Evidence has been gathered that use of an age-adjusted fibrin D-dimer cut-off value for patients above 50 years of age for ruling out deep venous thrombosis is just as safe as using a standard fibrin D-dimer cut-off value. Due to the lower number of false-positive results when using the age-adjusted cut-off values, it is therefore nationally recommended in Denmark that systematic use of a pretest clinical score is supported by fibrin D-dimer measurements using age-adjusted cut-off values for every ten-year interval in patients above 50 years of age, i.e. 0.6 mg/l fibrinogen equivalent units (FEU) for patients being 55-65 years of age, 0.7 mg/l FE/l for patients being 65-75 years and 0.8 mg/l FEU for patients above 75 years of age.