LAUSR

Abstract Background Antibiotic resistance has been identified as a public health threat both in the United States and globally. The United States published the National Strategy for Combating Antibiotic Resistance in 2014, which included goals to reduce inappropriate outpatient antibiotic use. Methods This cross-sectional study was conducted using National Health and Nutrition Examination Surveys (NHANES) years 1999–2018. Weighted prevalence of past 30-day nontopical outpatient antibiotic use was calculated, as well as the change in prevalence from 1999–2002 to 2015–2018 and 2007–2010 to 2015–2018, both overall and for subgroups. Associations with past 30-day nontopical outpatient antibiotic use in 2015–2018 were examined using predictive margins calculated by multivariable logistic regression. Results The overall prevalence of past 30-day nontopical outpatient antibiotic use adjusted for age, sex, race/ethnicity, poverty status, time of year of the interview, and insurance status from 1999–2002 to 2015–2018 changed significantly from 4.9% (95% CI, 3.9% to 5.0%) to 3.0% (95% CI, 2.6% to 3.0%), with the largest decrease among children age 0–1 years. From 2007–2010 to 2015–2018, there was no significant change (adjusted prevalence ratio [adjPR], 1.0; 95% CI, 0.8 to 1.2). Age was significantly associated with antibiotic use, with children age 0–1 years having significantly higher antibiotic use than all other age categories >6 years. Being non-Hispanic Black was negatively associated with antibiotic use as compared with being non-Hispanic White (adjPR, 0.6; 95% CI, 0.4 to 0.8). Conclusions While there were declines in antibiotic use from 1999–2002 to 2015–2018, there were no observed declines during the last decade.