Explaining socioeconomic differences in antibiotic prescribing for common infections in primary care: a population-based study in England

Background Levels of antimicrobial resistance are higher in more socioeconomically deprived areas, and antibiotic exposure is a key driver of antimicrobial resistance. Understanding where and why socioeconomic differences in antibiotic prescribing arise is essential for informing strategies to reduce differences in antibiotic exposure and, ultimately, antimicrobial resistance. We aimed to quantify and explain socioeconomic differences in antibiotic prescribing for common infections in primary care in England. Methods We conducted a population-based study of 17 million patients estimated to have been registered with a general practice in England in 2019, using national primary care data from Clinical Practice Research Datalink. We applied a distributional regression approach within the Generalised Additive Models for Location, Scale, and Shape framework to examine associations between area deprivation and antibiotic prescribing rates. We assessed whether differences were driven by consultation rates or probability of receiving antibiotics following consultation and quantified the contribution of vaccination uptake, smoking, and body mass index. Results Higher deprivation was associated with higher antibiotic prescribing rates for most respiratory tract indications. In children, prescribing rates were 44.8% (95% confidence interval [CI] 41.9% to 47.7%) higher for upper respiratory tract infections and 47.6% (95% CI 44.2% to 51.3%) higher for lower respiratory tract infections in the most versus least deprived twentile. In adults, prescribing rates for lower respiratory tract infections were 22.7% (95% CI 21.4% to 24.1%) higher in the most deprived twentile. Prescribing rates for other indications showed weak, U-shaped, or negative associations with deprivation. Prescribing differences were primarily driven by differences in consultation rates rather than probability of receiving antibiotics once consulted. Lower influenza vaccination uptake partly accounted for higher consultation rates for respiratory infections among more deprived children, while smoking prevalence contributed to differences among adults. Conclusions Socioeconomic differences in antibiotic prescribing vary by indication type and are largely explained by consultation frequency. Reducing the differences may require interventions that decrease the need to consult, e.g. improving influenza vaccination coverage in children and reducing smoking among adults, rather than focussing solely on prescribing behaviour.