Joinpoint regression analysis of suicides in Denmark during 1980-2015.

INTRODUCTION: Major advances have been achieved in suicide prevention over the past decades. Effective suicide prevention requires vigilant monitoring of suicide trends. The aim of this study was to assess the change in the Danish suicide rate over time using joinpoint regression analysis and to examine the distribution of suicide methods in the 1980-2015 period.

METHODS: Nationwide register data were obtained from the Central Research Register and the Danish Cause of Death Register. Rates were calculated per 100,000 persons by gender and agegroup. Joinpoint regression analysis was used to assess changes over time in the overall suicide rate.

RESULTS: The suicide rate declined from 40.4 (95% confidence interval (CI): 38.4-42.3) in 1980 to 11.9 (95% CI: 10.9-12.9) in 2015. A significant reduction ranging between 2 and 6% was observed during 1980-1999 after which the decrease was modest. The rate was higher for men than for women (rate ratio 1.9; 95% CI: 1.7-2.1), and more so by the end of the period (rate ratio = 2.4; 95% CI: 1.9-2.8). The suicide rate was found to increase with increasing age. Hanging, poisoning and shooting were the most frequent methods for men, whereas poisoning followed by hanging and drowning were the most frequent methods for women.

CONCLUSIONS: The suicide rate fell sharply between 1980 and 1999 in Denmark, but since then the decrease has been modest, especially since 2007. Further reduction in the suicide rate requires new and effective measures.

FUNDING: none.

TRIAL REGISTRATION: not relevant.