Abstract
The increase in oral anticoagulant (OA) treatment has led to development of new strategies for its control. We tested the efficacy of the GAO software (Dade Behring) in providing adequate acenocoumarol dosages for patients whose international normalised ratios (INRs) were no more than 0.5 points out of range. From December 1998 to August 1999, all outpatients in this setting were randomly assigned to receive computer-generated or traditionally fixed OA doses. Patients in their first 4 weeks of treatment were excluded. Overall, 8,352 dosages were calculated by the computer and 7,586 by the medical staff. The main endpoint of the study was the time spent in target INR range. The computer matched the traditional dosing, achieving a small but statistically significant greater efficacy in maintaining patients within the INR target range. The percentage of INR determinations over 5.5 was very low in both groups. Our results validate the computerised acenocoumarol dosing in our centre, achieving at least similar levels of effectiveness and safety compared with traditional dosage by medical staff.