The accuracy of healthcare worker versus self collected

• Published in: PloS one Vol. 15; no. 12; p. e0244417
• Main Authors: Tan, Seow Yen, Tey, Hong Liang, Lim, Ernest Tian Hong, Toh, Song Tar, Chan, Yiong Huak, Tan, Pei Ting, Lee, Sing Ai, Tan, Cheryl Xiaotong, Koh, Gerald Choon Huat, Tan, Thean Yen, Siau, Chuin, Jin, Dong-Yan
• Format: Journal Article
• Language: English
• Published: Public Library of Science 16.12.2020
• Subjects: Medical screening; Methods; Singapore
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0244417

Self-sampling for SARS-CoV-2 would significantly raise testing capacity and reduce healthcare worker (HCW) exposure to infectious droplets personal, and protective equipment (PPE) use. We conducted a diagnostic accuracy study where subjects with a confirmed diagnosis of COVID-19 (n = 401) and healthy volunteers (n = 100) were asked to self-swab from their oropharynx and mid-turbinate (OPMT), and self-collect saliva. The results of these samples were compared to an OPMT performed by a HCW in the same patient at the same session. In subjects confirmed to have COVID-19, the sensitivities of the HCW-swab, self-swab, saliva, and combined self-swab plus saliva samples were 82.8%, 75.1%, 74.3% and 86.5% respectively. All samples obtained from healthy volunteers were tested negative. Compared to HCW-swab, the sensitivities of a self-swab sample and saliva sample were inferior by 8.7% (95%CI: 2.4% to 15.0%, p = 0.006) and 9.5% (95%CI: 3.1% to 15.8%, p = 0.003) respectively. The combined detection rate of self-swab and saliva had a sensitivity of 2.7% (95%CI: -2.6% to 8.0%, p = 0.321). The sensitivity of both the self-collection methods are higher when the Ct value of the HCW swab is less than 30. The specificity of both the self-swab and saliva testing was 100% (95% CI 96.4% to 100%). Our study provides evidence that sensitivities of self-collected OPMT swab and saliva samples were inferior to a HCW swab, but they could still be useful testing tools in the appropriate clinical settings.