CHICAGO, Jan. 20 (Xinhua) -- A study found only 13 percent of outpatient antibiotic prescriptions were appropriate, with 36 percent considered potentially appropriate.
Jointly conducted by Northwestern Medicine, the University of Michigan and Harvard University's Brigham and Women's Hospital, the study for the first time evaluated all 91,738 diagnosis codes in ICD-10, a system used in the United States to code diagnoses, and categorized each for antibiotic appropriateness. It also examined all outpatient antibiotic prescriptions among a cohort of 19.2 million patients, irrespective of the reason or site of care.
The researchers then used a novel ICD-10-based classification scheme to evaluate 15.5 million outpatient antibiotic prescriptions filled in 2016 by a large cohort of privately insured U.S. children and non-elderly adults. They assigned each prescription fill to one of four categories: either "appropriate," "potentially appropriate," "inappropriate" or "not associated with a recent diagnosis code."
The researchers found that just 13 percent of prescriptions were appropriate, 36 percent were potentially appropriate and 23 percent were inappropriate.
They also found that 28 percent were not associated with any diagnosis code at all, suggesting that the rate of inappropriate prescriptions may in fact be even higher.
"This means that our prior methods of looking at antibiotic prescribing based on location or specific diagnosis code are missing a huge proportion of antibiotics," said co-author Jeffrey Linder, chief of general internal medicine and geriatrics in the department of medicine and a professor of medicine at Northwestern University Feinberg School of Medicine.
Beyond highlighting the widespread overuse of antibiotics in the United States, the study could also help facilitate future research.
Overuse of antibiotics contributes to the development of antibiotic resistance, a major public health concern; increases health-care costs; and exposes patients to unnecessary side effects.
The study was published on Jan. 16 in The British Journal of Medicine.
