tailieunhanh - Báo cáo y học: " Relationship between daylength and suicide in Finland"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Relationship between daylength and suicide in Finland. | Hiltunen et al. Journal of Circadian Rhythms 2011 9 10 http content 9 1 10 JOURNAL OF CIRCADIAN RHYTHMS RESEARCH Open Access Relationship between daylength and suicide in Finland Laura Hiltunen 1 Kirsi Suominen1 2 Jouko Lonnqvist1 3 and Timo Partonen1 Abstract Background Many previous studies have documented seasonal variation in suicides globally. We re-assessed the seasonal variation of suicides in Finland and tried to relate it to the seasonal variation in daylength and ambient temperature and in the discrepancy between local time and solar time. Methods The daily data of all suicides from 1969 to 2003 in Finland N 43 393 were available. The calendar year was divided into twelve periods according to the length of daylight and the routinely changing time difference between sun time and official time. The daily mean of suicide mortality was calculated for each of these periods and the 95 confidence intervals of the daily means were used to evaluate the statistical significance of the means. In addition daily changes in sunshine hours and mean temperature were compared to the daily means of suicide mortality in two locations during these afore mentioned periods. Results A significant peak of the daily mean value of suicide mortality occurred in Finland between May 15th and July 25th a period that lies symmetrically around the solstice. Concerning the suicide mortality among men in the northern location Oulu the peak was postponed as compared with the southern location Helsinki . The daily variation in temperature or in sunshine did not have significant association with suicide mortality in these two locations. Conclusions The period with the longest length of the day associated with the increased suicide mortality. Furthermore since the peak of suicide mortality seems to manifest later during the year in the north some other physical or biological signals besides the variation in daylight may be involved. In order to have novel means for .