Factors Related to Suicidal Ideation by Gender and Age Group in Korean Adults

According to the results of the age-standardized suicide rate (suicide deaths per 100,000 population) published by Organization for Economic Cooperation and Development countries from 2003 to 2019, the suicide rate in Korea is ranked first almost every year, so it should be managed at the national level. To reduce the suicide rate, many scholars are studying suicide. The suicidal process begins with suicidal ideation, progresses through suicide attempts, and ends with suicide. Among them, the frequency of suicidal thoughts was found to be highly correlated with suicide plans and attempts, and it is said that 60% of those who change from suicidal ideation to attempts appear within one year. Therefore, research related to suicidal ideation to lower the suicide rate will contribute to preventing suicide at an early stage.

This study used data from the Korea National Health and Nutrition Examination Survey (KNHANES). Among them, data from 2013, 2015, 2017, and 2019 surveyed adults were compared for suicidal ideation among 18,339 adults. Considering the characteristics of the KNHANES data, complex sample analysis was performed considering the primary extraction unit (region), stratification variables, and weights. The Rao-Scott χ² test was stratified by age group to confirm the distribution of suicidal ideation according to general characteristics. Univariate and multiple logistic regression analyses were performed to understand the effect on suicidal ideation.

Among all subjects, the rate of suicidal ideation was 4.75%, and among the age groups, the rate of suicidal thoughts was the highest among those over 80 years old (10.39%). Compared to those who were 50s, those in their 30s had the lowest suicidal ideation (odds ratio [OR], 0.52; 95% confidence interval [CI], 0.39-0.70), and those in their 80s had the highest rate of suicidal ideation (OR, 1.97; 95% CI, 1.38-2.82). Except for those in their 20s, the rate of suicidal ideation tends to increase with age. Overall, the lower 25% of the Euro Quality of Life-5 Dimensions (EQ-5D) index, depression lasting more than two weeks, and subjects with poor subjective health or high stress were more likely to have suicidal ideation. In particular, EQ-5D Index (OR, 5.86; 95% CI, 3.73-9.20), depressive symptoms (OR, 19.65; 95% CI, 9.94-38.83) in 20s, and stress in 80s (OR, 10.87; 95% CI, 5.63-20.96) was the highest, and those had the good subjective health perception in 30s (OR, 0.10; 95% CI, 0.05-0.20) was lowest. Participants in their 30s, 40s, and 60s who were divorced or widowed and those in their 50s and 60s who had never married or lived together were more likely to consider suicide ideation. Except for those in their 20s and 80s, the rate of suicidal ideation tends to increase with lower household income levels.

In the results of this study, it can be seen that a combination of factors such as a person's personality traits, stress or coping ability to various events, social support, and mental or physical limitations influence suicidal behavior. Suicidal ideation is not simply affected by a single factor but may be influenced by multiple factors.