Deep vein thrombosis: prophylaxis: for 4 to 6 weeks leads to fewer DVT but more minor bleeding than prophylaxis limited to hospital stay

Clinical bottom line (level 1a)

  1. Patients undergoing hip or knee arthroplasty who receive venous thromboembolism prophylaxis for 4-6 weeks compared with in-hospital are less likely to develop a DVT (NNT = 64 at 4-6 weeks) , but are more likely to have a minor bleed (NNH = 71 at 4-6 weeks) .
  2. There is no clear reduction in PE or increase in major bleeding on extended prophylaxis.
Eikelboom et al: Lancet 2001; 358 : 9-15
Expires May 2004

The study

Systematic review of all randomised trials of
  • Patients: undergoing hip or knee arthroplasty
  • Intervention: extended-duration anticoagulant thromboprophylaxis compared with placebo or untreated control
  • Outcome: venous thromboembolism, major or minor bleeding

Articles found in ?English only using Medline, Embase, January 1980 to July 2000 (search terms: detailed in text ) and searching bibliographies of retrieved articles, and contacting manufacturers of low-molecular weight heparins

Selection criteria: by 2 independent reviewers
Appraisal criteria: by 2 independent reviewers using Schultz criteria: randomisation, concealment allocation, blinding, completeness of follow-up
Articles excluded if:
  • venous thromboembolism not confirmed objectively
9 RCTs found using ardeparin, dalteparin, enoxaparin, nadroparin, and fixed-dose unfractionated heparin for 4-6 weeks
Study results were not found to be heterogeneous.

The evidence

Outcome Time to outcome CER OR
(95% CI)		 NNT
(95% CI)
DVT 4-6 weeks 47/1742
(2.7%)		 0.41
(0.24 to 0.68) 		64
(49 to 120)
PE 4-6 weeks 11/1744
(0.63%)		 0.43
(0.17 to 1.06) 		280
(NNT = 2700 to infinity;
NNH = 190 to infinity)
minor bleeding 4-6 weeks 48/1834
(2.62%)		 1.56
(1.08 to 2.26) 		-71
(-490 to -32)
major bleeding 4-6 weeks 5/1872
(0.27%)		 0.62
(0.22 to 1.75) 		990
(NNT = 500 to infinity;
NNH = 480 to infinity)

  • No difference in mortality was noted between the two groups.

Citation

  1. Eikelboom JW, Quinlan DJ, Douketis JD: extended-duration prophylaxis against venous thromboembolism after total hip or knee replacement: a meta-analysis of the randomised trials. Lancet 2001; 358 : 9-15
Search Terms:
Contributor: Chris Ball, May 2002
Reviewer:

Clinical Question.
Patient total hip or knee replacement
Intervention or Exposure venous thromboembolism prophylaxis for 4 to 6 weeks
Comparison prophylaxis in hospital
Outcome venous thromboembolism, bleeding