Economic evaluation of the use of nadroparin in the treatment of deep-vein thrombosis in Switzerland

A systematic review of economic analyses of low-molecular-weight heparin for the treatment of venous thromboembolism

INTRODUCTION

Public concerns about the increase in health care expenditure have prompted investigators to analyze the costs and benefits of health care interventions. We conducted a systematic review of economic analyses of venous thromboembolism treatment focusing on studies evaluating low-molecular-weight heparin.

MATERIALS AND METHODS

We identified studies by a MEDLINE search and a review of bibliographies of retrieved articles. From each eligible study, we extracted data on the study characteristics, the effectiveness, and the cost of managing the venous thromboembolism with respect to treatment. We critically appraised the studies according to the framework from the Users' Guides to the Medical Literature XIII: How to Use an Article on Economic Analysis of Clinical Practice.

RESULTS

Six of these eight economic analyses of venous thromboembolism treatment that met the inclusion criteria for this review showed that low-molecular-weight heparin is associated with less recurrent venous thromboembolism and is less costly than treatment with unfractionated heparin. Although discrete recurrent venous thromboembolism event rates were not included in the seventh study, these investigators concluded that the cost of low-molecular-weight heparin for the treatment of venous thromboembolism treatment was offset by the savings associated with fewer hospital admissions when low-molecular-weight heparin was used. In the eighth study, although the cost of treatment with low-molecular-weight heparin was higher than treatment with unfractionated heparin, the investigators concluded that low-molecular-weight heparin is cost-effective for inpatient management.

CONCLUSIONS

Low-molecular-weight heparin treatment may confer economic advantages over unfractionated heparin therapy because it does not require anticoagulant monitoring and it facilitates outpatient therapy.

Outpatient therapy with low molecular weight heparin for the treatment of venous thromboembolism: a review of efficacy, safety, and costs

PURPOSE

To summarize the evidence comparing the efficacy, safety, and costs of outpatient and inpatient treatment of venous thromboembolism.

METHODS

We searched the literature through March 2002 for studies comparing outpatient and inpatient treatment of venous thromboembolism with low molecular weight heparin or unfractionated heparin, and for studies addressing the costs of low molecular weight heparin use in any setting. We included studies with comparison groups or decision analyses.

RESULTS

Eight studies (three randomized trials and five cohort studies) compared outpatient use of low molecular weight heparin with inpatient use of unfractionated heparin in 3762 patients. The incidence of recurrent deep venous thrombosis was similar in the two groups (median, 4% [range, 0% to 7%] vs. 6% [range, 0% to 9%]), as was major bleeding (median, 0.5% [range, 0% to 2%] vs. 1% [range, 0% to 2%]). Use of low molecular weight heparin was associated with shorter hospitalization (median, 2.7 days [range, 0.03 to 5.1 days] vs. 6.5 days [range, 4 to 9.6 days]) and lower costs (median difference, 1600 dollars). Comparisons of outpatient and in-hospital use of low molecular weight heparin reported no difference in outcomes, but there were savings in hospitalization costs. Low molecular weight heparin was also found to be more cost saving and cost-effective than unfractionated heparin, with savings of 0% to 64% (median, 57%).

CONCLUSION

The evidence indicates that outpatient treatment of deep venous thrombosis with low molecular weight heparin is likely to be efficacious, safe, and cost-effective.

Management of venous thromboembolic disease in the lower limb

Thromboembolic disease continues to cause significant morbidity and mortality in our community, despite extensive research into the aetiological factors and significant resources invested in the development of pharmacological agents for treating this condition. Development of more sensitive and specific modalities for identifying venous thromboses has improved their early detection, particularly in the commonest site, the lower limb. A rational evidence-based management pathway has not been formulated as debate continues over the most appropriate method of treatment. This review outlines the pathophysiology of the disease, provides a clinical pathway for the management of lower limb thromboembolic disease using reliable available evidence and briefly discusses the efficacy of drug therapy.

Looking forward in the treatment of deep-vein thrombosis

Clinical guidelines developed by the American College of Chest Physicians (ACCP) for the management of venous thromboembolism (VTE) are based on current evidence from randomized clinical trials and amended in response to emerging results. The standard treatment for VTE comprises in-hospital treatment with dose-adjusted unfractionated heparin (UFH) for a minimum of 5 days and oral anticoagulants for at least 3 months. Recent clinical studies show that subcutaneous low-molecular-weight heparins (LMWHs) in fixed doses according to body weight are as effective and safe as intravenous UFH in the initial treatment of deep-vein thrombosis, with or without pulmonary embolism. There is also evidence that the optimal duration of secondary thromboprophylaxis depends on assessable thromboembolic risk factors. The 1998 ACCP guidelines take account of this new evidence by advocating LMWHs as an alternative to standard UFH for the initial treatment of VTE and risk stratification of patients to guide duration of secondary thromboprophylaxis. Outpatient treatment of VTE with LMWHs has been shown to be feasible and is increasingly used in clinical practice, offering substantial economic benefits. Certain LMWHs appear to be effective at a once-daily dose. Evidence is now emerging that may clarify the role of inferior vena cava filters and thrombolysis in VTE management. Future versions of the ACCP guidelines may be expected to reflect new data from ongoing trials.

Clinical and economic aspects of managing venous thromboembolism in the outpatient setting

Low-molecular-weight heparins (LMWHs) are at least as effective and safe as unfractionated heparin (UFH) in the prevention and initial treatment of venous thromboembolism (VTE), and their fixed-dose, once- or twice-daily dosing regimen without laboratory monitoring makes them suitable for outpatient use. Postoperative thromboprophylaxis usually continues until hospital discharge, but evidence demonstrates that the VTE risk persists for several weeks. Economic pressures, changes in clinical practice, and patient preferences make hospital stays shorter. As a result, outpatient thromboprophylaxis with LMWH has been investigated. LMWH self-administered at home once daily for up to 4 weeks after hospital discharge is safe and well tolerated and significantly reduces the incidence of postdischarge VTE after hip replacement. Targeted appropriately, extended thromboprophylaxis may be cost effective, and the development of an autoinjection device may increase the proportion of patients eligible for home management. LMWHs may also be of value as long-term secondary thromboprophylaxis in patients with contraindications to oral anticoagulants. Standard initial treatment for VTE comprises intravenous UFH administered to the patient in the hospital. However, three large-scale studies have demonstrated the efficacy and safety of outpatient treatment of acute VTE using LMWHs. The economic benefits of shortening or eliminating inpatient therapy are substantial, but successful home treatment requires careful patient selection, intensive education and a comprehensive system of professional support to optimize compliance and safety.

Low molecular weight heparin versus oral anticoagulants in the long-term treatment of deep venous thrombosis

PURPOSE

The purpose of this study was to evaluate whether low molecular weight heparin (LMWH) could be equal or more effective than conventional oral anticoagulants (OAs) in the long-term treatment of deep venous thrombosis (DVT).

METHODS

One hundred fifty-eight patients with symptomatic DVT of the lower limbs confirmed by means of duplex ultrasound scan were randomized to receive 3 to 6 months' treatment with nadroparine calcium or acenocoumarol. Quantitative and qualitative duplex scan scoring systems were used to study the evolution of thrombosis in both groups at 1, 3, 6, and 12 months.

RESULTS

During the 12-month surveillance period, two (2.5%) of the 81 patients who received LMWH and seven (9%) of the 77 patients who received OAs had recurrence of venous thrombosis (not significant). In the LMWH group no cases of major bleeding were found, and four cases (5.2%) occurred in the OA group (not significant). The mortality rate was nine (11.1%) in the LMWH group and 7.8% in the OA group (not significant). The quantitative mean duplex scan score decreased in both groups during the follow-up and had statistical significance after long-term LMWH treatment on iliofemoral DVT (1, 3, 6, and 12 months), femoropopliteal DVT (1-3 months), and infrapopliteal DVT (first month). Duplex scan evaluation showed that the rate of venous recanalization significantly increased in the common femoral vein at 6 and at 12 months and during each point of follow-up in the superficial and popliteal veins in the LMWH group. Reflux was significantly less frequent in communicating veins after LMWH treatment (17.9% vs 32.2% in the OA group). The reflux rates in the superficial (22.4% in the LMWH group, 30.6% in OA group) and deep (13.4% vs 17.7%) venous system showed no significant differences between groups.

CONCLUSIONS

The unmonitored subcutaneous administration of nadroparine in fixed daily doses was more effective than oral acenocoumarol with laboratory control adjustment in achieving recanalization of leg thrombi. With nadroparine, there was less late valvular communicating vein insufficiency, and it was at least as efficacious and safe as oral anticoagulants after long-term administration. These results suggest that LMWHs may therefore represent a real therapeutic advance in the long-term management of DVT.

Cost-effectiveness of low-molecular-weight heparin in the treatment of proximal deep vein thrombosis

OBJECTIVE

To estimate the cost-effectiveness of low-molecular-weight heparin (LMWH) in the treatment of proximal lower extremity deep venous thrombosis.

DESIGN

Cost-effectiveness analysis that includes the treatment of the index case and simulated 3-month follow-up.

SETTING

Acute care facility.

PATIENTS AND PARTICIPANTS

Hypothetical cohorts of 1,000 patients who present with proximal deep venous thrombosis.

INTERVENTIONS

Intravenous unfractionated heparin (UH), LMWH (40% at home, 60% in hospital), or selective UH/LMWH (UH for hospitalized patients and LMWH for patients treated at home).

MEASUREMENTS AND MAIN RESULTS

The outcomes were recurrent thrombosis, mortality, direct medical costs, and marginal cost-effectiveness ratios from the payer's perspective. At the base-case and under most assumptions in the sensitivity analysis, the LMWH and the selective UH/LMWH strategies dominate the UH strategy i.e., they result in fewer cases of recurrent thrombosis and fewer deaths, and they save resources. The savings occur primarily by decreasing the length of stay. The LMWH strategy resulted in lower costs as compared with the UH strategy when the proportion of patients treated at home was more than 14%. Treating 1, 000 patients with the LMWH strategy as compared with the UH/LMWH strategy would result in 10 fewer cases of recurrent thrombosis, 1.2 fewer deaths, at an additional cost of $96,822; the cost-effectiveness ratio was $9,667 and $80,685 per recurrent thrombosis or death prevented, respectively.

CONCLUSIONS

Treatment with LMWH leads to savings and better outcomes as compared with UH in patients with lower extremity deep venous thrombosis. The selective UH/LMWH strategy is an alternative option.

Formulary management of low molecular weight heparins

Low molecular weight heparins (LMWHs) are increasingly being utilised as anticoagulants in healthcare settings. These agents offer several advantages over standard unfractionated heparin. Indications for LMWHs include deep vein thrombosis and pulmonary embolism prophylaxis, deep vein thrombosis treatment, use in coronary procedures associated with a high risk for bleeding, and in acute coronary syndromes. Prior to being added to formularies, LMWHs should be evaluated for efficacy, safety and economic benefits over other anticoagulants. Institutions should be prepared to conduct their own economic assessments in the absence of readily available studies. There is clear evidence that LMWHs are cost saving or are at least cost effective as thromboprophylactic agents in major orthopaedic surgery. The economic benefits of LMWHs in other surgical situations is less clear. Consistent evidence from several countries indicate that LMWHs are cost saving as anticoagulants for the initial treatment of DVT. Further studies are needed to evaluate the efficacy, safety and economics of LMWHs in other conditions besides hip and knee arthroplasty and general surgery.