Anticoagulant treatment of patients in Swedish primary health care. Safety aspects.

Abstract

Assessing the quality of anticoagulant (AC) treatment in primary health care with regard to safety. Surveys of patients on AC treatment during 1999. Community health centres (CHCs) in the northeastern region of Stockholm County. Nine hundred and fifty-seven patients, from 16 CHCs. Rate of bleeding and thromboembolic events during AC treatment and rate of values within the recommended treatment interval. The reporting of prothrombin-time (PT) results changed during the year from PT values to international normalised ratio (INR). A total of 48 bleeding events in 44 patients were noted, i.e. 6.8 per 100 patient-years. Of these, ten were major bleedings, 1.4 per 100 patient-years, including three fatal bleedings, 0.4 per 100 patient-years. Six thrombo-embolic events were noted during treatment, i.e. 0.8 per 100 patient-years. Bleeding events were more common at INR values greater than 2.80 than at values of 2.80, [relative risk (RR) 3.30, 95% confidence interval 1.90-5.71]. Of all the noted PT values, 65% were within the recommended intervals (the most common being PT 15-25%) and of all noted INR values 60% (the most common being INR 2.1-3.0). No differences in the rate of bleeding or the number of thrombo-embolic events between the periods of PT and INR results were found. The rate of complications was low and AC treatment in primary health care seems to be as safe as in hospital clinics.