Suicide cases in developed and emerging countries: an analysis using wavelets

Casos de suicídio em países desenvolvidos e emergentes: uma análise usando ondaletas

ABSTRACT

Objective  The aim of this study was to use a wavelet technique to determine whether the number of suicides is similar between developed and emerging countries.

Methods  Annual data were obtained from World Health Organization (WHO) reports from 1986 to 2015. Discrete nondecimated wavelet transform was used for the analysis, and the Daubechies wavelet function was applied with five-level decomposition. Regarding clustering, energy (variance) was used to analyze the clusters and visualize the clustering process. We constructed a dendrogram using the Mahalanobis distance. The number of groups was set using a specific function in the R program.

Results  The cluster analysis verified the formation of four groups as follows: Japan, the United States and Brazil were distinct and isolated groups, and other countries (Austria, Belgium, Chile, Israel, Mexico, Italy and the Netherlands) constituted a single group.

Conclusion  The methods utilized in this paper enabled a detailed verification of countries with similar behaviors despite very distinct socioeconomic, geographic and climate characteristics.

World Health Organization; mental disorders; wavelet transform; clusters