Exploration on the influencing factors and establishment of a risk model for the time of virus turning negative of asymptomatic or mild Covid-19 (preprint)

Background: Patients are allowed to be released from quarantine after virus turns negative for asymptomatic or mild covid-19. Factors affecting the negative conversion of nucleic acid are unknown. Methods. This study included asymptomatic or mild covid-19 patients quarantined in Shanghai shelter hospital from April to May 2022. They were tested daily for SARS-CoV-2 nucleic acid. The clinical characteristics were collected. Univariate and multivariate Cox regression were used to explore the relationship between clinical characteristics and the time of virus turning negative (TTN), finally a risk model was established. Results. A total of 7836 patients enrolled were divided into training or validation set randomly. In training set, age (≥40 Y), symptoms (yes) , diabetes (yes) and vaccination status(yes) were correlated with TTN. We used HR values of the above factors in multivariate Cox regression as risk coefficients to build a risk model for predicting TTN. TTN of patients with high risk score was longer than with low risk score. This risk model has been well validated in the validation set and the complete set. Conclusions. Our study found that age, symptoms, diabetes and vaccination status were correlated with the TTN,and we first build a risk model to predict TTN in asymptomatic or mild Covid-19.

Clinical characteristics and risk factors for severe-critically ill COVID-19 adult patients in Jiangsu, China: a multiple-centered, retrospective study (preprint)

Background A number of reports have documented the clinical characteristics of patients with severe coronavirus disease 2019 (COVID-19) in Wuhan. Clinical features of severe-critically ill COVID-19 patients in Jiangsu, outside Wuhan, remains unknown. Methods This multi-centered retrospective study collected the information of 631 laboratory-confirmed COVID-19 patients hospitalized at 28 authorized hospitals in Jiangsu province between January 23, 2019 and March 13, 2020. Epidemiological and demographic information, clinical and radiological characteristics, laboratory results and treatment of these patients were analyzed. Results A total of 583 adult patients with laboratory-confirmed COVID-19 were enrolled for final analysis, including 84 severe-critically ill patients and 499 mild-moderate patients. Median age of the severe-critically ill patients was 57.0 years [interquartile range (IQR), 49.0-65.8], and 50 (59.5%) were males. Multisystemic laboratory abnormalities were observed on admission in severe-critically ill patients. The severe-critically ill patients showed more noticeable radiologic abnormalities and more coexisting health issues as compared to mild-moderate patients. Most of the severe-critically ill COVID-19 patients become deteriorated in two weeks after diagnosis. Age [odds ratio (OR) 1.08, 95% confidence interval (CI) (1.03-1.14)], D-dimer (OR 3.21, 95% CI 1.39-7.40), and lymphocytes (OR 0.28, 95% CI 0.04-0.88) were independently associated with the progression of severe-critically illness. Conclusions Older age, higher D-dimer levels and less lymphocyte counts on admission are potential risk factors for COVID-19 patients to develop into severe and critically illness. The results would help clinicians to identify high-risk patients in advance.