This is a summary, written by members of the CITF Secretariat, of:

Hohl CM, Hau JP, Vaillancourt S, Grant J, Brooks SC, Morrison LJ, Perry JJ, Rosychuk RJ; CCEDRRN investigators for the Network of Canadian Emergency Researchers and the Canadian Critical Care Trials Group. Sensitivity and Diagnostic Yield of the First SARS-CoV-2 Nucleic Acid Amplification Test Performed for Patients Presenting to the Hospital. JAMA Netw Open. 2022 Oct 3;5(10):e2236288. doi:

The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

A CITF-funded study, published in JAMA Network Open, revealed that the SARS-CoV-2 nucleic acid amplification test (NAAT) demonstrated a robust sensitivity of 96.2%, signifying efficacy in detecting infections. This performance remained consistent throughout the initial two weeks of symptoms. Moreover, the diagnostic yield of the test exhibited variability based on symptom duration, reaching its highest yield of 20% around day 10. This implies that individuals with persistent respiratory symptoms are more likely to receive a diagnosis of COVID-19. This study was led by Dr. Corinne Hohl (University of British Columbia).

The study aimed to assess the clinical sensitivityA highly sensitive test is effective at detecting individuals with the condition and minimizing the chances of false negatives, where the test incorrectly indicates that someone does not have the condition when they actually do. and the diagnostic yield of the SARS-CoV-2 nucleic acid amplification tests (NAATs) performed within 24 hours of arrival at participating emergency departments among a large nationally representative sample of patients. These were consecutive, eligible patients presenting for care at 47 hospitals. NAATs use many different methods to amplify and detect the virus, one of which is reverse transcription polymerase chain reaction (RT-PCR) performed on samples collected through swabbing the nose or throat.

Key findings:

  • The sensitivity of the SARS-CoV-2 NAAT was found to be high at 96.2%, indicating its efficacy in detecting SARS-CoV-2 infections, with little variation over the first two weeks of symptoms.
  • Among patients reporting COVID-19 symptoms, the sensitivity of the SARS-CoV-2 NAAT was 97.1% compared with 87.6% among patients without COVID-19 symptoms.
  • The diagnostic yieldThis refers to the efficacy of a diagnostic test in identifying cases of COVID-19 among all the people who are tested. of the SARS-CoV-2 NAAT was 12% and it varied depending on how long someone had symptoms. It was 8.1% within the first 24 hours of symptom onset and peaked around day 10 of symptoms at 20%, suggesting that patients with ongoing respiratory symptoms are more likely to receive a COVID-19 diagnosis.
  • Older patients, patients with chronic kidney disease or psychiatric conditions, and individuals reporting abdominal pain were more likely to get an initial false-negativeA test result that incorrectly indicates that the condition being tested for is not present when, in fact, the condition is actually present COVID-19 test result. People showing symptoms commonly linked to COVID-19, including cough, fever, and muscle aches, were less likely to have a false-negative test result.

The research findings highlight that NAATs demonstrate a strong ability to accurately detect SARS-CoV-2 infection, allowing a single negative test result to effectively rule out the virus for most individuals in the emergency department. However, the study suggests that individuals with a very high likelihood of being infected, coupled with an initial negative test result, might benefit from additional testing.

The study underscores the significance of accounting for clinical factors, such as how long symptoms have been present and individual patient characteristics, to optimize the interpretation of test results. This approach helps refine testing strategies and prevents unnecessary repeat testing.

This study involved 132, 760 patients, from 47 hospitals across seven provinces in Canada that are part of the Canadian COVID-19 Rapid Response Emergency Department Network (CCEDRRN), who came to the emergency department from March 1, 2020, to December 31, 2021 and were tested for COVID-19.