We often hear of inappropriate antibiotic use, including the wrong drug for the bug, the wrong duration of therapy, and the failure to scale down from a broad spectrum drug once the etiology of an infection is determined. But what if you took almost a third of your drug formulary and hurled it out the window, where it will do nothing except help kill off susceptible bacteria in the environment and select out resistant strains?
This, in effect, is what is happening in outpatient care settings, the CDC reported in a new study that estimates that 30% of all antibiotics used in outpatient settings are completely uneccessary.1
“We know that antibiotic resistance is one of the most urgent health threats of our time,” says lead author Katherine Fleming-Dutra, MD, a medical epidemiologist with the CDC’s Office of Antibiotic Stewardship in the Division of Healthcare Quality Promotion. “We estimate that about 2 million patients a year get antibiotic resistant infections and approximately 23,000 people die of these infections. That’s why it is so important to use antibiotics only when they are needed. Eliminating unnecessary antibiotic use is critical to slowing antibiotic resistance.”
Again, the study outcome goes beyond inappropriate to completely unnecessary.
“When we talk about the 30% of antibiotic use being unnecessary, that means no antibiotic was needed at all,” she says. “Inappropriate antibiotic use is probably a bit broader than that — when an antibiotic is needed but it’s the wrong antibiotic or the wrong dosage or the wrong duration. We really focused only on unnecessary use.”
The researchers derived the estimate by analyzing 2010-2011 data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey. Based on national guidelines and regional variation in prescribing, diagnosis-specific prevalence and rates of total and appropriate antibiotic prescriptions were determined. These rates were combined to calculate an estimate of the appropriate annual rate of antibiotic prescriptions per 1,000 patients.
Of the 184,032 sampled visits, 12.6% of visits resulted in antibiotic prescriptions, Fleming-Dutra and colleagues reported. Sinusitis was the single diagnosis associated with the most antibiotic prescriptions, followed by otitis media and pharyngitis. Collectively, acute respiratory conditions per 1,000 patient population led to 221 antibiotic prescriptions annually, but only 111 antibiotic prescriptions were estimated to be appropriate for these conditions. Per 1,000 population, among all conditions and ages combined in 2010-2011, an estimated 506 antibiotic prescriptions were written annually, and, of these, 353 antibiotic prescriptions were estimated to be appropriate antibiotic prescriptions.
“The data sets that we used include outpatients, physician offices, outpatient clinics, and the emergency department,” she tells Hospital Infection Control & Prevention. “But we only used patients that were discharged from the emergency department, so this does not include any hospitalized patients.”
Antibiotic stewardship has been heavily emphasized in hospitals, but must be applied to ambulatory care as well, she adds. Parental expectation of antibiotics for their sick children and a failure to communicate clearly that antibiotics have no effect on viral infections are likely contributing factors to unnecessary use, she says.
- Fleming-Dutra KE, Hersh AL, Shapiro DJ, et al. Prevalence of Inappropriate Antibiotic Prescriptions Among US Ambulatory Care Visits, 2010-2011 JAMA. 2016;315(17):1864-1873.