Time-dependent changes in the clinical characteristics and prognosis of hospitalized COVID-19 patients in Wuhan, China: A retrospective study.

Cases of coronavirus disease 2019 (COVID-19) have been breaking out around the world recently. However, the dynamic changes in the clinical symptoms and prognosis of COVID-19 patients remain unknown. According to the onset time of initial clinical symptoms, 843 COVID-19 patients admitted between Jan 22 and Feb 14, 2020 were divided into three groups: group A (Jan 21 to Jan 25, n = 324), group B (Jan 26 to Jan 31, n = 358) and group C (Feb 1 to Feb 10, n = 161). Data on the demographics, symptoms, first laboratory results, treatments and outcomes (within 12 days of hospitalization) were collected. The results showed that the median duration from symptom onset to admission shortened over time (13, 10 and 5 days, respectively, p < 0.05). Fewer patients had fever symptoms and bilateral pneumonia in group C than in the group A and B. Laboratory results showed that white blood cell, neutrophil, and platelet counts, lactic acid and D-dimer levels were lower, while lymphocyte, CD3, and CD8 counts were higher in group C. In addition, group C had more mild-moderate cases and fewer severe cases than the other two groups. More importantly, the incidence of complications (18.5%, 14.2% and 11.2%, respectively, p < 0.05) and all-cause mortality (11.7%, 8.4%, and 5.6%, respectively, p < 0.05) decreased over time. The clinical characteristics and prognosis of COVID-19 patients changed over time. Improved prognosis was found at a later stage.