Title: The Economics of Rapid Diagnostics to Reduce Antibiotic Prescribing in NHS Wales (TRaDe).
Funder: Health and Care Research Wales (Welsh Government)

Abstract: Background: The threat of the antimicrobial resistance (AMR) is a global health concern. By 2050, resistant infection could be responsible for 10 million deaths per year worldwide, at a cumulative cost of $100 trillion. Inappropriate use of antibiotics is one of the main drivers of AMR, with consequences of poorer health outcomes for the patient, increased risk of resistant infection in society, and increased healthcare costs. In Wales, approximately 3 in 10 prescriptions dispensed in primary care are for an antibiotic, over 20% of these will be unnecessary. Tackling antimicrobial resistance is a Welsh Government priority. Reducing unnecessary prescribing is prudent healthcare, but identifying bacterial infection can be challenging. The UK Action Plan to tackle AMR, developed collaboratively with devolved administrations, details an urgent need to support access to rapid diagnostics at the point of care (HM Government 2019). C-reactive protein (CRP) point-of-care test (POCT) is recommended for patients with suspected lower respiratory tract infection (LRTI) (NICE 2014) and increasingly used in Common Obstructive Pulmonary Disease pathways (Bulter 2019). Evidence of cost-effectiveness shows wide variation in the value of this test in routine clinical practice, compared to testing according to guidelines (Holmes et al. 2018. This suggests human behaviour impacts the value of the test. Behavioural economics blends economics and psychology to explain how people make decisions. Understanding decision-making behaviours relevant to the threat of AMR and antibiotic use is an important aspect of valuing interventions to reduce inappropriate prescribing (Lorencatto 2018). Aim: To investigate the economics of rapid diagnostics to reduce antibiotic prescribing in NHS Wales. Specifically to: use behavioural economics to inform benefit-risk assessment and value of diagnostics; (ii) evaluate the cost-effectiveness POCT to support antibiotic prescribing; (iii) understand subjective views of all stakeholders to support resource allocation decisions; and, (iv) report on prudent implementation of UK Government improvement targets for the percentage of antibiotic prescriptions supported by diagnostics. Plan of investigation: WP1: Large-scale online survey of public (n=1068) and healthcare professionals (n=250) eliciting benefit-risk, time and service delivery preferences, using discrete choice experiments. Participants choose between alternatives described by patient benefit-risk outcomes of antibiotic use, societal AMR risk. WP2: Prospective cohort study of patients, with symptoms of lower respiratory tract infection (LRTI) (n=170), measuring symptoms, utility, and resource use over 28-days, with 12-month SAIL linkage. WP3: Cost-effectiveness model of CRP POCT for LRTI where the antibiotic decision is unclear, incorporating the behavioural parameters (WP1), patient data (WP2) and a rapid review. WP4: Q-methodology enquiry with 50 stakeholders to obtain subjective viewpoints on antimicrobial stewardship and resource allocation. WP5: Synthesis of findings and co- production of recommendations for prudent execution of 2025 improvement targets. Potential benefits to the public and/or patients and service users: This work will provide high quality evidence on optimal allocation of scarce NHS resources to reduce inappropriate antibiotic prescribing in primary care, informed by public and healthcare professional preferences.

Lay abstract: This research will measure the value of diagnostic tests, which are quick and easy to perform, and help healthcare professionals identify whether the patient needs antibiotics. Antibiotic resistance is when bacteria change in ways that mean the medicines used to cure the infection no longer work. A growing number of infections, such as pneumonia, are becoming harder to treat, as the antibiotics used to treat them become less effective, leading to longer hospital stays, higher medical costs and more death. It is the biggest threat to health worldwide. Human behaviour plays a big part in the rise and spread of antibiotic resistance. Whilst antibiotic resistance occurs naturally, inappropriate use of antibiotics speeds this up. The Government have stressed an urgent need to improve access to tests that can help doctors decide if an antibiotic is necessary, but tests cost time and money. They are not available in every GP practice and my previous work showed that where a test is available, use is not always as recommended. We need to understand why this is. Decisions may be being influenced by perceptions of benefits and risks, or by the way the test is delivered (e.g. time you are willing to wait for the result). This has an impact on health and value for money. A course of antibiotics may cost the NHS less than £1, tests are likely to cost an additional £10, but cost of treating an illness caused by over prescribing of antibiotics can be £8,000, per patient. These costs are incurred at different times, by different people, but all are connected to decisions about prescribing and global health.

Research activity codes: 8.2 HEALTH AND WELFARE ECONOMICS
Health categories: INFECTION