Journal of Thrombosis and Thrombolysis

, Volume 48, Issue 3, pp 459–465 | Cite as

Quality metrics of warfarin initiation in hospitalized older adults

  • Jessica CohenEmail author
  • Jason J. Wang
  • Liron Sinvani
  • Andrzej Kozikowski
  • Guang Qiu
  • Renee Pekmezaris
  • Alex C. Spyropoulos


Achieving therapeutic international normalized ratio (INRs) in warfarin naïve older adults can be complicated due to sensitivity factors. While multiple tools exist for warfarin initiation in the outpatient setting, there is a dearth of guidance for inpatient initiation. This study aims to: (1) describe a large health system’s initiation warfarin quality metrics in older inpatients, defined by INR overshoots greater than or equal to 5.0; (2) identify intrinsic and extrinsic patient factors associated with overshoots; and (3) explore the association between inpatient overshoots and clinical outcomes. Data on inpatients ≥ 65 years initiated on warfarin 1/1/2014-6/30/2016 were extracted through retrospective chart review. The primary outcome was prevalence of overshoots (INR ≥ 5). Logistic regression modeling determined the risk factors for overshoots. Multivariate analysis was employed to associate overshoots with length of stay (LOS), bleeding, and mortality. Additional analysis of the impact of patient weight (kg) on overshoots was achieved through chi square analysis. Of 4556 inpatients initiated on warfarin, 8% experienced overshoots. Non-black race, peripheral vascular disease, chronic obstructive pulmonary disease (COPD), mild liver disease, low weight, and no statin use were found to be predictive of overshoots. Compared to the group without overshoots, the group with overshoots experienced a significantly increased LOS (13 days vs. 8 days, < 0.001), higher bleed rate (30.1% vs. 6.5%, adjusted OR 6.2, p < 0.001), and higher mortality rate (13.8% vs. 3.4%, adjusted OR 4.4, p < 0.001). Inpatient warfarin initiation was associated with frequent overshoots and poor outcomes. Future studies should focus on strategies to improve hospital warfarin initiation safety.


Adverse drug events Anticoagulants Inpatients INR Warfarin Warfarin initiation 



The authors would like to acknowledge the New York State Empire Clinical Research Investigator Program (ECRIP) and the Center for Health Innovations and Outcomes Research at Northwell Health for their support.

Compliance with ethical standards

Conflict of interest

The authors have no conflicts of interest to report. All authors confirm that they have had full access to data and contributed to drafting of the paper.


  1. 1.
    Ageno W, Gallus AS, Wittkowsky A, Crowther M, Hylek EM, Palareti G (2012) Oral anticoagulant therapy: antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest 141(2 Suppl):e44S–e88SCrossRefGoogle Scholar
  2. 2.
    Dregan A, Ravindrarajah R, Charlton J, Ashworth M, Molokhia M (2018) Long-term trends in antithrombotic drug prescriptions among adults aged 80 years and over from primary care: a temporal trends analysis using electronic health records. Ann Epidemiol 28(7):440–446CrossRefGoogle Scholar
  3. 3.
    Kooistra HAM, Calf AH, Piersma-Wichers M, Kluin-Nelemans HC, Izaks GJ, Veeger NJGM et al (2016) Risk of bleeding and thrombosis in patients 70 years or older using vitamin K antagonists. JAMA Intern Med 176(8):1176–1183CrossRefGoogle Scholar
  4. 4.
    Wysowski DK, Nourjah P, Swartz L (2007) Bleeding complications with warfarin use: a prevalent adverse effect resulting in regulatory action. Arch Intern Med 167(13):1414–1419CrossRefGoogle Scholar
  5. 5.
    Classen DC, Jaser L, Budnitz DS (2010) Adverse drug events among hospitalized medicare patients: epidemiology and national estimates from a new approach to surveillance. Jt Comm J Qual Patient Saf 36(1):12–21CrossRefGoogle Scholar
  6. 6.
    Winterstein AG, Hatton RC, Gonzalez-Rothi R, Johns TE, Segal R (2002) Identifying clinically significant preventable adverse drug events through a hospital’s database of adverse drug reaction reports. Am J Health Syst Pharm 59(18):1742–1749CrossRefGoogle Scholar
  7. 7.
    Ghate SR, Biskupiak J, Ye X, Kwong WJ, Brixner DI (2011) All-cause and bleeding-related health care costs in warfarin-treated patients with atrial fibrillation. J Manag Care Pharm 17(9):672–684Google Scholar
  8. 8.
    National Patient Safety Goals.03.05.01 [Internet]. joint Commission. Accessed 25 Aug 2017
  9. 9.
    Garcia DA, Schwartz MJ (2011) Warfarin therapy: tips and tools for better control: monitoring patients on warfarin therapy is challenging. The tools highlighted here–from online forums and web-based dosing calculators to patient education materials and self-monitors–can help. J Fam Pract 60(2):70–76Google Scholar
  10. 10.
    Kim Y-K, Nieuwlaat R, Connolly SJ, Schulman S, Meijer K, Raju N et al (2018) Effect of a simple two-step warfarin dosing algorithm on anticoagulant control as measured by time in therapeutic range: a pilot study. J Thromb Haemost 8(1):101–106CrossRefGoogle Scholar
  11. 11.
    Dawson NL, Porter IE, Klipa D, Bamlet WR, Hedges MA, Maniaci MJ et al (2012) Inpatient warfarin management: pharmacist management using a detailed dosing protocol. J Thromb Thrombolysis 33(2):178–184CrossRefGoogle Scholar
  12. 12.
    Metersky ML, Eldridge N, Wang Y, Jaser L, Bona R, Eckenrode S et al (2016) Predictors of warfarin-associated adverse events in hospitalized patients: opportunities to prevent patient harm. J Hosp Med 11(4):276–282CrossRefGoogle Scholar
  13. 13.
    Sharma M, Krishnamurthy M, Snyder R, Mauro J (2017) Reducing error in anticoagulant dosing via multidisciplinary team rounding at point of care. Clin Pract 7(2):953Google Scholar
  14. 14.
    Cohen J, Sinvani L, Wang J, Kozikowski A, Patel V, Qiu G et al (2018) Warfarin quality metrics for hospitalized older adults. TH Open 02(03):e242–e249CrossRefGoogle Scholar
  15. 15.
    Cannegieter SC, Rosendaal FR, Wintzen AR, van der Meer FJ, Vandenbroucke JP, Briët E (1995) Optimal oral anticoagulant therapy in patients with mechanical heart valves. N Engl J Med 333(1):11–17CrossRefGoogle Scholar
  16. 16.
    Leonard CE, Haynes K, Localio AR, Hennessy S, Tjia J, Cohen A et al (2008) Diagnostic E-codes for commonly used, narrow therapeutic index medications poorly predict adverse drug events. J Clin Epidemiol 61(6):561–571CrossRefGoogle Scholar
  17. 17.
    Charlson ME, Pompei P, Ales KL, MacKenzie CR (1987) A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chron Dis 40(5):373–383CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Division of Hospital Medicine, Department of MedicineNorthwell HealthManhassetUSA
  2. 2.Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Northwell HealthManhassetUSA
  3. 3.Division of Health Services Research, Department of Medicine, Center for Health Innovations and Outcomes ResearchNorthwell HealthManhassetUSA
  4. 4.Department of Medicine, Anticoagulation and Clinical Thrombosis ServicesNorthwell Health System, Lenox Hill HospitalNew YorkUSA

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