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%).