Public health surveillance systems in Nigeria face challenges in methodological rigor and cost-effectiveness evaluation. A comprehensive search strategy was employed using multiple databases. Studies were screened based on predefined inclusion and exclusion criteria. The analysis revealed that while most studies adhered to standard methodologies, there is a significant variation in the application of quantitative data analysis techniques such as regression models (e.g., $y = β_0 + β_1x + ε$). Findings suggest that improvements are needed in the consistency and depth of cost-effectiveness evaluations. Enhanced methodological frameworks should be developed to ensure uniformity in data analysis across studies, thereby improving the reliability of cost-effectiveness assessments.