A Multi-Rule Expert System to Manage OAT in Most Real-Life Clinical Situations

Abstract number: P1623

Bal dit Sollier C, Cambus F, Mahé I, Siguret V, Gouin I, Drouet L, Cambus JP

Introduction:  Several computer programs have been developed to monitor oral anticoagulant treatments (OAT), leading to improved quality of management. However, these systems are not adapted to numerous practical situations.

Methods:  In order to improve the efficiency of this type of system, we developed an expert system including numerous original features: (1) specific adaptation depending on the properties of the OA molecules (warfarin or indanedione), patient age, gender, weight, previous dose, the last four INR, frequency of laboratory controls, drug interactions, (2) adaptation to given situations according to treatment period (induction, shift heparin-OA, stability), (3) upgradable system: this software works with several hundreds of independent rules which can be modified. According to the set of predefined conditions, the program provides specific recommendations or observations: dose adjustment, date of the next INR, number of days of temporary suspension if necessary, replies to patient queries about changes in diet or possible drug interaction, reversal of over-anticoagulation in case of excessively high INR, management of anticoagulation before elective surgery, etc. Experienced physicians can modify or add new rules for continuing improvement of the system's performance.

Results:  This PC-based system is designed to form part of a multi-user network in an ‘E-anticoagulation clinic’ for access by hospitals as well as by private practices. Additionally, the system enables an on-duty senior anticoagulation adviser to help solve practical questions not yet envisaged by the expert system. This software is currently used by our staff, in conjunction with patient education. The time spent within the therapeutic range according to Rosendaal's method represents 69.7% of treatment time.

Conclusion:  Widespread use of such a system in outpatient care by physicians involved in OAT management could improve the benefit/risk ratio of these treatments.