[Indirect comparisons in drug assessment reports on the GENESIS group (SEFH) webpage]

Cost-Effectiveness Analysis of Apixaban Versus Edoxaban in Patients with Atrial Fibrillation for Stroke Prevention

OBJECTIVE

Our objective was to assess the cost effectiveness of apixaban versus edoxaban in the prevention of stroke and systemic embolism (SE) in patients with atrial fibrillation (AF) in Spain.

METHODS

We customized a Markov model with ten health states to estimate the lifetime economic and clinical outcomes in 6-week cycles. The efficacy (clinical event rates per 100 patient-years) and safety data were derived from a pairwise indirect treatment comparison. The analysis was conducted from both the national health service (NHS) and societal perspectives, and included pharmaceutical costs (retail price plus value-added tax (VAT) and applicable national deductions) according to daily dosages (apixaban 10 mg (5 mg twice daily (bid)) and edoxaban 60 or 30 mg) and complications and disease-management costs, obtained from national databases. Utilities for quality-adjusted life-year (QALY) calculations reflected EuroQoL 5-Dimension scores in patients with AF. An annual discount rate of 3% was applied for costs (€, year 2019 values) and outcomes.

RESULTS

In a 1000-patient cohort, apixaban 5 mg bid versus edoxaban 60 mg could avoid five strokes, six major bleedings and 29 clinically relevant non-major bleedings (CRNMBs). Compared with edoxaban 30 mg, apixaban could avoid 21 strokes and two SEs. An increase in bleedings was observed with apixaban (seven haemorrhagic strokes, 48 major bleedings and 17 CRNMBs). Apixaban yielded 0.04 additional QALYs compared with edoxaban 60 mg or 30 mg. Incremental costs/QALY were €9639.33 and €354.22 for apixaban versus edoxaban 60 mg and edoxaban 30 mg, respectively, from the NHS perspective and €7756.62 for apixaban versus edoxaban 60 mg from the societal perspective. Apixaban was dominant versus edoxaban 30 mg from the societal perspective. Sensitivity analyses confirmed the robustness of the model.

CONCLUSIONS

This study suggests that apixaban 5 mg bid is a cost-effective alternative to edoxaban for stroke prevention in the AF population in Spain.

A checklist for critical appraisal of indirect comparisons

The aim of this study was to develop a user-friendly checklist for critical appraisal of indirect comparisons of drugs, considering clinical, methodological/statistical and quality aspects, mainly to be applied in drug evaluation in the decision-making context. After conducting a review of the literature, we used group consensus to establish the key points of the checklist, focusing mainly on indirect comparisons, but including topics related to network meta-analysis or multiple treatment comparisons. The coordinating group elaborated the first draft, which was reviewed by external experts, re-evaluated by the coordinating group and finally assessed by 23 drug evaluation experts trained in indirect comparisons, who applied the checklist to one study. The Kappa index of agreement was calculated and the final checklist was developed by group consensus including the external experts. The checklist has two parts. The first consists of three eliminatory key questions while the second includes 17 items: 5 regarding quality, 5 regarding clinical issues and 7 dealing with methodology/statistics. The median kappa values of the 23 evaluations were 0.83 (range 0.67-0.93), 0.61 (0.54-0.91) and 0.36 (0.22-1) with regard to quality, clinical aspects and methodology/statistics, respectively. A structured checklist was developed to facilitate critical appraisal of key issues in indirect comparisons, including comments for assessing the consequences of its application to drug evaluation in the decision-making context. Agreement between reviewers in clinical and quality items was good, but weaker in methodology/statistics ones.