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


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.


Anticoagulation Atrial fibrillation Cost-effectiveness Pharmacist Singapore Warfarin 



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.


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)


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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

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