This study investigates the rate of completed suicide in the general population in East Azerbaijan Province during the years 2007 to 2018, where there are limited documents about suicide. The trend of suicide cases was decreasing between 2007 and 2014, but from 2015 to 2018 has been increasing with a smooth slope. Totally, the incidence rate of suicide has increased slightly during the study period from 2007 to 2018. The pattern of suicide trend in the present study is in line with the trend of all Iranian completed suicide cases reported by Razai et al. .
The incidence rate of suicide in males was higher than in females all over the years. The highest incidence rate was in men, 6.17 per 100000 in 2008. For females, the highest suicide rate was 2.16 per 100,000 in 2018. Our findings were congruent with other studies done in various provinces of Iran [15,16,17]. A systematic review and meta-analysis study in Iran revealed that western regions have shown the highest suicide rate 12.9 per 100,000 .
In this study, we compared suicide incidence trends via two valid registry-based systems including legal medicine and DRIS while most studies have only evaluated the trend of suicide through a single database. In this province, the incidence rates of suicide based on legal medicine were higher than DRIS around all years and there was a noticeable difference in the number of suicides between the two databases.
In the present study, 2422, and 1783 suicide cases ( total incidence rate 5.94 vs 4.4 per 100,000) were reported by legal medicine and DRIS in East Azerbaijan Province during the period 2007–2018, respectively. Hajebi et al. found the incidence rate of suicide ranged from 1.76 to 2.23 per 100,000 persons among Iranian from 2009 to 2012 based on National Suicide Registration System . Similar to the present study in Hajebi study and also a recently published study in 2021 by Mahdavi, the hanging was the most common suicide methods among all country suicide cases .
In the present study, the mean and median age of suicide death was 34.07 and 31 years, respectively and 67.5% were males, and 64.63% were married. The highest suicide rates were found in the age groups of 15–24 (26.21%) and 25–59 years (61.82%), the majority of suicidal people used hanging (61.6%) as the suicide method. Occupation distribution was (36.5%) unemployment or free, and secondary education level was 58.1%, and the urban setting was 69.2%. Currently, a study in agreement with our study that performed based on the Iranian forensic medicine during 2016 and 2018 found that the median age of suicide cases was 31 years, and 30 to 59 age group was prevalent category and 71.2% were men .
The findings of the present study were in agreement with the study in Brazil, the incidence rate of suicide has increased from 5.84 per 100,000 persons in 2000 to 7.23 per 100,000 in 2015 and represents a 19% increase in the incidence of suicide deaths over the period .
In the present study, males have committed suicide more than two times than females. According to the WHO report in 2016, the mortality rate by suicide in males has been about twice that of females . Likewise, the male to female sex ratio was 1.4 in the Zhong study, and suicide in men has been observed 40% higher than in women . In the study in Brazil from 1980 to 2009, the male to female sex ratio was more than 4 times . In the study by Sharafkhani et al. in Oromiya, Iran, the ratio of the odds of suicide steer to death in males was 3 times higher than that of females . However, in most findings, suicide attempts have been more prevalent among females. Using harsher and aggressive methods including the hanging methods and firearms are the main reasons for the significant difference in suicide mortality in males compared to females that increased fatal and decreased odds of survival. In contrast, females tend to medication overdose and poisoning that are fewer considered to be lethal .
Likewise, in the present study, more than 61% of participants used the hanging suicide method. Evidence indicates the use of violent and aggressive methods for suicide growths the hazard of completed suicide 12 times . Drug and substance abuse and also mental-neurological problems are other reasons for high suicide rates among males . The same results were found in the USA and Brazil that 72% of suicide cases were committed using firearms [13, 26]. Despite that, hanging is the most commonly used suicide method globally; however, the distribution of the methods is diverse among various settings.
In the recent decade, the concern of suicide death has shifted from developed and industrialized countries and now to Asia . Decreasing social and mental health supports and also social happiness, alterations in the family and community habits and customs are the most important factors in rising of suicide and suicidal behaviors over the last year s
In the present study, the majority of suicidal cases were observed in the age groups of 25–59 and 15–25 years, which were consistent with the results of previous studies [16, 28, 29]. This shows the essence of paying attention to this group of people, as they are the productive generation of the community. The suicidal behaviors distribution and correlated factors in the age group of 15–29 years have been the focus of various studies, proposing the role of family conflicts and divorce, disturbing hormonal fluctuations and mental health status, and access to the firearm as the main elements for the high incidence rate in this people [3, 30]. In Iran, one of the factors that belong in the event of Konkoor as a national university entrance exam that imposes great pressure on Iranian adolescences at this age group, and the higher suicidal behaviors incident in June and July might also be attributed to the same event .
Comparing the incidence rate of the present study with other studies shows that the suicide mortality in East Azerbaijan Province is lower than most European countries and the USA [32, 33] and also lower than in Eastern Provinces of Iran including Ilam ; however, it is slightly higher than whole country suicide mortality rates which shows the necessity to pay attention to this social concern issue in this province, as the fourth populous province of Iran.
Strengths and limitations
The main strength of this study is using two valid suicide registry-based systems including legal medicine and DRIS to prevent the possibility of under-reporting which rare studies focused on. Nevertheless, this study had limitations. First, we did not calculate age standard mortality rates; however, the age distribution in this province and age categories are similar to the age distribution of the national population and there are no differences between those.
Second, we used only one data source (DRIS source) for presenting study results due to the unavailability and inaccessibility of participant’s characteristics and ethical limitations of suicide cases in legal medicine.