CAUSES OF DEATH AMONG MUSCOVITES BEFORE AND DURING THE COVID-19 PANDEMIC
A relatively low rate of mortality from COVID-19 in Russia sparked a debate on the completeness of registration of deaths from coronavirus infection. A multiple death cause analysis helps to reveal comorbidity of the virus and chronic diseases, mortality from which has markedly increased, serving the argument in this discussion. Purpose: to compare frequency of the leading causes of death in Moscow before and during the pandemic and to evaluate possible underestimation of mortality from coronavirus infection in major classes of diseases. Material and Methods. The authors have analyzed data from the Moscow integrated medical information and analysis system (EMIAS) on deaths from February to May 2020. The leading death causes were identified for two periods: February and March (period I) and April and May (period II) for major classes of diseases. The authors have compared the number of deaths from these causes. For diseases whose death rate significantly increased in the period II, association with SARS-COV-2 infection was evaluated. Also, the frequency of indication of these diseases as concomitant to COVID-19 was analysed. Analysis of associations of the virus with chronic diseases was carried out by calculating corresponding frequencies which were compared using the Chi-square criterion. Results. The number of deaths in April-May were 40.8% higher in males compared to February-March and 34.3% higher in females. The number of deaths from infectious diseases has increased to a greater extent (10.3 times in males and 12.7 times in females), deaths from diseases of the endocrine system (2.6 and 2.2 times, respectively), symptoms, signs and ill-defined conditions (by 64.7% and 70.7%) and deaths from diseases of the genitourinary system among males (by 64.7%). The number of deaths from neoplasms has decreased (by 5.2% and 5.7%) and deaths from injuries and poisoning (by 24.4% and 27.1%). Conclusions. The structure of death causes among Muscovites during the pandemic has changed due to both the increased mortality from diseases that were often associated with coronavirus infection and the increased share of deaths from infectious diseases. According to the results received, these include type 2 diabetes mellitus, obesity, chronic tubulointerstitial nephritis, polycystic kidney disease, chronic coronary heart disease, disease of cerebral vascular (I67.8), cerebral infarction, chronic obstructive pulmonary disease. Given the super-mortality from these diseases and the undetermined causes of death, the actual number of deaths from COVID-19 may double the number of confirmed cases. Presumably, the post-mortem examination of individuals with suspected coronavirus infection does not reveal all cases of infection.