Does poverty increase antibiotic prescribing rates through underlying health conditions? Ecological study using parallel mediation analysis

OBJECTIVE: Effect of social determinants on antibiotic prescribing rates is poorly studied in modern literature. The objective of this study was to explore the effect of the prevalence of poverty (annual household income <$24,999) in each state on antibiotic prescribing rates in outpatient settings per 1,000 population through chronic health conditions (ie, prevalence of obesity, diabetes, and chronic obstructive pulmonary disease) while also adjusting for confounders (ie, prevalence of population aged ≥65 years and physician density in each state). DESIGN: Ecological study. PARTICIPANTS: Entire US population. METHODS: Prevalence estimates from all 51 states were used to calculate direct, indirect, and total effects of poverty on the rates of antibiotic prescribing through parallel mediation analysis using linear regression with chronic health conditions (obesity, diabetes, and chronic obstructive pulmonary disease) as mediators. I obtained these data from point-prevalence estimates of 2020 survey results from the Behavioral Risk Factor Surveillance System for rates on poverty, obesity, diabetes, chronic obstructive pulmonary disease, and population aged ≥ 65 years. I also used the Antibiotic Resistance & Patient Safety Portal for antibiotic prescribing rates per 1,000 population and the Association of American Medical Colleges database for the physician density per 100,000 population. RESULTS: For every percentage increase in prevalence of poverty in each state, the antibiotic prescribing rate increased by 17.4 courses per 1,000 population (95% bootstrap confidence interval, 9.2–24.9) using indirect effects of poverty through mediators. CONCLUSIONS: Antibiotic stewardship programs should consider targeting social determinants of health along with underlying health conditions of patients being treated with antibiotics.