J Hosp Infect. 2022 Feb 22:S0195-6701(22)00060-3. doi: 10.1016/j.jhin.2022.02.010. Online ahead of print.
ABSTRACT
BACKGROUND: Decisions to isolate patients at risk of having COVID-19 in the emergency department must be rapid and accurate to ensure prompt treatment and maintain patient flow whilst minimising nosocomial spread. Reverse transcription polymerase chain reaction (RT-PCR) assays are too slow to achieve this, and near-patient testing is being used increasingly to facilitate triage. The ID NOW SARS-CoV-2 assay is an isothermal nucleic acid amplification near-patient test which targets the RNA-dependent-RNA-polymerase gene.
AIM: To assess the diagnostic performance of ID NOW as a COVID-19 triage tool for medical admissions from the emergency department of a large acute hospital.
METHODS: All adult acute medical admissions from the ED between 31st March to 31st July 2021 with valid ID NOW and RT-PCR results were included. The diagnostic accuracy of ID NOW (sensitivity, specificity, positive predictive value, negative predictive value) was calculated against the laboratory reference standard. Discrepant results were further explored using cycle threshold values (Ct) and clinical data.
FINDINGS: 2.0% (124/6050) of medical admissions were SARS-CoV-2 positive on RT-PCR. Compared to PCR, ID NOW had a sensitivity and specificity of 83.1% (95% CI:75.4-88.7) and 99.5% (95% CI:99.3-99.6) respectively. Positive (PPV) and negative predictive values (NPV) were 76.9% (95% CI:69.0-83.2) and 99.6% (95% CI:99.5-99.8). The median time from arrival in the ED to ID NOW result was 59 minutes.
CONCLUSION: ID NOW provides a rapid and reliable adjunct for the safe triage of COVID-19 and can work effectively when integrated into an ED triage algorithm.
PMID:35217130 | PMC:PMC8863956 | DOI:10.1016/j.jhin.2022.02.010