LAUSR

Abstract Inappropriate use of antibiotics is among the key drivers of antimicrobial resistance (AMR). Antibiotic use in Northern Ireland (NI) is the highest in the UK and approximately 80% is prescribed in primary care. Little information however exists about the patient and prescriber factors driving this. We described the trend in NI primary care total antibiotic prescribing 2010–2019 and conducted a cross-sectional study using a random sample of individuals registered with an NI GP on 1st January 2019. We used multilevel logistic regression to examine how sociodemographic factors and urinary catheter use was associated with the likelihood of being prescribed an antibiotic during 2019, adjusting for clustering at GP practice and GP federation levels. Finite mixture modelling (FMM) was conducted to determine the association between the aforementioned risk factors and quantity of antibiotic prescribed (defined daily doses). The association between age and antibiotic prescription differed by gender. Compared to males 41–50 years, adjusted odds of prescription were higher for males aged 0–10, 11–20 and 51 + years, and females of any age. Catheter use was strongly associated with antibiotic prescription (aOR = 6.82, 95% CI 2.50–18.64). Socioeconomic deprivation and urban/rural settlement were not associated in the multilevel logistic analysis. GP practices and federations accounted for 1.24% and 0.12% of the variation in antibiotic prescribing respectively. FMM showed associations between larger quantities of antibiotics and being older, male and having a catheter. This work described the profile of individuals most likely to receive an antibiotic prescription in NI primary care and identified GP practice as a source of variation; suggesting an opportunity for reduction from effective interventions targeted at both individuals and general practices.