Retrospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jan 16, 2021; 9(2): 344-356
Published online Jan 16, 2021. doi: 10.12998/wjcc.v9.i2.344
Risk factors associated with acute respiratory distress syndrome in COVID-19 patients outside Wuhan: A double-center retrospective cohort study of 197 cases in Hunan, China
Xing-Sheng Hu, Chun-Hong Hu, Ping Zhong, Ya-Jing Wen, Xiang-Yu Chen
Xing-Sheng Hu, Chun-Hong Hu, Department of Oncology, the Second Xiangya Hospital of Central South University, Changsha 410011, Hunan Province, China
Ping Zhong, Department of Dermatology, Nanchong Central Hospital, Nanchong 637000, Sichuan Province, China
Ya-Jing Wen, Department of Clinical Medicine, Chengdu Medical College, Chengdu 610000, Sichuan Province, China
Xiang-Yu Chen, Department of Radiology, the Second Xiangya Hospital of Central South University, Changsha 410011, Hunan Province, China
Author contributions: Hu XS designed the study, acquired and analyzed the data, and wrote the paper; Hu CH designed the research and contributed to the data analysis; Zhong P and Wen YJ contributed to the analysis and interpretation of the data, and drafted the article; Chen XY designed the research, revised the paper, and supervised the report; All authors made critical revisions related to important intellectual content of the manuscript and gave final approval of the version of the article to be published.
Supported by The Natural Science Foundation of Hunan Province, No. 2019JJ40435.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the Second Xiangya Hospital of Central south university (2020-017).
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent. Written informed consent was waived by the Ethics Committee of the designated hospital.
Conflict-of-interest statement: We have no financial relationships to disclose.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Xiang-Yu Chen, MD, Associate Professor, Department of Radiology, the Second Xiangya Hospital of Central South University, No. 139 Renmin Road Central, Changsha 410011, Hunan Province, China.
Received: October 16, 2020
Peer-review started: October 16, 2020
First decision: October 27, 2020
Revised: October 30, 2020
Accepted: November 12, 2020
Article in press: November 12, 2020
Published online: January 16, 2021

There have been few reports on the risk factors for acute respiratory distress syndrome (ARDS) in coronavirus disease 2019 (COVID-19), and there were obvious differences regarding the incidence of ADRS between Wuhan and outside Wuhan in China.


To investigate the risk factors associated with ARDS in COVID-19, and compare the characteristics of ARDS between Wuhan and outside Wuhan in China.


Patients were enrolled from two medical centers in Hunan Province. A total of 197 patients with confirmed COVID-19, who had either been discharged or had died by March 15, 2020, were included in this study. We retrospectively collected the patients’ clinical data, and the factors associated with ARDS were compared by the χ² test, Fisher’s exact test, and Mann-Whitney U test. Significant variables were chosen for the univariate and multivariate logistic regression analyses. In addition, literature in the PubMed database was reviewed, and the characteristics of ARDS, mortality, and biomarkers of COVID-19 severity were compared between Wuhan and outside Wuhan in China.


Compared with the non-ARDS group, patients in the ARDS group were significantly older, had more coexisting diseases, dyspnea, higher D-dimer, lactate dehydrogenase (LDH), and C-reactive protein. In univariate logistic analysis, risk factors associated with the development of ARDS included older age [odds ratio (OR) = 1.04), coexisting diseases (OR = 3.94), dyspnea (OR = 17.82), dry/moist rales (OR = 9.06), consolidative/mixed opacities (OR = 2.93), lymphocytes (OR = 0.68 for high lymphocytes compared to low lymphocytes), D-dimer (OR = 1.41), albumin (OR = 0.69 for high albumin compared to low albumin), alanine aminotransferase (OR = 1.03), aspartate aminotransferase (OR = 1.02), LDH (OR = 1.02), C-reactive protein (OR = 1.04) and procalcitonin (OR = 17.01). In logistic multivariate analysis, dyspnea (adjusted OR = 27.10), dry/moist rales (adjusted OR = 9.46), and higher LDH (adjusted OR = 1.02) were independent risk factors. The literature review showed that patients in Wuhan had a higher incidence of ARDS, higher mortality rate, and higher levels of biomarkers associated with COVID-19 severity than those outside Wuhan in China.


Dyspnea, dry/moist rales and higher LDH are independent risk factors for ARDS in COVID-19. The incidence of ARDS in Wuhan seems to be overestimated compared with outside Wuhan in China.

Keywords: Acute respiratory distress syndrome, COVID-19, Risk factor, Mortality, Severity, Dyspnea

Core Tip: Some of the risk factors associated with the incidence of acute respiratory distress syndrome in coronavirus disease 2019 include older age, coexisting diseases, dyspnea, dry/moist rales, consolidative/mixed opacities, lower lymphocytes/albumin, higher D-dimer, alanine aminotransferase/aspartate aminotransferase, lactate dehydrogenase, C-reactive protein, and procalcitonin. Logistic multivariate analysis showed that dyspnea, dry/moist rales, and higher lactate dehydrogenase were three independent risk factors. The incidence of acute respiratory distress syndrome in coronavirus disease 2019 was higher in Wuhan than outside Wuhan in China, which may be due to a lack of sufficient medical resources in the early period of the epidemic in Wuhan.