Seasonal Mortality Patterns Analyzing Epidemiological Impact of COVID-19 on Overall Mortality Rates in Belgrade, Serbia Over Three-Year Period (2020–2023): Mental Health Consequences and Public Health Implications

<b>Background/Objectives</b>: Seasonal variations in mortality rates are well-documented, particularly during the winter months when mortality typically increases. This rise in mortality, ranging from 5% to 25%, is often associated with chronic cardiovascular and respiratory diseases. Understanding these seasonal fluctuations is essential for guiding public health interventions. This study analyzes mortality rates and excess mortality in Belgrade from March 2020 to May 2023, focusing on the impact of the COVID-19 pandemic on overall mortality trends. The primary objective of this study is to assess the impact of the COVID-19 pandemic on mortality rates in Belgrade during the study period. The first secondary objective is to evaluate seasonal variations in mortality, with a focus on the 10.57% overall increase in mortality, and to highlight the 34.23% rise in winter mortality recorded in 2020. The second secondary objective is to assess the effectiveness of public health measures in mitigating excess mortality during this period. <b>Methods</b>: A descriptive epidemiological approach was used to analyze monthly mortality data from the City Bureau of Statistics. Mortality rates were standardized using direct standardization and compared winter (December-February) and non-winter (March-November) periods. Trends, percentage increases, and age-specific mortality were analyzed based on the 2011 census methodology. <b>Results</b>: Mortality rates in Belgrade ranged from 1115.67 to 1267.19 deaths per 100,000 inhabitants, with an average of 1205.62. Standardized mortality rates ranged from 936.49 to 1111.67, averaging 1021.64. The winter months showed higher mortality, averaging 1716 deaths per 100,000, compared to 1558 in the non-winter months. <b>Conclusions</b>: The winter months exhibited significantly higher mortality rates, likely exacerbated by the COVID-19 pandemic. Targeted public health policies and interventions are necessary to reduce seasonal mortality risks during future public health crises.