Dynamics of Regional Mortality Rates From Cardiac Causes in Russia 2019–2020

Aim      To analyze the dynamics of standardized mortality ratios (SMR) (2019–2020) for the cardiological causes indicated as the primary (original) cause of death, in regions of the Russian Federation, based on the RF State Statistics Service Brief Nomenclature of Causes of Death (RFSSS BNCD). Reports have indicated substantial changes in the indexes and structure of mortality since the beginning of the COVID-19 pandemic in many countries.

Material and methods  RFSSS data on numbers of deaths were analyzed according to BNCD and mid-year population in single year of age groups in 2019 and 2020. SMRs were determined for 23 cardiological causes of death listed in the BNSD in a separate line; the average regional SMR value and the standard deviation were provided; and SMRs were compared both among 4 groups (with a previously described method) and by 23 RFSSS BNCD causes using the Wilcoxon test.

Results In 2020 vs. 2019, the mean regional SMR for cardiological causes increased by 12.07±9.86 % (from 301.02±77.67 to 336.15±84.5 %; р<0.0001). Decreases in SMR were found in 9 of 82 regions; however, only in two of them (the Republic of Ingushetia and the Sakhalin Region), SMR was decreased for all 4 groups of causes. In both 2019 and 2020 (60.9±13.8 and 62.5±12.8 %, respectively), the highest proportion of deaths was related with the 1^st group of causes (chronic ischemic heart disease, IHD), with an increase in SMR of 18.66±33.28 % (р<0.0001). Increases in SMR were found in 75 regions while in the other regions, decreases in SMRs were observed. For the 2^nd group of causes (myocardial infarction, other acute forms of IHD, sudden cardiac death), the mean regional SMR increased in 2020 by 3.2±18.1 % (р=0.3). Increased SMRs were noted in 54 regions. The proportion of the 2^nd group in cardiological mortality was 17.3±9.7 % in 2019 and 16.1±9.6 % in 2020. The mean regional SNR for the 3^rd group of causes (heart defects, myocardial diseases, etc.) increased in 2020 by 11.6±23.1 % (р=0.006). The mean regional proportion of causes for this group did not significantly changed compared to 2019 (17.5±8.2 and 17.1±7.3 %, respectively); however, the contribution of this group was greater than the contribution of the 2^nd group. Increases in SMR were observed in 65 regions, while the contribution of causes related with arterial hypertension did not significantly change. Significant mid-regional differences in SMR values, dynamics of SMRs for different causes, and increases in the coefficient of variation were noted for almost all causes of death. Significant differences between 2019 and 2020 were found for 3 of 23 causes: other forms of chronic IHD (decreased SMRs in 15 regions and increased SMRs in the others), atherosclerotic heart disease (decreased SMRs in 38 regions), and alcoholic cardiomyopathy (decreased SMRs in 28 regions).

Conclusion      During the COVID-19 pandemic, the SMR for cardiological causes was increased. Considerable regional differences in values and dynamics of SMR for individual causes call for attention to the unification of the criteria for clinical diagnosis.

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