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Thromb Haemost 1989; 62(02): 729-732
DOI: 10.1055/s-0038-1646892
Original Article
Schattauer GmbH Stuttgart

Poor Compliance Is a Major Factor in Unstable Outpatient Control of Anticoagulant Therapy

S Kumar
The General Infirmary, Leeds, UK
,
J R M Haigh
The General Infirmary, Leeds, UK
,
L E Rhodes
The University Department of Medicine and Department of Haematology, Leeds, UK
,
S Peaker
The General Infirmary, Leeds, UK
,
J A Davies
The General Infirmary, Leeds, UK
,
B E Roberts
The University Department of Medicine and Department of Haematology, Leeds, UK
,
M P Feely
The General Infirmary, Leeds, UK
› Author Affiliations
Further Information

Publication History

Received 15 December 1988

Accepted after revision 27 April 1989

Publication Date:
30 June 2018 (online)

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Summary

Control of oral anticoagulant therapy in outpatients is often unsatisfactory. The contribution of poor compliance with prescribed warfarin to unstable anticoagulant control was investigated prospectively using low-dose phenobarbitone as an indicator of compliance in 30 out-patients, 15 with stable and 15 with unstable control. Following entry to the study, there was no significant change in anticoagulation (p = 0.36) in the group with stable control. In the group who previously had unstable control, there was a significant change in INR (p = 0.0045) and anticoagulant control greatly improved. It appears that the considerable fluctuation in INR seen in many of the latter patients before the study was due to poor compliance and that entering them into the study modified their behaviour. Two patients in this group who continued to have unstable anticoagulant control were shown to be poorly compliant using the phenobarbitone indicator. The results suggest that, in outpatients, poor compliance is the major cause of unstable anticoagulation with warfarin.

Keywords

Warfarin therapy - Unstable anticoagulation - Poor compliance
 

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