The Use of Low-Dose Warfarin as Prophylaxis for Central Venous Catheter Thrombosis in Patients With Cancer: A Meta-Analysis

Krista Rawson

Christine V. Newburn-Cook

meta-analysis, central venous; thrombosis
ONF 2007, 34(5), 1037-1043. DOI: 10.1188/07.ONF.1037-1043

Purpose/Objectives: To determine whether the use of low-dose warfarin could reduce the incidence of thrombosis in patients with cancer who have a central venous catheter (CVC).

Data Sources: MEDLINE®, CINAHL®, CANCERLIT®, EMBASE®, and the Cochrane Library.

Data Synthesis: Meta-analysis of four studies (N = 1,236 patients) revealed that 6.4% of warfarin-treated patients experienced a thrombotic event compared with 7.5% in the control (no treatment) group. The risk difference for thrombus formation was not significant (2.0%, confidence interval = -9.0% to 5.0%).

Conclusions: The administration of warfarin did not reduce the incidence of symptomatic or asymptomatic CVC-associated thrombosis in patients with cancer.

Implications for Nursing: Using research findings to inform clinical nursing practice is important in caring for patients and providing optimal and improved patient outcomes. Prophylactic use of low-dose warfarin may not prevent thrombus formation and is associated with potentially adverse patient outcomes.

Jump to a section


    Agnelli, G. (1997). Venous thromboembolism and cancer: A two-way clinical association. Thrombosis and Haemostasis, 78, 117-120.
    Bern, M.M., Lokich, J.J., Wallach, S.R., Bothe, A.J., Benotti, P.N., Arkin, C.F., et al. (1990). Very low doses of warfarin can prevent thrombosis in central venous catheters: A randomized prospective trial. Annals of Internal Medicine, 112, 423-428.
    Bona, R.D. (1999). Thrombotic complications of central venous catheters in cancer patients. Seminars in Thrombosis and Hemostasis, 25, 147-155.
    Bona, R.D., Sivjee, K.Y., Hickey, A.D., Wallace, D.M., & Wajcs, S.B. (1995). The efficacy and safety of oral anticoagulation in patients with cancer. Thrombosis and Haemostasis, 74, 1055-1058.
    Clagett, G.P., Anderson, F.A., Levine, M.N., Salzman, E.W., & Wheeler, H.B. (1992). Prevention of venous thromboembolism. Chest, 102(Suppl. 4), 391S-407S.
    Clarke, M., & Oxman, A.D. (Eds.). (2003). Cochrane reviewers' handbook 4.1.6. Retrieved February 1, 2003, from
    Coccheri, S., Palareti, G., & Cosmi, B. (1999). Oral anticoagulant therapy: Efficacy, safety and the low dose controversy. Haemostasis, 29, 150-165.
    Couban, S., Goodyear, M., Burnell, M., Dolan, S., Wasi, P., Macleod, D., et al. (2005). Randomized double blind placebo-controlled study of lowdose warfarin for the prevention of central venous catheter-associated thrombosis in patients with cancer. Journal of Clinical Oncology, 23, 4063-4069.
    Deeks, J.J., Altman, D.G., & Bradburn, M.J. (2001). Statistical methods for examining heterogeneity and combining results from several studies in meta-analysis. In M. Egger, G. Davey Smith, & D.G. Altman (Eds.), Systematic reviews in health care: Meta-analysis in context (2nd ed., pp. 285-312). London: BMJ Publishing
    De Takats, G. (1950). Anticoagulant therapy in surgery. JAMA, 142, 527-534.
    Dickersin, K., & Berlin, J.A. (1992). Meta-analysis: State-of-the-science. Epidemiologic Reviews, 14, 154-176.
    Egger, M., Ebrahim, S., & Smith, G.D. (2002). Where now for meta-analysis? International Journal of Epidemiology, 31, 1-5.
    Hardy, R.J., & Thompson, S.G. (1998). Detecting and describing heterogeneity in meta-analysis. Statistics in Medicine, 17, 841-856.
    Heaton, D.C., Han, D.Y., & Inder, A. (2002). Minidose (1 mg) warfarin as prophylaxis for central vein catheter thrombosis. Internal Medicine Journal, 32, 84-88.
    Hylek, E.M., Regan, S., Go, A.S., Hughes, R.A., Singer, D.E., & Skates, S.J. (2001). Clinical predicators of prolonged delay in return of the international normalized ratio to within the therapeutic range after excessive anticoagulation with warfarin. Annals of Internal Medicine, 135, 393-400.
    Jadad, A.R., Moore, R.A., Carroll, D., Jenkinson, C., Reynolds, D.J., Gavaghan, D.J., et al. (1996). Assessing the quality of reports of randomized clinical trials: Is blinding necessary? Controlled Clinical Trials, 17, 1-12.
    Kakkar, A.K., & Williamson, R.C. (1998). Thromboprophylaxis in the cancer patient. Haemostatis, 28(Suppl. 3), 61-65.
    Kuruvilla, M., & Gurk-Turner, C. (2001). A review of warfarin dosing and monitoring. Baylor University Medical Center Proceedings, 14, 305-308.
    Lee, A.Y., & Levine, M.N. (2003). Venous thromboembolism and cancer: Risks and outcomes. Circulation, 107(Suppl. 1), I17-I21.
    Levine, M.N., Raskob, G., Landefeld, S., & Kearon, C. (2001). Hemorrhagic complications of anticoagulant treatment. Chest, 119(Suppl. 1), 108S-121S.
    Lip, G.Y., Chin, B.S., & Blann, A.D. (2002). Cancer and the prothrombotic state. Lancet Oncology, 3, 27-34.
    Montori, V., Swiontkowski, M.F., & Cook, D.J. (2003). Methodological issues in systematic reviews and meta-analyses. Clinical Orthopaedics and Related Research, 413(1), 43-54.
    Pineo, G., & Hull, R.D. (2003). Coumarin therapy in thrombosis. Hematology/Oncology Clinics of North America, 17, 201-216.
    Prandoni, P., Piccioli, A., & Girolami, A. (1999). Cancer and venous thromboembolism: An overview. Haematologica, 84, 437-445.
    Schulz, K., Chalmers, I., Hayes, R., & Altman, D.G. (1995). Empirical evidence of bias: Dimensions of methodological quality associated with estimates of treatment effects in controlled trials. JAMA, 273, 408-412.
    Schwartz, J.D., & Simantov, R. (1998). Thrombosis and malignancy: Pathogenesis and prevention. In Vivo, 12, 619-624.
    Solymoss, S. (2000). Risk factors for thromboembolism: Pathophysiology and detection. Canadian Medical Association Journal, 163, 991-994.
    Sorensen, H.T., Mellemkajaer, L., Olsen, J.H., & Baron, J.A. (2000). Prognosis of cancers associated with venous thromboembolism. New England Journal of Medicine, 343, 1846-1850.
    Wickham, R., Purl, S., & Welker, D. (1992). Long-term central venous catheters: Issues for care. Seminars in Oncology Nursing, 8, 133-147.
    Young, A.M., Begum, G., Billingham, L.J., Hughes, A.I., Kerr, D.J., Rea, D., et al. (2005). WARP-A multicentre prospective randomised controlled trial (RCT) of thrombosis prophylaxis with warfarin in cancer patients with central venous catheters (CVCs) [Abstract 8004]. Journal of Clinical Oncology, 23(Suppl. 1), 16S.