Trends in Outpatient Antibiotic Use in 3 Health Plans

Previous analyses of data from 3 large health plans suggested that the substantial downward trend in antibiotic use among children appeared to have attenuated by 2010. Now, data through 2014 from these same plans allow us to assess whether antibiotic use has declined further or remained stable.

Population-based antibiotic-dispensing rates were calculated from the same health plans for each study year between 2000 and 2014. For each health plan and age group, we fit Poisson regression models allowing 2 inflection points. We calculated the change in dispensing rates (and 95% confidence intervals) in the periods before the first inflection point, between the first and second inflection points, and after the second inflection point. We also examined whether the relative contribution to overall dispensing rates of common diagnoses for which antibiotics were prescribed changed over the study period.

We observed dramatic decreases in antibiotic dispensing over the 14 study years. Despite previous evidence of a plateau in rates, there were substantial additional decreases between 2010 and 2014. Whereas antibiotic use rates decreased overall, the fraction of prescribing associated with individual diagnoses was relatively stable. Prescribing for diagnoses for which antibiotics are clearly not indicated appears to have decreased.

These data revealed another period of marked decline from 2010 to 2014 after a relative plateau for several years for most age groups. Efforts to decrease unnecessary prescribing continue to have an impact on antibiotic use in ambulatory practice.