Abstract
Many hospitals have implemented warfarin dosing nomograms to improve patient safety. To our knowledge, no study has assessed the impact inpatient warfarin initiation has in both medical and surgical patients, on safety outcomes post discharge. To evaluate the impact of a suggested institutional nomogram for the initiation of warfarin, the primary endpoint was the incidence of bleeding throughout follow up. Secondary endpoints included the composite of INR changes ≥0.5/day and INR >4. Patients were followed for a period of 2 weeks post-discharge. The composite endpoint was evaluated for an effect on reaching therapeutic INR, time to reach therapeutic INR, and bleeding events throughout follow up. A single center retrospective study comparing the safety of adherence vs. non-adherence to a warfarin nomogram. A total of 206 patients were included, 73 patients in the nomogram adherence vs. 133 in the nonadherence arm. There was no difference in the proportion of patients who bled throughout the follow up period, adherence 9.6% vs. nonadherence to the nomogram 13.5%, p = 0.407. There was however a statistical difference in the mean total number of bleeding events, 0.096 (7/73) in the adherence vs. 0.158 (21/133) in the non-adherence arm, p = 0.022. There was also no difference in the composite endpoint, 19.2% in the adherence vs. 28.6% in the non-adherence arm p = 0.180. A positive correlation between the inpatient composite and risk of bleeding throughout follow up was noted. The findings of this study support adherence to the nomogram as opposed to non-adherence.
Similar content being viewed by others
References
The Joint Commission (2016) National patient safety goals effective January 2017. Hospital Accreditation Program. https://www.jointcommission.org/assets/1/6/NPSG_Chapter_HAP_Jan2017.pdf. Accessed 9 Dec 2016
Dager WE (2007) Improving anticoagulation management in patients with atrial fibrillation. Am J Health Syst Pharm 64:2279–2280
Wong YM, Quek YN, Tay JC et al (2011) Efficacy and safety of a pharmacist-managed inpatient anticoagulation service for warfarin initiation and titration. J Clin Pharm Ther 36:585–591
Nisly S, Shiltz ED, Vanarsdale V et al (2013) Implementation of an order set to adhere to national patient safety goals for warfarin therapy. Hosp Pharm 48:828–832
Donovan JL, Drake JA, Whittaker P et al (2006) Pharmacy-managed anticoagulation: assessment of in-hospital efficacy and evaluation of financial impact and community acceptance. J Thromb Thrombolys 22:23–30
Crowther MA, Ginsberg JB, Kearon C et al (1999) A randomized trial comparing 5-mg and 10-mg warfarin loading doses. Arch Int Med 159:46–48
Harrison L, Johnston M, Massicotte MP et al (1997) Comparison of 5-mg and 10-mg loading doses in initiation of warfarin therapy. Ann Int Med 126:133–136
Oake N, Fergusson DA, Forster AJ et al (2007) Frequency of adverse events in patients with poor anticoagulation: a meta-analysis. CMAJ 176:1589–1594
Rao SV, O’grady K, Pieper KS et al (2006) A comparison of the clinical impact of bleeding measured by two different classifications among patients with acute coronary syndromes. J Am Coll Cardiol 47:809–816
Serebruany VL, Atar D (2007) Assessment of bleeding events in clinical trials-proposal of a new classification. Am J Cardiol 99:288–290
Razouki Z, Ozonoff A, Zhao S et al (2014) Improving quality measurement for anticoagulation: adding international normalized ratio variability to percent time in therapeutic range. Circ Cardiovasc Qual Outcomes 7:664–669
Jackson SL, Peterson GM, Vial JH et al (2004) Improving the outcomes of anticoagulation: an evaluation of home follow-up of warfarin initiation. J Int Med 256:137–144
Dager WE, Branch JM, King JH et al (2000) Optimization of inpatient warfarin therapy: impact of daily consultation by a pharmacist-managed anticoagulation service. Ann Pharmacother 34:567–572
Yoo SH, Kwon SU, Jo MW et al (2012) Age- and weight-adjusted warfarin initiation nomogram for ischaemic stroke patients. Eur J Neurol 19:1547–1553
Roberts GW, Helboe T, Nielsen CB et al (2003) Assessment of an age-adjusted warfarin initiation protocol. Ann Pharmacother 37:799–803
Roberts GW, Adams R (2006) Impact of Introducing anticoagulation-related prescribing guidelines in a hospital setting using academic detailing. Ther Clin Risk Manag 2:309–316
Asnis PD, Gardner MJ, Ranawat A et al (2007) The effectiveness of warfarin dosing from a nomogram compared with house staff dosing. J Arthroplasty 22:213–218
Anderson DR, Wilson SJ, Blundell J et al (2002) Comparison of a nomogram and physician-adjusted dosage of warfarin for prophylaxis against deep-vein thrombosis after arthroplasty. J Bone Joint Surg Am 84-A:1992–1997
Nutescu EA, Wittkowsky AK, Burnett A et al (2013) Delivery of optimized inpatient anticoagulation therapy: consensus statement from the anticoagulation forum. Ann Pharmacother 47:714–724
Holbrook A, Schulman S, Witt DM et al (2012) Evidence-based management of anticoagulant therapy: antithrombotic therapy and prevention of thrombosis, 9th ed: American college of chest physicians evidence-based clinical practice guidelines. Chest 141:e152S–e184S
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Ethical approval
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of study formal consent is not required.
Appendix: Warfarin Order Form and Nomogram
Appendix: Warfarin Order Form and Nomogram
Rights and permissions
About this article
Cite this article
Chamoun, N., Macías, C.G., Donovan, J.L. et al. Implications of an inpatient warfarin dosing nomogram on safety outcomes post-discharge. J Thromb Thrombolysis 43, 454–462 (2017). https://doi.org/10.1007/s11239-016-1462-0
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11239-016-1462-0