Effectiveness and safety of different duration of thromboprophylaxis in 16,865 hip replacement patients - A real-word, prospective observational study

- The benefits and harms of drug thromboprophylaxis well known from RCT in THR
- Similar risk of VTE or bleeding irrespective of treatment duration in real life THR
- Direct comparison between VTE and bleeding did not favor extended treatment in THR
- Results from RCT was not confirmed in real life THR settings
- Confounding by indication may be the limitation of our study

IntroductionClinical 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.Material and methodsAmong 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.ResultsThe 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.ConclusionsIn 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.