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Individual and monitoring centre influences upon anticoagulation control of AF patients on warfarin: a longitudinal multi-centre UK-based study

Lookup NU author(s): Dr Salah Abohelaika, Dr Hilary Wynne, Dr Peter Avery, Dr Lisa Jones, Professor Farhad Kamali



This is the authors' accepted manuscript of an article that has been published in its final definitive form by Wiley-Blackwell Publishing, Inc., 2018.

For re-use rights please refer to the publisher's terms and conditions.


Objectives: Time within therapeutic INR range (TTR) predicts benefits/risk of warfarin therapy. Identification of individual- and centre-related factors that influence TTR, and addressing them to improve anticoagulation control, are important. This study examined the impact of individual and centre-related factors upon long-term anticoagulation control in atrial fibrillation patients in seven UK-based monitoring services. Methods: Data between 2000 and 2014 on 25,270 patients (equating to 203,220 patient years) [18,120 (71.7%) in general practice, 2,348 (9.3%) in hospital-based clinics and 4,802 (19.0%) in domiciliary service] were analysed.Results: TTR increased with increasing age, peaking around 77% at 70-75 years, and then declined, was lower in females than males, and in dependent home-monitored patients than those attending clinic (P<0.0001). TTR, number of dose changes and INR monitoring events, and the probability of TTR≤ 65%, differed across the centres (P<0.0001). Conclusions: Although all the participating centres ostensively followed a standard dosing algorithm, our results indicate that variations in practice do occur between different monitoring sites. We suggest feedback on TTR for individual monitoring sites gauged against the average values reported by others would empower the individual centres to improve quality outcomes of anticoagulation therapy by identifying and adjusting contributory factors within their management system.

Publication metadata

Author(s): Abohelaika S, Wynne H, Avery P, Robinson B, Jones L, Tait C, Dickinson B, Salisbury J, Nightingale J, Green L, Kamali F

Publication type: Article

Publication status: Published

Journal: European Journal of Haematology

Year: 2018

Volume: 101

Issue: 4

Pages: 486-495

Print publication date: 01/10/2018

Online publication date: 27/06/2018

Acceptance date: 24/06/2018

Date deposited: 25/06/2018

ISSN (print): 0902-4441

ISSN (electronic): 1600-0609

Publisher: Wiley-Blackwell Publishing, Inc.


DOI: 10.1111/ejh.13130


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