What drives antibiotic use in the community? A systematic review of determinants in the human outpatient sector

Inadequate and excessive use of antibiotics in humans, animals, and plants has been identified among the key drivers of antibiotic resistance (ABR). In human medicine, the great majority of antibiotics are prescribed in the outpatient sector with profound differences in antibiotic consumption across various geographical scales and between health care sectors; raising questions around the underlying drivers. Moving beyond individual patient-related determinants, determinants of antibiotic use in the outpatient sector were categorized as compositional, contextual and collective, enabling an analysis of potential area effects on antibiotic use. 592 variables identified in 73 studies were sorted into 46 determinant groups. Compositional determinants provided the strongest evidence with age, education, employment, income, and morbidity exhibiting a clear influence on antibiotic use. Regarding contextual and collective determinants, deprivation, variables around health care services, Hofstede's dimensions of national culture and regulation affect antibiotic use. The results are biased towards high-income and western countries, often relying on secondary data. However, the findings can be used as signposts for associations of certain variables with antibiotic use, thereby enabling further research and guiding interventions.