Background: Acute otitis media (AOM) accounts for 24.5 million physician office visits and 15 million antibiotic prescriptions annually in the United States. The 7-valent pneumococcal conjugate vaccine (PCV7) has reduced invasive pneumococcal disease and pneumonia, but few studies have examined the vaccine's effect on rates of AOM and costs that accrue from it. Zhou and colleagues studied the effect of the PCV7 vaccine on reducing AOM in children younger than two years, as well as the vaccine's effect on the costs of ambulatory visits and antibiotic prescriptions associated with AOM.

The Study: The authors obtained data from commercial databases containing information from a nationwide selection of self-insured employers. Data on children younger than two years were included in the analysis. Records for ambulatory visits from January 1997 to December 2004 were reviewed to identify those with a primary diagnosis of AOM. The authors calculated the decrease in ambulatory visits for AOM during that period. Costs were estimated using mean payments for office visits and antibiotic prescriptions.

Results: There was a large increase in enrollees who were included in the databases, from about 20,000 in 1997 to 150,000 in 2004. During this same time frame, the visit rate for AOM in children younger than two years decreased by 929 visits per 1,000 person-years (95% confidence interval [CI], 917 to 940 visits), or 42.7 percent (P < .001). This decrease occurred in managed and nonmanaged care plans, regardless of covariates and interactions. Rates of antibiotic prescriptions for AOM decreased by 522 prescriptions per 1,000 children with AOM (95% CI, 513 to 530 prescriptions), or 41.9 percent (P < .001). Costs for an individual AOM-related visit and antibiotic prescription increased during the study. However, these increases were offset by a 32.3 percent decrease in the estimated annual national costs for AOM-related visits and antibiotic prescriptions during the study.

Conclusion: Since the introduction of PCV7, rates of ambulatory visits, antibiotic prescriptions, and associated costs decreased markedly. Although adherence to guide-lines aimed at reducing inappropriate antibiotic prescribing may have contributed to this decrease, the gradual declines are consistent with the increasing rates of PCV7 vaccination during the study. AOM-related medical costs decreased by an estimated $460 million annually. The authors noted that the estimates are based on data for privately insured patients. Therefore, these estimates may be conservative because they did not include persons with Medicaid or persons without insurance.