risks of VTE were 1.1% (short), 1.4% (standard), and 1.0% (extended), yielding aHRs of 0.83 (95% CI: 0.52-1.31) and 0.82 (95% CI: 0.50-1.33) for short and standard versus extended treatment. The risk of major bleeding was 1.1% (short), 1.0% (standard), and 0.7% (extended), resulting in aHRs of 1.64 (95% CI: 0.83-3.21) and 1.24 (95%CI: 0.61-2.51) for short and standard versus extended thromboprophylaxis. Direct comparison between benefits and harms using net clinical benefit analyses did not favor any of the three treatment durations. The same results were found for VTE or death.
  
  
  CONCLUSIONS
  In a real-word observational cohort of unselected THR patients, we observed no difference in the risks of symptomatic VTE, VTE/ death or bleeding with respect to thromboprophylaxis duration.
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Alle 43-45 8200 Aarhus N, Denmark. Electronic address: abp@clin.au.dk.
authors.forename: Alma B
authors.initials: AB
authors.lastname: Pedersen
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Alle 43-45 8200 Aarhus N, Denmark. Electronic address: hts@clin.au.dk.
authors.forename: Henrik Toft
authors.initials: HT
authors.lastname: Sorensen
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Alle 43-45 8200 Aarhus N, Denmark. Electronic address: fm@clin.au.dk.
authors.forename: Frank
authors.initials: F
authors.lastname: Mehnert
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Alle 43-45 8200 Aarhus N, Denmark. Electronic address: spj@clin.au.dk.
authors.forename: Soren Paaske
authors.initials: SP
authors.lastname: Johnsen
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Sdr. Boulevard 29, 5000 Odense C, Denmark. Electronic address: soeren.overgaard@rsyd.dk.
authors.forename: Soren
authors.initials: S
authors.lastname: Overgaard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use*; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D002648:Child; D015331:Cohort Studies; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D064887:Observational Studies as Topic; D011446:Prospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D054556:Venous Thromboembolism / Q000188:drug therapy*; D055815:Young Adult
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight
keywords: Anticoagulant drugs; Hemorrhage; Hip prosthesis; Treatment Effectiveness; Venous Thromboembolism