Lisette van Dam

Chapter 3 46 Costs The estimated total 1-year health care costs per patient for all diagnostic scenarios are shown in Figure 3 and Table 3 . Although MRDTI itself is more expensive than CUS, health care costs of diagnostic management strategies including MRDTI (range €1219 to €1296) were calculated to be comparable or lower than diagnostic strategies without MRDTI (range €1278 to €1529) because of superior specificity (sensitivity, 97-99% vs 98-100%; specificity, 90-100% vs 60-84%). Figure 3 . One-year health care costs per patient for the 10 diagnostic scenarios, and a scenario to treat all, treat none and treat those with a likely clinical probability and/or abnormal D-dimer without diagnostic imaging. CDR+DD, clinical decision rule + D-dimer testing; CUSi, compression ultrasonography is positive, negative, or inconclusive; FN, false negatives; FP, false positives. When CDR and D-dimer testing were applied as initial diagnostic tests, health care costs were lower, even considering the higher false negative rate. This could be explained by the lower initial diagnostic costs, because of decreased imaging costs, and the lower false-positive rate. The diagnostic strategy including CDR and D-dimer testing, CUS and subsequent MRDTI in case of an inconclusive CUS was associated with the lowest 1-year health care costs of €1219 (scenario 10). The diagnostic strategy including CUS (normal/abnormal) and treatment in all patients