Sensitivity of id now and rt–pcr for detection of sars-cov-2 in an ambulatory population

Abstract

Diagnosis of SARS-CoV-2 (COVID-19) requires confirmation by reverse transcription– polymerase chain reaction (RT–PCR). Abbott ID NOW provides fast results but has been criticized for low sensitivity. Here we determine the sensitivity of ID NOW in an ambulatory population presented for testing. The study enrolled 785 symptomatic patients, of whom 21 were positive by both ID NOW and RT–PCR, and 2 only by RT–PCR. All 189 asymptomatic patients tested negative. The positive percent agreement between the ID NOW assay and the RT–PCR assay was 91.3%, and negative percent agreement was 100%. The results from the current study were included into a larger systematic review of literature where at least 20 subjects were simultaneously tested using ID NOW and RT–PCR. The overall sensitivity for ID NOW assay was calculated at 84% (95% confidence interval 55–96%) and had the highest correlation to RT–PCR at viral loads most likely to be associated with transmissible infections.