PSU3 A Framework for Evaluating the Health and Cost Implications of Antimicrobial Resistance in the Context of Surgical Procedures

Antimicrobial resistance (AMR) has the potential to impact on the sustainability of non-essential surgical procedures, though attempts to quantify this have been limited. This work provides a framework for quantifying the health and cost implications of AMR in the context of surgical procedures. We identified three pathways through which AMR impacts on costs and health outcomes of surgery. Firstly, AMR reduces the efficacy of antibiotic prophylaxis, leading to increased rates of surgical site infections (SSIs). Secondly, AMR reduces the efficacy of antibiotics used to treat SSIs. Thirdly, as SSI rates increase and infections become difficult to treat, surgical procedures may no longer be conducted where the risk-benefit profile is considered unfavourable. We developed a model structure allowing these AMR effects to be quantified and applied the model to two surgical procedures: emergency hip fracture operation and elective bowel resection for cancer patients. Evidence was sought from the literature to parameterise the model. Where evidence was sparse key parameters were prioritised for a structured expert elicitation exercise. The framework allowed us to explore different scenarios with respect to potential future levels of AMR and how AMR impacts on costs and health outcomes. A paucity of data was highlighted on several key parameters: the likely impact of current AMR on SSI risk, the efficacy of antibiotics for treating SSIs and impact of current AMR on treatment efficacy, and how SSI risk influences whether surgery goes ahead. These aspects of the model were informed using structured expert elicitation. This framework provides an important contribution to understanding the mechanisms by which AMR impacts on surgery, how these impacts can be quantified, the evidence required, and where evidence gaps could be addressed by further research. The framework provides the starting point from which different interventions to mitigate these effects can be appraised.