Who receives anticoagulant treatment with warfarin and why? A population-based study in Finland

To ascertain the age and gender distribution of patients receiving anticoagulant (AC) treatment with warfarin, and to establish the prevalence of AC treatment and its indications among the Finnish population.

A cross-sectional study in which the patients were identified from the patient records of health centres.

Primary health care in the Hospital District of South Ostrobothnia in Finland.

Those inhabitants of 15 municipalities in the study area who received AC treatment with warfarin on 1 April 2004. The total number of inhabitants was 132 621 at the end of 2003.

Patient age and gender distributions, the prevalence of AC treatment in the study area, and indications for AC treatment.

Altogether 2389 patients were identified, 51.4% of them men. The mean age of the patients was 72.4 years. The prevalence of AC treatment was 1.8%; when age-adjusted to match the Finnish population it was 1.64%. The proportion of men receiving AC treatment was higher than that of women in all age groups. Atrial fibrillation (AF) was the most common main (60.2%) and second (7.2%) indication for AC treatment.

Compared with Finnish figures 12 years earlier the prevalence of AC treatment has more than doubled, and the proportion of AF among indications has increased from 47% to 67%. New current care guidelines on AF and the increasing proportion of the elderly among the population are probable explanations.