Age-adjusted D-dimer for the diagnosis of deep vein thrombosis:

ObjectiveIn the diagnosis of deep vein thrombosis, new D-dimer cut-off values were defined by multiplying 10 µg/L × age. The objective of the present study is to define a more specific age-adjusted value, including the pre-test Wells score, without worsening sensitivity.MethodsWe designed a case–control study in patients attended in the emergency department with clinically suspected deep vein thrombosis. Demographics, Wells score, D-dimer and ultrasound data were collected. In low and intermediate clinical probability cases for deep vein thrombosis, we determined the specificity and sensitivity (false-negative rates) for the following cut-off values of D-dimer: age × 10 µg/L, age × 15 µg/L, age × 20 µg/L, age × 25 µg/L and age × 30 µg/L. The cut-off value with maximum specificity without any false-negative result (sensitivity 100%) was identified.ResultsWe included 138 consecutive patients, 39.9% were men and the mean age was 71.6 years. Deep vein thrombosis was diagnosed in 16.7% of patients and the Well...