Nearly One in Four Antibiotic Prescriptions Were Unnecessary in Study of Privately Insured Patients in 2016

Rockville, Md., Jan. 17, 2019 (GLOBE NEWSWIRE) -- Of the 15.5 million antibiotic prescriptions filled in 2016 by a population of 19.2 million privately insured children and adults under age 65, nearly one quarter were unnecessary, according to a new study funded by the Agency for Healthcare Research and Quality (AHRQ).

The study, published today in BMJ, concluded that an additional 36 percent of antibiotic prescriptions in 2016 were only “potentially appropriate.” The analysis provides the most comprehensive estimates to date of inappropriate prescribing of antibiotics among people with private, employer-sponsored insurance.  Appropriate antibiotic prescribing means that the medication is recommended for the patient’s condition.

“This study shows how data and analytics can help us identify and understand important challenges facing the American health care system,” said AHRQ Director Gopal Khanna, MBA.  “We now need to use these data to spur change in the prescribing of these very common medications.”

The AHRQ-funded study was conducted by researchers at Northwestern University Feinberg School of Medicine, the University of Michigan Medical School, and Brigham and Women's Hospital/Harvard Medical School. Their findings were based on a combined analysis of a U.S. medical claims database and the 2016 version of an international system for categorizing diseases (ICD-10-CM).  Researchers studied whether antibiotic prescriptions listed in the claims database were appropriate using over 90,000 diagnosis codes in ICD-10-CM.

Researchers’ analysis of the data showed that of the 15.5 million filled antibiotic prescriptions:

• 3.6 million, or 23 percent, were prescribed for conditions for which an antibiotic is almost never recommended, such as acute upper respiratory conditions
• 5.5 million, or 36 percent, were prescribed for conditions for which an antibiotic is only sometimes recommended, such as acute sinusitis or acute suppurative otitis media (bacterial infection of the middle ear)
• 2.0 million, or 13 percent, were prescribed for conditions for which an antibiotic is nearly always recommended, like bacterial pneumonia or urinary tract infections 

The remaining 28 percent of the antibiotic prescriptions were not associated with a recent diagnosis code, researchers found. Some may have been sent to pharmacies after telephone or online consultations that do not result in claims, for example. Others could have been prescribed during visits that were paid out of pocket and not captured in the medical claims database, such as retail clinic and dental visits.  Many of these antibiotic prescriptions may have been inappropriate as well.

Among the inappropriate prescriptions, 71 percent were written in office settings, 6 percent in urgent care centers, and 5 percent in emergency departments, researchers found. Among the 7.6 million unique enrollees who accounted for the 15.5 million antibiotic prescriptions filled in 2016, 52 percent filled one antibiotic prescription; 24 percent filled two; 11 percent filled three; and 13 percent filled four or more.  Researchers estimated that 14 percent of the enrollees filled at least one inappropriate antibiotic prescription during 2016.

“Our study shows the unacceptable scale of inappropriate antibiotic prescribing in the United States,” said Jeffrey Linder, M.D., Professor of Medicine at Northwestern University Feinberg School of Medicine in Chicago. “It underscores the need to learn more about prescriptions that aren’t justified by a diagnosis – or are written after no diagnosis at all.”

Given the importance of combating antibiotic resistance, researchers note that their classification scheme could facilitate future efforts to measure comprehensively outpatient antibiotic appropriateness in the U.S., and could be adapted for use in other countries that are using ICD-10 codes. 

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Karen Migdail
                    Agency for Healthcare Research and Quality
                    301-427-1855
                    newsroom@ahrq.hhs.gov