Prospective comparative study of computer programs used for management of warfarin.

AIMS To compare the effectiveness of three computerised systems that are currently used for assisting warfarin control in outpatients with the customary dosing method used by experienced medical staff. METHODS A pilot randomised study of three systems with a follow up independently randomised study of two of these was made on 186 patients receiving long term treatment or who had recently started warfarin treatment and had been discharged from hospital. RESULTS All three computerised systems seemed to give satisfactory control compared with the traditional dosing method. For patients receiving more intensive treatment with an assigned target range of 3.0-4.5 computerised dosage programs achieved significantly better control; the medical staff undertreated such patients almost 50% of the time. CONCLUSION Computer based programs can assist outpatient anticoagulant control with warfarin during both early and long term treatment. For most patients the control achieved is as good as that obtained by the customary method of dosing, by experienced clinic doctors, although the latter tend to be too conservative when dosing patients within the intense target range of 3.0 to 4.5 International Normalised Ratio (INR). The computers were significantly more successful in this higher range.