Application of a decision support tool for anticoagulation in patients with non-valvular atrial fibrillation.
BACKGROUND
Atrial fibrillation affects more than two million Americans and results in a fivefold increased rate of embolic strokes. The efficacy of adjusted dose warfarin is well documented, yet many patients are not receiving treatment consistent with guidelines. The use of a patient-specific computerized decision support tool may aid in closing the knowledge gap regarding the best treatment for a patient.


METHODS
This retrospective, observational cohort analysis of 6,123 Ohio Medicaid patients used a patient-specific computerized decision support tool that automated the complex risk-benefit analysis for anticoagulation. Adverse outcomes included acute stroke, major gastrointestinal bleeding, and intracranial hemorrhage. Cox proportional hazards models were developed to compare the group of patients who received warfarin treatment with those who did not receive warfarin treatment, stratified by the decision support tool's recommendation.


RESULTS
Our decision support tool recommended warfarin for 3,008 patients (49%); however, only 9.9% received warfarin. In patients for whom anticoagulation was recommended by the decision support tool, there was a trend towards a decreased hazard for stroke with actual warfarin treatment (hazard ratio 0.90) without significant increase in gastrointestinal hemorrhage (0.87). In contrast, in patients for whom the tool recommended no anticoagulation, receipt of warfarin was associated with statistically significant increased hazard of gastrointestinal bleeding (1.54, p = 0.03).


CONCLUSIONS
We have shown that our atrial fibrillation decision support tool is a useful predictor of those at risk of major bleeding for whom anticoagulation may not necessarily be beneficial. It may aid in weighing the benefits versus risks of anticoagulation treatment.
Wess
Mark L
ML
Division of General Internal Medicine, University of Cincinnati Medical Center, Cincinnati, OH 45267-0535, USA. mark.wess@uc.edu
Schauer
Daniel P
DP
Johnston
Joseph A
JA
Moomaw
Charles J
CJ
Brewer
David E
DE
Cook
E Francis
EF
Eckman
Mark H
MH
D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D015331:Cohort Studies; D020000:Decision Support Systems, Clinical; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008484:Medicaid; D008485:Medical Audit; D050316:Medical Order Entry Systems; D008875:Middle Aged; D009820:Ohio; D010818:Practice Patterns, Physicians'; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D020521:Stroke / Q000517:prevention & control; D014481:United States; D014859:Warfarin / Q000009:adverse effects*
D000925:Anticoagulants; D014859:Warfarin