Document Type : Original Article


Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran


BACKGROUND: Despite new anticoagulants’ developments, warfarin is still one of the most
commonly used medicines, particularly in the cardiovascular system. One of the significant challenges
with warfarin is the prevalence of dangerous side effects such as bleeding and drug and food
interactions, which can negatively affect patients if not adequately controlled. As health‑care team
members, nurses have a crucial role in prescribing this medicine and educating patients. In this
regard, this study was conducted to determine the knowledge and practice of nurses working in the
cardiovascular wards regarding warfarin.
MATERIALS AND METHODS: In this cross‑sectional, descriptive study, knowledge and practice
of 239 nurses working in the cardiovascular wards of teaching hospitals affiliated to Iran University
of Medical Sciences have been investigated using European Cardiovascular Nurses Knowledge
questionnaire on anticoagulants and the checklist for high‑risk drugs safety instructions. The sampling
was performed through the stratified sampling method with proportional allocation. Data were analyzed
using the SPSS software version 16 through descriptive and inferential statistics (independent t‑test,
one‑way analysis of variance, and Pearson correlation coefficient) (Inc., Chicago, IL, USA).
RESULTS: The mean scores of knowledge (18.51 ± 3.87) and practice (10.53 ± 2.12) were
slightly higher than the median, and the lowest mean score was related to knowledge on drug
interactions (7.62). The practice had a statistically significant relationship with knowledge (P ˂ 0.001).
Regarding demographic variables, there was a statistically significant relationship between nurses’
knowledge and the education level (P = 0.009) and nurses’ practice and age (P = 0.022), work
experience (P = 0.032), and work experience in cardiovascular wards (P = 0.036).
CONCLUSIONS: Based on the findings of this study, the knowledge of nurses working in the
cardiovascular wards about warfarin was not sufficient, and their practice was of poor quality. Nurses’
lack of knowledge and improper practice can jeopardize drug safety in patients and cause serious
side effects such as bleeding. Proper training of nursing students and nurses about warfarin as a
high‑risk drug, its side effects, and drug‑food interactions, and the emphasis on patient education in
patients receiving this medicine can effectively reduce the incidence of side effects.


  1. Loo SY, Dell’Aniello S, Huiart L, Renoux C. Trends in the
    prescription of novel oral anticoagulants in UK primary care. Br
    J Clin Pharmacol 2017;83:2096‑106.
    2. Bai DS, Xia BL, Zhang C, Ye J, Qian JJ, Jin SJ, et al. Warfarin
    versus aspirin prevents portal vein thrombosis after laparoscopic
    splenectomy and azygoportal disconnection: A randomized
    clinical trial. Int J Surg 2019;64:16‑23.
    3. Sonuga BO, Hellenberg DA, Cupido CS, Jaeger C. Profile and
    anticoagulation outcomes of patients on warfarin therapy in an
    urban hospital in Cape Town, South Africa. Afr J Prim Health
    Care Fam Med 2016;8:e1‑8.
    4. Mega JL, Simon T. Pharmacology of antithrombotic drugs: An
    assessment of oral antiplatelet and anticoagulant treatments.
    Lancet 2015;386:281‑91.
    5. January CT, Wann LS, Alpert JS, Calkins H, Cigarroa JE, Conti JB,
    et al. 2014 AHA/ACC/HRS guideline for the management of
    patients with atrial fibrillation: A report of the American College
    of Cardiology/American Heart Association task force on practice
    guidelines and the heart rhythm society. J Am Coll Cardiol
    6. Hosseindokht M, Boroumand M, Salehi R, Mandegary A,
    Talasaz AH, Pourgholi L, et al. Association between four
    microRNA binding site‑related polymorphisms and the risk of
    warfarin‑induced bleeding complications. EXCLI J 2019;18:287‑99.
    7. Levi M, Eerenberg E, Kamphuisen P. Bleeding risk and reversal
    strategies for old and new anticoagulants and antiplatelet agents.
    J Thromb Haemost 2011;9:1705‑12.
  2. 8. Witt DM, Delate T, Clark NP, Martell C, Tran T, Crowther M, et al.
    Twelve‐month outcomes and predictors of very stable INR control
    in prevalent warfarin users. J Thromb Haemost 2010;8:744‑9.
    9. Semakula JR, Mouton JP, Jorgensen A, Hutchinson C, Allie S,
    Semakula L, et al. A cross‑sectional evaluation of five warfarin
    anticoagulation services in Uganda and South Africa. PLoS One
    10. Ferguson C, Inglis SC, Newton PJ, Middleton S, Macdonald PS,
    Davidson PM. The caregiver role in thromboprophylaxis
    management in atrial fibrillation: A literature review. Eur J
    Cardiovasc Nurs 2015;14:98‑107.
    11. Nelson WW, Desai S, Damaraju CV, Lu L, Fields LE,
    Wildgoose P, et al. International normalized ratio stability in
    warfarin‑experienced patients with nonvalvular atrial fibrillation.
    Am J Cardiovasc Drugs 2015;15:205‑11.
    12. Couris R, Tataronis G, McCloskey W, Oertel L, Dallal G, DwyerJ,
    et al. Dietary Vitamin K variability affects international normalized
    ratio (INR) coagulation indices. Int J Vitam Nutr Res 2006;76:65‑74.
    13. Kimmel SE, Chen Z, Price M, Parker CS, Metlay JP, Christie JD,
    et al. The influence of patient adherence on anticoagulation control
    with warfarin: Results from the international normalized ratio
    adherence and genetics (IN‑RANGE) study. Arch Intern Med
    14. Wilson FL, Racine E, Tekieli V, Williams B. Literacy, readability
    and cultural barriers: Critical factors to consider when educating
    older African Americans about anticoagulation therapy. J Clin
    Nurs 2003;12:275‑82.
    15. Amiri M, Kargar M, Borhanihaghighi A, Soltani F, Zare N. The
    effect of nurse‑led care on stability time in therapeutic range of
    INR in ischemic stroke patients receiving warfarin. Appl Nurs
    Res 2017;33:96‑101.
    16. Raberi MP, Jamshidi N, Soltani Nejad A, Sabzevari S. Effects of
    nurse education on both patients’ satisfaction of teaching patients,
    and nurses’ knowledge, attitude and performance in intensive
    care units of teaching hospitals. J Health Care 2011;13:30-36.
    17. Piazza G, Nguyen TN, Cios D, Labreche M, Hohlfelder B,
    Fanikos J, et al. Anticoagulation‑associated adverse drug events.
    Am J Med 2011;124:1136‑42.
    18. Abd Elrahman Yones FE, Qalawa SA. Assessment of nurses’
    performance regarding caring of patients on anticoagulant
    therapy in port‑said hospitals. Port Said Sci J Nurs 2019;6:1‑15.
    19. IrajpourA, FarziS, SaghaeiM, RavaghiH. Effect of interprofessional
    education of medication safety program on the medication error
    of physicians and nurses in the intensive care units. J Educ Health
    Promot 2019;8:196.
    20. Dhamija M, Kapoor G, Juneja A. Infusional chemotherapy and
    medication errors in a tertiary care pediatric cancer unit in a
    resource‑limited setting. J Pediatr Hematol Oncol 2014;7:412‑5.
    21. Hajibabaee F, Joolaee S, Peyravi H, Haghani H. The relationship
    of medication errors among nurses with some organizational and
    demographic characteristics. Iran J Nurse Res 2011:83‑92.
    22. Farzi S, Irajpour A, Saghaei M, Ravaghi H. Weak professional
    interactions as main cause of medication errors in intensive care
    units in Iran. Iran Red Crescent Med J 2017;19:1-7.
    23. Ferguson C, Hickman LD, Phillips J, Newton PJ, Inglis SC, Lam L,
    et al. An mHealth intervention to improve nurses’ atrial fibrillation
    and anticoagulation knowledge and practice: The EVICOAG
    study. Eur J Cardiovasc Nurs 2019;18:7‑15.
    24. Oterhals K, Deaton C, De Geest S, Jaarsma T, Lenzen M, Moons P,
    et al. European cardiac nurses’ current practice and knowledge
    on anticoagulation therapy. Eur J Cardiovasc Nurs 2014;13:261‑9.
    25. Esfahani AK, Varzaneh FR, Changiz T. The effect of clinical
    supervision model on high alert medication safety in intensive
    care units nurses. Iran J Nurs Midwifery Res 2016;21:482‑6.
    26. Ferguson C, Inglis SC, Newton PJ, Middleton S, Macdonald PS,
    Davidson PM. Education and practice gaps on atrial fibrillation
    and anticoagulation: A survey of cardiovascular nurses. BMC
    Med Educ 2016;16:9.
    27. WangY, Kong MC, Lee LH, Ng HJ, KoY. Knowledge, satisfaction,
    and concerns regarding warfarin therapy and their association
    with warfarin adherence and anticoagulation control. Thromb
    Res 2014;133:550‑4.
    28. Hsu JC, Maddox TM, Kennedy KF, Katz DF, Marzec LN,
    Lubitz SA, et al. Oral anticoagulant therapy prescription in
    patients with atrial fibrillation across the spectrum of stroke risk:
    Insights from the NCDR PINNACLE registry. JAMA Cardiol
    29. Nasser S, Mullan J, Bajorek B. Challenges of older patients’
    knowledge about warfarin therapy. J Prim Care Community
    Health 2012;3:65‑74.
    30. Rodwin BA, Salami JA, Spatz ES, Valero‑Elizondo J, Virani SS,
    Blankstein R, et al. Variation in the use of warfarin and direct
    oral anticoagulants in atrial fibrillation and associated cost
    implications. Am J Med 2019;132:61‑70.e1.
    31. LK Leung L. Direct oral Anticoagulants and Parenteral Direct
    Thrombin Inhibitors: Dosing and Adverse Effects; 2019.
    Available from:‑o
    ch_result&selectedTitle=1 ~ 150&usage_type=default&display_
    rank=1#H1. [Last accessed on 2019 Jun 06].
    32. Abraham NS, Singh S, Alexander GC, Heien H, Haas LR,
    Crown W, et al. Risk of gastrointestinal bleeding with dabigatran,
    rivaroxaban, and warfarin: Population based cohort study. BMJ
    33. Piran S, Schulman S, Panju M, Pai M. Oral anticoagulant dosing,
    administration, and storage: A cross‑sectional survey of Canadian
    health care providers. J Thromb Thrombolysis 2018;45:180‑5.
    34. Ndosi ME, NewellR. Nurses’ knowledge of pharmacology behind
    drugs they commonly administer. J Clin Nurs 2009;18:570‑80.
    35. Raja Lexshimi R, Daud F, Zulkifli SZ. Knowledge, attitude and
    practice of nurses in administering oral medication at medical
    Ward, Universiti Kebangsaan Malaysia medical centre. medicine
    and health 2009;12:16-24.
    36. Livne Y, Peterfreund I, Sheps J. Barriers to patient education and
    their relationship to nurses’ perceptions of patient education
    climate. Clin Nurs Stud 2017;5:65.
    37. Flanders SA. Effective patient education: Evidence and common
    sense. Medsurg Nurs 2018;27:55‑8.
    38. Cheragi MA, Manoocheri H, Mohammadnejad E, Ehsani SR.
    Types and causes of medication errors from nurse’s viewpoint.
    Iran J Nurs Midwifery Res 2013;18:228‑31.
    39. Raja B, Kumar P, Ali S, Shah H, Awan MF. Medication
    administration errors: A study of frequency and contributing
    factors among nurses working at tertiary care hospitals.
    40. Aliurst S. Nurses must improve their knowledge of pharmacology.
    Br J Nurs 2016;12:608.
    41. Jeanes A, Taylor D. Drugs update. Stopping the drugs trolley.
    Nurs Times 1992;88:27‑9.
    42. Diaz‑Quijano FA, Martínez‑Vega RA, Rodriguez‑Morales AJ,
    Rojas‑Calero RA, Luna‑González ML, Díaz‑Quijano RG.
    Association between the level of education and knowledge,
    attitudes and practices regarding dengue in the Caribbean region
    of Colombia. BMC Public Health 2018;18:1‑10.
    43. BayoumiI, DolovichL, HutchisonB, HolbrookA. Medication‑related
    emergency department visits and hospitalizations among older
    adults. Can Fam Physician 2014;60:e217‑22.