Network meta-analysis
The network graph illustrates that the most common comparison performed
in our network analysis was between DHCA and MHCA (Figure 5).
Differences found in the pairwise comparisons sustained their
significance in the network meta-analysis. The use of DHCA and MHCA were
associated with significantly higher operative mortality compared with
the use of mild HCA (OR, 1.71, 95% CI 1.23-2.39, P-value = 0.0014 and
OR, 1.50, 95%CI 1.12-2.00, P-value = 0.007, respectively). Utilization
of DHCA was associated with a higher incidence of postoperative stroke
compared with the use of MHCA (OR, 1.46, 95% CI, 1.19-1.78,
P-value<0.001) and mild HCA (OR, 1.50, 95% CI, 1.14-1.98,
P-value = 0.004).
No difference in the postoperative incidence of AKI was found between
the different hypothermia levels (Figure 5).
Indirect and direct estimates did not differ significantly, as it’s
shown in overlapping confidence intervals in netsplit plots (Figure 2,
3, 4). Differences between effect estimates based on direct versus
indirect evidence were not significant. Inconsistency was not
significant for operative mortality (p = 0.21), stroke (p = 0.55) and
AKI (p = 0.20). Quadratic net heat plots explored inconsistency of
indirect and direct comparisons in network meta-analysis (Supplementary
Material, Figures S1-S3). The net heat plot for outcome AKI showed
relatively higher inconsistency between the different comparisons
compared with other outcome measures (Supplementary Material, Figure
S3). Heterogeneity within direct estimates was low for all outcome
measures (I2 = 0-19.7%).