Does the environment affect suicide rates in Spain? A spatiotemporal analysis.

INTRODUCTION

Suicide is an important public health problem, it represents one of the major causes of unnatural death, and there are many factors that affect the risk of suicidal behaviour. The present study analyzes the temporal and spatial variations of mortality by suicide in Spain and its relationship with gross domestic product (GDP) per capita.

MATERIAL AND METHODS

A retrospective study was performed, in which deaths by suicide, sex and age group in 50 Spanish provinces between 2000 and 2012 were analyzed. The annual trend of suicide mortality was assessed using Kendall's tau-b correlation coefficient. Seasonality and monthly and weekly behaviour were evaluated by performing the ANOVA test and the Bonferroni adjustment. Finally, the relationship between GDP per capita and suicide was studied.

RESULTS

Between 2000 and 2012, 42,905adult people died by suicide in Spain. The annual average incidence rate was 95 suicides per million population. The regions located in the south and in the northwest of the country registered the highest per capita mortality rates. There is a decreasing trend in mortality by suicide over the period studied (CC=-.744; P=.0004) in adults over the age of 64, and a seasonal behaviour was identified with summer maximum and autumn minimum values (f=.504; P<.0001). The regions with the highest GDP per capita showed the lowest mortality by suicide (r=-.645; P<.0001) and the relationship is stronger among older age groups.

CONCLUSIONS

Mortality by suicide does not follow a homogenous geographical distribution in Spain. Mortality in men was higher than in women. Over the period of study, there has been a decrease in mortality by suicide in Spain in adults over the age of 64. The seasonal cycle of suicides and the inverse relationship with GDP per capita found in this study, provide information which may be used as a tool for developing prevention and intervention strategies.