Experience with INR self-management: patient selection and complication rates.

BACKGROUND: INR self-management can reduce the risk of complications for patients with indication of long-term oral anticoagulation therapy. However, little is known about early indicators of complication risk.

METHODS: In a prospective study on 330 consecutive patients all participants were informed about oral anticoagulation by a structured teaching program. The two groups were divided as to whether they received usual medical care provided by a family physician (n=220) or self-management (n=110) on a portable coagulation monitor (CoaguChek System). After a mean follow up of 13.3+/-4.4 months, the participants of the study were interviewed by a structured questionnaire to obtain information about hemorrhagic and thromboembolic complications as well as survival.

RESULTS: In comparison to patients under usual care, patients with INR selfmanagement were significantly younger (58 vs 64 years) and had fewer comorbidities (diabetes and hypertension) as well as a higher ejection fraction (53.6 vs 51.1%). Indication for anticoagulation, age and heart rhythm explained 58% of the differences between the management groups. There was no significant difference in the overall complication rates between the two groups (usual care vs selfmanagement): major bleeding 0.5 vs 0.9%, cerebral embolism (TIA or stroke) 1.9 vs 0.9%, hospital admission 2.3 vs 1.8%. A high BMI (OR=1.5; 95% CI 1.06-1.25; p=0.001) or a high therapeutic INR range (OR=2.42; 95% CI 1.16-5.1; p=0.019) is associated with a higher complication rate.

CONCLUSIONS: Complication rates for patients with long-term oral anticoagulant therapy did not differ significantly between usual care and self-management. Rather, the patient's body weight and the requirement of high anticoagulation intensity drive the complication risk under both management systems.