HARVARD GAZETTE ARCHIVES

Jeffrey Linder, instructor of medicine at HMS, says that unnecessary prescriptions drive up health care costs and can increase the likelihood of the development of drug-resistant bacteria. (Staff photo T.J. Kirkpatrick/Harvard News Office)

That's the conclusion of a new study of national treatment data by faculty at Harvard Medical School and the Harvard School of Public Health.

The study used information from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey to examine the treatment of 4,158 cases of sore throat in children age 3 to 17 from 1995 to 2003.

Though the study showed a decline in antibiotic prescribing over the study period, from 66 percent of cases to 54 percent, researchers concluded that many children are still receiving unnecessary antibiotics each year.

That's because most sore throats in children are caused by respiratory viruses like those that cause colds and cannot be treated with antibiotics. The only common cause of sore throats that can effectively be treated with antibiotics is the group A beta-hemolytic streptococci bacteria, familiar to parents as the cause of strep throat.

Health officials estimate that just between 15 percent and 36 percent of children with sore throats actually have strep. If the study's findings hold true for the entire population, that means between 1.3 million and 2.8 million children with sore throats are getting antibiotics unnecessarily each year. Jeffrey Linder, instructor of medicine at Harvard Medical School and Brigham and Women's Hospital, and the study's lead author, said the unnecessary prescriptions drive up health care costs and can increase the likelihood of the development of drug-resistant bacteria. Most troubling though, he said, is that doctors are exposing these children to the possible side effects of drugs unnecessarily.

"Probably the most important issue, in my mind, is exposing kids unnecessarily to a medicine," Linder said. "Kids are exposed to all the risks of the medicine with no possible benefit."

The study was conducted with Professor of Medicine and Professor of Health Policy and Management David W. Bates of Brigham and Women's Hospital, Instructor in Ambulatory Care and Prevention and in Pediatrics Grace M. Lee of Children's Hospital, and Associate Professor of Ambulatory Care and Prevention and of Pediatrics Jonathan A. Finkelstein, also of Children's Hospital. It appeared in the Nov. 9 issue of the Journal of the American Medical Association.

The study also showed that doctors are underusing a common test for strep and overprescribing broad-spectrum antibiotics when they do prescribe the drugs. The test, which can confirm the presence of the bacteria that causes strep throat, was used in just over half the cases where doctors prescribed antibiotics. Though the test is not necessary for every sore throat a doctor sees, Linder said it should be conducted before a doctor prescribes antibiotics. Treatment guidelines for strep recommend a narrow-spectrum antibiotic, such as penicillin or amoxicillin, but the study showed that doctors are also prescribing broad-spectrum antibiotics, which were the chosen drug in 27 percent of prescriptions over the study period.

Linder, interested in the appropriate use of prescriptions, said he thought that childhood sore throat, which offers a clear choice for physicians and a widely accepted test on which to base results, would be one area where doctors were largely getting their prescription habits right.

"I was particularly interested in pediatric sore throat. This is an area where hopefully doctors are getting close to 100 percent," Linder said. "We found that was not the case."

A variety of factors are likely at play in the overprescribing of antibiotics, Linder said. In part, it may be a doctor's desire to help his or her patient, or a parent pressuring the doctor to write a prescription in an effort to get their child some relief.

Linder said it may be difficult to tell a strep infection from other kinds of infections, but it is usually easy to tell whether a child has a cold or other viral illness. If a doctor suspects strep, Linder said, the doctor should do the test first.