2.5. Statistical Analysis

Outcome measurements were analyzed in subgroups according to stem cell source or bone trabecula assessment methods. Because the included outcome measurements were continuous data, as well as unit differences, we used standard mean difference (SMD) and 95% confidence interval (CI) for the analysis. Heterogeneity of the included studies was assessed by I², which was considered as low, moderate, and high heterogeneity when the value of I² was 25%, 50%, and 75%, respectively [25]. The choice of the random effect model and fixed effect model is determined by I², and the former is executed when I² > 50% and P < 0.1. Otherwise, the latter is executed. Statistical analysis of all data was performed by using STATA software version 16.0 and RevMan 5.3 for Windows. In this meta-analysis, the results were considered statistically significant when P < 0.05.