The Use of Oral Anticoagulants (Warfarin) in Older People
The population of older adults at risk for thromboembolic disease, including venous thromboembolism and systemic thromboses, is rapidly expanding because of increased longevity and improved therapy for cardiovascular disease. Despite this, anticoagulants, particularly oral anticoagulants, are still underused in older patients. The guideline presents current recommendations for indications and use of oral anticoagulants in older adults, based upon consensus review of current research, and the level of evidence for each recommendation. The use of unfractionated heparin (UH) and low molecular weight heparin (LMWH) are also mentioned in the context of the guidelines.

Only indications for therapy with oral warfarin are considered, and the recommendations are focused largely on the use of warfarin. Indications and use of other new anticoagulants, aspirin, UH, and LMWH are not discussed herein unless warfarin is considered an option.

Prevention of thromboembolism is only considered with respect to the use of oral warfarin. Treatment with oral warfarin for venous thromboembolism and systemic embolism is considered for indications in which substantial evidence is available to evaluate and recommend its use. Thus not all outcomes of use of oral anticoagulants are considered here.

The guideline presented here is abstracted from that developed by the Sixth American College of Chest Physicians (ACCP) Consensus Conference on Antithrombotic Therapy (January 2001) and adapted for use in older adults. The methodological Grades are Grade A: based on randomized trials with consistent results; Grade B: randomized trials with inconsistent results or substantial methodologic weaknesses; and Grade C: observational studies or generalization from randomized trials from one group of patients to a different group, with a C+ given when the generalization is secure or the data from observational studies is overwhelming. The assessment of the benefit versus the risk leads to the strength of the recommendation. That is, Grade 1 is a strong recommendation in which the risk/benefit ratio is clear; Grade 2 is a weaker recommendation.

The recommendations of the sixth ACCP consensus conference on anticoagulation included herein have undergone a further review and evaluation for their relevance and applicability to older adults by the Clinical Practice Committee of the American Geriatrics Society.

Implementation of the recommendations of the guideline for the use of oral anticoagulants in older people would be expected to decrease the incidence of thromboembolic disease with their associated costs, despite the increased burden and cost of therapy and monitoring and the increased risk of bleeding that the use of oral anticoagulants in older adults may incur. The actual cost analysis is not provided as it pertains to each indication.


*Sixth ACCP Consensus Conference on Antithrombotic Therapy. Chest. 2001;119(1 suppl):1S-370S.