Outpatient antibiotic prescribing in the United States remained unchanged over a 3-year period despite efforts to limit inappropriate antimicrobial use, according to researchers.
The data, which include only prescriptions for insured patients and do not show use of antibiotics by the uninsured, show that further efforts are needed to control antibiotic use in the context of resistance, they wrote in Infection Control & Hospital Epidemiology.
“The findings of this study are concerning but more than anything, they give us important insight into the ongoing challenges of getting health care providers to change their prescribing habits to help prevent antibiotic resistance,” Keith Kaye, MD, MPH, president of the Society for Healthcare Epidemiology of America, told Infectious Disease News. “While the resources and investments made to identify and raise awareness regarding overuse of antibiotics are important, they are not enough.”
To assess levels of prescribing in the outpatient setting, researcher Michael J. Durkin, MD, MPH, an assistant professor of medicine at the Washington University School of Medicine, and colleagues conducted a retrospective study of antibiotic prescriptions made between Jan. 1, 2013, and Dec. 31, 2015, using an Express Scripts Holding company database of insured members.
The researchers found about 98 million outpatient prescriptions filled by 39 million patients. The most commonly prescribed drugs were amoxicillin, amoxicillin/clavulanate, azithromycin, cephalexin and ciprofloxacin. They also found that rates of prescriptions varied significantly by season because antibiotics were much more likely to be prescribed in February than they were to be prescribed in September, with a peak-to-trough ratio (PTTR) of 1.42 (95% CI, 1.39-1.61).
Michael J. Durkin
Similarly, azithromycin (PTTR = 2.46; 95% CI, 2.44-3.47), amoxicillin (PTTR = 1.52; 95% CI, 1.42-1.89) and amoxicillin/clavulanate (PTTR = 1.78; 95% CI, 1.68-2.29) had peaks and troughs in February and August.
The common use of those three drugs in winter could be partly appropriate, the researchers said, because diseases like pneumonia are more prevalent then. Likewise, peak use of cephalexin and ciprofloxacin in the summer, when urinary tract infections and skin and soft tissue infections are more common, could be partly appropriate. However, Durkin and colleagues also cited literature suggesting that wintertime prescription increases could be due to inappropriate antibiotic use for viral infections.
Even so, the researchers said current efforts to control antibiotic use are falling short. Durkin suggested that health care systems abide by the CDC Core Elements of Outpatient Antibiotic Stewardship, meant to educate caregivers on the topic. The Core Elements also include recommendations for accountability in prescribing, enacting policies to improve antibiotic prescribing, and tracking and reporting antibiotic unitization to providers. Even measures as simple as having posters promoting stewardship can bring about improvement, the researchers noted.
Although interventions and their effectiveness vary, Durkin and colleagues said further research on antibiotic prescribing is needed, along with further efforts at convincing providers to be better stewards.
“Additional work is needed to better link antibiotic prescriptions to indications to better quantify and trend inappropriate antibiotic prescribing practices,” they wrote. “However, in our opinion, additional interventions, beyond guidelines and educational materials, will be required to substantially improve antibiotic prescribing at a national level.” – by Joe Green
Disclosures: Durkin reports that he has created continuing education materials for Medscape, and funding for those materials was provided to Medscape through an unrestricted educational grant from Merck. Kaye reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.