Figure 1 Flowchart of study design. Training cohort: From 17 January to 4 February 2020, 30 confirmed COVID-19 patients were enrolled from the COVID-19 ward of Qingdao Thorax Hospital, and 78 suspected patients (with SARS-CoV-2 testing negative) were enrolled from the fever clinic of Qingdao Municipal Hospital as controls. Validation cohort: From 4 February to 28 February 2020, 30 confirmed COVID-19 patients were enrolled from the COVID-19 ward of Qingdao Thorax Hospital, and 74 suspected patients (with SARS-CoV-2 testing negative) were enrolled from the fever clinic of Qingdao Municipal Hospital as controls. The variable coefficients in model A were integrated to obtain a simplified prediction model (model B). Consistency evaluation of model A and model B were verified in all subjects, including the training cohort and validation cohort. The ETLC prediction (E – epidemiological history; T – body temperature; L – leukocytes count; C – chest CT) scoring was established according to this simplified prediction model (model B).