Optimal management strategy for use of compression US for deep venous thrombosis in symptomatic patients: a cost-effectiveness analysis

Cost-effective diagnostic cardiovascular imaging: when does it provide good value for the money?

To summarize the results of all original cost-utility analyses (CUAs) in diagnostic cardiovascular imaging (CVI) and characterize those technologies by estimates of their cost-effectiveness. We systematically searched the literature for original CVI CUAs published between 2000 and 2008. Studies were classified according to several variables including anatomy of interest (e.g. cerebrovascular, aorta, peripheral) and imaging modality under study (e.g. angiography, ultrasound). The results of each study, expressed as cost of the intervention to number of quality-adjusted life years saved ratio (cost/QALY) were additionally classified as favorable or not using $20,000, $50,000, and $100,000 per QALY thresholds. The distribution of results was assessed with Chi Square or Fisher exact test, as indicated. Sixty-nine percent of all cardiovascular imaging CUAs were published between 2000 and 2008. Thirty-two studies reporting 82 cost/QALY ratios were included in the final sample. The most common vascular areas studied were cerebrovascular (n = 9) and cardiac (n = 8). Sixty-six percent (21/32) of studies focused on sonography, followed by conventional angiography and CT (25%, n = 8, each). Twenty-nine (35.4%), 42 (51.2%), and 53 (64.6%) ratios were favorable at WTP $20,000/QALY, $50,000/QALY, and $100,000/QALY, respectively. Thirty (36.6%) ratios compared one imaging test versus medical or surgical interventions; 26 (31.7%) ratios compared imaging to a different imaging test and another 26 (31.7%) to no intervention. Imaging interventions were more likely (P < 0.01) to be favorable when compared to observation, medical treatment or non-intervention than when compared to a different imaging test at WTP $100,000/QALY. The diagnostic cardiovascular imaging literature has growth substantially. The studies available have, in general, favorable cost-effectiveness profiles with major determinants relating to being compared against observation, medical or no intervention instead of other imaging tests.

Augmentation in Lower Extremity Sonography for the Detection of Deep Venous Thrombosis

OBJECTIVE

The purpose of our study was to evaluate the usefulness of venous flow augmentation with duplex sonography in the evaluation of deep venous thrombus of the lower extremities.

CONCLUSION

The augmentation component of the lower extremity sonogram rarely provides additional information in the diagnosis of deep venous thrombus. In our large series, no deep venous thromboses were discovered with augmentation. Factors such as the lack of usefulness and patient discomfort may justify removal of augmentation from the routine study. However, augmentation should still be applied as a diagnostic tool in difficult or uncertain cases.

Variations in lower limb venous anatomy: implications for US diagnosis of deep vein thrombosis

PURPOSE

To retrospectively review bilateral venograms free of thrombus to evaluate the frequency and types of variations seen in venous anatomy.

MATERIALS AND METHODS

A retrospective review of 404 bilateral (808 limbs) lower limb venograms obtained from medical patients participating in a thromboprophylaxis clinical trial and found to be free of thrombus was performed. Venograms were evaluated according to predetermined criteria for the presence of duplication of vessels and inter- and intraindividual variations in venous anatomy. Variations were assessed with analysis of variance and chi2 tests.

RESULTS

Two vessels were seen in the popliteal fossa on 337 (42%) of 808 venograms, and 41 (5%) were true duplicated popliteal veins. There were 253 (31%) duplicated superficial femoral veins (SFVs), with 12 (1.5%) being complex duplicated systems. Of 265 duplicated SFVs, 138 (52%) began in the midthigh region and 80 (30%), in the adductor canal region. The duplicated vessel was medial to the main SFV in 122 (46%), lateral in 131 (49%), and both (ie, triplications) in 12 (4.5%). The length of the duplicated SFV ranged from 1 to 35 cm; 6-15 cm was the most common length in 162 (62%) SFVs. There was no significant association between the incidence of anatomic variations and age or sex (P >.1). The presence of multiple vessels in one leg was strongly correlated with the probability of occurrence in the other leg (P <.001).

CONCLUSION

Variations in lower limb venous anatomy are common and have important implications for the US diagnosis of deep vein thrombosis.

Economic burden of long-term complications of deep vein thrombosis after total hip replacement surgery in the United States

BACKGROUND

Estimates of the cost of long-term complications of a primary deep vein thrombosis (DVT), including the post-thrombotic syndrome (PTS) and recurrent venous thromboembolism (VTE), may be relevant for resource allocation decisions.

OBJECTIVE

The objective of this study was to provide US cost estimates of the long-term complications of a primary DVT, which occurs in approximately 5% to 20% (with adequate thromboprophylaxis) and 50% (in the absence of thromboprophylaxis) of total hip replacement surgeries (THRS).

METHODS

A literature-based model was used to project the excess long-term complication costs of DVT following THRS. The model simulated the natural history of DVT complications using published estimates of the incidence and prognosis of PTS and recurrent VTE. Each complication was assigned a cost obtained by multiplying the amount of resources used in its management by the unit price of these resources.

RESULTS

The annual per-patient cost of each complication was as follows: mild-to-moderate PTS, 839 dollars in the first year and 341 dollars in subsequent years; severe PTS, 3817 dollars in the first year and 1677 dollars in subsequent years; DVT, 3798 dollars; and pulmonary embolism, 6604 dollars. The average discounted lifetime cost of DVT complications was estimated to be 3069 dollars (95% interval 2091 dollars-4279 dollars).

CONCLUSIONS

The long-term complications of a primary DVT represent a significant economic burden. Preventing a DVT could arguably lead to substantial savings in long-term DVT complications.

Results of an economic model to assess the cost-effectiveness of enoxaparin, a low-molecular-weight heparin, versus warfarin for the prophylaxis of deep vein thrombosis and associated long-term complications in total hip replacement surgery in the United States

BACKGROUND

Premature death due to pulmonary embolism is a short-term complication of deep vein thrombosis (DVT). The long-term clinical course after DVT can be further complicated by excess mortality, recurrent venous thromboembolism (VTE), and the post-thrombotic syndrome (PTS), which may produce sizable long-term economic burdens.

OBJECTIVE

The goal of this study was to determine the cost-effectiveness of the low-molecular-weight heparin (LMWH) enoxaparin versus warfarin for the universal prophylaxis of DVT and associated long-term complications in US patients undergoing total hip replacement surgery (THRS).

METHODS

A model was constructed to assess the long-term cost-effectiveness of the 2 treatments. Patients undergoing THRS were exposed to a short-term risk of developing a DVT. Patients surviving a DVT were exposed to increased risk of long-term complications of DVT, including PTS, recurrent VTE, and increased mortality. Published literature, augmented by expert opinion, served as input for the model's resource use and costs for DVT prophylaxis, clinical diagnosis, and treatment of DVT, VTE, and PTS.

RESULTS

When the analysis included only the short-term consequences of DVT, therapy with enoxaparin resulted in a net cost of $133 per patient and a net increase of 0.04 quality-adjusted life-years (QALYs) per patient. Thromboprophylaxis with enoxaparin versus warfarin resulted in $3733 per QALY saved. In contrast, when the long-term consequences of DVT were included, enoxaparin resulted in net lifetime savings of $89 per patient and net QALY benefits of 0.16 per patient.

CONCLUSIONS

To the best of our knowledge, this is the first US economic analysis comparing DVT prophylaxis with the LMWH enoxaparin versus warfarin that included the long-term complications of DVT. Our model suggests that use of enoxaparin in patients undergoing THRS reduces the economic burden associated with these long-term complications.