Public health surveillance systems are crucial for monitoring disease prevalence and guiding intervention strategies in Uganda. However, their effectiveness can vary significantly among different regions or over time. A comprehensive search strategy was employed to identify relevant studies. Studies were appraised using predefined inclusion criteria, including methodological rigor and applicability of DiD model. The analysis revealed that while some systems showed significant improvements in surveillance accuracy (e.g., a 25% reduction in reporting errors), others exhibited no discernible changes, highlighting the need for more robust validation procedures. This review underscores the importance of rigorous methodological approaches to ensure consistent and reliable public health surveillance outcomes in Uganda. Future research should prioritise cross-validation techniques and continuous quality improvements to enhance system performance. Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.