A meta-analysis published in Mayo Clinic Proceedings shows that fractional exhaled nitrous oxide (FeNO) is a good evidence-based adjunct test for asthma.
Although about 24 million Americans are diagnosed with asthma every year, there is no single test that can diagnose the disease. Common symptoms, such as shortness of breath, wheezing, and cough, are relatively nonspecific, and physicians may use multiple tests and observations to reach an accurate diagnosis.
In order to assess the accuracy and reliability of one of these tests that can be added to the clinician’s toolbox to diagnose asthma — fractional exhaled nitric oxide (FeNO) concentration — researchers gathered and analyzed data from previous peer-reviewed studies. They conclude that the FeNO test has moderate accuracy for patients aged 5 and older. Their results are reported in Mayo Clinic Proceedings.