There is good news and bad news about the war against antibiotic resistance in the United States, according to a study by researchers at the San Francisco VA Medical Center (SFVAMC).
“The good news is antibiotics are being used less often in situations where they are not needed, such as to treat the common cold and mild bronchitis,” said Michael Steinman, MD, SFVAMC staff physician.
“The troubling news is that when doctors do turn to an antibiotic they are increasingly turning to broad-spectrum agents. These often provide little or no advantage over narrow-spectrum antibiotics when treating things like respiratory infections or sinusitis,” Steinman said. Even worse, needlessly exposing bacteria to these potent agents leads to the creation of resistant strains and sets the stage for a global public health crisis, Steinman said.
The study will appear in the April 1 issue of the Annals of Internal Medicine.
Researchers looked at the prescribing behavior of physicians between 1991 and 1999. They compared data gathered during the first two-year period and the last two-year period covered by the National Ambulatory Medical Care Survey conducted by the Centers for Disease Control and Prevention. The survey included a nationally representative sample of community-based outpatient clinics.
Investigators found that the use of antibiotics to treat the common cold and acute respiratory tract infections decreased. However, use of broad-spectrum antibiotics increased from 24 percent of antibiotic prescriptions in adults to 48 percent and from 24 percent to 40 percent in children.
Only the most virulent strains of bacteria survive being challenged by these powerful drugs, and that’s a big problem, Steinman said. “When someone is seriously ill and needs one of these powerful agents they won’t be effective anymore,” he said. The spread of these multi-resistant strains of bacteria is a serious threat to public health, Steinman said.
In addition to promoting bacterial resistance, the observed prescribing behavior of antibiotics by physicians can also be quite costly in terms of dollars, Steinman said. Broad-spectrum antibiotics cost the healthcare system 10 times more than narrow-spectrum antibiotics, according to estimates based on the average wholesale price. A typical seven-day course of broad-spectrum antibiotic can cost around $50, while a narrow-spectrum course costs around $5.
Steinman said that the challenge for researchers is figuring out why physicians prescribe the way that they do. He proposes several possibilities, including the mistaken belief by some physicians that the newer drugs are better than the older ones. Patient expectation may also play a role, he said. “We need to research ways of improving prescribing behavior and think about novel ways to change what’s going on during those office visits.”
Additional authors on the study include senior author C. Seth Landefeld, MD, SFVAMC associate chief of staff for geriatrics and extended care and UCSF professor of medicine, chief of geriatrics and director of the UCSF Center on Aging; Ralph Gonzales, MD, MSPH, UCSF associate professor of medicine; and Jeffrey A. Linder, MD, MPH, of Brigham and Women’s Hospital and Harvard University Medical School.
Research support for Steinman and Landefeld was provided by the VA National Quality Scholars Program. Gonzales’ research was supported by the Robert Wood Johnson Foundation Minority Medical Faculty Development Program. Linder’s research was supported by a National Research Service Award. Landefeld also received grant support from the National Institute on Aging, the John A. Hartford Foundation, Dartmouth College, and a grant to Dartmouth College from the Pfizer Foundation.