Analysis Of Seasonal Variations Of Suicides In The Arhangelsk Region In Relation To Geoclimatic Factors

Aim of the study. Current research is an extension of the study of seasonality of suicidal behavior in the regions contrasting in main geoclimatic factors in relation to such variables as day longitude and ambient temperature (comparison of Arkhangelsk and Odessa). Methods. Analysis is based on 3326 suicide cases in the city of Arkhangelsk in the period from 1991 to 2013. All data were processed statistically, previously being reduced to a single scale, taking into account the different number of days in the months of the year. To study the null statistical hypothesis about the equality of the proportions of suicides per month of the year, a binomial criterion with a two-sided critical region was used. Results. In both regions under study for the last 17 years lowering suicide trend is observed. In Arkhangelsk from March to August (6 months per year) suicides are higher than expected, while all remaining months show lower incidence of suicides. The most marked rise is registered in May, the lowest fall - in December. Thus, the Autumn rise does not exist in Arkhangelsk. The pattern in Odessa resembles that one in Arkhangelsk with some peculiarities - the rise is registered from April to August, i.e. 5 months per year. Variations of suicide mortality are correlated both with the length of the day and temperature curve during a year, mostly with the derivative of the average monthly temperature. Data obtained are discusses from the point of view of existing differences between regions and possible influence of social factors and alcohol consumption pattern. Conclusion. Suicide seasonality pattern is slightly different in Arkhangelsk and Odessa (in Arkhangelsk Spring rise starts earlier), but there are no critical differences in association with the day light and ambient temperature changes between regions.