Validation of reported risk factors for disease classification and prognosis in COVID-19: a descriptive and retrospective study

Li Tan; Xia Kang; Xinran Ji; Qi Wang; Yongsheng li; Qiongshu Wang; Hongming Miao

The copyright holder for this preprint . https://doi.org/10.1101/2020.04.05.20053769 doi: medRxiv preprint 6 To investigate the mortality-associated risk factors, COVID-19 patients were classified into cured and died groups (Table S1 ). The serum levels of CRP, PCT, IL-6, percentage of lymphocytes (LYM%), lactic acid and Ct values of viral tests were measured dynamically. The levels of CRP in peripheral blood increased quickly after the symptom onset and further increased to the end around 4 weeks later in the dead cases, while the levels of CRP in survivors fluctuated very little (Fig. 1A) . Similar trend was obtained for the PCT level, although it just began to increase 25 days after disease onset (Fig. 1B) . The blood IL-6 levels in dead cases increased rapidly in the early phase and rose to an extraordinary level before death (Fig. 1C) . In contrast, after the symptom onset, the LYM% in dead cases deceased quickly and sustained in a low level (Fig. 1D ). For the levels of blood lactic acid, there was a narrow time window in which we could distinguish the died and cured groups (Fig. 1E) . From 8 days after disease onset, the pre-died patients had an obviously higher levels of viral load indicated by ORF1ab Ct values than the survivors did (Fig. 1F ).