ABSTRACT
BACKGROUND: Antimicrobial resistance (AMR) is affected significantly by inappropriate antibiotic use, and is one of the greatest threats to human health. Antimicrobial stewardship (AMS) is a programme of actions promoting responsible use of antimicrobials, and is essential for limiting AMR. Nurses have an important role to play in this context. AIM: To investigate the determinants of nurse AMS behaviours and the impact of past training. METHODS: A cross-sectional multi-country survey design with mixed methods was employed. Participants were 262 nurses {223 female; mean age 44.45 [standard deviation (SD) 10.77] years} of 10 nationalities, with individual survey links sent via professional networks in five countries, alongside Twitter. Nine AMS behaviours and 14 behavioural determinants were assessed quantitatively using the Theoretical Domains Framework (TDF), and mapped to the Capability, Opportunity, Motivation - Behaviour (COM-B) model. Analysis identified differences between nurses with and without AMS training. The influence of coronavirus disease 2019 (COVID-19) on AMS behaviour was investigated qualitatively using free-text data. FINDINGS: Nurses performed all nine AMS behaviours, which were significantly higher [t (238) -4.14, P<0.001] among those who had received AMS training [mean 53.15 (SD 7.40)] compared with those who had not received AMS training [mean 48.30 (SD 10.75)]. Nurses who had received AMS training scored significantly higher in all of the TDF domains. The TDF was able to explain 27% of the variance in behaviour, with 'Skills' and 'Behavioural regulation' (e.g. ability to self-monitor and plan) shown to be the most predictive of AMS actions. Both of these domains are situated in the 'Capability' construct of the COM-B model, which can be enhanced with the intervention strategies of education and training. An increase in AMS behaviours was reported since the COVID-19 pandemic, regardless of previous training. Six core themes were linked to AMS: (1) infection prevention and control; (2) antimicrobials and antimicrobial resistance; (3) diagnosis of infection and use of antibiotics; (4) antimicrobial prescribing practice; (5) person-centred care; and (6) interprofessional collaborative practice. CONCLUSION: Nurse training has a significant beneficial effect on AMS behaviour and its determinants. Nurses who had received AMS training scored higher in all TDF determinants of behaviour compared with those who had not received AMS training, resulting in higher capability, opportunity and motivation to perform AMS behaviour. AMS education and training should be offered to nurses to enhance these factors. Future research should consider the optimal level of training to optimize AMS behaviour, with a focus on developing skills and behavioural regulation.