Public health surveillance systems are crucial for monitoring disease prevalence and guiding intervention strategies in Tanzania. However, their effectiveness varies, necessitating methodological evaluation. A mixed-method approach including quantitative surveys and qualitative interviews was employed to assess the system's performance. Data were collected from to , covering 50% of Tanzania’s population. There was a significant improvement in patient outcomes (p < 0.05) associated with timely reporting through surveillance systems compared to baseline levels. The quasi-experimental design effectively revealed the impact of surveillance systems on clinical outcomes, offering insights for system enhancement and policy development. Future studies should consider expanding the sample size and incorporating longitudinal data collection methods. Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.