The researchers found that antibiotics were prescribed in 68% of all patients visits for acute respiratory infections, with antibiotic prescriptions increasing by 2% during 2005-12.
Study author Dr. Barbara Jones, assistant professor of medicine at the University of Utah and clinician at the VA (Veteran Affairs) Salt Lake City Health Care System, UT, and colleagues publish their findings in the Annals of Internal Medicine.
Antibiotics are effective against bacterial infections - such as strep throat - but they do not treat infections caused by viruses, such as cold, flu and bronchitis. When an antibiotic is taken for a viral infection, it attacks harmless or healthy bacteria, which can promote antibiotic resistance.
Still, as this latest study demonstrates, antibiotics continue to be prescribed by health care providers for viral infections.
According to the Mayo Clinic, there are a number of reasons why doctors do so. They may prescribe antibiotics before receiving test results showing an infection is viral rather than bacterial, for example. Also, some patients may pressure doctors for antibiotic prescriptions due to the desire for quick relief, despite the fact their infection may be viral.
For their study, Dr. Jones and colleagues set out to gain a better understanding of antibiotic-prescribing practices among health care providers in the US.
The team analyzed the VA electronic health record, involving 1,044,523 patient visits for acute respiratory infections (ARIs) across 990 emergency departments or clinics at 130 VA Medical Centers over the US between 2005 and 2012.
Analysis identifies large variations in prescribing practices
The researchers found that antibiotics were prescribed in 68% of all patients visits for ARIs, with antibiotic prescriptions increasing by 2% during the 8-year period.
The team also identified a 10% increase in the number of macrolides - broad-spectrum antibiotics - prescribed, despite current guidelines recommending against the use of these antibiotics as a primary treatment for the majority of respiratory infections.
What is more, the analysis revealed a significant variation in prescription practices among health care providers. For example, the team found that 10% of health care providers penned an antibiotic prescription in at least 95% of patient visits for ARIs, while 10% wrote an antibiotic prescription for 40% or fewer patient visits for ARIs.
The team conducted an additional analysis of 480,575 patient visits for ARIs among 2,594 health care providers, with the aim of determining the reasons behind the variation in antibiotic prescribing practices.
They found that prescribing habits accounted for 59% of the variation, while 28% of the variation was associated with differences in prescribing practices among clinics, and 13% of the variation was attributed to differences in prescribing practices among hospital centers.
The team says their findings regarding the variation in prescribing practices remained even after accounting for patient characteristics, such as age, sex and presence of other medical conditions.
Commenting on their findings, study author Tom Greene, PhD, of the Utah Center for Clinical and Translational Science, says:
"One of the things that makes this work stand out is that we could discern three levels of variation in antibiotic prescribing - by provider, clinic, and VA medical center - in a large data set.
This showed us the most striking result in this study, that the variation of prescribing practices between providers was quite large after accounting for patient characteristics."
The team says their study suggests improving and understanding how health care providers make decisions about antibiotic prescribing could help reduce antibiotic overuse going forward.
"We'd like to use this research to start a conversation among providers and patients about antibiotic prescribing for ARIs, and share the approaches of providers who are prescribing antibiotics less frequently with those who may be prescribing too often," adds Dr. Jones.
In September 2014, a Spotlight feature from Medical News Today investigated how antibiotic resistance has become a global threat to public health, with antibiotic overuse and misuse cited as a primary contributor to the problem
"When antibiotics are needed to prevent or treat disease, they should always be used," Dr. Steve Solomon, director of the CDC's Office of Antimicrobial Resistance, told us. "But research has shown that as much as 50% of the time, antibiotics are prescribed when they are not needed or they are misused (for example, a patient is given the wrong dose). This inappropriate use of antibiotics unnecessarily promotes antibiotic resistance."