Lisette van Dam

Chapter 3 50 anticoagulation treatment. It is possible that the mortality risk as a result of anticoagulant-related bleeding is underestimated, as this was extrapolated from randomized controlled trials that included low-risk patients. As a result, the treat all strategy provided the lowest possible mortality in our analysis. Nevertheless, we do not consider this strategy a good advice. Third, long-term complications of a missed DVT, including post-thrombotic syndrome (PTS), chronic thrombo-embolic pulmonary hypertension (CTEPH) and post-PE syndrome due to delayed or total lack of anticoagulant treatment, were not included in the analyses. 37-39 The reason is difficulty in estimating the impact of these long-term complications on health care costs. Fourth, we estimated costs per prevented death, whereas in the Netherlands only threshold for costs per QALY are used. These QALY thresholds roughly translate to 0.5 to 2 million euros per prevented death in our population. Based on this range of acceptability thresholds the diagnostic scenarios including CUS alone, CUS followed by MRDTI in case of an inconclusive CUS and treat all were potential optimal strategies. Finally, this analysis was based on a Dutch health care setting and health care costs for DVT may vary by country. Also, the hospital length of stay (LOS) may differ in other settings. For the current analysis, LOS was based on available literature which included no studies specifically in patients with suspected recurrent DVT. It is therefore possible, that the true LOS is higher due to higher comorbidity rate in suspected recurrent DVT patients compared to patients with suspected first DVT episode. On the other hand, most studies were performed before the DOAC era and thus LOS in these studies may be longer due to routine laboratory monitoring and injectable bridging therapy in anticoagulant management with LMWHs and VKA’s. We performed a sensitivity analysis to compare the total health care costs in the setting with 3 hospitalization days instead of 7.2 days and did not find relevant differences. Clinical implications What is the relevance of our findings for clinical practice? First, our model shows that there is a very small difference in the total 1-year health care costs between the different diagnostic scenarios. In contrast to what many clinicians may believe, strategies including MRDTI were not more expensive than strategies without