Overprescribing antibiotics has major healthcare consequences

Robin Wulffson MD's picture
antibiotics, overprescribing, viral infections, sinusitis, seniors
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Overprescribing of antibiotics has major consequences to Americans ranging in age from infants to seniors.

Two new studies addressing antibiotic prescribing were published online on September 24 in the Archives of Internal Medicine. One evaluated geographic variations in antibiotic prescribing among seniors. The other investigated the prescribing of antibiotics to adults with sinusitis.

The geographic study was conducted by researchers affiliated with the Graduate School of Public Health, University of Pittsburgh, Pennsylvania. They noted that the consequences of antibiotic overuse are substantial, especially among seniors, who are more susceptible to adverse reactions. They noted that previous studies focused on geographic variations in prescribing; however, they did not evaluate these variations among seniors.

The researchers accessed Medicare Part D data from January 1, 2007, through December 31, 2009 (comprising 1.0-1.1 million patients per year). They examined geographic variation in antibiotic use among seniors in 306 Dartmouth Atlas of Health Care hospital referral regions, 50 states and the District of Columbia; in addition they reviewed four national regions (South, West, Midwest, and Northeast). They also examined the quarterly change in antibiotic use across the four regions. Differences in patient demographics, insurance status, and clinical characteristics were adjusted for the regions.

After adjusting for population characteristics, the investigators found substantial geographic and quarterly variation in outpatient antibiotic prescribing existed across regions. This variation could not be explained by differences in the prevalences of the underlying conditions. For example, the ratios of the 75th percentile to the 25th percentile of adjusted annual antibiotic spending were 1.31 across states and 1.32 across regions. The highest antibiotic use was in the South, where 21.4% of patients per quarter used an antibiotic; the lowest antibiotic use was in the West, where 17.4% of patients per quarter were prescribed an antibiotic. Regardless of region, the rate of antibiotic use was highest in the first quarter (20.9% in January through March) and was lowest in the third quarter (16.9% in July through September).

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The authors wrote: “Areas with high rates of antibiotic use may benefit from targeted programs to reduce unnecessary prescription. Quality improvement programs can set attainable targets using the low-prescribing areas as a reference, particularly targeting older adults.”

The sinusitis study was conducted by researchers affiliated with the Centers for Disease Control and Prevention. The authors noted that acute sinusitis is diagnosed in over 3 million visits annually among adults and children in the US. Of these, more than 80% result in an antibiotic prescription; however, many of these prescriptions may be unnecessary. They note that sinusitis is most often of viral origin; thus, antibiotics are not indicated for many of these infections. They noted that in light of recent studies and new treatment guidelines, they sought to examine visit rates and antibiotic prescribing patterns for adults with acute sinusitis in the United States.

The researchers reviewed 2000 to 2009 data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey, along with standard diagnostic criteria from the International Classification of Diseases, Ninth Revision, Clinical Modification. The investigators estimated the annual number of acute sinusitis visits per 1,000 adults in the US. The primary outcomes measures were the percentage of office visits for acute sinusitis in which any antibiotic was prescribed as well as the percentage of antibiotic visits in which amoxicillin was prescribed. Prior to 2012, amoxicillin was the recommended empirical treatment for acute bacterial sinusitis; however, current guidelines recommend amoxicillin-clavulanate (Augmentin). The researchers excluded patient visits that had concomitant diagnoses (i.e., urinary tract infections) that might require antibiotics. They also excluded were visits that resulted in hospitalizations and visits in which patients were prescribed vancomycin or an aminoglycoside (both are antibiotics).

They noted that 83% of patients diagnosed as having acute sinusitis received an antibiotic, despite mounting evidence that the benefits of antibiotic treatment for sinusitis are limited. In addition, they found that the rate of antibiotic prescribing did not change significantly during the study period. In addition, the choice of antibiotics did not follow guidelines in place during the study period. Amoxicillin, the recommended agent during the period studied, was prescribed in only 17% of cases. The other most commonly prescribed antibiotics were macrolides (i.e., Zithromax; 29%), quinolones (i.e., Avelox; 19%), and amoxicillin-clavulanate (16%).

The authors concluded that changes in prescribing behavior of healthcare providers for sinusitis are urgently needed to improve healthcare quality and stem the rising tide of antibiotic resistance in the United States.

References:
Archives of Internal Medicine
Archives of Internal medicine

See also:
Antibiotics worthless for most throat infections

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