Age and chest radiography as possible parameters for rapid triage in COVID-19 outbreak surge (preprint)

ABSTRACT

BackgroundTo evaluate the utility of age and chest radiography(CXR) in triaging COVID-19 patients for hospitalization versus isolation in non-hospital facilities, we examined how age and CXR at diagnosis were associated with clinical needs from late-January to early-April. MethodsClinical status of all COVID-19 cases was monitored for national disease surveillance. Cases were isolated in hospitals until SARS-CoV-2 RNA was undetectable on PCR. Age and CXR results on admission were analysed for association with oxygen supplementation and mechanical ventilation, the outcomes of interest.ResultsTill 4 April 2020, there were 1,481 COVID-19 cases in Singapore. Overall, 11.4% required supplemental oxygen while 4.8% required mechanical ventilation and intensive care. The respective proportions increased to 40.9% and 16.5% for cases aged ≥70 years. As a predictor of subsequent mechanical ventilation, age had an area under the receiver operator characteristic curve(AUROC) of 0.772 (95%CI0.699-0.845). A combined criterion of either an abnormal CXR or age≥55 years had a sensitivity of 86.7% and specificity of 58.0% for the same outcome. A similar performance was observed for predicting oxygen supplementation needs.ConclusionsAge and CXR at diagnosis may be valuable in excluding severe disease, allowing safe triage for isolation in non-hospital facilities.