Exploring antimicrobial stewardship in UK veterinary medicine and livestock agriculture : a mixed-method, one health approach

Abstract

Antimicrobial resistance (AMR) poses a profound threat to human and animal health. More research has focused on drivers of inappropriate antimicrobial prescribing and usage in human medicine than in veterinary medicine. This thesis helps address this gap by exploring antimicrobial stewardship in UK livestock farming. It consists of six empirical studies and uses a mixed-method approach. Three qualitative studies explored farm vets’ and farmers’ beliefs about AMR and about antimicrobial prescribing, usage, and stewardship. Study One used qualitative interviews with farm vets (n = 13); results indicated vets understand their stewardship responsibilities but feel they cannot always prescribe in line with stewardship ideals due to contextual factors. Study Two used qualitative interviews with farmers (n = 12); results indicated farmers want to be antimicrobial stewards, but they feel constrained from making changes by external forces. Study Three used a secondary analysis of the combined datasets from Studies One and Two (n = 25) and identified that vets and farmers share a sense of ambivalence towards stewardship; they take some ownership for stewardship, but also engage in other-blaming for AMR. Three quantitative studies further explored the qualitative findings. Study Four used vignettes with farm vets (n = 16) to compare ‘ideal’ and ‘real-world’ prescribing and identify a clinical scenario for use in Study Five. Results showed antimicrobial prescribing was higher in ‘real-world’ than ‘ideal’ situations. Study Five used an experimental vignette and cross-sectional design with farm vets (n = 97) to assess the effects of context, values, and beliefs on vets’ prescribing. Results indicated context (vet-farmer relationship under pressure) and beliefs about responsibility for preventing AMR were associated with vets’ prescribing, but values and beliefs about causing AMR were not. Vets believed other groups had greater responsibility for causing and preventing AMR. Study Six used a cross-sectional survey to explore antimicrobial usage behaviours, knowledge, and beliefs about responsibility for AMR in vet students (n = 573). Results indicated vet students’ behaviours were responsible, knowledge about AMR was moderate to good, and they believed vets have less responsibility than other groups for causing or preventing AMR. Findings are discussed in terms of two key themes; ‘Psychological distancing: a barrier to stewardship’ and ‘Positive interactions: facilitating stewardship’. Findings are considered from a social ecological perspective, highlighting the need for stewardship interventions at multiple levels, and from a social identity perspective, highlighting the importance of emphasising a common goal of stewardship, to reduce psychological distancing and increase positive interactions between individuals and groups.