Self-harm characteristics of younger-old and older-old adults admitted to emergency departments: a nationwide study

1. Introduction

Suicide is a major public health issue worldwide [1, 2], particularly in South Korea, where the suicide rate has ranked the highest among all 38 developed nations of the Organization for Economic Cooperation and Development (OECD) since 2003 [3]. Suicide rates increase with age and have been shown to be almost 13-fold higher in older adults compared to teenagers [4]. Thus, suicide in older adults is expected to be an increasingly important problem, due to aging worldwide population. This is also a particular concern in South Korea, where the average life expectancy is 83.3 years and aging is projected to be the most rapid among OECD countries [5, 6]. As life expectancy becomes longer, there is a growing need to consider that older adults do not comprise a homogeneous population group. Some studies demonstrate that suicide rates differ remarkably among specific older age subgroups [7]. It is important to examine suicide patterns of older adults with age-specific subgroup classification.

Self-harm is defined as any act of self-poisoning or self-injury carried out by a person, irrespective of motivation [8]. Self-harm, sometimes called self-injurious behavior, is often considered to be on the spectrum of suicidal behaviors, with self-harm at the less intense end of the spectrum, and suicidal thinking, suicide attempts, and death by suicide on the continuum of increasing severity [9]. Self-harm is a major risk factor for self-harm repetition and suicide [10, 11, 12]. While self-harm and suicide are two distinct behaviors, they are both often linked to mental health problems Indeed, older adults who self-harm have a 67 times higher risk of committing suicide compared to younger adults [13]. An understanding of the nature of self-harm in later life is essential for the provision of more effective healthcare to older adults, particularly in the hospital emergency department, the first place where medical assistance is provided following self-harm or a suicide attempt [14].

There is a lack of studies investigating specific age groups of older adults. Classification of these groups varies from study to study [15, 16]. In this study, we used a national injury registry to identify the characteristics of elderly self-harm and compare these between younger-old (65 to 79 years) and older-old (≥80 years) adults who were admitted to emergency departments in South Korea.

2. Methods

3. Results

3.1 Study population

Among a total of 2,116,039 patients registered in the EDIIS database during the 8-year study period, 259,367 with trauma were aged ≥65 years. Following the exclusion of patients due to missing data (1736) or an age >95 years (1788), 256,397 patients were included in the final analysis. The process of subject selection is shown in Fig. 1. There was a total of 5986 patients (aged between 65 and 94 years) with self-harm behavior. The overall self-harm rate was 2.36%. Self-harm incidence increased with age through the mid-70s, peaking at age 75 years (3.59%, 95% confidence interval, 3.27%–3.91%) (Fig. 2).

Fig. 1.Study population.

Fig. 2.Incidence rate of self-harm in the study population.

4. Discussion

Self-harm among the elderly is an important public health concern, as it is a major risk factor for eventual suicide and life expectancy is increasing rapidly worldwide. However, most studies analyzing self-harm in the elderly have focused on older adults as a single group [19, 20]. This retrospective study used a large sample from the EDIIS database. Patients who were ≥65 years of age were categorized into a 65–79 age group (younger-old) and an 80–95 age group (older-old). We found that the incidence of self-harm peaked in the mid-70s and that the two groups exhibited significant differences in the motivation for self-harm and some demographic variables, such as sex, alcohol consumption status, previous suicide history, and injury location. There was no significant difference in vital signs at the time of the emergency department visit; however, older-old adults had a poorer mental status and a higher risk of in-hospital mortality. We chose the stepwise regression to find the relatively significant factors among many variables, although its statistical limitation due to multiple comparison. As a result, risk factors for self-harm in older adults included male sex, no alcohol consumption, emergency medical service use, and the method of self-harm (fall from height, hanging/strangulation).

The identified risk factors for in-hospital mortality across all age groups were identical to those reported in previous studies on self-harm and suicide [8, 21, 22]. Older men who had attempted self-harm (via fall from height, hanging, or poisoning) and did not consume alcohol were more likely to have been successful in their suicide attempt. However, these risk factors were not significantly different between the age groups. The effect of the naturally resilient physical status of older age could be influenced by the higher mortality of older-old rather than differences in prehospital characteristics.

Analyzing the characteristics of self-harm is important for preventing injuries and fatal outcomes. Our results showed that self-harm in younger-old adults was more frequently related to alcohol consumption; this suggested that self-harm in this age group was often an impulsive act [23, 24]. The higher prevalence of planned self-harm in older-old adults may account for their higher mortality rate.

The type of self-harm method used is an important predictor of recurrent self-harm and subsequent mortality. It is well known that violent methods such as falls from height and cutting are more lethal than non-violent methods, such as self-poisoning. Lethal methods, are linked to fatal repetitive episodes [25]. However, there were no differences in self-harm methods between younger-old and older-old adults in the present study, despite a poorer mental status at the time of arrival at the emergency department and a higher hospital mortality rate in older-old adults. A similar method with different clinical outcomes might be due to the resilient physical status of older age compared with younger age. The motivation for self-harm among older-old adults was distinctly different from that of younger-old adults. While older-old adults were more frustrated by their health problems, they were less affected by relationship problems compared to younger-old adults. Previous studies have shown that physical illness in the elderly is linked to self-harm, which is often more severe compared to younger age groups [22, 26]. A multidisciplinary approach for understanding the orientation of self-harm is required in the emergency department, in order to decrease the incidence of suicide mortality [27, 28]. This study implies that case management of self-harm patients needs to focus especially on older-old people with health problems. This study could initiate the development of community-based suicide prevention programs that are age- and motivation-specific.

This study had some limitations. First, as this study retrospectively analyzed patient surveillance data from participating hospitals, sampling bias may have occurred. Potential sampling bias was likely minimal, as the participating hospitals were located in 13 of the 17 provinces in South Korea. However, the hospitals were also mainly located in urban rather than rural areas. Second, there were quite a few missing values for explanatory and outcome variables (e.g., occupation and education level) that were only defined as mandatory at admission. Although the large size of sample produced statistically significant results, missing data might have influenced the outcome with selection bias. Third, the registry only included patients who visited emergency departments; therefore, there may have been selection bias due to the fact that completed suicides and cases of self-harm that did not require emergency care were not accounted for. Fourth, various sociocultural factors such as religion, which possibly affects self-harm and suicide, were not considered in this study. Previous studies demonstrated that religious service attendance protects against suicide attempts and possibly protects against suicide [29, 30].

5. Conclusions

In conclusion, the incidence of self-harm in older adults peaked in the mid-70s and decreased thereafter. A higher mortality rate was observed among older-old adults, and this may be attributed to resilient physical status naturally derived from older age compared to younger age, although they have similar self-harm methods with different motivations. Therefore, prevention should focus on understanding self-harm motivations using a multidisciplinary approach.

Availability of Data and Materials

The data presented in this study are available on reasonable request from the corresponding author.

Author contributions

KYJ—Conceptualization, data curation, formal analysis, writing original draft, visualization; WCC and TK—Methodology, writing review and editing, supervision. All authors have read and approved the manuscripts

Ethics approval and consent to participate

This study was approved by the Institutional Review Board of Ewha Womans University Seoul hospital (IRB no. SEUMC 2021-11-042); the requirement for informed consent was waived due to the use of a retrospective study design. The study protocol satisfied the requirements specified under the Ministerial Decree of Health and Welfare passed by the National Bioethics Committee.

Acknowledgment

Thanks to all the peer reviewers for their opinions and suggestions.

Funding

This research was supported by Chung-ang university Research Grants in 2022 and a fund by Research of Korea Disease Control and Prevention Agency (Fax number: +82-2-3410-0017).

Conflict of interest

The authors declare no conflict of interest. Won Chul Cha is serving as one of the Editorial Board members of this journal. We declare that Won Chul Cha had no involvement in the peer review of this article and has no access to information regarding its peer review. Full responsibility for the editorial process for this article was delegated to OK.