• Katia Bruxvoort, Christopher F Tenggardjaja, Jeff Slezak, Jonathan C Gullett, Benjamin Broder, Claire H Park, Michael Aragones, Cheryl Mercado, Katherine Wong, Steven McLaren, and Steven J Jacobsen.
• Department of Research & Evaluation, Kaiser Permanente Southern California, 100 South Los Robles Avenue, Pasadena, CA 91101, USA. Electronic address: Katia.Bruxvoort@kp.org.
• Am J Emerg Med. 2021 Dec 1; 50: 381387381-387.

BackgroundProvider-collected nasopharyngeal specimens for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) molecular testing are the standard of care in many clinical settings, but patient-collected saliva and anterior nares specimens are less invasive and more flexible alternatives. Prior studies comparing specimen types for SARS-CoV-2 molecular testing have been limited by small sample sizes and low pretest probability. We conducted a large observational study among symptomatic adults at 7 emergency departments of Kaiser Permanente Southern California to examine sensitivity of SARS-CoV-2 molecular tests by specimen type and patient characteristics.MethodsProvider-collected nasopharyngeal/oropharyngeal (NP/OP) specimens and patient-collected saliva and anterior nares specimens were collected at the same visit and analyzed with the Roche cobas® SARS-CoV-2 assay. Patients were considered truly positive for SARS-CoV-2 if any of the three specimens was positive and negative if all three specimens were negative. Factors associated with discordant and missed positive results were examined with multivariable logistic regression.ResultsOf 2112 patients, 350 (16.6%) were positive for SARS-CoV-2. Sensitivity of NP/OP was 93.7% (95% confidence interval [CI] 90.6%-96.0%), sensitivity of saliva was 87.7% (83.8%-91.0%), and sensitivity of anterior nares was 85.4% (81.3%-89.0%). Patients ages 18-39 years versus ≥40 years were more likely to have discordant results [adjusted odds ratio (aOR) 1.97 (1.12-3.45)], as were patients with <4 symptoms versus ≥4 [aOR 2.43 (1.39-4.25)]. Cycle threshold values were higher for saliva and anterior nares than NP/OP specimens, as well as for specimens in discordant versus concordant sets and patients with fewer symptoms.ConclusionThis study provides robust evidence that patient-collected saliva and anterior nares are sensitive for SARS-CoV-2 molecular testing in emergency department settings, particularly among adults ages ≥40 years and those with multiple symptoms. Higher sensitivity of provider-collected NP/OP specimens must be weighed against the benefits of patient-collected specimens in tailored strategies for SARS-CoV-2 testing.Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.

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