Cost-effectiveness of performing reference ultrasonography in patients with deep vein thrombosis

Background: The diagnosis of recurrent ipsilateral deep vein thrombosis (DVT) with compression ultrasonography (CUS) may be hindered by residual intravascular obstruction after previous DVT. A reference CUS, an additional ultrasound performed at anticoagulant discontinuation, may improve the diagnostic work-up of suspected recurrent ipsilateral DVT by providing baseline images for future comparison. Objectives: To evaluate the cost-effectiveness of routinely performing reference CUS in DVT patients. Methods: Patient-level data from a prospective management study (Theia study; NCT02262052) and claims data were used in a decision analytic model to compare 12 scenarios for diagnostic management of suspected recurrent ipsilateral DVT. Estimated healthcare costs and mortality due to misdiagnosis, recurrent venous thromboembolism, and bleeding during first year of follow-up after presentation with suspected recurrence were compared. Results: All six scenarios including reference CUS had higher estimated one-year costs (€1763-€1913), than the six without reference CUS (€1192-€1474). Costs were higher because reference CUS results often remained unused, as 20% of patients (according to claims data) would return with suspected recurrent DVT. Estimated mortality was comparable in scenarios with (14.8-17.9 per 10,000 patients) and without reference CUS (14.0-18.5 per 10,000). None of the four potentially most desirable scenarios included reference CUS. Conclusions: One-year healthcare costs of diagnostic strategies for suspected recurrent ipsilateral DVT including reference CUS are higher compared to strategies without reference CUS, without mortality benefit. These results can inform policy-makers regarding use of healthcare resources during follow-up after DVT. From a cost-effectiveness perspective, the findings do not support the routine application of reference CUS.