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

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.

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.

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.

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.