Health plans vary widely in the prescribing of antibiotics

Research Activities, July 2010, No. 359

Unnecessary antibiotic use continues to be a problem in the United States, particularly when it comes to treating acute respiratory tract infections. Up to half of all patients with this condition receive antibiotics, although only a small number of cases are actually bacterial (instead of viral) infections that respond to antibiotics. A new study finds that antibiotic prescribing varies substantially among commercial health plans.

Armed with such information, researchers can target high-prescribing health plans with quality improvement programs aimed at reducing antibiotic use, suggest the study authors. They analyzed data submitted by 229 commercial health plans participating in the 2005 Healthcare Effectiveness Data and Information Set. These plans represent 42.9 million enrollees, with children comprising 27 percent. The researchers calculated the rate of each plan's antibiotic utilization per member per year (PMPY) from pharmacy claims billed for patients up to age 64. The researchers also estimated the costs associated with antibiotic therapy.

The average rate of antibiotic use was 0.88 prescription fills PMPY. However, this use varied widely among plans, ranging from 0.64 antibiotic fills PMPY at the 5th percentile of plans to 1.08 fills PMPY at the 95th percentile of plans. Antibiotic prescription rates also varied by age and sex, with the most fills (0.24 fills PMPY) for males aged 0-9 years. Overall, just under half (47 percent) of all antibiotics dispensed across health plans were of the broad-spectrum variety. Interestingly, higher antibiotic use rates were found for plans with the highest "excellent" accreditation status and for plans with a smaller percentage of board-certified physicians.

The researchers also observed regional differences in antibiotic use, with plans located in the South having a 21 percent higher rate of use and those in the Northeast the lowest at 9 percent. Antibiotic costs averaged $49 PMPY. The researchers estimated that a health plan with 250,000 members at the 90th percentile of antibiotic costs could save $4.1 million annually if it reduced its antibiotic costs to the 25th percentile. The study was supported in part by the Agency for Healthcare Research and Quality (HS13915).

See "Variation in outpatient antibiotic prescribing in the United States," by Michael A. Steinman, M.D., Katherine Y. Yang, Pharm.D., M.P.H., Sepheen C. Byron, M.H.S., and others in the December 2009 American Journal of Managed Care 15(12), pp. 861-868.

Current as of July 2010
Internet Citation: Health plans vary widely in the prescribing of antibiotics: Research Activities, July 2010, No. 359. July 2010. Agency for Healthcare Research and Quality, Rockville, MD.