In-hospital mortality in COVID-19 vs. pre-COVID-19 era in the Split-Dalmatia County, Croatia

Abstract Background The COVID-19 pandemic marked 2020 with numerous consequences for the health of the population. Therefore, this study aimed to explore whether the COVID-19 pandemic affected in-hospital mortality. Methods We employed a cross-sectional comparative study using two different time periods, pre-COVID-19 (2019 year) and COVID-19 era (2020 year) to explore possibilities of COVID-19 influences in-hospital mortality in Split-Dalmatia County, Croatia. The research used data from the national information system on hospitalizations from the Clinical Hospital Center Split, University Hospital Split. The indicators were statistically analyzed. The z-score test for two population proportions is used. Results In 2020, there was a significantly higher in-hospital mortality compared to 2019 (z = 9.0827; p < 0.00001), which was supported by a significant increase in mortality from respiratory diseases according to the comparison of disease categories of International Statistical Classification of Diseases and Related Health Problems (ICD-10) (z = 9.0427; p < 0.00001). Within hospital departments, significantly higher mortality was in the Intensive Care Unit (z = 5.2763; p < 0.00001) and the Infectious Diseases Department (z = 9.6982; p < 0.00001). Among deaths in 2020 with confirmed COVID-19, there were significantly more positive among deaths from respiratory diseases (z=-17.4462; p < 0.00001). There was no difference in mortality rates between 2020 and 2019 by age. Conclusions The results of the study indicate that COVID-19 has a contribution to hospital mortality. Given that the pandemic has not yet completed additional research, it will be necessary to obtain a more complete picture of the impact of COVID-19 on hospital mortality in Split-Dalmatia County, as well as in other regions and countries. Key messages The results of the study indicate that COVID-19 has a contribution to hospital mortality. Given that the pandemic has not yet completed additional research, it will be necessary to obtain a more complete picture of the impact of COVID-19 on hospital mortality.