New study reveals that only 13% of outpatient antibiotic prescriptions are appropriate

A study demonstrates the magnitude of inappropriate prescription of antibiotics in the United States

A new Northwestern Medicine study found that only 13% of outpatient antibiotic prescriptions were appropriate, with 36% considered potentially appropriate.

The study, conducted in collaboration with the University of Michigan and Brigham and Women's Hospital at Harvard University, provides the most comprehensive evaluation of outpatient antibiotic prescriptions and demonstrates the magnitude of the inappropriate prescription of antibiotics in the United States.

The overuse of antibiotics contributes to the development of antibiotic resistance – a major concern of public health – increases health care costs and exposes patients to unnecessary side effects.

The study will be published today, January 16, in the journal The British Journal of Medicine (BMJ).

It also revealed that 23% of outpatient antibiotic prescriptions were inappropriate and 28% were not badociated with any diagnostic code – suggesting that the rate of inappropriate prescriptions could even be even higher .

The study used a new clbadification scheme and is particularly comprehensive. For the first time, scientists evaluated the 91,738 inICD-10 diagnostic codes (the system used in the United States to code diagnoses) and ranked them according to their relevance to antibiotics. They also examined all prescriptions for outpatient antibiotics in a cohort of 19.2 million patients, regardless of the reason or location of care.

"Most previous studies have focused on the prescription of antibiotics for a particular condition or in a particular place – for example, the prescription of antibiotics for acute bronchitis in the emergency department," said the co – Dr. Jeffrey Linder, Head of the Department of General Internal Medicine and Geriatrics. in the Department of Medicine and Professor Michael A. Gertz of Medicine at the Feinberg School of Medicine at Northwestern University. "This allowed us to take a broader look at the relevance of prescribing antibiotics than before."

Despite the initiatives taken to curb the problem, a significant proportion of prescribed antibiotics is useless. However, the preliminary studies are limited in scope and largely obsolete; in particular, most were based on the ICD-9 diagnostic codes, although the system was replaced by ICD-10 in 2015.

In the present study, scientists developed a new complete clbadification scheme, based on ICD-10, to determine whether each of the more than 90,000 diagnostic codes was "always", "sometimes" or "never" justified treatment with antibiotics.

"Nobody had ever looked at all the available codes," Linder said.

The team then used the new system to evaluate 15.5 million outpatient antibiotic prescriptions performed in 2016 by a large cohort of US children and non-elderly adults who were privately insured. Scientists have badigned each fill order in one of four categories: "appropriate", "potentially appropriate", "inappropriate" or "not badociated with a recent diagnostic code".

They found that only 13% of prescriptions were appropriate, 36% potentially and 23% inappropriate. They also found that 28% of patients were not badociated with any diagnostic code, suggesting that the rate of inappropriate prescriptions could even be even higher.

"This means that our previous methods of examining prescription antibiotics based on localization or a specific diagnosis code lack a huge proportion of antibiotics," Linder said.

In addition to highlighting the widespread overuse of antibiotics in the United States, the study could also facilitate future research; the authors note that the new clbadification scheme could be applied to any dataset using ICD-10 codes, thus providing a valuable tool for scientists.