Statistical Analysis
We used R version 4.3.0 for performing the statistical analysis. I2 and χ2 statistics were applied for assessing the heterogeneity of the studies and the significance level for heterogeneity between the studies was considered I2 > 50% and P value <0.1. We used a random effect model so as to compute Pooled Hazard Ratio with 95% confidence interval and the Inverse Variance method was applied to weight the studies. The researchers also used funnel plot and Eggers’ test to check the publication bias in the studies and the asymmetric funnel plot was considered as a possible publication bias. Sensitivity analysis was utilized to examine the heterogeneity source between the records. The significance level in this study was considered < 0.05.
Figure 1. PRISMA flow diagram illustrating the process of selection studies in the meta-analysis