Validation of Lung Ultrasound for Coronavirus Disease 2019 Prognostication in an International Multicenter Cohort Study

Background. Despite many studies evaluating lung ultrasound (LUS) for coronavirus disease 2019 (COVID-19) prognostication, the generalizability and utility across clinical settings are uncertain. Methods. Adults (≥18 years of age) with COVID-19 were enrolled at 2 military hospitals, an emergency department, home visits, and a homeless shelter in the United States, and in a referral hospital in Uganda. Participants had a 12-zone LUS scan performed at time of enrollment and clips were read off-site. The primary outcome was progression to higher level of care after the ultrasound scan. We calculated the cross-validated area under the curve for the validation cohort for individual LUS features. Results. We enrolled 191 participants with COVID-19 (57.9% female; median age, 45.0 years [interquartile range, 31.5- 58.0 years]). Nine participants clinically deteriorated. The top predictors of worsening disease in the validation cohort measured by cross-validated area under the curve were B-lines (0.88 [95% confidence interval {CI}, .87-.90]), discrete B-lines (0.87 [95% CI, .85-.88]), oxygen saturation (0.82 [95%, CI, .81-.84]), and A-lines (0.80 [95% CI, .78-.81]). Conclusions. In an international multisite point-of-care ultrasound cohort, LUS parameters had high discriminative accuracy. Ultrasound can be applied toward triage across a wide breadth of care settings during a pandemic.