At-home tool may predict who needs strep tests - study

Plugging a few symptoms into an at-home tool may help people avoid unnecessary doctors' visits and tests for strep throat, suggests a new study.

The tool requires data that are not yet readily available. But the study's authors from Boston Children's Hospital found the tool could potentially prevent 230,000 trips to U.S. doctors' offices every year for suspected strep throat.

"One thing that can be frustrating for families is if they come in with the expectation they'll be tested for something and they're not," Dr. Andrew Fine, the study's lead author, told Reuters Health.

The new tool, he said, could help people realize their risk of strep throat is low and stop them from making an appointment with their doctors. That may prevent them from getting unnecessary tests and unnecessary treatments - like antibiotics, which contribute to the problem of drug resistance.

Currently, about 12 million Americans visit doctors every year with sore throats, the researchers write in the Annals of Internal Medicine.

Accepted medical guidelines suggest doctors use an office-based tool that takes into account symptoms and physical examination results to determine a person's risk for strep throat. If the risk is low, guidelines recommend against testing or treating the patient.

For the new study, the researchers used information collected between September 2006 and December 2008 from 71,776 people over age 15 who visited CVS MinuteClinics in six states for sore throats.

They used people's medical records and strep test results to test a tool that calculated a "home score." It's similar to the one used in doctors' offices.

"The tool that the doctors use includes physical examination findings," Fine said. "We've removed those for the home scores so that anyone without medical training can assign themselves a score based two symptoms - fever and cough."

The tool also takes into account how common strep throat has been in the person's community during the past two weeks before calculating the home score.

"The thing here is that what you want to know the most … is do the people around you have strep throat," Dr. Kenneth Mandl, the study's senior author, said.

That number, however, is not commonly available in most areas.

The tool measures risk on a scale from 0 to 100. For the new study, anyone with a score below 10 was considered at low risk for strep throat.

Overall, Fine and his colleagues found that 90 percent of the people who scored below 10 on the at-home tool would have tested negative for strep throat. That means there would be 27 fewer doctors' visits for every one person with strep throat who was missed by the tool.

As for those people with strep throat who would be missed, Mandl said the chance for them to go on and have serious complications is small.