Antibiotic Prescribing for Acute Respiratory Infections in Kentucky Medicaid: Opportunities for Stewardship.

BACKGROUND

Inappropriate antibiotic prescribing for acute respiratory infections (ARIs) is a major stewardship target. We examined antibiotic prescribing in Kentucky Medicaid from 2022 to 2024 and identified factors associated with inappropriate ARI prescribing to inform stewardship targeting.

METHODS

Retrospective analysis of linked pharmacy and medical claims in Kentucky Medicaid. Prescriptions for beneficiaries with an outpatient ARI diagnosis within seven days of dispensing were classified for appropriateness using a three-tiered diagnostic classification framework, with Tier 3 considered inappropriate. Multivariable logistic regression with prescriber-clustered standard errors assessed patient, provider, and contextual factors.

RESULTS

Of 2,386,291 ARI antibiotic prescriptions, 437,193 (18.3%) were inappropriate. Four conditions accounted for 87.0%: viral upper respiratory infection, bronchitis, non-suppurative otitis media, asthma and allergy. Azithromycin accounted for 38.3% of inappropriate prescriptions and was the most common antibiotic for both viral upper respiratory infection and bronchitis. Advanced practice providers accounted for 67% of antibiotic volume and 65% of inappropriate prescriptions despite lower adjusted odds than adult primary care physicians. Rural residence was associated with higher odds of inappropriate prescribing [Adjusted Odds Ratio (AOR): 1.25]. Inappropriate prescribing declined 21% overall, driven by a 26% reduction between 2022 and 2023 with a modest increase in 2024.

CONCLUSIONS

Inappropriate ARI antibiotic prescribing in Kentucky Medicaid is concentrated in a small set of conditions and antibiotics. Distinguishing prescribing volume from appropriateness has direct implications for stewardship targeting, and the longitudinal surveillance infrastructure developed here is replicable by other state health departments.