Anticoagulation
===============

* David A. Fitzmaurice

*   © 2004 Canadian Medical Association or its licensors

Jo-Anne Wilson and associates1 suggest that centralized anticoagulation clinics perform better than, and are preferred by patients over, individual family physicians. However, it is not clear what management of anticoagulation by a family physician entails. As I understand it, usual care in Canada consists of having blood taken at a laboratory remote from the physician's office, with the physician being responsible for dosing and arranging follow-up. This differs from the preferred UK model of primary care management, in which the INR is determined in the physician's office through point-of-care testing, with dosing undertaken by a practice nurse using computerized decision-support software, with minimal clinical input from the physician. There is a robust body of evidence to demonstrate the greater clinical effectiveness of this model of care (the “Birmingham model”) over specialist-run hospital-based clinics.2

It is difficult to interpret the results as stated by Wilson and associates,1 i.e., INR within the therapeutic range ± 0.2 INR units. This so-called extended range is fairly meaningless, especially on its own, so comparison with previous results is impossible. We have demonstrated that at least 2 outcome parameters should be expressed.3 This problem negates the statement that “The care provided in both arms of this study would be regarded as high quality”1 compared with that reported in other studies. 

One other striking feature of this study is the degree of overtesting. If anticoagulation control was as good as the authors describe, why were patients tested 11 to 13 times over a 3-month period? The average number of tests in the United Kingdom is 6 to 8 over a full year.2

The serious flaws in this paper mean that its conclusions are less than robust, and we should be concerned that policy-makers will take its headline message — “family physicians bad” — at face value. I would be grateful if the authors would acknowledge that family physicians can deliver high-quality care, albeit not within the current model of service delivery.

**David A. Fitzmaurice** Department of Primary Care and General Practice University of Birmingham Birmingham, UK

## Footnotes

*   Competing interests: None declared.

## References

1.  1. Wilson SJA, Wells PS, Kovacs MJ, Lewis GM, Martin J, Burton E, et al. Comparing the quality of oral anticoagulant management by anticoagulation clinics and by family physicians: a randomized controlled trial. CMAJ 2003;169(4): 293-8.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czo5OiIxNjkvNC8yOTMiO3M6NDoiYXRvbSI7czoyMjoiL2NtYWovMTcwLzQvNDQ3LjMuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9) 

2.  2. Fitzmaurice DA, Hobbs FDR, Murray ET, Holder RL, Allan TF, Rose PE. Oral anticoagulation management in primary care with the use of computerized decision support and near-patient testing. Randomized, controlled trial. Arch Intern Med 2000;160:2343-8.
    
    [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1001/archinte.160.15.2343&link_type=DOI) 
    
    [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=10927732&link_type=MED&atom=%2Fcmaj%2F170%2F4%2F447.3.atom) 
    
    [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=000088705800014&link_type=ISI) 

3.  3. Fitzmaurice DA, Gee KM, Kesteven P, Murray ET, McManus RM. A systematic review of outcome measures reported for the therapeutic effectiveness of oral anticoagulation. J Clin Pathol 2003; 56:48-51.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6OToiamNsaW5wYXRoIjtzOjU6InJlc2lkIjtzOjc6IjU2LzEvNDgiO3M6NDoiYXRvbSI7czoyMjoiL2NtYWovMTcwLzQvNDQ3LjMuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9)