Diagnostic accuracy of the FebriDx host response point-of-care test in patients hospitalised with suspected COVID-19

Abstract

Introduction: Management of the COVID-19 pandemic is hampered by long delays associated with centralised laboratory PCR testing. In hospitals this leads to poor patient flow and nosocomial transmission and so rapid, accurate diagnostic tests are urgently required. The FebriDx is a point-of-care test that detects an antiviral host response protein in finger prick blood within 10 min, but its accuracy for the identification of COVID-19 is unknown. Methods: We performed a real-world diagnostic accuracy study of FebriDx in hospitalised patients during the first wave of the pandemic. Measures of diagnostic accuracy were calculated based on FebriDx results compared to the reference standard of SARS-CoV-2 PCR on combined nose and throat swabs. A multivariable predictive model including FebriDx, age, sex, and clinical characteristics was developed and underwent internal validation. Results: FebriDx was performed on 251 patients and gave a valid result in 248. 118 of 248 (48%) were PCR positive for COVID-19. FebriDx results were available after 10 min compared with 1.7 (1.6 to 2.1) hours with point-of-care PCR testing and 23.4 (17.2 to 31.1) hours with laboratory PCR testing. Sensitivity of FebriDx for the identification of COVID-19 was 93% (110/118; 95% CI 87 to 97%) and specificity was 86% (112/130; 95%CI 79 to 92%). Positive and negative likelihood ratios were 6.73 (95%CI 4.37 to 10.37) and 0.08 (95%CI 0.04 to 0.15) respectively. In the multivariate model age, sex and other clinical features did not contribute significantly to the effect of the FebriDx result in distinguishing patients with and without COVID-19. Conclusions: During the first wave of the pandemic, FebriDx had high accuracy for the identification of COVID-19 in hospitalised adults and could be deployed as a front door triage tool.

Clinical characteristics, symptoms and outcomes of 1054 adults presenting to hospital with suspected COVID-19: A comparison of patients with and without SARS-CoV-2 infection

“…10 Even faster, finger-prick host response point-of-care testing also has the potential to streamline triage and patient care decisions. 32 In conclusion, this study of adults presenting to hospital with suspected COVID-19 shows there are significant differences in the clinical characteristics, symptoms, and clinical outcomes of patients testing positive and negative for SARS-CoV-2 infection. These data can be used to inform healthcare planning in preparation for the next phase of the pandemic.…”

“…These challenges may be addressed by implementing molecular point-of-care testing for SARS-CoV-2 [10] . Even faster, finger-prick host response point-of-care testing also has the potential to streamline triage and patient care decisions [32] .…”

Swab-Seq: A high-throughput platform for massively scaled up SARS-CoV-2 testing

“…The SwabSeq diagnostic platform complements traditional clinical diagnostics tests 25 , as well as the growing arsenal of point-of-care rapid diagnostic platforms 26 emerging for COVID-19, by increasing test capacity to meet the needs of both diagnostic and widespread surveillance testing. Looking forward, SwabSeq is easily extensible to accommodate additional pathogens and viral targets.…”

A model to identify individuals with a high probability of a SARS-CoV-2 infection

“…Persons with a high probability of a SARS-CoV-2 infection should be tested with priority if testing resources are limited. Recently, Clark et al reported that the FebriDx point-of-care test which is based on the detection of the antiviral host response protein MxA had high accuracy to identify COVID-19 during the first wave 1 . They suggested that in hospitals, MxA positive patients should have a PCR test for confirmation or exclusion of COVID-19 with priority.…”