Many Antibiotics Prescribed Without ‘Clear Rationale,’ Study Says

February 05, 2020 - Nearly half (45 percent) of Medicaid antibiotic prescriptions between 2004 and 2013 were prescribed without a clear rationale, a new study published in Health Affairs on Monday found. 

The study is the first to comprehensively measure antibiotic prescribing for Medicaid patients in the US. Findings suggest gaps in needed oversight to ensure appropriate prescribing behaviors. 

The study flags high rates of outpatient prescriptions for antibiotics among Medicaid patients. It shows that nearly one in five outpatient prescriptions for antibiotics were written without a diagnosis of an infection and 28 percent were not at all associated with any visits to a clinic.

Researchers from Northwestern University and Brigham and Women’s Hospital used Medicaid claims data to conduct the evaluation, with a total of 298 million antibiotic prescriptions filled by 53 million Medicaid patients. Findings suggest that 45 percent of Medicaid antibiotic prescriptions were written without a clear rationale throughout the 10-year study period.

“It’s concerning that nearly half of antibiotics are prescribed without a visit or without a clear rationale,” says senior study author Jeffrey Linder, chief of general internal medicine and geriatrics at Northwestern University Feinberg School of Medicine’s department of medicine. 

The study highlights the need for monitoring prescribing behaviors. “We are not keeping track of and do not have a system to ensure high-quality antibiotic prescribing in the US,” Linder adds. 

Findings call into question the effectiveness of efforts aimed at curbing inappropriate antibiotic prescribing. Whether there is a clinical explanation for the many cases where antibiotics prescriptions were written without an office visit remains unclear, despite the study findings. 

Lead study author Michael Fischer, a physician in Brigham’s Division of Pharmacoepidemiology and Pharmacoeconomics explains that because the analyses was based on claims data, “We assume that most of these prescriptions were associated with a telephone interaction, although some communication may have occurred over email, via web portals or in informal, uncaptured visits.” But these would be “blind spots” for interventions aimed at improving antibiotic usage.

“If we’re thinking about how to improve antibiotic use, we need to understand the context in which antibiotics are being prescribed,” Fischer said.  

The study comes as the US Food and Drug Administration and the Centers for Disease Control and Prevention, among many others, have been working to help monitor antibiotic prescribing and promote appropriate antibiotic use. 

The need for appropriate antibiotic prescribing behaviors becomes increasingly crucial in the face of the growing public health threat that is antibiotic resistance. “Indiscriminate use of antibiotics is increasing the prevalence of antibiotic-resistant bacteria and rendering them ineffective,” Linder noted. 

The Access to Medicine Foundation released a new benchmark report in January scoring efforts made by 30 pharmaceutical companies to limit antimicrobial resistance. The report highlighted some progress since 2018, but most companies needed to step up efforts. 

“Change is not happening at the scale needed to radically impact the threat from drug resistance,” the report stated.  

The study follows on the heels of a January study in which Northwestern University and Brigham and Women’s Hospital researchers found that only 13 percent of outpatient antibiotic prescriptions were appropriate, though 36 percent were considered potentially appropriate. 

With antibiotics exposing patients to adverse drug events including the life-threatening Clostridium difficile, FDA launched an information-sharing tool to manage antibiotic use in 2017.

“Prescribing a drug that’s only going to be met with resistance from the bacteria or fungus it’s intended to treat doesn’t help that patient, and it has broader public health consequences that cannot be ignored,” Former FDA Commissioner Scott Gottlieb said in December 2017. “Under the old approach, it took too long to update each individual drug’s labeling with information needed for susceptibility testing and it was clear a more centralized approach was needed.”