(CBS News) Doctors may be overprescribing antibiotics at alarming rates for sore throats and acute bronchitis.
A research letter published in JAMA Internal Medicine on Oct. 3 examined nationally representative surveys of physician and emergency room care in the U.S. from 1996 to 2010. The authors discovered that the national antibiotic prescription rate for adults with a sore throat was 60 percent -- meaning one is prescribed in about 60 percent of visits for this health problem -- and the rate was 73 percent for bronchitis.
For the most part, these two conditions can't be treated by antibiotics because more often than not they are caused by a virus. Antibiotics are only effective against strep throat, and only 10 percent of the patients who came in actually had that illness. Most cases of bronchitis are also caused by viruses, and the respiratory infection will often resolve within a week anyway.
"We know that antibiotic prescribing, particularly to patients who are not likely to benefit from it, increases the prevalence of antibiotic-resistant bacteria, a growing concern both here in the United States and around the world," senior author Dr. Jeffrey A. Linder, a physician and researcher in the Division of General Medicine and Primary Care at Brigham and Women's Hospital, said in a press release.
The Centers for Disease Control and Prevention says enough antibiotics are prescribed each year to give them to four out five Americans.
Antibiotic overuse can lead to antibiotic-resistant viruses and bacteria when germs that are resistant to medications survive and pass on their genetic information to other germs. This creates "superbugs" that no medication will work against.
The CDC expressed concern at the growing rate of antibiotic-resistant infections, reporting that23,000 Americans currently die from these diseases each year. It could get so bad that one day something as simple as a skinned knee could become deadly, World Health Organization (WHO) Director-General Dr. Margaret Chan said in March 2012.
Many medical groups have been encouraging doctors to use antibiotics as a last-case scenario, including to treat sinusitis in kids.
Still, only 44 percent of Americans recognizeantibiotic overuse as "somewhat or a big problem" and 47 percent understand that overuse of antibiotics can hurt someone other than themselves, according to a November 2012 survey.
The researchers behind the new study also found that primary care visits because of sore throats dropped from 7.5 percent in 1997 to 4.3 percent of visits in 2010. The number of people going to the emergency room for a sore throat did not change throughout the study period. The rate of physicians prescribing antibiotics for that health woe remained at 60 percent.
Dr. Ralph Gonzales, who has studied antibiotic prescribing at the University of California, San Francisco, told Reuters the new study was welcome news because not everyone was getting antibiotics, dropping overall rates.
"At least from a public health perspective, we're having a lower impact on resistance," Gonzales, who wasn't involved in the new research, said.
However, the number of people who went to the doctor because of acute bronchitis -- which was 1.1. million in 1996 -- more than tripled to 3.4 million by 2010. In addition, antibiotic prescribing rates in the emergency room went up from 69 percent to 73 percent during the study period.
"In addition to contributing to the prevalence of antibiotic resistant bacteria, unnecessary use of antibiotics also adds financial cost to the health care system and causes adverse effects for those taking the medication," said Barnett, adding that in most cases, these illnesses should be treated with rest and fluids and do not even require a doctor's visit.
The research was also presented at IDWeek 2013 in San Francisco on Oct. 3.
Michelle Castillo, CBS News