Statistics

Pearson’s correlation coefficient was used to analyze the correlation between multiple SARS-CoV-2 antibody tests and clinical features. The degree of correlation was weak for values belonging to the range 0.10 ≤ r <0.30, moderate for values of 0.30 ≤ r <0.50, and strong correlation for r ≥ 0.50, as previously guided [9]. The Mann-Whitney U test was conducted to evaluate the statistical significance of the difference in clinical aspects according to the SARS-CoV-2 IgG S/CO value. Statistical analyses were performed using SPSS version 24 (IBM Corporation, New York, NY) and MedCalc version 18 (MedCalc Software, Mariakerke, Belgium).