Analysis of Symptom Spectra and Associated Factors Among 536 Respondents During the COVID-19 Epidemic in China: A Cross-Sectional Study

Abstract

Purpose

This study aims to identify common COVID-19 symptoms and asymptomatic infection rates during the epidemic in China. We also introduce the concepts of “Time-point asymptomatic rate” and “Period asymptomatic rate”.

Object and Methods

A questionnaire survey was conducted online from December 2022 to January 5, 2023, collecting demographic characteristics, laboratory results, clinical symptoms, lifestyle and vaccination history. Statistical methods were used to analyze symptom characteristics, associated factors, and patterns during an 8-day observation period. Numerical variables were described by median M (Q1-Q3) or mean and standard deviation (). Categorical variables are described by frequency (N), ratio (%) or rate (%). The influencing factors were studied by Wilcoxon or Kruskal-Willis H rank sum test or logistic regression analysis, and the trend of symptom incidence by Spearman rank correlation. P value being ≤0.05 was statistically significant.

Results

Out of 536 participants, 493 (91.98%) were infected, with 3 asymptomatic cases and 490 symptomatic cases within 8 days. The time-point asymptomatic rate increased from 0.61% on day 1 to 15.42% on day 8. Fever, cough, and fatigue were the main symptoms, with additional symptoms such as vomiting, diarrhea, and hyposmia reported. Symptom durations varied, with cough and expectoration lasting longer and vomiting and diarrhea lasting shorter. Several symptoms showed a downward trend over time.

Conclusion

Our online survey highlighted that most COVID-19 patients experienced symptoms, and the time-point asymptomatic rate showed a dynamic change among the infected population. Onset patterns and demographic factors influence symptom occurrence and duration. These findings have implications for clinical practitioners and decision-makers in public health measures and strategies.

Keywords:

• Novel coronavirus infection
• onset patterns
• clinical features
• associated factors
• time-point asymptomatic
• period asymptomatic rate

Data Sharing Statement

The datasets analyzed during the current study are available from the corresponding author upon reasonable request.

Ethics Approval and Informed Consent

The present study was conducted after the approval of the institutional review board of the Medicine School of Jinan University and adhered to the guidelines outlined in the Declaration of Helsinki. All patient data were anonymized.

Acknowledgments

The authors would like to thank Dr Zhiyong Hong at Public Health Agency of Canada, Professor Qingshan Chen and Associate Professor Dalin Lu at Department of Epidemiology of Medicine School of Jinan University for their technical support and guidance. In particular, the concepts of “Time-point asymptomatic rate” and “Period asymptomatic rate” first proposed by Professor Qingshan Chen are the innovation and motivation of this study.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.

Additional information

Funding

This study was supported by the Key-Area Research and Development Program of Guangdong Province (No. 2019B111103001) and the National Natural Science Foundation of China (grant number: 82003522).