Cost-effectiveness analysis of iStent Inject® implantation during cataract surgery compared to cataract surgery alone for mild to moderate open-angle glaucoma patients in Spain

Objective: To estimate the cost-effectiveness of two trabecular micro-bypass stent implants (iStent inject (R)) during cataract surgery, compared to cataract surgery alone, in patients with cataracts and mild-to-moderate primary Open Angle Glaucoma (OAG) in the Spanish National Health System (SNHS). Methods: A Markov model was used to simulate the progression of OAG patients, undergoing either cataract-iStent Inject (R) surgery or cataract surgery alone, over a lifetime horizon. Health states of glaucoma were based on the Hodapp-Parrish-Anderson criteria. Efficacy and resource use were obtained from published literature and validated by experts. Costs ((sic), 2020) were obtained from the Spanish database eSalud. The incremental cost-effectiveness ratio (ICER) expressed as cost per quality-adjusted life-year (QALY) gained was calculated. A societal perspective was also explored. Sensitivity analysis tested the robustness of results. Results: Cataract-iStent Inject (R) surgery was more effective and costly than cataract surgery alone, with an ICER of 12,676.48/QALY. The probability of iStent Inject being cost-effective was 90.9% and 78.4%, at a willingness-to-pay of (sic)30,000/QALY and (sic)21,000/QALY, respectively. From a societal perspective, Cataract-iStent Inject (R) surgery was cost-saving compared to cataract surgery alone. Conclusion: Cataract-iStent Inject (R) surgery was cost-effective (SNHS perspective) or cost-saving (societal perspective) compared to cataract surgery alone in patients with mild-to-moderate OAG.