tetano
Editor, Senior Moderator
Diagn Progn Res
. 2021 Dec 24;5(1):24.
doi: 10.1186/s41512-021-00113-7.
Urgent care study of the LumiraDx SARS-CoV-2 Ag Test for rapid diagnosis of COVID-19
Jared Gresh[SUP] 1 2 [/SUP], Harold Kisner[SUP] 1 3 [/SUP], Brian DuChateau[SUP] 4 [/SUP]
Affiliations
Abstract
Background: Testing individuals suspected of severe acute respiratory syndrome-like coronavirus 2 (SARS-CoV-2) infection is essential to reduce the spread of disease. The purpose of this retrospective study was to determine the false negativity rate of the LumiraDx SARS-CoV-2 Ag Test when utilized for testing individuals suspected of SARS-CoV-2 infection.
Methods: Concurrent swab samples were collected from patients suspected of SARS-CoV-2 infection by their healthcare provider within two different urgent care centers located in Easton, MA, USA and East Bridgewater, MA, USA. One swab was tested using the LumiraDx SARS-CoV-2 Ag Test. Negative results in patients considered at moderate to high risk of SARS-CoV-2 infection were confirmed at a regional reference laboratory by polymerase chain reaction (PCR) using the additional swab sample. The data included in this study was collected retrospectively as an analysis of routine clinical practice.
Results: From October 19, 2020 to January 3, 2021, a total of 2241 tests were performed using the LumiraDx SARS-CoV-2 Ag Test, with 549 (24.5%) testing positive and 1692 (75.5%) testing negative. A subset (800) of the samples rendering a negative LumiraDx SARS-CoV-2 Ag Test was also tested using a PCR-based test for SARS-CoV-2. Of this subset, 770 (96.3%) tested negative, and 30 (3.8%) tested positive. Negative results obtained with the LumiraDx SARS-CoV-2 Ag test demonstrated 96.3% agreement with PCR-based tests (CI 95%, 94.7-97.4%). A cycle threshold (C[SUB]T[/SUB]) was available for 17 of the 30 specimens that yielded discordant results, with an average C[SUB]T[/SUB] value of 31.2, an SD of 3.0, and a range of 25.2-36.3. C[SUB]T[/SUB] was > 30.0 in 11/17 specimens (64.7%).
Conclusions: This study demonstrates that the LumiraDx SARS-CoV-2 Ag Test had a low false-negative rate of 3.8% when used in a community-based setting.
Keywords: Antigen testing; COVID-19; Community-based setting; False negative; Rapid diagnosis; SARS-CoV-2.
. 2021 Dec 24;5(1):24.
doi: 10.1186/s41512-021-00113-7.
Urgent care study of the LumiraDx SARS-CoV-2 Ag Test for rapid diagnosis of COVID-19
Jared Gresh[SUP] 1 2 [/SUP], Harold Kisner[SUP] 1 3 [/SUP], Brian DuChateau[SUP] 4 [/SUP]
Affiliations
- PMID: 34952653
- DOI: 10.1186/s41512-021-00113-7
Abstract
Background: Testing individuals suspected of severe acute respiratory syndrome-like coronavirus 2 (SARS-CoV-2) infection is essential to reduce the spread of disease. The purpose of this retrospective study was to determine the false negativity rate of the LumiraDx SARS-CoV-2 Ag Test when utilized for testing individuals suspected of SARS-CoV-2 infection.
Methods: Concurrent swab samples were collected from patients suspected of SARS-CoV-2 infection by their healthcare provider within two different urgent care centers located in Easton, MA, USA and East Bridgewater, MA, USA. One swab was tested using the LumiraDx SARS-CoV-2 Ag Test. Negative results in patients considered at moderate to high risk of SARS-CoV-2 infection were confirmed at a regional reference laboratory by polymerase chain reaction (PCR) using the additional swab sample. The data included in this study was collected retrospectively as an analysis of routine clinical practice.
Results: From October 19, 2020 to January 3, 2021, a total of 2241 tests were performed using the LumiraDx SARS-CoV-2 Ag Test, with 549 (24.5%) testing positive and 1692 (75.5%) testing negative. A subset (800) of the samples rendering a negative LumiraDx SARS-CoV-2 Ag Test was also tested using a PCR-based test for SARS-CoV-2. Of this subset, 770 (96.3%) tested negative, and 30 (3.8%) tested positive. Negative results obtained with the LumiraDx SARS-CoV-2 Ag test demonstrated 96.3% agreement with PCR-based tests (CI 95%, 94.7-97.4%). A cycle threshold (C[SUB]T[/SUB]) was available for 17 of the 30 specimens that yielded discordant results, with an average C[SUB]T[/SUB] value of 31.2, an SD of 3.0, and a range of 25.2-36.3. C[SUB]T[/SUB] was > 30.0 in 11/17 specimens (64.7%).
Conclusions: This study demonstrates that the LumiraDx SARS-CoV-2 Ag Test had a low false-negative rate of 3.8% when used in a community-based setting.
Keywords: Antigen testing; COVID-19; Community-based setting; False negative; Rapid diagnosis; SARS-CoV-2.