1. Use of the novel molecular point-of-care testing, the QIAstat-Dx Respiratory SARS-CoV-2 Panel, was associated with a much shorter time to results compared to laboratory PCR testing.
2. Point-of-care testing demonstrated superior specificity and sensitivity to standard PHE RdRP and E gene assay for COVID-19.
Evidence Rating Level: 2 (Good)
Study Rundown: As the SARS-CoV-2 pandemic continues to ravage healthcare systems throughout the world, the need for rapid, effective testing for the virus has become more important than ever. Although several tests for the virus now exist, a major bottleneck is the long wait time to receive results. This, in turn, leads to patients being isolated too late, going through multiple bed transfers and exposing numerous others in the hospital to the virus. This prospective, interventional trial compared standard laboratory testing for COVID-19, PHE RdRp and E Gene assay testing, with a novel “point-of-care” screen, the QIAstat-Dx Respiratory SARS-CoV-2 Panel. Overall, the QIAstat-Dx screen significantly reduced the median time from presentation to receiving a designated COVID bed in hospital by as much as 20 hours; likewise, point-of-care testing was associated with fewer bed changes on average, and a higher overall sensitivity and specificity than either PHE RdRp and E Gene assays. Although this study provides strong support of this novel point-of-care testing method, there are some shortcomings. A major limitation of this study was that it was not randomized, due to this being deemed unethical in light of the global pandemic and may have resulted in patients with a higher likelihood of COVID being chosen for rapid, point-of-care testing. Similarly, given the poor sensitivity of the RdRp assay, it is possible that the QIAstat-Dx test may have had false negatives that the laboratory PCR test did not detect. This study also was only conducted on symptomatic patients, and thus its use as a screening tool in minimally-symptomatic or asymptomatic patients is unknown.
Click to read the study in The Lancet Respiratory Medicine
Click to read an accompanying editorial in The Lancet Respiratory Medicine
Relevant Reading: Evaluation of the QIAstat-Dx Respiratory SARS-CoV-2 Panel, the first rapid multiplex PCR commercial assay for SARS-CoV-2 detection.
In-Depth [prospective cohort]: This single-center, prospective, non-randomized interventional study was conducted between March 20 and April 29, 2020, and recruited 500 patients for the point-of-care COVID testing group, and 555 patients for the laboratory PCR group. Median age was 68 years in the former group, and 70 years in the latter, with roughly half being female and the majority being of White British ethnicity in both groups. The point-of-care group had a higher median NEWS2 score (an indicator of disease severity) than the control group (5 [IQR=3-6] vs. 4 [IQR=2-6]). Overall, the median time from presentation to hospital to arrival in a designated COVID ward was significantly lower in the point-of-care group than the laboratory PCR group (8.0h [IQR=6.0-15.0] vs. 28.8h [IQR=23.5-38.9], respectively; difference = 20.8h [IQR=18.4-21.2], p<0.0001). Patients in the point-of-care group also underwent fewer bed transfers on average (0.9 moves (SD=0.5) vs. 1.4 (SD=0.7), difference = 0.5 [95% CI = 0.4-0.6], p<0.0001). The QIAstat-Dx point-of-care test showed strong diagnostic test accuracy (sensitivity = 99.4% [95% CI = 96.9-100] & specificity = 98.6% [95% CI = 96.5-99.6]) compared to the PHE RdRp and E gene assays (sensitivity = 89.5% (95% CI = 83.6-93.9)).
Image: PD
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