Interobserver Agreement of Lung Ultrasound Findings of COVID-19

Abstract

Background: Lung ultrasound (LUS) has received considerable interest in the clinical evaluation of patients with COVID-19. Previously described LUS manifestations for COVID-19 include B-lines, consolidations, and pleural thickening. The interrater reliability (IRR) of these findings for COVID-19 is unknown.Methods: This study was conducted at conducted at two academic medical centers between 03/2020-06/2020. Nine physicians (hospitalists: n=4; emergency medicine: n=5) independently evaluated n=20 LUS scans (n=180 independent observations) collected from RT-PCR confirmed COVID-19 patients. These studies were randomly selected from an image database consisting of COVID-19 patients evaluated in the emergency department with portable ultrasound devices. Physicians were blinded to any patient information or previous LUS interpretation. Kappa values (κ) were used to calculate IRR.Findings: There was substantial IRR on the following items: normal LUS scan (κ=0.79 [95% CI: 0.72-0.87]), presence of B-lines (κ=0.79 [95% CI: 0.72-0.87]), >=3 B-lines observed (κ=0.72 [95% CI: 0.64-0.79]). Moderate IRR was observed for the presence of any consolidation (κ=0.57 [95% CI: 0.50-0.64]), subpleural consolidation (κ=0.49 [95% CI: 0.42-0.56]), and presence of effusion (κ=0.49 [95% CI: 0.41-0.56]). Fair IRR was observed for pleural thickening (κ=0.23 [95% CI: 0.15-0.30]).Interpretation: Many LUS manifestations for COVID-19 appear to have moderate to substantial IRR across providers from multiple specialties utilizing differing portable devices.Trial Registration: This analysis was conducted as part of an ongoing study investigating the role of POCUS for COVID-19 that is being conducted at four medical centers in the United States (Clinicaltrials.gov Registration: NCT04384055). Funding Statement: None.Declaration of Interests: Andre Kumar, MD, MEd is a paid consultant for Vave Health, which manufactures one of the ultrasound devices used in this study. His consultant duties include providing feedback on product development. The other authors do not have any items to disclose.Ethics Approval Statement: This study has received institutional review board (IRB) approval at all participating sites.