[Deep venous thrombosis in young women in Norway]

The incidence and distribution of risk factors in non-pregnant women diagnosed with deep vein thrombosis is not well known and was the target of the present study. The medical records of 102 non-pregnant women aged 15-44 hospitalized with deep vein thrombosis at two major Norwegian hospitals were examined retrospectively. The overall incidence of first event of deep vein thrombosis remained fairly constant over the 10-year study period and was estimated at 10.5 per 100,000 women-years. The incidence increased with age and was found twice as high for women 35-44 years of age when compared with the 15-34 age group. Forty-three (42%) of the patients had no identifiable risk factors. Surgery or trauma was found in 37 (36%) of the patients, eight (8%) had a diagnosis of associated cancer, and five (5%) were drug addicts. Five of eight patients registered with immobilization had immobilizing chronic neurological diseases. Thirty-nine (38%) of the patients used oral contraceptives at the time of diagnosis, and 14 of the 39 users of oral contraceptives were identified with medical risk factors. Over the 10-year study period there was no change in the incidence of venous thromboembolism and the risk profile among cases remained constant.