SEASONAL AND MONTHLY CHANGES OF MORTALITY IN RUSSIAN FEDERATION REGIONS WITH DIFFERENT CLIMATE AND GEOGRAPHIC VARIABLES

The mortality general and cardiovascular (CVD) are not the same during the year, as there are seasonal and monthly specifics which are actively studied in European countries.
Aim. To study excessive mortality during winter from all causes and CVD in RF regions with different climate and geographic characteristics comparing to European data and to analyze monthly mortality levels.
Material and methods. To compare and evaluate the dynamics of excessive winter period mortality in three RF regions: Ivanovskaya, Saratovskaya and Arkhangelskaya regions and to compare with excessive mortality in European countries the calculation performed of the index of excessive mortality during the winter (EMDW). The latter was calculated according to the mortality from all causes and from cardiovascular diseases separately. Calculations for every 12 months included December of the previous year and January-February of the next year. To measure monthly values the mean range of the month was calculated by the absolute quantity of deaths by the period analyzed — absolute mortality rates from all causes and from CVD by every year ranged from 1 to 12 and then the mean value of the range for every month was evaluated.
Results. Mean 8-year EMDW in analyzed regions was from 3,5% in Saratovskaya to 6,5% in Ivanovskaya regions; EMDW for CVD was higher than 10% and maximum in Saratovskaya region (14,3%). Mean EMDW in the regions analyzed of RF was significantly lower (p<0,05), than in Europe and significantly lower than in Southern Europe. Reasons for lower EMDW in the regions studied the inhabitants’ adaptation to low temperatures during the winter, inferior part of senile folks in Russia that is more sensitive to winter time lower temperatures and due to central rooms heating. In analysis of monthly mortality rates the leader by the deaths prevalence was January, on the second place was march, which was similar by all causes and by CVD in Ivanovskaya and Saratovskaya regions and slightly differed in Arkhangelskaya region, where on the second place was February. The third by the all cases was may. In Ivanovskaya and Saratovskaya regions median ranges of the third by deaths month from all cases and from CVD were the same, and in Arkhangelskaya they differed. Maximum range value and hence the lowest mortality rate was in July-September.

Conclusion. Excessive mortality in winter, measured by EMDW, is 3,5-6,5% by any cause and 12,0-14,0% — by CVD. Until now there is no clear understanding of the mechanisms and determinants for this, however during the XXth century the prominence of this has lowered much. Among the contributions to this loweringduring the winter are good central room heating and immunization against viral infections of the risk groups. Further studies required to analyze regional specifics of excessive mortality during the winter and monthly.

1. Fowler T, Southgate RJ, Waite T et al. Excess Winter Deaths in Europe: A multi-country descriptive analysis. Eur J Public Health 2014; 11, pii: cku073.

2. Mercer JB Cold — an underrated risk factor for health. Environmental Research 2003; 92:8-13.

3. Boytsov SA, Lukyanov MM, Kontsevaya AV, et al. Features of seasonal cardiovascular mortality in winter in Russian regions with different climatic and geographical characteristics. J. Rational Pharmacotherapy in Cardiology. 2013; 9(6): 627-32. Russian (Бойцов С. А., Лукьянов М. М., Концевая А. В. и соавт. Особенности сезонной смертности населения от болезней системы кровообращения в зимний период в регионах Российской Федерации с различными климато-географическими характеристиками. Рациональная фармакотерапия в кардиологии 2013; 9(6): 627-32).

4. Healy JD. Excess winter mortality in Europe: a cross country analysis identifying key risk factors. J Epidemiol Commun Health 2003; 57: 784-9.

5. Falagas ME, Karageorgopoulos DE, Moraitis LI, et al. Seasonality of mortality: the September phenomenon in Mediterranean countries. CMAJ 2009; DOI:10.1503/ cmaj. 090694.

6. Unified Interdepartmental Statistical Information System (UniSIS) 2014, http://www. fedstat.ru/indicators/start.do. Russian (Единая межведомственная информационно – статистическая система (ЕМИСС), дата выгрузки данных март 2014). http://www. fedstat.ru/indicators/start.do).

7. Eurowinter Group. Cold exposure and winter mortality from ischaemic heart disease, cerebrovascular disease, respiratory disease, and all causes in warm and cold regions of Europe. Lancet 1997; 349: 1341-6.

8. Analitis A, Katsouyanni K, Biggeri A, et al. Effects of Cold Weather on Mortality: Results From 15 European Cities Within the PHEWE Project. American Journal of Epidemiology 2008; 168, 12: 1397-408.

9. Hopstock LA, Wilsgaard T. Seasonal variation in incidence of acute myocardial infarction in a sub-Arctic population: the Tromsø Study 1974-2004. Eur J Cardiovasc Prev Rehabil 2011; Apr;18(2):320-5. doi: 10.1097/HJR.0b013e32833c7c28.

10. Eng H, Mercer JB. Mortality from cardiovascular diseases and its relationship to air temperature during the winter months in Dublin and Oslo/Akershus. Int J Circumpolar Health 2000; 59:176-81.

11. Environmental burden of disease associated with inadequate housing. A method guide to the quantification of health effects of selected housing risks in the WHO European Region. World Health Organization 2011.

12. Marti-Soler Н, Gubelmann С, Aeschbacher S et al. Seasonality of cardiovascular risk factors: an analysis including over 230 000 participants in 15 countries. Heart 2014;100:1517-23 doi:10.1136/heartjnl-2014-305623.

13. Hajat S, Kovats RS, Lachowycz K (2007). Heat-related and cold-related deaths in England and Wales: who is at risk? Occupational and Environmental Medicine, 64: 93-100.

14. Rudge J (1996). British weather: conversation topic or serious health risk? International Journal of Biometeorology, 39: 151-5.

15. Tanner LM, Moffatt S, Milne E et al. Socioeconomic and behavioural risk factors for adverse winter health and social outcomes in economically developed countries: a systematic review of quantitative observational studies. J Epidemiol Community Health 2013; 67:1061-7 doi:10.1136/jech-2013-202693.

16. Carson C, Hajat S, Armstrong B, et al. Declining vulnerability to temperature related mortality in London over the 20th century. Am J Epidemiol 2006; 164: 77-84.