BACKGROUND: Widespread use of broad-spectrum antibiotics contributes to increasing rates of bacterial resistance to antibiotics. Second-generation macrolides have become popular for use among children because of their broad spectrum and favorable dosing and side-effect profiles, although experts do not generally recommend them for use as initial treatment of infections among younger children. OBJECTIVE: To assess trends in second-generation macrolide use from 1996 to 2000 among children treated as outpatients in 9 US health plans, including associated diagnoses and use as initial treatment. METHODS: We sampled claims data for 25000 children, 3 months to <18 years of>age, who were enrolled between September 1, 1995, and August 31, 2000, in each of 9 US health plans. Medications dispensed were linked with ambulatory visit claims to assign diagnoses. Dispensings without another antibiotic dispensing recorded in the previous 42 days were analyzed as initial treatment of a new illness episode. We analyzed trends in prescribing overall, for initial therapy, and, within specific diagnoses, for differences among health plans. RESULTS: From 1995-1996 to 1999-2000, although overall antibiotic use decreased from 1.15 to 0.91 dispensings per person-year, second-generation macrolide use increased from 0.022 to 0.063 dispensings per person-year. Use as a proportion of all antibiotic dispensings increased from 1.9% to 6.9%, and use as initial therapy increased from 1.4% to 6%. For children <6 years of>age, second-generation macrolide use as initial therapy increased from 0.9% to 5.0% for otitis media and from 5.2% to 24.0% for pneumonia. There was a wide range of prescribing rates among health plans during the last year of the study, from 0.006 to 0.135 dispensings per person-year. CONCLUSIONS: Despite recent trends toward decreased antibiotic use among children, the use of second-generation macrolides among children has increased dramatically, even among younger children, for whom use for initial treatment of illness is not recommended. Large differences in prescribing rates exist among health plans. Continued efforts to promote the use of narrower-spectrum agents when appropriate are needed.

BACKGROUND: High rates of antibiotic prescribing to children contribute to antibiotic resistance in the community. The Centers for Disease Control and Prevention, in collaboration with other national and state level organizations, have actively promoted more judicious prescribing for children. OBJECTIVE: We sought to assess changes in the rate of antibiotic prescribing from 1996-2000 in 9 US health plans, patterns of diagnosis and treatment responsible for these trends, and changes in the use of first-line antimicrobial agents. DESIGN/METHODS: We analyzed claims data for dispensed medications and physician visits from 9 health plans. Each provided data on 25,000 children aged 3 months to <18 years enrolled between September>1, 1995, and August 31, 2000. Antibiotic dispensings were linked with an ambulatory visit claim to assign diagnosis. Antibiotic dispensings per person-year (antibiotics/p-y) were calculated for the age groups 3 months to <3 >years, 3 years to <6 >years, and 6 years to <18 years. The contribution of each diagnosis to changes in the overall rate of antibiotic use was determined. Generalized linear mixed models were used to test for trend and assess differences in rates by site. RESULTS: From>1996-2000, antibiotic rates for children 3 months to <3 years decreased from 2.46 to 1.89 antibiotics>/p-y (24%); for children 3 years to <6 years from 1.47 to 1.09 antibiotics>/p-y (25%); and for children 6 to <18 years from 0.85 to 0.69 antibiotics>/p-y (16%). The reduction varied among health plans from 6% to 39% for children 3 months to <3 years. A decrease in prescriptions for otitis media accounted for>59% of the total decrease, and was primarily accounted for by a decrease in the rate of diagnosis of this condition. The proportion of first-line penicillins increased from 49% to 53%, with health plans with the lowest initial rates increasing most. CONCLUSIONS: Antibiotic prescribing decreased significantly between 1996 and 2000, concurrent with decreased frequency of diagnosis of potential bacterial infections, especially otitis media. Attention by public health and professional organizations and the news media to antibiotic resistance may have contributed to changes in diagnostic thresholds, resulting in more judicious prescribing.