Diagnostic Performance of CT and Reverse Transcriptase-Polymerase Chain Reaction for Coronavirus Disease 2019: A Meta-Analysis

Abstract

Background

Recent studies have suggested that chest computed tomography (CT) scans could be used as a primary screening or diagnostic tool for coronavirus disease 2019 (COVID-19) in epidemic areas.

Purpose

To perform a meta-analysis to evaluate diagnostic performance measures, including predictive values, of chest CT and initial reverse transcriptase-polymerase chain reaction (RT-PCR).

Materials and Methods

MEDLINE and Embase were searched from January 1, 2020 to April 3, 2020 for studies on COVID-19 that reported the sensitivity and/or specificity of CT scans and/or RT-PCR assays. The pooled sensitivity and specificity were estimated by using random-effects models. The actual prevalence (i.e., the proportion of confirmed patients among those tested) in eight countries was obtained from web sources, and the predictive values were calculated. Meta-regression was performed to reveal the effect of potential explanatory factors on the diagnostic performance measures.

Results

The pooled sensitivity was 94% (95% CI: 91%, 96%; I ² =95%) for chest CT and 89% (95% CI: 81%, 94%; I ² =90%) for RT-PCR. The pooled specificity was 37% (95% CI: 26%, 50%; I ² =83%) for chest CT. The prevalence of COVID-19 outside China ranged from 1.0% to 22.9%. For chest CT scans, the positive predictive value (PPV) ranged from 1.5% to 30.7%, and the negative predictive value (NPV) ranged from 95.4% to 99.8%. For RT-PCR,the PPV ranged from 47.3% to 96.4%, while the NPV ranged from 96.8% to 99.9%. The sensitivity of CT was affected by the distribution of disease severity, the proportion of patients with comorbidities, and the proportion of asymptomatic patients (all p < 0.05). The sensitivity of RT-PCR was negatively associated with the proportion of elderly patients ( p = 0.01).

Conclusion

Outside of China where there is a low-prevalence of COVID-19 (1-22.9%), chest CT screening of patients with suspected disease had low positive predictive value (1.5-30.7%).