Cost effectiveness of enoxaparin as prophylaxis against venous thromboembolic complications in acutely ill medical inpatients: modelling study from the hospital perspective in Germany.

OBJECTIVE: To estimate, from the hospital perspective in Germany, the cost effectiveness of the low-molecular-weight heparin (LMWH) subcutaneous enoxaparin sodium 40 mg once daily (ENOX) relative to no pharmacological prophylaxis (NPP) and relative to subcutaneous unfractionated heparin (UFH) 5,000 IU three times daily (low-dose UFH [LDUFH]). Each is used in addition to elastic bandages/compression stockings and physiotherapy in the prevention of venous thromboembolic events (VTE) in immobilised acutely ill medical inpatients without impaired renal function or extremes of body weight.

METHODS: The incremental cost-effectiveness ratios (ICERs) of the 'additional cost for ENOX per clinical VTE avoided versus NPP' and 'additional cost for ENOX per episode of major bleeding avoided versus LDUFH' were chosen as target variables. The target variables were quantified using a modelling approach based on the decision-tree technique. Resource use during thromboprophylaxis, diagnosis and treatment of VTEs, episode of major bleeding and secondary pneumonia after pulmonary embolism (PE) was collected from a hospital survey. Costs were exclusively those to hospitals incurred by staff expenses, drugs, devices, disposables, laboratory tests and equipment for diagnostic procedures. These costs were determined by multiplying utilised resource items by the price or tariff of each item as of the first quarter of 2003. Safety and efficacy values of the comparators were taken from the MEDENOX (prophylaxis in MEDical patients with ENOXaparin) and the THE-PRINCE (THromboEmbolism-PRevention IN Cardiac or respiratory disease with Enoxaparin) trials and from a meta-analysis. The evaluation encompassed 8 (6-14) days of thromboprophylaxis plus time to treat VTE and episode of major bleeding in hospital. Point estimates of all model parameters were applied exclusively in the base-case analysis.

RESULTS: There were incremental costs of euro 1,106 for ENOX per clinical VTE avoided versus NPP (1 euro approximately equals 1.07 US dollars; average of the first quarter of 2003). ENOX dominated LDUFH: cost savings of euro 55,825 were obtained and 7.7 episodes of major bleeding were avoided by ENOX compared with LDUFH, each per 1000 patients. In comprehensive sensitivity analyses, the robustness of the model and its results was shown.

CONCLUSIONS: Results of this evaluation suggest that, in immobilised acutely ill medical inpatients, ENOX may offer hospitals in Germany a very cost-effective option for thromboprophylaxis compared with NPP and a cost-saving alternative compared with LDUFH.