In the U.S, nearly one in three antibiotic prescriptions is "inappropriate," said a study. Experts say overuse of antibiotics leads to more antibiotic-resistant infections -- affecting two million people and killing 23,000 each year.
The study found that in the United States in 2011, 262 million outpatient antibiotic prescriptions were dispensed -- almost one for each of the nation's 300 million people.
To find out how many of these prescriptions were unnecessary, Katherine Fleming-Dutra, a doctor with the US Centers for Disease Control and Prevention, and colleagues studied a national medical care survey to estimate the rates of outpatient oral antibiotic prescribing by age and diagnosis.
The most common diagnoses associated with antibiotic prescriptions were sinusitis, ear infections and sore throats. Taken together, "acute respiratory conditions" led to 221 antibiotic prescriptions annually per thousand people. However, just 111 antibiotic prescriptions "were estimated to be appropriate for these conditions," said the study.
For all conditions and ages studies, an estimated 506 antibiotic prescriptions were written annually per thousand people. Of these, 353 antibiotic prescriptions were estimated to be appropriate.
"Half of antibiotic prescriptions for acute respiratory conditions may have been unnecessary, representing 34 million antibiotic prescriptions annually," said the study.
"Collectively, across all conditions, an estimated 30 percent of outpatient, oral antibiotic prescriptions may have been inappropriate."
The study called for a 15 percent reduction in overall antibiotic use to meet the goal -- set by the recent White House National Action Plan for Combating Antibiotic-Resistant Bacteria -- for cutting inappropriate use among outpatients by 50 percent by 2020.
Researchers said they hoped their findings would encourage and inform antibiotic stewardship programs over the next few years, to offer better guidance to doctors.
An accompanying editorial in JAMA described the research's estimates on overprescribing as "conservative," and said they offer an "important and useful starting point."
Two strategies are needed to curb antibiotic overuse, added the editorial by Pranita Tamma and Sara Cosgrove of the Johns Hopkins University School of Medicine.
They include educating patients about the role of antibiotics and "changing clinician behavior to alleviate concerns related to diagnostic uncertainty, alienating patients, and not conforming to peer practices."