The exact place of PCR and chest CT in screening, staging, and diagnosis of Covid-19: A meta-analysis
Abstract Introduction: Nowadays there is an ongoing acute respiratory outbreak causing by the novel highly contagious coronavirus (nCoV). There are two diagnostic protocol based on chest CT scan and quantitative reverse-transcription polymerase chain reaction (RT-PCR) which their diagnostic accuracy is under the debate. We designed this meta-analysis study to determine the diagnostic value of initial chest CT scan in patients with nCoV infection in comparison with RT- PCR.Search strategy and statistical analysis: Three main databases the PubMed (MEDLINE), Scopus, and EMBASE was systematically searched for all published literatures from January 1st, 2019, to the 27th march 2020 with key grouping of “COVID19 virus”, “2019 novel coronavirus”, “Wuhan coronavirus”, “2019-nCoV”, “X-Ray Computed Tomography”, “Polymerase Chain Reaction”, “Reverse Transcriptase PCR”, and “PCR Reverse Transcriptase”. All relevant case- series, cross-sectional, and cohort studies were selected. Data extraction was done in Excel 2007 (Microsoft Corporation, Redmond, CA) and their analysis was performed using STATA v.14.0SE (College Station, TX, USA) and RevMan 5.Result: From first recruited 668 articles we end up to the final 47 studies, which comprised a total sample size of 4238 patients. In compare to RT-PCR, the overall sensitivity, specificity, positive predictive value, and negative predictive value of chest CT scan were 86% (95% CI: 83% -90%), 43 % (95% CI: 26% -60%), 67% (95% CI: 57% -78%), and 84% (95% CI: 74% -95%) respectively. However the RT-PCR should be repeated for three times in order to give the 99% accuracy especially in negative samples.Conclusion: According to the acceptable sensitivity of chest CT scan, it can be employed complement to RT-PCR to diagnosis patients who are clinically suspicious for nCoV.