Dementia poses a significant public health challenge worldwide, necessitating a deeper understanding of its risk factors to inform preventive strategies. This retrospective longitudinal study leveraged clinical data from a tertiary care database to investigate the risk factors associated with an incident dementia diagnosis. The study cohort comprised individuals aged 50 years and older. Key variables including age, income, comorbidities such as depressive disorder, osteoporosis, stroke, and metabolic conditions like type 2 diabetes and hypertension were analyzed by using Cox regression analysis. The study cohort included 127,016 adults 50 years and older. The results revealed that advancing age, with individuals aged 70-79 years having ahazard ratio (HR) of 3.9 (95% confidence interval (CI), 2.6-5.8), and those aged 80 years and above having an HR of 11.6 (95% CI, 7.7-17.3), lower income status (patients with no income or occupation had a notably higher risk of dementia diagnosis, with an HR of 2.0 (95% CI, 1.4-2.8)), depressive disorder (HR of 3.3 (95% CI, 3.3-3.7)), osteoporosis (HR of 1.2 (95% CI, 1.1-1.4)), and stroke (HR of 2.5 (95% CI, 2.3-2.7)) were significantly associated with an increased risk of incident dementia. However, no significant associations were observed for type 2 diabetes, hypertension, obesity, or underweight status managed in tertiary care. The findings underscore the importance of considering a wide range of factors in understanding dementia risk and highlight the potential utility of routinely collected clinical data for comprehensive risk assessment. Further investigation into additional variables and multi-center studies may provide deeper insights into the complex interplay of risk factors contributing to dementia onset.