Advertisement

International Journal of Clinical Pharmacy

, Volume 38, Issue 5, pp 1230–1240 | Cite as

Modelling the cost-effectiveness of pharmacist-managed anticoagulation service for older adults with atrial fibrillation in Singapore

  • Wen Bing Brandon Chua
  • Hua Heng McVin Cheen
  • Ming Chai Kong
  • Li Li Chen
  • Hwee Lin WeeEmail author
Research Article

Abstract

Background Oral anticoagulation with warfarin is the cornerstone therapy in atrial fibrillation (AF) for stroke prevention. Multi-disciplinary anticoagulation management services have been shown to be cost-effective in the United States, Hong Kong and Thailand, but the findings are not readily generalizable to Singapore’s healthcare system. Objective This study aimed to evaluate the cost-effectiveness of pharmacist-managed anticoagulation clinic (ACC) compared with usual care (UC) for the management of older adults with AF receiving oral anticoagulation with warfarin. Setting Pharmacist-managed ACC in an academic medical centre. Method A Markov model with 3-month cycle length and 30-year time horizon compared costs and quality-adjusted life-years (QALYs) of ACC and UC from the patient’s and healthcare provider’s perspectives. Four pathways based on time in therapeutic range (TTR) were: ACC TTR < 70 %, ACC TTR ≥ 70 %, UC TTR < 70 % and UC TTR ≥ 70 %. A hypothetical cohort of 70-year-old Singaporean AF patients receiving warfarin was utilised. Local data from national disease registries, patient surveys and hospital databases were used. When local data was not available, published studies on Asian populations were utilized when available. One-way sensitivity analyses and probabilistic sensitivity analyses were performed to account for uncertainties. Costs and QALYs were discounted annually by 3 %. Main outcome measure Costs and QALYs of ACC and UC. Results Pharmacist-managed ACC was found to dominate UC in all comparisons. It improved effectiveness by 0.19 and 0.13 QALYs at TTR < 70 % and TTR ≥ 70 % respectively compared with UC. From the patient’s perspective, ACC reduced costs by SG$1222.67 (€1110.24) for TTR < 70 % and SG$1008.16 (€915.46) for TTR ≥ 70 %. Similar trends were observed from the healthcare provider’s perspective, with ACC reducing costs by SG$1444.79 (€1311.94) for TTR < 70 % and SG$1269.17 (€1152.46) for TTR ≥ 70 % compared with UC. The results were robust to variations of the parameters over their plausible ranges in one-way sensitivity analyses. Probabilistic sensitivity analyses demonstrated that ACC was cost-effective more than 79 % of the time from both perspectives at a willingness-to-pay threshold of SG$69,050 (€62,701) per QALY. Conclusion Pharmacist-managed ACC is more effective and less costly compared with UC regardless of the quality of anticoagulation therapy. The findings support the current body of evidence demonstrating the cost-effectiveness of ACC.

Keywords

Anticoagulation Atrial fibrillation Cost-effectiveness Pharmacist Singapore Warfarin 

Notes

Acknowledgments

The authors would like to thank all pharmacists at the Singapore General Hospital Outpatient Anticoagulation Clinic for their support throughout the conduct of the study.

Funding

The study was funded by the National University of Singapore Undergraduate Final Year Project Fund.

Conflicts of interest

All authors declare no conflict of interest.

Supplementary material

11096_2016_357_MOESM1_ESM.docx (50 kb)
Supplementary material 1 (DOCX 50 kb)

References

  1. 1.
    Feinberg WM, Blackshear JL, Laupacis A, Kronmal R, Hart RG. Prevalence, age distribution, and gender of patients with atrial fibrillation. Analysis and implications. Arch Intern Med. 1995;155:469–73.CrossRefPubMedGoogle Scholar
  2. 2.
    Lip GY, Wang KL, Chiang CE. Non-vitamin K antagonist oral anticoagulants (NOACs) for stroke prevention in Asian patients with atrial fibrillation: time for a reappraisal. Int J Cardiol. 2015;180:246–54.CrossRefPubMedGoogle Scholar
  3. 3.
    Sullivan PW, Arant TW, Ellis SL, Ulrich H. The cost effectiveness of anticoagulation management services for patients with atrial fibrillation and at high risk of stroke in the US. Pharmacoeconomics. 2006;24:1021–33.CrossRefPubMedGoogle Scholar
  4. 4.
    Hori M, Connolly SJ, Zhu J, Liu LS, Lau CP, Pais P, et al. Dabigatran versus warfarin: effects on ischemic and hemorrhagic strokes and bleeding in Asians and non-Asians with atrial fibrillation. Stroke. 2013;44:1891–6.CrossRefPubMedGoogle Scholar
  5. 5.
    National Registry of Diseases Office: Latest publications. www.nrdo.gov.sg. Accessed 15 February 2015.
  6. 6.
    Schulman S, Kearon C. Subcommittee on Control of Anticoagulation of the S, Standardization Committee of the International Society on T, Haemostasis. Definition of major bleeding in clinical investigations of antihemostatic medicinal products in non-surgical patients. J Thromb Haemost. 2005;3:692–4.CrossRefPubMedGoogle Scholar
  7. 7.
    Department of Statistics Singapore. Latest data. http://www.singstat.gov.sg/statistics/latest-data. Accessed 5 Dec 2014.
  8. 8.
    The World Bank. Price level ratio of PPP conversion factor (GDP) to market exchange rate. http://data.worldbank.org/indicator/PA.NUS.PPPC.RF. Accessed 7 April 2016.
  9. 9.
    World Health Organization. World Health Statistics 2015. http://www.who.int/gho/publications/world_health_statistics/2015/en/. Accessed 7 April 2016.
  10. 10.
    Goto S, Zhu J, Liu L, Oh B-H, Wojdyla DM, Aylward P, et al. Efficacy and safety of apixaban compared with warfarin for stroke prevention in patients with atrial fibrillation from East Asia: a subanalysis of the Apixaban for reduction in stroke and other thromboembolic events in atrial fibrillation (ARISTOTLE) trial. Am Heart J. 2014;168:303–9.CrossRefPubMedGoogle Scholar
  11. 11.
    Wong KSL, Hu DY, Oomman A, Tan R-S, Patel MR, Singer DE, et al. Rivaroxaban for stroke prevention in East Asian patients from the ROCKET AF trial. Stroke. 2014;45:1739–47.CrossRefPubMedGoogle Scholar
  12. 12.
    Department of Statistics Singapore: publications and papers. www.singstat.gov.sg/publications/publications-and-papers/population. Accessed 7 Oct 2014.
  13. 13.
    Friberg L, Hammar N, Pettersson H, Rosenqvist M. Increased mortality in paroxysmal atrial fibrillation: report from the Stockholm Cohort-Study of Atrial Fibrillation (SCAF). Eur Heart J. 2007;28:2346–53.CrossRefPubMedGoogle Scholar
  14. 14.
    Laupacis A, Boysen G, Connolly S, Ezekowitz M, Hart R, James K, et al. Risk factors for stroke and efficacy of antithrombotic therapy in atrial fibrillation. Analysis of pooled data from five randomized controlled trials. Arch Intern Med. 1994;154:1449–57.CrossRefGoogle Scholar
  15. 15.
    Fang MC, Go AS, Hylek EM, Chang Y, Henault LE, Jensvold NG, et al. Age and the risk of warfarin-associated hemorrhage: the anticoagulation and risk factors in atrial fibrillation study. J Am Geriatr Soc. 2006;54:1231–6.CrossRefPubMedPubMedCentralGoogle Scholar
  16. 16.
    Freeman JV, Zhu RP, Owens DK, Garber AM, Hutton DW, Go AS, et al. Cost-effectiveness of dabigatran compared with warfarin for stroke prevention in atrial fibrillation. Ann Intern Med. 2011;154:1–11.CrossRefPubMedGoogle Scholar
  17. 17.
    The EuroQol Group. EuroQol-a new facility for the measurement of health-related quality of life. Health Policy. 1990;16:199–208.CrossRefGoogle Scholar
  18. 18.
    van Hout B, Janssen M, Feng Y-S, Kohlmann T, Busschbach J, Golicki D, et al. Interim scoring for the EQ-5D-5L: mapping the EQ-5D-5L to EQ-5D-3L value sets. Value in Health. 2012;15:708–15.CrossRefPubMedGoogle Scholar
  19. 19.
    Eckman MH, Rosand J, Greenberg SM, Gage BF. Cost-effectiveness of using pharmacogenetic information in warfarin dosing for patients with nonvalvular atrial fibrillation. Ann Intern Med. 2009;150:73–83.CrossRefPubMedGoogle Scholar
  20. 20.
    Kang EJ, Ko SK. A catalogue of EQ-5D utility weights for chronic diseases among noninstitutionalized community residents in Korea. Value Health. 2009;12(Suppl 3):S114–7.CrossRefPubMedGoogle Scholar
  21. 21.
    Abdin E, Subramaniam M, Vaingankar JA, Luo N, Chong SA. Measuring health-related quality of life among adults in Singapore: population norms for the EQ-5D. Qual Life Res. 2013;22:2983–91.CrossRefPubMedGoogle Scholar
  22. 22.
    Gallagher AM, Setakis E, Plumb JM, Clemens A, van Staa TP. Risks of stroke and mortality associated with suboptimal anticoagulation in atrial fibrillation patients. Thromb Haemost. 2011;106:968–77.CrossRefPubMedGoogle Scholar
  23. 23.
    You JH, Chan FW, Wong RS, Cheng G. Cost-effectiveness of two models of management for patients on chronic warfarin therapy—a Markov model analysis. Thromb Haemost. 2003;90:1106–11.PubMedGoogle Scholar
  24. 24.
    Saokaew S, Permsuwan U, Chaiyakunapruk N, Nathisuwan S, Sukonthasarn A, Jeanpeerapong N. Cost-effectiveness of pharmacist-participated warfarin therapy management in Thailand. Thromb Res. 2013;132:437–43.CrossRefPubMedGoogle Scholar
  25. 25.
    Feigin VL, Forouzanfar MH, Krishnamurthi R, Mensah GA, Connor M, Bennett DA, et al. Global and regional burden of stroke during 1990–2010: findings from the global burden of disease study 2010. Lancet. 2014;383:245–54.CrossRefPubMedPubMedCentralGoogle Scholar
  26. 26.
    Hanger HC, Wilkinson TJ, Fayez-Iskander N, Sainsbury R. The risk of recurrent stroke after intracerebral haemorrhage. J Neurol Neurosurg Psychiatry. 2007;78:836–40.CrossRefPubMedPubMedCentralGoogle Scholar
  27. 27.
    Poon MT, Fonville AF. Al-Shahi Salman R. Long-term prognosis after intracerebral haemorrhage: systematic review and meta-analysis. J Neurol Neurosurg Psychiatry. 2014;85:660–7.CrossRefPubMedGoogle Scholar
  28. 28.
    Organisation for Economic Co-operation and Development/World Health Organization. Health at a Glance: Asia-Pacific. www.oecd-ilibrary.org/social-issues-migration-health/health-at-a-glance-asia-pacific-2014_health_glance_ap-2014-en. Accessed 29 Mar 2015.
  29. 29.
    Qureshi W, Mittal C, Patsias I, Garikapati K, Kuchipudi A, Cheema G, et al. Restarting anticoagulation and outcomes after major gastrointestinal bleeding in atrial fibrillation. Am J Cardiol. 2014;113:662–8.CrossRefPubMedGoogle Scholar
  30. 30.
    Fang MC, Go AS, Chang Y, Hylek EM, Henault LE, Jensvold NG, et al. Death and disability from warfarin-associated intracranial and extracranial hemorrhages. Am J Med. 2007;120:700–5.CrossRefPubMedPubMedCentralGoogle Scholar
  31. 31.
    Toyoda K, Okada Y, Kobayashi S. Early recurrence of ischemic stroke in Japanese patients: the Japan standard stroke registry study. Cerebrovasc Dis. 2007;24:289–95.CrossRefPubMedGoogle Scholar
  32. 32.
    Yokota C, Minematsu K, Hasegawa Y, Yamaguchi T. Long-term prognosis, by stroke subtypes, after a first-ever stroke: a hospital-based study over a 20-year period. Cerebrovasc Dis. 2004;18:111–6.CrossRefPubMedGoogle Scholar
  33. 33.
    Nakatani D, Sakata Y, Suna S, Usami M, Matsumoto S, Shimizu M, et al. Incidence, predictors, and subsequent mortality risk of recurrent myocardial infarction in patients following discharge for acute myocardial infarction. Circ J. 2013;77:439–46.CrossRefPubMedGoogle Scholar
  34. 34.
    Smolina K, Wright FL, Rayner M, Goldacre MJ. Long-term survival and recurrence after acute myocardial infarction in England, 2004 to 2010. Circ Cardiovasc Qual Outcomes. 2012;5:532–40.CrossRefPubMedGoogle Scholar
  35. 35.
    Ministry of Health Singapore: Hospital bill size. www.moh.gov.sg/content/moh_web/home/costs_and_financing/HospitalBillSize.html. Accessed 30 Jan 2015.
  36. 36.
    Saokaew S, Permsuwan U, Chaiyakunapruk N, Nathisuwan S, Sukonthasarn A. Effectiveness of pharmacist-participated warfarin therapy management: a systematic review and meta-analysis. J Thromb Haemost. 2010;8:2418–27.CrossRefPubMedGoogle Scholar
  37. 37.
    Aguilar MI, Hart R, Pearce LA. Oral anticoagulants versus antiplatelet therapy for preventing stroke in patients with non-valvular atrial fibrillation and no history of stroke or transient ischemic attacks. Cochrane Database Syst Rev. 2007;3:CD006186.Google Scholar

Copyright information

© Springer International Publishing 2016

Authors and Affiliations

  • Wen Bing Brandon Chua
    • 1
  • Hua Heng McVin Cheen
    • 2
    • 3
  • Ming Chai Kong
    • 2
  • Li Li Chen
    • 2
  • Hwee Lin Wee
    • 3
    Email author
  1. 1.Department of PharmacyKK Women’s and Children’s HospitalSingaporeSingapore
  2. 2.Department of PharmacySingapore General HospitalSingaporeSingapore
  3. 3.Department of Pharmacy, Faculty of ScienceNational University of SingaporeSingaporeSingapore

Personalised recommendations