Non-visit-based and non-infection-related antibiotic use in the US: a cohort study of privately insured patients during 2016-2018

Fischer, Michael A; Mahesri, Mufaddal; Lii, Joyce; Linder, Jeffrey A

BACKGROUND: Ambulatory antibiotic prescriptions without a clinic visit or without documentation of infection could represent overuse and contribute to adverse outcomes. We aim to describe US ambulatory antibiotic prescribing, including those without an associated visit or infection diagnosis. METHODS: We conducted an observational cohort study using data of all patients receiving antibacterial, antibiotic prescriptions from 04-01-2016 to 06-30-2018, in a large US private health insurance plan. We identified outpatient antibiotic prescriptions as: (1) associated with a clinician visit and an infection-related diagnosis; (2) associated with a clinician visit, but no infection-related diagnosis; or (3) not associated with an in-person clinician visit in the seven days prior to the prescription (non-visit-based). We then assessed whether non-visit-based antibiotic prescriptions (NVBAP) differed from visit-based antibiotics by patient, clinician, or antibiotic characteristics using multivariable models. FINDINGS: The cohort included 8·6M enrollees who filled 22·3M antibiotic prescriptions. NVBAP accounted for 31%(6·9M) of fills and non-infection-related prescribing accounted for 22%(4·9M). NVBAP rates were lower for children than for adults (0-17 years old, 16%; 18-64 years old, 33%; > 65 years old, 34%). Among most commonly-prescribed antibiotic classes, NVBAP was highest for penicillins (36%), and lowest for cephalosporins (25%) and macrolides (25%). Specialist physicians had the highest rate of NVBAP (38%), followed by internists (28%), family medicine (20%), and pediatricians (10%). In multivariable models, NVBAP was associated with increasing age and NVBAP was less likely for patients in the South, with more baseline clinical visits, or with chronic lung disease. INTERPRETATION: Over half of ambulatory antibiotic use was either non-visit based or non-infection-related. Particularly given healthcare changes due to the COVID-19 pandemic, efforts to improve antibiotic prescribing must account for non-visit-based and non-infection-related prescribing. FUNDING: This work was supported by a grant from the Agency for Healthcare Research and Quality (R01HS024930).