Quality assessment and statistical analysis

There is currently no accepted tool for evaluating the quality of cellular studies, as the included studies only calculate the pooled culture success with no control group. The adjusted Methodological Index for Non-Randomized Studies (MINORS) scale was applied to assess the quality of the included literature that comprised eight entries with a total of 16 points[20]. Funnel plots and Egger’s test were used to detect publication bias. Statistical significance was set at P < 0.05 (two-sided). STATA 17.0 software was used for the meta-analysis of the incidence of each outcome event. Heterogeneity among studies was estimated using the χ² test and I² statistics. If P was < 0.1 and I² was > 50%, heterogeneity was deemed to be present among the included studies, and the random effects model was used for combined analysis. Otherwise, a fixed effects model was used. An additional subgroup analysis according to sex, tissue source, differentiation type, pTNM stage, growth factors employed, and digestive enzymes used was conducted to probe the influencing factors.