Statistical analysis

We used Stata17 for statistical analysis. Odds ratio (OR) and their 95% confidence interval (CI) were used to represent the effects of the statistical analysis. Heterogeneity between the studies was evaluated using I² values. An I² value of ≤ 50% indicated low heterogeneity, prompting the selection of a fixed effect model for statistical aggregation. Otherwise, indicated high heterogeneity, prompting the selection of a random effect model for statistical aggregation. The sensitivities of the results were evaluated by transforming the two analysis models. The Egger’s test was used to analyze publication bias for risk factors with more than nine articles. The stability of the results for risk factors with publication bias was evaluated using the clipping method. Statistical significance was set at P < 0.05.