Economic evaluation of antimicrobial usage surveillance in livestock

There is increased pressure by governments and industry to develop national antimicrobial usage (ABU) surveillance programmes in animals. This article presents a methodological approach to conduct cost-effectiveness analysis (CEA) of such programmes.

We propose seven objectives of ABU surveillance: quantification of usage, detection of trends, detection of hotspots, identification of risk factors, facilitate research, evaluate impact of policies and disease, and demonstrate compliance with regulations. Achievement of these objectives should support decision process on interventions, generate trust, incentivise reduction in ABU and reduce the risk of antimicrobial resistance. CEA can be conducted for each objective by dividing the cost of the programme with the surveillance capacity (performance) to meet these objectives. We suggest that precision and accuracy of surveillance outputs can be used as performance indicators. Precision depends on the level of surveillance coverage (SC) and surveillance representativeness (SR). Accuracy is influenced by the quality of the farm records and SR. We argue that there is an increase in marginal cost per each unit increase of SC, SR and data quality. This is due to increasing difficulty to recruit farmers due to potential barriers such as staff capacity, capital availability, computing literacy and availability, and geographical difference, amongst other factors. We conduct a simulation model to test the approach using the quantification of ABU as primary objective, and we provide evidence of the application of the law of diminishing returns. CEA can be used to support decisions regarding the level of coverage, representativeness and data quality required in ABU programmes.