Yuting Zhang of the University of Pittsburgh said the overuse of antibiotics is common and can lead to unnecessary spending on prescription medicine, as well as increase the risk for adverse effects and anti-microbial resistance.
Zhang and colleagues analyzed Medicare Part D data from 2007 to 2009 -- involving about 1 million patients per year -- to examine geographic variation in antibiotic use among older adults in 306 hospital referral regions, 50 states and the District of Columbia.
The study, published in Online First by Archives of Internal Medicine, found the highest antibiotic use was in the South and the lowest was in the West. In the South, 21.4 percent of patients per quarter used an antibiotic whereas 17.4 percent of patients per quarter used an antibiotic in the West, while the Midwest was at 19.2 percent.
"Although older adults may have higher risk for adverse outcomes from infection, they may also be at particularly high risk for adverse outcomes from antibiotic use," Zhang said in a statement. "Therefore, it might be necessary to target some quality improvement initiatives toward this age group."