OBJECTIVE
To identify the leading causes of in-hospital deaths of persons aged 18 years and older in 2019 and 2022 according to medical certificates of cause of death and to discuss the problems of their assessment.
MATERIALS AND METHODS
The source of information was anonymized personal data on deaths of persons aged 18 years and older obtained from the electronic database of the Main Directorate of the Civil Registry Office of the Moscow Region for 2019 and 2022 (2020 and 2021 were not included in the study due to the COVID-19 pandemic), and the average annual population (Rosstat data). The primary or underlying cause-of-death (UCD) by ICD-10 classes were analyzed to determine the proportion of each ICD-10 class and in-hospital mortality (IHM) per 100.000 population over 18. Then, six disease classes, the proportion of which did not exceed 1% and class S00-T98 (external causes of death), were excluded from the analysis, and deaths from individual causes were analyzed.
RESULTS
The proportion of in-patient deaths was 37% in 2019 and 43.2% in 2022 of all deaths. IHM from all causes increased by 17% (due to COVID-19). In 2022, compared to 2019, the IHM decreased in 5 classes and increased in 7 classes. The increase (decrease) of IHM from individual causes (by ICD codes) varied from hundredths of a percent to a dozen percent. Class IX (circulatory diseases) ranked first for the IHM causes (258 cases per 100.000 people in 2019 and 219 cases per 100.000 people in 2022; 48.5% and 35.3% of in-hospital deaths). The second most common UCD s in 2019 were class II (neoplasms; 16.1%, 85.1 per 100.000 people), and in 2022, class XXII (COVID-19; 109.9 per 100.000 people, or 17.7%). Digestive system diseases were ranked third in 2019 and fourth in 2022. In total, 1.359 ICD-10 codes were included in the UCD analysis, of which 25% belonged to the class of neoplasms. The leading causes of IHM were reported both based on ICD-10 codes and the usual names of diseases for clinicians. The highest rates of IHM in 2019 and 2022 were reported for stoke (96.4 and 74.9 per 100.000 people), malignant neoplasms (C00-C97: 82.9 and 82.1 per 100.000 people), chronic forms of coronary heart disease (81.1 and 74.3 per 100.000 people), myocardial infarction (25.8 and 20.9 per 100.000 people) and diabetes mellitus (18.6 and 25.5 per 100.000 people). These five causes (30% of the ICD-10 codes used) totaled 57.6% in 2019 and 54.3% (excluding COVID-19-related deaths) in 2022 of the IHM. Many ICD terms have no clinical equivalents, which is why, probably, the proportion of deaths with codes «.8» or «.9» meaning «other specified» (form of the disease) or «other unspecified» (form of the disease) was 19%.
CONCLUSION
Analysis of in-hospital mortality by primary causes of death and ICD-10 classes is insufficient to optimize medical care and reduce mortality. For all ICD-10 codes specified in Part I and II, analysis is impossible without software and expert consensus on causes of death grouping.
