A rapid influenza diagnostic test (RIDT) is a type of antigen detection test that detect influenza viral nucleoprotein antigen. Commercially available RIDTs can provide results within 30 minutes or less. However, researchers at Loyola University Medical Center reported, "We determined four years ago that the rapid tests for influenza detected only 50 percent of the patients who were positive. I can flip a coin and get the same results as I could with those tests. So what’s the value of the tests? People who actually are infected with H1N1 are being sent home without treatment. Those in high-risk groups could face serious illness. As for the others: maybe they go back to work; maybe the children go back to school and infect others."
A study published in The New England Journal of Medicine concludes that that one test generated a false negative 49 percent of the time, meaning it detected H1N1 only 51 percent of the time. Another study published in the Journal of Clinical Virology found another test generated a false negative 82.2 percent of the time, detecting H1N1 only 17.2 percent of the time.
A study in Emerging Infectious Diseases, published by the Centers for Disease Control (CDC), found that a test generated a false negative 88.9 of the time, detecting H1N1 only 11.1 percent of the time.[1]