The incidence rates of suicide attempts and successful suicides in seven climatic conditions in Iran from 2001 to 2014: a systematic review and meta-analysis

Suicide is a social problem which can be influenced by geographical, cultural, economic, social, and environmental factors. The aim of the present study was to perform a systematic review and meta-analysis in order to evaluate the relationship of rates of suicide attempts and successful suicides with seven climatic conditions in Iran.
The present study was a systematic review and meta-analysis on the incidence rates of suicide attempts and successful suicide in seven climatic areas of Iran which was carried out by reviewing the published papers between 2001 and 2014. Using the keywords suicide, attempted suicide, incidence, Iran and combined terms, two trained investigators searched SID, ISI, Pubmed, Google Scholar, Irandoc, Scopus, and Magiran databases and all the relevant articles were extracted independently by them. The results were analyzed by using weighted average and Poisson distribution.
Among 74 articles, 30 were eligible for our study. The highest level of suicide attempts belonged to the climate area 5 (Isfahan, Yazd, Semnan and Qom cities ) with and incidence rate of 114.7/100000 people and the least belonged to the climate area 6(Chaharmahal and Bakhtiaree, kohkiloyeh and BoyerAhmad, Khuzestan Province) with the incidence rate of 37/ 100000 people. The highest and lowest incidence rates of successful suicide belonged to climate area 1 (Ilam, Lorestan, Hamadan, Kurdistan and Kermanshah) and climate area 5 with incidence rates of 12.9 and 2.8/100000 people respectively. Climate zone 5 had the highest incidence rate of suicide attempts and lowest rate of successful suicide.
According to the findings of this study, the incidence of suicide and successful suicide can be influenced by climatic factors. Based on the results of the studies conducted in different regions of the world, geographical and climatic factors can affect the incidence rates of suicide attempts and successful suicides. This was an ecological study. In order to find the association of climate factors with suicide attempts and successful suicides, further studies should be done on individual level.