Seasonal variation in mortality in Moscow

Background Seasonal variation in mortality has been investigated in many countries but not, until recently, in Russia. There are some grounds for suspecting that it may differ in Russia from what is seen in western countries. This paper explores patterns of seasonal variation in mortality in Moscow between 1993 and 1995. Methods Analysis was based on individual data on deaths occurring in Moscow between January 1993 and December 1995, grouped by four-week period and by calendar month and on mean monthly temperature in Moscow for the same period. Crude, smoothed and deseasonalized trends were inspected. Auto-correlation functions were estimated and deaths were regressed against temperature. Results As in other northern hemisphere countries, there is a winter excess of deaths but this is much smaller than in many western countries. It is restricted to some causes of death, such as ischaemic heart disease and cerebrovascular disease, and is associated with low temperature. In contrast, there is a marked summer increase in deaths among young people, especially from accidents and other deaths associated with alcohol consumption. Over the three-year period studied, there was an initial underlying increase in alcohol-related deaths that subsequently fell, coinciding with a previously observed increase in life expectancy. Conclusions It is possible that the low level of excess winter mortality reflects warmer indoor environments than in the west. The seasonal variation of deaths among young people reinforces evidence of the important role of alcohol in the Russian mortality crisis.