How to consider the broader economic value of antimicrobial stewardship interventions: A novel approach to cost-effectiveness evaluation.

BACKGROUND: All antibiotic use can contribute to antimicrobial resistance. By improving antibiotic prescribing, antimicrobial stewardship interventions can produce direct cost and outcome changes to those receiving the interventions, while altering long-term antimicrobial resistance trajectories to generate indirect benefits for future populations. To compare the cost-effectiveness of different antimicrobial stewardship interventions, we have to consider both the short-term direct costs and clinical outcomes, and the long-term indirect benefits to future populations. However, uncertainties for the long-term benefits are considerable, which inhibits analyses and decision-making inference. OBJECTIVE: To describe the limitations of conventional cost-effectiveness analyses in evaluating antimicrobial stewardship interventions, and propose a novel approach for comparing the cost-effectiveness of different antimicrobial stewardship interventions that bypasses the need to explicitly estimate indirect long-term benefits. SOURCES: We performed a non-systematic literature review to identify key limitations of conventional cost-effectiveness evaluation when applied to antimicrobial stewardship interventions. CONTENT: We propose a novel approach for evaluating the cost-effectiveness of antimicrobial stewardship interventions, which considers the monetary value of present-day sacrifices needed to preserve antibiotic effectiveness for future populations. We illustrate our method with a worked example, and discuss the limitations and assumptions surrounding our proposed approach. IMPLICATIONS: Our study responds directly to calls for adapting current health technology assessment methods for interventions with complex externalities. Our proposed method is pragmatic and necessary to support rational prioritisation of stewardship interventions under finite budgets.