Rapid Flu Test Cuts Antibiotic Use in Adults

January 22, 2007

ROCHESTER, N.Y. -- When a rapid test catches the flu, it reduces inappropriate use of antibiotics in adults, according to researchers here.

ROCHESTER, N.Y., Jan. 22 -- When a rapid test catches the flu, it reduces inappropriate use of antibiotics in adults, according to researchers here.

The rapid test -- with results available in minutes -- has already been shown to reduce antibiotic use among children, according to Ann Falsey, M.D., of the University of Rochester Medical Center and Rochester General Hospital.

Now a retrospective chart review of four flu seasons at the hospital shows a similar pattern for adults, Dr. Halsey and colleagues reported online today in the Archives of Internal Medicine.

"I was pleasantly surprised by the results," Dr. Falsey said. "Rapid testing does give physicians evidence to discontinue antibiotics, and some physicians are responding to the evidence."

The report will appear in the Feb. 26 issue, but it was released to journalists early because of its public health importance.

During the winters of 1999 through 2003, the hospital conducted influenza testing - either with the rapid test or through culture -- for all patients with acute cardiopulmonary diseases admitted from Nov. 15 through April 15.

Of 166 patients with documented influenza, the researchers reported, 86 were positive on the rapid test (Ag+) and 80 were either negative or did not have the rapid test performed (Ag0).

Analysis of the groups found:

  • Antibiotics were used in 74 of the 86 Ag+ patients (86%), compared with 79 of 80 Ag0 patients (99%). The difference was statistically significant at P=0.002.
  • Antibiotics were stopped in 12 Ag+ 86 patients (14%), compared with two of the Ag0 patients (2%). The difference was significant at P=0.01.
  • Antiviral use was greater in the Ag+ patients -- 73% versus 8% -- which was significant at P

The researchers noted the study was limited by its retrospective nature, in that the different clinical characteristics of the groups contributed to variations in management.

On the other hand, multivariate analysis showed that rapid test status was significantly associated with antibiotic use, "providing evidence that the test results were affecting management," they said.