Frequency and clinical features of suicide attempts in elderly patients in Japan
Correspondence: Koji Kato, MD, Department of Psychiatry, Tokai University School of Medicine, 143 Shimokasuya, Isehara-shi, Kanagawa 259-1143, Japan. Email: email@example.com
The objective of this study was to investigate the clinical features of suicide attempts in elderly patients (≥65 years) in Japan. We enrolled 546 patients who attempted suicide and were hospitalized for inpatient treatment. Characteristics were compared between the elderly and non-elderly patients. Compared with the non-elderly group, the incidence of mood disorders was significantly higher and the average length of stay in the intensive care unit and the duration of hospitalization were significantly longer in the elderly group. Elderly patients hospitalized for attempted suicide were more likely to have mood disorders than the non-elderly.
THE ANNUAL SUICIDE rate in Japan is 24.9 per 100 000 and has remained high since it initially exceeded 30 000 (31 755) in 1998. In 2010, 31 690 people committed suicide, of whom 37.8% (11 982) were 60 years of age or older. Psychiatric illness has been associated with suicide attempts by the elderly, especially: (i) depression; (ii) social isolation from family, friends, and the community; (iii) physical illness; (iv) chronic pain; (v) family discord; and (vi) financial problems.
These studies have identified several risk factors for suicide in the elderly population, but few reports have studied the clinical characteristics and risk factors for suicide attempts among elderly patients taken to the emergency rooms in Japan. The aim of the present study was to investigate the frequency and clinical features of suicide attempts in elderly patients treated at a major emergency room in Japan.
This retrospective study was conducted at the Advanced Critical Care Center of Tokai University Hospital. Our hospital does not have a psychiatric ward and practices only liaison psychiatry. A total of 863 patients who had attempted suicide were treated at this hospital between April 2010 and October 2011. Of these 863 patients, 546 were subsequently hospitalized. We chose these hospitalized patients for our study to exclude cases of minor self-injury. In addition, interviews with individuals who had made serious but non-fatal suicide attempts provided additional information.
Psychiatric diagnoses were made according to the DSM-IV-TR. Psychiatric morbidity was assessed using the Mini International Neuropsychiatric Interview. We included patients diagnosed with dementia according to the DSM-IV and those with scores of 20 or less on the revised Hasegawa's Dementia Scale. Patients who required a respirator were categorized as in a serious condition.
Categorical variables were compared using Fisher's exact test. Continuous variables were examined using the Mann–Whitney U-test. For all analyses, a two-tailed P < 0.05 was accepted as a statistically significant difference. Statistical analyses were conducted using pasw Statistics 18 for Windows (spss, Chicago, IL, USA).
This retrospective study was conducted by reviewing medical records of the selected patients. The Institutional Review Board for Clinical Research of the Tokai University School of Medicine approved the protocol for this medical record review.
The patients hospitalized for attempted suicide were divided into two groups: an elderly group (≥65 years of age) and a non-elderly group (<65 years of age). The baseline characteristics of these patients are summarized in Table 1.
Table 1. Patient characteristics
|Age, mean (SD)||73.4 (6.2)||35.8 (12.4)|| || |
|Sex (male), n (%)||33 (46.5)||145 (30.5)||Fisher||0.010|
|Unmarried, n (%)||30 (42.3)||316 (66.5)||Fisher||<0.001|
|Years of formal education, mean (SD)||10.6 (2.1)||11.8 (2.2)||MWU (z = −4.604)||<0.001|
|Jobless, n (%)||25 (35.2)||181 (38.1)||Fisher||0.695|
|Living alone, n (%)||17 (23.9)||90 (18.9)||Fisher||0.337|
|Physical disorder, n (%)||56 (78.9)||98 (20.6)||Fisher||<0.001|
|Psychiatric history, n (%)||27 (38.0)||358 (75.4)||Fisher||<0.001|
|Family psychiatric history, n (%)||9 (12.7)||140 (29.5)||Fisher||0.003|
|Family suicide attempt history, n (%)||4 (5.6)||46 (9.7)||Fisher||0.377|
|Suicide attempt history, n (%)||7 (9.9)||236 (49.7)||Fisher||<0.001|
|Alcohol intake at suicide attempt, n (%)||13 (18.3)||83 (17.5)||Fisher||0.868|
|Method of attempted suicide, n (%)|| || || || |
|Drug overdose||17 (23.9)||327 (68.8)||Fisher||<0.001|
|Others†||24 (33.8)||21 (4.4)||Fisher||<0.001|
|Major psychiatric disorders|| || || || |
|Mood disorders, n (%)||50 (70.4)||129 (27.2)||Fisher||<0.001|
|Anxiety disorders, n (%)||10 (14.1)||104 (21.9)||Fisher||0.159|
|Serious condition, n (%)||42 (59.2)||141 (29.7)||Fisher||<0.001|
|Length of stay|| || || || |
|At the hospital in days, mean (SD)||18.7 (38.3)||9.0 (17.9)||MWU (z = −4.870)||<0.001|
|In the intensive care unit in days, mean (SD)||12.6 (17.2)||6.6 (8.7)||MWU (z = −4.909)||<0.001|
|Hospital transfer, n (%)||31 (43.7)||98 (20.6)||Fisher||<0.001|
Psychiatric characteristics of elderly patients who attempted suicide
The proportion of patients with mood disorders was significantly higher in the elderly group than in the non-elderly (Table 1).
Length of stay at the hospital or in the intensive care unit
The proportion of elderly patients in a serious condition was significantly higher than in the non-elderly (Table 1), while elderly patients had a longer average length of stay at the hospital and in the intensive care unit (ICU).
We investigated the clinical characteristics of elderly patients admitted to our hospital after a suicide attempt. This is the first study to compare the clinical and demographic characteristics of elderly patients with the non-elderly at an emergency room in Japan. Seventy-one of the 546 patients (13.0%) who had attempted suicide and were subsequently hospitalized were older than 65 years of age. The proportion of patients with mood disorders was significantly higher in the elderly group than the non-elderly. The elderly patients were kept longer in the ICU and at the hospital than the non-elderly, and they were more often listed as being in a serious condition.
Several studies have reported that mood disorders are major risk factors for suicide in elderly patients. In this study, the frequency of patients with mood disorders was significantly higher in the elderly group than that in the non-elderly. While mood disorders may be a significant risk factor for suicide in elderly patients in Japan, only 15 of the 50 elderly patients (30%) in this study were diagnosed with mood disorders before suicide attempts. Suominen et al. reported that most elderly patients who attempted suicide had also contacted primary health-care services during the previous 12 months, but only 4% had been diagnosed with a mood disorder (although the diagnostic rate rose to 57% after the attempt). Thus, relatively few of these elderly patients had been diagnosed and treated for a mood disorder, highlighting the importance of screening and assessment of depression in elderly patients by family physicians.
The average length of stay at the hospital and in the ICU was significantly longer, and the severity of injury was higher in the elderly group (more than 50% were classified as being in a serious condition). The incidence of drug overdose (23.9%) was significantly lower, but the rate of toxin ingestion or cutting/stabbing was significantly higher in the elderly group than in the non-elderly. In general, elderly patients may choose more destructive methods when they attempt suicide, leading to more severe injuries and longer hospitalization. For example, Conwell and Thompson reported that older adults tend to act on suicidal thoughts with greater lethality of intent and implementation and use more immediately lethal means.
Seven of these 71 elderly patients (9.9%) in this study were also diagnosed with dementia. Harwood et al. compared completed suicide with control patients who died of natural causes in hospital. The rate of dementia was only 5.6% in their study sample, suggesting that although cognitive decline may be a factor contributing to suicide in certain individuals, it is not of major importance as a risk factor at population level.
The present study has two limitations that must be acknowledged and addressed. First, this study was a preliminary retrospective study. Second, the number of cases was rather small, because only one institution was involved; this study should be expanded to multiple institutions.
The percentage of patients with mood disorders and the incidence of major physical disorders were also significantly higher in the elderly group. Elderly patients attempted suicide using more lethal methods, and therefore may be more likely to succumb to their injuries; however, this was only a preliminary study, and the clinical features of elderly patients who attempt suicide must be studied in a larger patient sample.
The authors declare that they did not receive any funding or grants for conducting the research. All authors declare that they have no conflicts of interest.