RCTs and PSM studies sensitivity analysis
Two RCTs and seven PSM studies included 5425 patients. Baseline characteristics of the included studies are detailed in Supplementary Table 5.
The network graph is displayed in Supplementary Figure S4. Combining strictly RCTs and PSM studies resulted in sustained significant higher risk of operative mortality for MHCA when compared with mild HCA (OR, 1.45, 95% CI, 1.05-2.00, P-value = 0.029) (Supplementary Figure S5). Furthermore, sensitivity analysis confirmed significant higher risk of postoperative stroke for DHCA when compared with MHCA and mild HCA (OR, 1.61, 95% CI, 1.18-2.20, P-value = 0.0029 and OR, 1.74, 95% CI, 1.09-2.77, P-value = 0.019) (Figure 6). No difference in postoperative AKI among different levels of hypothermia was found (Supplementary Figure S6). Indirect and direct estimates did not differ significantly, with low inconsistency (Figure 6, Supplementary Figure S5, S6). Differences between effect estimates based on direct evidence were not significant. Heterogeneity/inconsistency were not significant for operative mortality(p = 0.72), stroke (p = 0.47) and AKI (p = 0.45). Quadratic net heat plots for outcomes postoperative stroke and mortality are presented in Supplementary Material, Figure S7 and S8. Heterogeneity was low for all outcome measures (I2 = 0%).