Nearly one-third of Americans prescribed antibiotics during doctor’s office visits probably should not have received the drugs, were not given a long enough course or did not get the right dose, according to new research.
The new study into how doctors prescribe antibiotics to Americans in outpatient settings comes as rates of antibiotic resistant bacterial infections are on the rise. Up to 23,000 Americans die and 2 million more become sick due to antibiotic resistant bacteria each year, according to the Centers for Disease Control and Prevention (CDC), and scientists have found rates of such infections on the rise.
“This study shows that there certainly is a lot more work to be done,” said Dr Katherine E Fleming-Dutra, a CDC researcher and lead author on the study. “It is so critical to preserve antibiotics for the future, to make sure they work.”
The study of 184,032 visits, titled Prevalence of Antibiotic Prescriptions Among US Ambulatory Care Visits, 2010-2011 and published in the Journal of the American Medical Association, comes as a White House panel of experts convened to work on the issue push doctors to halve the prescribing of antibiotics in such settings by 2020.
The study used two national surveys to estimate the rate of “inappropriate” antibiotic prescribing in primarily doctor’s office settings. Both the National Ambulatory Medical Care Survey (NHAMCS) and the National Hospital Ambulatory Medical Care Survey are conducted by the federal government. The NHAMCS also samples visits to emergency departments of hospitals.
Each year, physicians who participate in the two surveys record between one and four weeks of patient visits as a sample, giving researchers a window into private and hospital outpatient practices. The National Center for Health Statistics then collects and analyzes the data.
The “inappropriate” prescribing the study refers to includes times when patients should not have taken antibiotics at all, or did not receive a long enough course or the right dose to effectively cure an infection.
The study’s nearly two dozen authors used data from the geographical region with the lowest antibiotic prescribing rate to estimate how many of the prescriptions were needed, excluding some illnesses. Researchers assumed that antibiotics were always necessary for urinary tract infections and pneumonia, even though in actual patient settings this is unlikely.
The results showed that up to 30% of the antibiotics prescribed by doctors to American outpatients were likely inappropriate. At the population level, the study found a remarkable estimate: 506 of every 1,000 Americans are prescribed antibiotics each year.
Sinusitis, better known as a sinus infection, topped the list of diagnoses likely to see patients sent home with antibiotics. The condition was cited in 56 of 1,000 antibiotic prescriptions.
Ear infections (or otitis media) accounted for 47 prescriptions for every 1,000 people, and sore throats (pharyngitis) were responsible for 43. Collectively, upper respiratory infections accounted for 221 antibiotic prescriptions, but researchers found just 111 of those were appropriate.
The number of Americans who received prescriptions, and the amount that is appropriate, are both conservative estimates.
A 2011 study found that an average of eight out of 10 Americans (or 842 prescriptions per 1,000 people) were prescribed a course of antibiotics each year, that half of the use of antibiotics in children was inappropriate, and that 25% of adult antibiotics prescriptions are for diagnoses that rarely call for such drugs.
In a 2013 report on antibiotic resistance by the CDC, an estimated 50% of antibiotic prescriptions were found to have been “not needed or not optimally effective as prescribed”.
In the same report, the CDC also called on the FDA to phase out all antibiotic use in animals grown as food when they are used as growth stimulants. Scientists believe that animals grown as food use as much, and probably more, antibiotics than humans.
Such antibiotic use is problematic because it reduces overall effectiveness of the drugs as bacteria evolve to combat them, making the antibiotics less or not at all effective against common germs.