Results:
OF the total 106 COVID-19 patients who entered the study, 69 cases were discharged from the hospital alive while the other 37 cases died. The mean age of the patients was 58.99±15.94 years and 56.6% of them were male. Moreover, the patients’ average length of stay in hospital was 11.79±8.22 days. Based on the disease outcome, the patients were divided into two groups: the survived and the deceased (Table 1). The demographic information and comorbidities of each group of the patients are represented in Table 1.
The results showed a significant difference between the two groups in terms of D-dimer, LDH, PT, and INR levels. However, in terms of hemoglobin level and platelet count, the differences between the two groups were not found to be statistically significant. More specifically, serum D-dimer level, LDH, PT, and INR in the deceased patients were significantly higher than those of the surviving patients (Table 2).
In order to determine the relationship between mortality and the variables under investigation, binary logistic regression was applied on the data, the result of which are presented in Table 3 below. As can be seen, the results indicated that serum D-dimer level had a significant effect on predicting mortality in a way that for each unit of increase in D-dimer level, mortality risk increased by 0.99% (OR=0.994; 95%CI: 0.992-0.997). In order to determine the cutoff point of serum D-dimer level for the prediction of mortality, Receiver Operating Characteristic (ROC) curve was used. Figure 1 shows the related ROC curve. The area under the ROC curve was obtained to be 85% for D-dimer. Then, based on the figure, its cutoff point was determined to be 450 μg/dL with the sensitivity of 98% and specificity of 97%.