Dabigatran etexilate for the prevention of venous thromboembolism in patients undergoing elective hip and knee surgery: a single technology appraisal.

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of dabigatran etexilate (DBG) for the prevention of venous thromboembolism (VTE) in patients undergoing elective hip and knee surgery based upon a review of the manufacturer's submission to the NICE as part of the single technology appraisal (STA) process. The submission's evidence came from three reasonable-quality trials comparing DBG with enoxaparin, and a comparison of DBG with fondaparinux based on the relative efficacy and safety as derived from a mixed treatment comparison (MTC) meta-analysis. DBG (220 mg and 150 mg once daily) is not inferior to enoxaparin (40 mg once daily and 30 mg twice daily) in terms of major VTE or VTE-related events (secondary outcome). Meta-analysis shows that 220 mg DBG is not inferior to enoxaparin (40 mg once daily or 30 mg twice daily) in reducing total VTE and all-cause mortality (primary outcome) in total hip or knee replacement, whereas there is uncertainty around the clinical effectiveness of 150 mg DBG for this outcome. In the MTC analysis DBG compared favourably with the other interventions, with the exception of extended enoxaparin and fondaparinux. The adverse event profile was not significantly different in those receiving DBG and those receiving enoxaparin. The submitted two-phase economic model compares DBG with enoxaparin and fondaparinux in total hip and knee replacement. The model structure is appropriate and the model assumptions are reasonable. The health states, costs, utilities and recurrence rates used are considered to be appropriate for the required analysis. The model estimated that at the licensed dose of 220 mg once daily DBG dominates enoxaparin in both total hip replacement and total knee replacement and that at the lower dose of 150 mg once daily DBG dominates enoxaparin in total hip replacement and enoxaparin dominates DBG in total knee replacement. DBG is less cost-effective than fondaparinux in total hip replacement at both doses; the cost per quality-adjusted life-year of fondaparinux versus DBG is 11,111 pounds and 6857 pounds for the higher and lower doses of DBG respectively. In total knee replacement, both DBG doses are dominated by fondaparinux. For DBG versus all comparators in all cases the cost-effectiveness results are based on small incremental cost and health benefits. Weaknesses of the submitted evidence include that methods used for screening studies, data extraction and applying quality assessment criteria to included studies, as well as key details of trials included in the MTC, were not adequately described. In addition, some input parameters into the modelling process are incorrect. The ERG was unable to correct all of these mistakes and the impact on the model results is therefore unknown. The National Institute for Health and Clinical Excellence guidance issued as a result of the STA states that DBG is recommended as an option for the primary prevention of VTE events in adults who have undergone elective total hip or knee replacement surgery.