H Hakko1, P Räsänen, J Tiihonen. 1. University of Oulu, Department of Psychiatry, Finland. hhakko@sun3.oulu.fi
Abstract
BACKGROUND: Because secular trends in seasonality of different types of suicides has not been studied before, we utilized a novel statistical method to evaluate this phenomenon by using national Finnish suicide statistics during 1980-95. METHODS: Rates were analyzed with ordinary linear regression analysis. Secular trends were evaluated using ratio-statistic and its 95% confidence intervals. RESULTS: The rate of violent suicides increased before year 1990 and decreased since that. The nonviolent suicide rate increased continuously. The decreasing tendency of seasonality in nonviolent suicides and a slight decrease in violent suicides are seen within the three successive time periods studied. CONCLUSIONS: Trends in rates and in seasonality of suicides might be related to changes in the health politics in Finland. LIMITATIONS: The short time-series and lack of studying associations of suicides with socioeconomic, environmental or biological factors are limitations of our study. CLINICAL RELEVANCE: Studying the time-dependent changes in rates and in seasonality of suicides provide a novel perspective for the evaluation of the aetiology of suicidal behaviour.
BACKGROUND: Because secular trends in seasonality of different types of suicides has not been studied before, we utilized a novel statistical method to evaluate this phenomenon by using national Finnish suicide statistics during 1980-95. METHODS: Rates were analyzed with ordinary linear regression analysis. Secular trends were evaluated using ratio-statistic and its 95% confidence intervals. RESULTS: The rate of violent suicides increased before year 1990 and decreased since that. The nonviolent suicide rate increased continuously. The decreasing tendency of seasonality in nonviolent suicides and a slight decrease in violent suicides are seen within the three successive time periods studied. CONCLUSIONS: Trends in rates and in seasonality of suicides might be related to changes in the health politics in Finland. LIMITATIONS: The short time-series and lack of studying associations of suicides with socioeconomic, environmental or biological factors are limitations of our study. CLINICAL RELEVANCE: Studying the time-dependent changes in rates and in seasonality of suicides provide a novel perspective for the evaluation of the aetiology of suicidal behaviour.
Authors: Ingo W Nader; Jakob Pietschnig; Thomas Niederkrotenthaler; Nestor D Kapusta; Gernot Sonneck; Martin Voracek Journal: PLoS One Date: 2011-02-24 Impact factor: 3.240