Up to 25% of Antibiotics Could Be Inappropriate

Nearly one-fourth of antibiotic prescriptions are inappropriate, according to the results of a recent study.

While previous studies have utilized pre-2015 data to show trends in inappropriate prescribing of antibiotics, none have used a comprehensive classification scheme of diagnosis codes found in ICD-10-CM, according to the study authors.

For their cross-sectional study, they examined data from 19.2 million entries from the MarketScan Commercial Claims and Encounters database, 2016, and developed a classification scheme that determined whether each of the 91,738 ICD-10-CM codes “always,” “sometimes,” or “never” justified the use of antibiotics.

All filled antibiotic prescriptions were then classified using these codes, with the main outcome being the proportion of fills that were “appropriate” (associated with at least 1 “always” code), “potentially appropriate” (associated with at least 1 “sometimes” but no “always” codes), “inappropriate” (associated with at least 1 “sometimes” but no “always” always codes), and “not associated with a recent diagnosis code.”

Overall, among 15,455,834 antibiotic prescription fills, the most common antibiotics were azithromycin (19%), amoxicillin (18.2%), and amoxicillin-clavulanate (11.6%). Among these, 12.8% were appropriate, 35.5% were potentially appropriate, 23.2% were inappropriate, and 28.5% were not associated with a recent diagnosis code. Among the 3,592,183 inappropriate fills, 70.7% were written in office-based settings, 6.2% in urgent care centers, and 4.7% in emergency departments. In 2016, 14.1% of the 19,203,264 enrollees filled at least 1 inappropriate antibiotic prescription.

“This study provides the most recent and comprehensive estimates of outpatient antibiotic appropriateness in the US privately insured population to date. Our results show the scale of inappropriate antibiotic prescribing at both the prescription and population levels.”

—Michael Potts

Reference:

Chua K, Fischer MA, Linder JA. Appropriateness of outpatient antibiotic prescribing among privately insured US patients: ICD-10-CM based cross sectional study [published online January 16, 2019]. BMJ. doi: https://doi.org/10.1136/bmj.k5092.

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