Statistical analysis
All statistical analyses were fulfilled using IBM SPSS Statistics
software (Version 24) (IBM SPSS Statistics, Armonk, USA). The normality
of variables was established using the Kolmogorov- Smirnov test. To
compare variables with non-normal distribution, Mann–Whitney U test was
employed. The predictive value of serum D-dimer level was determined via
measuring the Area Under Receiver Operating Characteristic (AUROC)
curve. Finally, the optimal threshold value was obtained via the
calculation of Youden index. A p-value of less than 0.05 was regarded to
be statistically significant.