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1 Kucirka LM, Lauer SA, Laeyendecker O, Boon D, Lessler J. Variation in false-negative rate of reverse transcriptase polymerase chain reaction–based SARS-CoV-2 tests by time since exposure. Annals of Internal Medicine. 2020; 10:M20-1495.

2 Hébert H, Chatziperi A, Zheng H, Meng W, Smith B, Colvin L, et al. Perioperative management of patients with suspected or confirmed COVID-19: review and recommendations for perioperative management from a retrospective cohort study. British Journal of Anaesthesia. 2020; 125(6), 895e911.

3 COVIDSurg Collaborative. Mortality and pulmonary complications in patients undergoing surgery with perioperative SARSCoV-2 infection: an international cohort study. Lancet 2020; 396, 27-38.

4 Association of Surgeons of Great Britain & Ireland, Association of Coloproctology of Great Britain & Ireland, Association of Upper Gastrointestinal Surgeons, The Royal College of Radiologists, Royal College of Surgeons of Edinburgh, Royal College of Surgeons of England, et al. Guidelines for pre-operative COVID-19 testing for elective cancer surgery. [cited 20 May]. Available from url:

5 Woloshin S, Patel N, Kesselheim AS. False negative tests for SARS-CoV-2 infection: challenges and implications. New England Journal of Medicine 2020; 383(6), e38. org/doi/full/10.1056/NEJMp2015897

6 Templeton K. 2020. (Personal communication)

7 Oran DP, Topol EJ. Prevalence of asymptomatic SARS-CoV-2iInfection: a narrative review. Annals of Internal Medicine. 2020; 173(5), 362-367.

8 Tu Y-P, Jennings R, Hart B, Cangelosi G, Wood R, Wehber K, et al. Patient-collected tongue, nasal, and mid-turbinate swabs for SARS-CoV-2 yield equivalent sensitivity to health care worker collected nasopharyngeal swabs. medRxiv 2020:2020.04.01.20050005

9 Kojima N, Turner F, Slepnev V, Bacelar A, Deming L, Kodeboyina S, et al. Self-collected oral fluid and nasal swabs demonstrate comparable sensitivity to clinician collected nasopharyngeal swabs for Covid-19 detection. medRxiv 2020:2020.04.11.20062372

10 Wyllie AL, Fournier J, Casanovas-Massana A, Campbell M, Tokuyama M, Vijayakumar P, et al.  Saliva or nasopharyngeal swab specimens for detection of SARSCoV-2. New England Journal of Medicine. 2020; 383, 1283-1286. 10.1056/NEJMc2016359