Chest
Original ResearchAntithrombotic TherapyRelative Effects of Two Different Enoxaparin Regimens as Comparators Against Newer Oral Anticoagulants: Meta-analysis and Adjusted Indirect Comparison
Section snippets
Search Strategy
We conducted a systematic review of the literature to identify knee or hip surgery trials involving the oral anticoagulants dabigatran, rivaroxaban, or apixaban compared with once-daily or bid enoxaparin. A search was conducted of MEDLINE, EMBASE, and Cochrane library. The exact search strategy is shown in e-Appendix 1. We also checked the bibliographies of included trials for any relevant studies.
Eligibility Criteria
The specific inclusion criteria for randomized controlled trials (RCTs) were (1) double-blind
Study Selection, Design, and Methodology
Fourteen double-blind randomized trials met the inclusion criteria (four dabigatran,11, 12, 13, 14 six rivaroxaban,15, 16, 17, 18, 19, 20 and four apixaban21, 22, 23, 24 trials); the study selection process is shown in Figure 1. Five of the 14 trials used enoxaparin 30 mg bid as the control arm while the remaining nine used once-daily enoxaparin 40 mg. Study methods are shown in Table 1.
Quality Assessment
The quality of studies is shown in e-Table 1. Randomization methods were adequate and sufficiently described
Discussion
Our adjusted indirect comparison indicates that once-daily 40-mg enoxaparin is associated with a significantly inferior effect (about 30% less benefit) for prevention of total VTE and 45% less benefit for symptomatic VTE as compared with bid 30-mg enoxaparin. The direction of effect is consistent, irrespective of whether the adjusted indirect comparison was performed through the apixaban or dabigatran or rivaroxaban trials dataset, or whether we used total VTE or symptomatic VTE as the outcome
Acknowledgments
Author contributions: Dr Loke is the guarantor for the manuscript.
Dr Kwok: contributed to the study by performing the search, screening search results and reviewing abstracts for study selection, extracting the data, performing the data analysis, and writing the manuscript.
Dr Pradhan: contributed to the study by screening search results and reviewing abstracts for study selection, extracting the data, and writing the manuscript.
Dr Yeong: contributed to the study by screening search results and
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Funding/Support: The authors have reported to CHEST that no funding was received for this study.
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