Tutorial presented by Dr Owen Seddon, Consultant in Infectious Diseases and Microbiology

Like most physiological tests, the result from a COVID-19 test should be used to aid a diagnosis of COVID-19, and not confirm the diagnosis. It is important that the test is interpreted in the clinical context. 

The following table outlines the test characteristics of the LumeraDx COVID test (specificity 99.6% and sensitivity 73.3%), comparing the predictive values in populations with different prevalence.

It demonstrates that:

• if you have a patient who you deem likely to have COVID-19 following clinical assessment, and their COVID-19 test is positive, you can have good confidence in a positive result
• if you have a patient who you deem unlikely to have COVID-19 following clinical assessment, and their COVID-19 test is negative, you can have good confidence in a negative result
• if the test result conflicts with your clinical assessment of the patient, it is important to re-examine the patient and repeat the test

Where there is ongoing uncertainty about the patient’s COVID status, it is important to protect the patient from risk of infection to and from others, for example in a cubicle, or in a waiting area with good social distancing.