Skip to main content

Advertisement

SpringerLink
Log in

The effect of warfarin knowledge on anticoagulation control among patients with heart valve replacement

  • Research Article
  • Published:
International Journal of Clinical Pharmacy Aims and scope Submit manuscript

Abstract

Background Although novel oral anticoagulants have been applied into clinical practice, warfarin remains the only approved oral anticoagulant for heart valve replacement. Currently, an increasing number of Chinese clinical pharmacists provide patients with warfarin education. However, little research to date has been carried out to evaluate the relationship between warfarin knowledge level and anticoagulation control among patients with heart valve replacement. Objective To evaluate knowledge of warfarin and the relationship between knowledge level and anticoagulation control among patients with heart valve replacement. Setting Fujian Medical University Union Hospital, China. Method A prospective and cross-sectional study was designed to evaluate the warfarin education of inpatients new to warfarin therapy using a validated Anticoagulation Knowledge Assessment questionnaire. Included patients were followed up for at least 3 months. Data were retrieved from hospital databases and telephone follow up. Main outcome measure Spearman’s rho correlation analysis was used to assess the relationships between time in therapeutic range and warfarin knowledge level. Results 383 patients were included. The mean age of patients was 50.3 ± 7.9 years. The mean knowledge questionnaire score was 62.3 ± 8.8%. The majority of incorrect answers related to drug–warfarin interaction. Five of the frequently incorrect questions covered drugs, herbs and diet that affect warfarin therapy. There were significant correlations between total questionnaire score and time in therapeutic range (rho = 0.539, P < 0.001), or percentage of international normalized ratio measurements within range (rho = 0.416, P < 0.001). There were significant correlations between patients’ educational level and total questionnaire score (rho = 0.357, P = 0.001). No significant correlations were found between income or living area and total questionnaire score (rho = 0.110, P = 0.435; rho = 0.161, P = 0.149). Conclusion Patient knowledge level of anticoagulation therapy affects anticoagulation control. Education for patients new to warfarin and the evaluation of knowledge by validated questionnaire is recommended for better INR control.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1

Similar content being viewed by others

References

  1. Zhang J, Liu M, Chen Q, Wu J, Cao H. Outcomes of an online pharmacist-managed anticoagulation clinic for individuals on warfarin therapy living in rural communities. Thromb Res. 2017;157:136–8.

    Article  CAS  Google Scholar 

  2. Zhang J, Tian L, Zhang Y, Shen J. The influence of VKORC1 gene polymorphism on warfarin maintenance dosage in pediatric patients: a systematic review and meta-analysis. Thromb Res. 2015;136(5):955–61.

    Article  CAS  Google Scholar 

  3. Zhang J, Tian L, Huang J, Huang S, Chai T, Shen J. Cytochrome P450 2C9 gene polymorphism and warfarin maintenance dosage in pediatric patients: a systematic review and meta-analysis. Cardiovasc Ther. 2016;35(1):26.

    Article  CAS  Google Scholar 

  4. Shrestha S, Sapkota B, Kumpakha A, Acharya U, Sharma R. Evaluation of patients’ knowledge on warfarin in outpatient pharmacy of a tertiary care cardiac center. BMC Res Notes. 2015;8(1):429.

    Article  Google Scholar 

  5. Nybo MS, Skov J. Patient knowledge of anticoagulant treatment does not correlate with treatment quality. Pub Health. 2016;141:17–22.

    Article  CAS  Google Scholar 

  6. Winans ARM, Rudd KM, Triller D. Assessing anticoagulation knowledge in patients new to warfarin therapy. Ann Pharmacother. 2010;44(7):1152–7.

    Article  Google Scholar 

  7. Tang EO, Lai CS, Lee KK, Wong RS, Cheng G, Chan TY. Relationship between patients’ warfarin knowledge and anticoagulation control. Ann Pharmacother. 2003;37:34–9.

    Article  Google Scholar 

  8. Briggs AL, Jackson TR, Bruce S, Shapiro NL. The development and performance validation of a tool to assess patient anticoagulation knowledge. Res Soc Adm Pharm Rsap. 2005;1(1):40–59.

    Article  Google Scholar 

  9. Ryals CA, Pierce KL, Baker JW. INR goal attainment and oral anticoagulation knowledge of patients enrolled in an anticoagulation clinic in a veterans affairs medical center. J Manag Care Pharm. 2011;17(2):133–42.

    PubMed  Google Scholar 

  10. World Health Organization [webpage on the Internet]. Process of translation and adaptation of instruments. 2017. http://www.who.int/substance_abuse/research_tools/translation/en/. Accessed 10 Nov 2017.

  11. Rosendaal FR, Cannegieter SC, van der Meer FJ, Briet E. A method to determine the optimal intensity of oral anticoagulant therapy. Thromb Haemost. 1993;69(3):236–9.

    Article  CAS  Google Scholar 

  12. Witt DM, Sadler MA, Shanahan RL, Mazzoli G, Tillman DJ. Effect of a centralized clinical pharmacy anticoagulation service on the outcomes of anticoagulation therapy. Chest. 2005;127(5):1515–22.

    Article  Google Scholar 

  13. Wang Y, Kong MC, Lee LH, Ng HJ, Ko Y. Knowledge, satisfaction, and concerns regarding warfarin therapy and their association with warfarin adherence and anticoagulation control. Thromb Res. 2014;133(4):550–4.

    Article  CAS  Google Scholar 

  14. Xingang L, Shusen S, Qiaoyu W, Buxing C, Zhigang Z, Xiaowei X. Assessment of patients’ warfarin knowledge and anticoagulation control at a joint physician- and pharmacist-managed clinic in China. Patient Prefer Adherence. 2018;12:783–91.

    Article  Google Scholar 

  15. Pourafkari L, Baghbani-Oskouei A, Taban-Sadeghi M, Salamzadeh V, Ghaffari S, Savadi-Oskouei S, et al. Factors influencing various aspects of patients’ knowledge of oral anticoagulation. J Cardiovasc Pharmacol. 2018;1:174–9.

    Article  Google Scholar 

  16. Oramasionwu CU, Bailey SC, Duffey KE, Shilliday BB, Brown LC, Denslow SA, et al. The association of health literacy with time in therapeutic range for patients on warfarin therapy. J Health Commun. 2014;19(sup2):19–28.

    Article  Google Scholar 

  17. Matalqah LM, Khaldoon R, Sulaiman SAS, Hassali MA, Kader SAS. An instrument to measure anticoagulation knowledge among Malaysian community: a translation and validation study of the Oral Anticoagulation Knowledge (OAK) test. Asian J Biomed Pharm Sci. 2013;3(20):30–7.

    Google Scholar 

  18. Alphonsa A, Sharma KK, Sharma G, Bhatia R. Knowledge regarding oral anticoagulation therapy among patients with stroke and those at high risk of thromboembolic events. J Stroke Cerebrovasc Dis. 2015;24(3):668–72.

    Article  Google Scholar 

  19. Davis NJ, Billett HH, Cohen HW, Arnsten JH. Impact of adherence, knowledge, and quality of life on anticoagulation control. Ann Pharmacother. 2005;39(4):632–6.

    Article  Google Scholar 

Download references

Acknowledgements

The authors thank Li Li, Fang Fu, Lina Gao, Xiaojuan Lin, Sha Ma, Haiping Wang for their assistance with education and assessment for patients. We also thank Jin Xie, Dongyang Mao for helping to sort out the questionnaire data.

Funding

This study was supported by the Natural Science Foundation of Fujian Province of China [Grant Number 2018Y0037]

Author information

Authors and Affiliations

  1. Department of Pharmacy, Fujian Medical University Union Hospital, Fuzhou, 350001, China

    Tingting Wu, Wenjun Chen, Jingnan Fu, Xiaotong Xia & Jinhua Zhang

  2. College of Pharmacy, Fujian Medical University, Fuzhou, 350108, China

    Tingting Wu, Wenjun Chen, Jingnan Fu, Xiaotong Xia & Jinhua Zhang

  3. Fujian Maternity and Children Health Hospital, Fuzhou, 350001, China

    Hua Cao

  4. Department of Cardiac Surgery, Fujian Medical University Union Hospital, Fuzhou, 350001, China

    Hua Cao

Authors
  1. Hua Cao
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Tingting Wu
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Wenjun Chen
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Jingnan Fu
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Xiaotong Xia
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Jinhua Zhang
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Jinhua Zhang.

Ethics declarations

Conflicts of interest

The authors declare that they have no conflicts of interest.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Cao, H., Wu, T., Chen, W. et al. The effect of warfarin knowledge on anticoagulation control among patients with heart valve replacement. Int J Clin Pharm 42, 861–870 (2020). https://doi.org/10.1007/s11096-020-01043-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11096-020-01043-y

Keywords

Search

Navigation