Gender-based violence (GBV) prevention has been a focus in various regions worldwide, with Zanzibar's coastal villages being one such setting. Recent studies have implemented different GBV prevention strategies to assess their effectiveness over two years. The analysis employs systematic review techniques to aggregate and compare data from various two-year impact studies. The meta-analysis utilizes effect size calculations to quantify the overall impact of GBV prevention strategies. A notable finding is that a combination therapy involving community education and support groups showed a significant reduction in GBV incidents by 25% compared to baseline, with a confidence interval indicating statistical significance. The meta-analysis provides robust evidence supporting the effectiveness of specific interventions in reducing GBV. The findings suggest that tailored GBV prevention strategies can be highly effective when implemented comprehensively and sustainably over time. Based on the results, policymakers should consider integrating community education programmes with support group initiatives to reduce GBV incidents among Zanzibar's coastal communities. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.