Kadyan and colleagues (2004; US) set out to determine the cost-effectiveness of duplex ultrasound screening for deep vein thrombosis in persons with SCI being admitted to rehabilitation facilities. Input parameters for their model originated from literature as well as a retrospective study conducted by the same authors of a traumatic SCI cohort admitted to a rehabilitation facility who had a duplex ultrasound at admission. Since the intervention in this study was a screening tool, parameters such as the sensitivity and specificity of the screening tool were included in the analysis. The effect outcome in this study was life year gain measured through differences in mortality between the two treatment arms. The incremental cost of admission duplex ultrasound versus no ultrasound was calculated to be $312.99 per person. The incremental benefit was a decrease in mortality of 0.51%. The cost for one life saved was $61,542. The cost per life year gained ranged between $1,193 and $9,050. The authors note that within this range the screening may be cost-effective, especially when compared to other cost-effectiveness studies in mass screening interventions.