Comparative analysis of mortality rates during the Covid 19 pandemic process

Background and Aim: The COVID-19 pandemic not only resulted in deaths directly attributable to the infectious agent but also led to an increase in indirect mortality due to restricted access to healthcare services and broader social and economic disruptions. This study aims to investigate monthly cause-specific mortality data between 2015 and 2021 for Turkey, Germany, Spain, South Korea, Japan, and Finland, with a particular emphasis on quantifying non-COVID-19 excess deaths during the 2020–2021 period and assessing the influence of pandemic-related policy measures on these mortality outcomes. Material and Methods: The study utilizes monthly mortality data categorized into seven major causes of death (based on ICD-10 classification) for six countries covering the years 2015–2021, along with annual population data, two policy indices from the Oxford COVID-19 Government Response Tracker (Stringency Index and Economic Support Index), and a newly constructed Health Index developed for this thesis. First, using data from the 2015–2019 period, linear regression models were constructed separately for each country and cause of death to estimate expected deaths for the years 2020–2021. Subsequently, excess mortality figures were calculated by comparing observed and expected values. These non-COVID-19 excess deaths were used as the dependent variable in a fixed effects panel data model, with the three policy indices serving as independent variables. Furthermore, country comparisons were conducted using excess deaths normalized by population. Results: Excess mortality by cause of death (total, COVID-19-related, non-COVID-19, and cumulative) exhibits notable cross-country differences. According to the model results, the effects of policy indices vary both across countries and by causes of death. The Health Index significantly reduced excess deaths related to respiratory and circulatory system diseases in some countries, while in others, it was associated with an increase. Although the Stringency Index occasionally demonstrated a mitigating effect, it generally showed a positive association with excess mortality. The impact of the Economic Support Index was generally limited, but its influence was more pronounced in certain countries. These findings indicate that the components of pandemic policy responses have heterogeneous effects depending on the national context and specific causes of death. Conclusion: The policy measures implemented in response to the COVID-19 pandemic have influenced not only the spread of infection but also indirect mortality. This study highlights the critical role of healthcare system capacity and policy design in shaping mortality outcomes during the pandemic. The disaggregated analysis of policy indices by specific causes of death offers valuable insights for developing more targeted strategies in future crisis scenarios. In this regard, the study provides an original contribution to the literature, both methodologically and empirically. Keywords: COVID-19, excess mortality, indirect mortality, policy indices