OTOR and COVID-19: Our results revealed that increased FDP (SMD 1.046 (0.371-1.722, P = 0.002, I2 = 88.9%) and decreased antithrombin (SMD -0.798 (-1.217-0.379), P<0.001, I2 = 72.2%) were associated with the worsening of COVID-19 (Table 2, Supplementary Figure 2).