Antibiotic Prescriptions Associated with Outpatient Visits for Acute Upper Respiratory Tract Infections among Adult Medicaid Recipients in North Carolina

Abstract

North Carolina and the southeastern United States have the highest antimicrobial resistance rates for common respiratory tract pathogens in the nation. The excessive use of antibiotics for common outpatient infections is a major contributing factor in the emergence of antibiotic resistant bacteria. To estimate the prevalence of oral antibiotic treatment for acute, nonbacterial respiratory tract infections among adult Medicaid recipients in North Carolina, and to describe a pilot project aimed at reducing the prevalence of oral antibiotic treatment among this population. Using administrative claims data, we identified 24,137 Medicaid recipients, aged 18 to 64 years, who made at least one outpatient physician visit for acute nasopharyngitis (ICD-9, 460.x), acute pharyngitis (462.x), acute upper respiratory infection (465.9), acute bronchitis (466.0), or influenza (487.1) between October 1, 2000, and March 29, 2001. We excluded adults with chronic bronchitis (ICD-9, 491.x), emphysema (492.x), asthma (493.x), or chronic obstructive pulmonary disease (496.x). Pharmacy claims data were used to identify oral antibiotic treatment that occurred within 5 days of the outpatient visit. Overall, 63% (n = 15,189) of Medicaid recipients who made at least one outpatient visit during the observation period for one of the study conditions had a prescription filled for an oral antibiotic within 5 days. Residence in a rural county (64% vs. urban, 61%, p < 0.01) and in the eastern region of the state (65% vs. western region, 59%, p < 0.01) was associated with receipt of an antibiotic. Compared with the other principal study diagnoses, patients with acute bronchitis (44% of all outpatient visits) were 2.88 (95% CI = 2.72, 3.05) times more likely to receive oral antibiotic treatment after multivariate adjustment. The prevalence of oral antibiotic treatment among adult Medicaid beneficiaries diagnosed with nonspecific upper respiratory infections, colds, pharyngitis, bronchitis, and influenza is high and varies significantly across patient demographics and geography. Interventions to reduce antibiotic prescribing are needed to reduce the progression of antimicrobial resistance.