Meta-regression
In univariable meta-regression analysis, there was no significant
association between the hypothermic circulatory arrest time and the
reoperation for bleeding (β-coefficient 0.007 [95% CI -0.004 to
0.0019], z-value = 1.26, p = 0.207). In addition, the bubble plot
demonstrated that the effect size of reoperation for postoperative
bleeding enhanced with increasing the duration of hypothermic
circulatory arrest time; however, the regression line did not show a
good fit of the data because most studies were relatively far to it
(Figure 8).
Multivariable meta-regression analysis showed that age and male gender
significantly impacted on the reoperation for postoperative bleeding
(Table 3).