Prevalence and risk factors of suicide in a rural area of Shandong province in mainland China: a case control study

Objective: Suicide is a major public health problem in China, particularly in rural areas. This study aimed to examine the rate and the risk factors for suicide in a rural area of China. Methods: The mortality data of two counties in Shandong Province from January 1st, 2004 to December 31st 2005 were used. Death information was collected via face-to-face interview with informant(s). Psychological autopsy was conducted on 137 completed suicides and 137 matched controls died from other illnesses. Chi-square/Fisher exact and multiple logistic regression were used for bivariate analyses and predictor analyses, respectively. Results: The suicide rate was 20.90 per 100,000 persons per year with almost equal rates of males and females. Among those with the age over 40 years old, the suicide rate in males was significantly higher than that in females. The peak of suicide fell in the age group of 70-79 years for males and the age group of ≥ 80 years for females. The most commonly used method for suicide was pesticide ingestion (76.7%). Poor interpersonal relationship (OR=12.79), childhood adversities (OR=7.26), a history of mental illness (OR=5.95), adverse life event(s) within 1 year prior to death (OR=3.19), and unstable extravert personality traits (OR=6.12) were independent risk factors for suicide. Male gender positively interacted with majority of these risk factors, especially with a history of mental illness (OR=17.89). Advanced age positively interacted with all independent risk factors, with a history of mental illness having the largest OR of 1.51 as every 10 year of age advancement. In bivariate analyses, a history of previous suicide attempt (OR=13.06), a family history of suicide (OR=7.08), and unstable introvert personality trait (OR=1.83) were also associated with increased risk for suicide; and stable extravert personality trait (OR=0.21) was associated with decreased risk for suicide. Conclusions: In this rural population of mainland China, the risk for suicide was almost equal in both males and females with the elderly having the highest risk. The positive interactions of advanced age and male gender with independent risk factors suggest that suicide prevention strategies targeting specific groups with different risk factors are essential.Objective: Suicide is a major public health problem in China, particularly in rural areas. This study aimed to examine the rate and the risk factors for suicide in a rural area of China. Methods: The mortality data of two counties in Shandong Province from January 1st, 2004 to December 31st 2005 were used. Death information was collected via face-to-face interview with informant(s). Psychological autopsy was conducted on 137 completed suicides and 137 matched controls died from other illnesses. Chi-square/Fisher exact and multiple logistic regression were used for bivariate analyses and predictor analyses, respectively. Results: The suicide rate was 20.90 per 100,000 persons per year with almost equal rates of males and females. Among those with the age over 40 years old, the suicide rate in males was significantly higher than that in females. The peak of suicide fell in the age group of 70-79 years for males and the age group of ≥ 80 years for females. The most commonly used method for suicide was pesticide ingestion (76.7%). Poor interpersonal relationship (OR=12.79), childhood adversities (OR=7.26), a history of mental illness (OR=5.95), adverse life event(s) within 1 year prior to death (OR=3.19), and unstable extravert personality traits (OR=6.12) were independent risk factors for suicide. Male gender positively interacted with majority of these risk factors, especially with a history of mental illness (OR=17.89). Advanced age positively interacted with all independent risk factors, with a history of mental illness having the largest OR of 1.51 as every 10 year of age advancement. In bivariate analyses, a history of previous suicide attempt (OR=13.06), a family history of suicide (OR=7.08), and unstable introvert personality trait (OR=1.83) were also associated with increased risk for suicide; and stable extravert personality trait (OR=0.21) was associated with decreased risk for suicide. Conclusions: In this rural population of mainland China, the risk for suicide was almost equal in both males and females with the elderly having the highest risk. The positive interactions of advanced age and male gender with independent risk factors suggest that suicide prevention strategies targeting specific groups with different risk factors are essential