A new study of outpatient antibiotic prescribing within Veterans Affairs (VA) medical facilities suggests the agency's antibiotic stewardship efforts are having an impact.
The study, presented last week at the European Congress of Clinical Microbiology and Infectious Diseases (ECCMID), found that outpatient antibiotic across the VA system fell by 3.9% a year from 2011 through 2018. The most significant decline was seen in the use of ciprofloxacin.
The VA system provides care to more than 9 million veterans at more than 1,200 clinics across the country, and over the past decade it has implemented several initiatives to reduce the unnecessary use of antibiotics both in inpatient and outpatient settings. While previous studies have shown declines in inpatient antibiotic use at VA hospitals in the wake of these efforts, this is one of the first to look at the nationwide impact on VA outpatient prescribing.
The study's lead author, Haley Appaneal, PharmD, PhD, of the Providence VA Medical Center in Rhode Island, said a decline in outpatient antibiotic use isn't necessarily surprising, given the VA's stewardship efforts and a growing awareness of antibiotic resistance. But she and her colleagues didn't expect to see as much of an impact.
"The VA is an integrated health system, so you expect that some of the stuff you do in the inpatient setting to be expanded to the outpatient [setting]," Appaneal said. "We really expected most of the impact to be on the inpatient side, but our study showed antibiotics decreased in outpatients, too, which is great."
Significant decline in fluoroquinolone use
To assess outpatient antibiotic use in the VA system, Appaneal and her colleagues used VA pharmacy datasets and calculated the annual use in days of therapy (DOT) per 100 visits. They also looked specifically at the five most commonly prescribed outpatient antibiotics (doxycycline, azithromycin, amoxicillin/clavulanate, amoxicillin, and cephalexin) and the most commonly prescribed fluoroquinolone (ciprofloxacin).
Overall antibiotic use fell from 39.6 DOT per 100 visits in 2011 to 29.4 DOT in 2018, with ciprofloxacin use declining by 12.6% per year. Appaneal attributed that decline in part to an overall national effort to reduce the use of ciprofloxacin and other fluoroquinolones, which have been associated with increased risk of disabling and potentially permanent side effects involving tendons, muscles, joints, nerves, and the central nervous system. The Food and Drug Administration has updated the warning label on fluoroquinolones on several occasions in recent years to alert the public to these risks, and the VA has issued warnings as well.
"We've got the FDA warnings, the VA warnings…I think all of that really played a large part in the reduction of fluoroquinolones," Appaneal said.
Other significant declines were observed for sulfamethoxazole/trimethoprim (around 7% a year), amoxicillin (2.9%), and cephalexin (2.1%). But use of the three most widely prescribed antibiotics (doxycycline, azithromycin, and amoxicillin/clavulanate),which are mainly used for upper respiratory tract infection, skin infections, and sexually transmitted infections, remained stable over the study period.
Appaneal said that finding suggests VA facilities still have some work to do on appropriate prescribing, especially for upper respiratory tract infections, which are frequently caused by viruses and don't require antibiotics. Appaneal also noted that because the patients in the VA system are mostly older white men, the results may not be generalizable. In addition, the study could not account for prescriptions obtained outside of VA pharmacies.
Larger declines needed
The stewardship initiatives launched by the Veterans Health Administration (VHA) over the past decade include the National Antimicrobial Stewardship Task Force, which was launched in 2011 and has helped VA facilities develop and implement stewardship programs. In 2014, the VHA required all VA hospitals to have an inpatient stewardship program.
Appaneal said she thinks the VHA's focus on stewardship, along with monthly meetings of the task force in which providers can share their success stories, have played a significant role in these reductions. And having a large, national dataset that allows researchers to track and monitor antibiotic use and resistance across the system also helps.
"That helps for targeting areas that we need to work on," she said.
Jeffrey Linder, MD, MPH, a primary care physician at Northwestern's Feinberg School of Medicine who studies inappropriate prescribing but was not involved in this study, said the observed decline in outpatient antibiotics in the VA is good news and a sign that outpatient prescribing may be headed in the right direction.
But he cautioned that if an estimated 30% to 50% of outpatient antibiotics prescribed in the United States are inappropriate, as studies have shown, a 4% annual decline may not make too much of a dent.
"It's the right direction, but it would be good to know if the magnitude is really moving the needle, and that overall inappropriate antibiotic use is going down in a meaningful amount," Linder said.
