Value of the D-dimer test in diagnosing deep vein thrombosis in rehabilitation inpatients

Objective: To assess the utility of the D-dimer test-a widely available, less costly, and less time-consuming test than others used to diagnose or exclude deep vein thrombosis (DVT) and pulmonary embolism. Design: Blind comparison. Setting: An inpatient rehabilitation facility in Turkey. Participants: Sixty-eight consecutive inpatients being rehabilitated after stroke, spinal cord injury, hip arthroplasty, or traumatic brain injury. Interventions: A latex D-dimer assay was performed on each patient at admission and then weekly throughout the hospital stay. Color Doppler ultrasonography of the lower limbs was also done for each patient at admission and was repeated when indicated by clinical signs and symptoms of DVT or by elevated D-dimer levels. Main Outcome Measures: Patients' clinical findings, D-dimer test results, and ultrasonography results were recorded. Sensitivity, specificity, and positive and negative predictive values were calculated for the D-dimer test, each clinical finding, and combinations of D-dimer results and clinical findings in relation to DVT diagnosis. Results: The sensitivity and negative predictive value of the D-dimer test were high, at 95.2% and 96.2%, respectively. The specificity and positive predictive value were low, at 55.3% and 48.7%, respectively. No single clinical finding was reliably diagnostic for DVT. Conclusions: The D-dimer assay is a reliable method for ruling out DVT. In the rehabilitation setting, it can be used as a routine screening test or to assess cases of suspected DVT. D-dimer testing may reduce the need for sophisticated, time-consuming, and expensive diagnostic workup of rehabilitation inpatients, a group that is at increased risk for DVT.