Evaluation of a decision support system for initiation and control of oral anticoagulation in a randomised trial

Abstract Objectives: To determine whether a computerised decision support system for initiation and control of oral anticoagulant treatment improves quality of anticoagulant control achieved by trainee doctors. Design: Randomised controlled trial. Setting: District general hospital in North London. Subjects: 148 inpatients requiring start of warfarin treatment. Interventions: Management by trainee doctors (to achieve therapeutic range of international normalised ratio of 2 to 3) with indirect assistance from computerised decision support system (intervention group) or without such assistance (control group). Main outcome measures: Median time to therapeutic range, stable dose, and first pseudoevent (excessive international normalised ratio after therapeutic range has been reached) and person time spent in the therapeutic range. Results: 72 patients were randomised to the intervention group and 76 to control group. Median time to reach international normalised ratio of ≥2 was not significantly different in the two groups (3 days). Median time to achieve a stable dose was significantly lower in intervention group than in controls (7 days v 9 days, P=0.01) without excessive overtreatment or undertreatment with anticoagulant. Patients in intervention group spent greater proportion of time in therapeutic range, both as inpatients (59% v 52%) and outpatients (64% v 51%). Conclusion: The computerised decision support system was safe and effective and improved the quality of initiation and control of warfarin treatment by trainee doctors. Key messages The quality of control of warfarin doses during initiation and maintenance of oral anticoagulation is generally poor We investigated whether a computerised decision support system for initiation and control of oral anticoagulation improved quality of anticoagulant control achieved by trainee doctors The median time to achieve a stable dose was significantly lower in the group assisted by the decision support system than in controls, without excessive overtreatment or undertreatment with anticoagulant Patients in the group with the decision aid spent more time within the therapeutic range both as inpatients and outpatients The computerised decision support system was safe and effective and improved quality of initiation and control of warfarin treatment by trainee doctors

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