Skip to main content

Implications of an inpatient warfarin dosing nomogram on safety outcomes post-discharge

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.

This is a preview of subscription content, access via your institution.

References

  1. 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

  2. Dager WE (2007) Improving anticoagulation management in patients with atrial fibrillation. Am J Health Syst Pharm 64:2279–2280

    Article  PubMed  Google Scholar 

  3. 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

    CAS  Article  PubMed  Google Scholar 

  4. 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

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  5. 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

    Article  Google Scholar 

  6. 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

    CAS  Article  Google Scholar 

  7. 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

    CAS  Article  PubMed  Google Scholar 

  8. 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

    Article  PubMed  PubMed Central  Google Scholar 

  9. 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

    Article  PubMed  Google Scholar 

  10. Serebruany VL, Atar D (2007) Assessment of bleeding events in clinical trials-proposal of a new classification. Am J Cardiol 99:288–290

    Article  PubMed  Google Scholar 

  11. 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

    Article  PubMed  Google Scholar 

  12. 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

    CAS  Article  Google Scholar 

  13. 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

    CAS  Article  PubMed  Google Scholar 

  14. 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

    Article  PubMed  Google Scholar 

  15. Roberts GW, Helboe T, Nielsen CB et al (2003) Assessment of an age-adjusted warfarin initiation protocol. Ann Pharmacother 37:799–803

    CAS  Article  PubMed  Google Scholar 

  16. 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

    Article  PubMed  PubMed Central  Google Scholar 

  17. 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

    Article  PubMed  Google Scholar 

  18. 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

    Article  PubMed  Google Scholar 

  19. 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

    Article  PubMed  Google Scholar 

  20. 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

    CAS  Article  PubMed  PubMed Central  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Nibal Chamoun.

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

figure a
figure b

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

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

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11239-016-1462-0

Keywords

  • Warfarin
  • Anticoagulation
  • Nomograms
  • Inpatient
  • Safety