Human umbilical cord blood-derived mesenchymal stem cell therapy in experimental spinal cord injury: A systematic review and meta-analysis

Figure 2 Forest plot of the primary meta-analysis evaluating the effect of human umbilical cord blood-derived mesenchymal stem cell transplantation on functional recovery in experimental spinal cord injury. The plot displays the standardized mean difference (SMD) with 95% confidence intervals for each of the six included studies (R1-R6). All outcomes have been harmonized to the convention that higher values indicate better functional recovery. The size of each square represents the weight of the study in the random-effects model, with larger squares indicating greater weight. Horizontal lines represent 95% confidence intervals for individual studies. The diamond represents the pooled SMD (2.35, 95% confidence interval: 0.89-3.80). Substantial heterogeneity was observed (I² = 81.8%, P < 0.001), indicating that while the average effect is positive, the true effect in a new study could range from possible harm to substantial benefit. The dashed vertical line at SMD = 0 indicates no effect. CI: Confidence interval; SMD: Standardized mean difference; hUCB-MSCs: Human umbilical cord blood-derived mesenchymal stem cells.