Background: Treatment of otitis media is the most frequent reason for administering antibiotics to children in the United States. However, only limited data are available on medical effectiveness of antibiotic prescribing patterns for otitis media and their associated expenditures or the factors that influence antibiotic prescribing.
Methods: The study population consisted of 131 169 children during 1991 and 157 065 children during 1992 who were </=13 years of age and enrolled in Colorado's fee-for-service Medicaid program. Among these children, 5127 (1991) and 7254 (1992) were enrolled in the cohort treated for a "new" episode of acute otitis media. An analysis using this cohort was performed to document the antibiotics used to treat a new episode of acute otitis media, factors influencing antibiotic selection, and the short-term outcomes of therapy. An analysis using the entire Medicaid population was performed to document the annual use of antibiotics for otitis, the associated antibiotic expenditures, and factors influencing antibiotic selection.
Results: In the cohort analysis, office-based physicians prescribed second- and third-generation cephalosporins more often than did physicians in other settings (17% vs 9.7% and 11.8%), whereas hospital clinics prescribed trimethoprim plus sulfamethoxazole more frequently than did office-based physicians (19.2% vs 7.1% and 10.9%). Family physicians prescribed second- and third-generation cephalosporins more often than did pediatricians (16.6% vs 12.3%) but trimethoprim plus sulfamethoxazole and erythromycin plus sulfisoxazole less often than did pediatricians (10.5% vs 17%). The average rate of prescribing a second course of antibiotics within 24 days after initial antibiotic treatment of a new acute otitis media episode was 11.6% when less expensive antibiotics (amoxicillin, trimethoprim plus sulfamethoxazole, or erythromycin plus sulfisoxazole) were prescribed, and 13.2% when more expensive antibiotics (cefaclor, amoxicillin plus clavulanate, or cefixime) were prescribed. The average adverse drug reaction rate was 5.9% when less expensive antibiotics were prescribed, compared with 6.1% when more expensive antibiotics were prescribed. In each of the two study years, amoxicillin accounted for almost half of the total antibiotic fills but only 9% to 10% of the expenditures. Low-cost antibiotics (amoxicillin, trimethoprim plus sulfamethoxazole, and erythromycin plus sulfisoxazole) were prescribed for 66% to 67% of the total fills and accounted for 21% of the total projected expenditures. More expensive antibiotics (cefaclor, cefixime, amoxicillin plus clavulanate) prescribed for 30% of the fills generated 76% to 77% of expenditures. Cefaclor, prescribed for 17% to 18% of the total fills, generated 43% to 45% of total antibiotic expenses.
Conclusions: The findings of this study document a preference for amoxicillin as the initial antibiotic for a new episode of acute otitis media. Although there was a wide variation in the selection of antibiotics to treat otitis, the more expensive antibiotics were not associated with better outcomes. This wide variation has important financial implications because of differences in antibiotic costs. Changes in prescribing patterns among initially uncomplicated children that reduce the use of high-cost antibiotics could reduce expenditures substantially without compromising short-term outcomes.