INTRODUCTION

In Japan, over 20,000 people die by suicide each year, making suicide a critical public health concern.¹ It is estimated that for every suicide, there are more than 20 attempts, underscoring the scale of the issues.² A history of one or more previous suicide attempts (SA) or self-harm is recognized as the strongest predictor of death by suicide.³ Consequently, preventing reattempts among suicide attempt survivors is a high-priority objective within comprehensive suicide prevention measures.^{2, 4}

Surveillance plays an essential role in public health practice by guiding prevention efforts, monitoring interventions, and evaluating their outcomes. The importance of establishing surveillance systems for SA has been emphasized by the World Health Organization (WHO).⁵ Internationally, various models exist. For instance, the National Self-harm Registry Ireland, the world's first national registry for self-harm, has been collecting data from emergency departments for over 20 years, significantly contributing to policy-making and prevention strategies.⁶

In Japan, suicide attempters account for approximately 15% of patients transported to emergency and critical care centers (ECCCs), where critically ill patients receive initial treatment.⁷ This indicates that SA consumes significant emergency medical resources, necessitating attention from ECCCs and the establishment of a surveillance system to optimize the allocation of these limited resources.

Although several regions or institutional surveys on SA have been conducted in Japan,⁸ a continuous nationwide surveillance system has not been established until recently. A comprehensive, real-time, nationwide system could offer valuable insights into the risk and protective factors associated with suicidal behavior, which might otherwise remain unidentified. Comparing SA data with suicide statistics help to identify demographic differences between individuals who attempt suicide and those who die by suicide. These insights can inform targeted interventions, such as providing intensive support for youth and women who are at higher risk of repeated attempts.

In response to these needs, the Japanese Society for Emergency Medicine (JSEM) and the Japan Suicide Countermeasures Promotion Center (JSCP) collaborated to establish the JAPAN Registry of Self-Harm and Suicide Attempts (JA-RSA) in December 2022.⁹ This registry represents the first nationwide surveillance system for self-harm and SA in Japan. JSEM, an academic society of emergency physicians and other emergency medical professionals, aims to advance and disseminate emergency medical care while enhancing health and welfare nationwide.¹⁰ Meanwhile, JSCP, a nationally designated research organization under the Law on Promotion of Surveys and Research to Facilitate Comprehensive and Effective Implementation of Suicide Countermeasures and Utilization, etc. of Outcomes Thereof (Law No. 32 of 2019), is dedicated to creating a society where no one is driven to suicide.¹¹

The JA-RSA initiative has begun continuous data collection and is actively expanding the number of participating institutions. While achieving nationwide participation remains a long-term goal, the preliminary profile of registered cases during the first 13 months provides valuable insights and demonstrates the registry's potential for future analyses. This study primarily aims to describe the initial findings from JA-RSA, the first nationwide registry of self-harm and SA in Japan. As a secondary objective, we also compare these findings with national suicide statistics to provide contextual insights that may inform future prevention strategies.

MATERIALS AND METHODS

RESULTS

A total of 1987 hospital presentations were enrolled in JA-RSA during the study period. Table 1 shows the hospital information for the participating institutions in JA-RSA from 2022 to 2023. The median number of patients per year was 11,832, with a median of 83 SA patients expected annually. Approximately 20% of the hospitals provided tertiary emergency care exclusively, while psychiatric care for emergency patients was available at all hospitals.

The basic characteristics of the cases enrolled are presented in Table 2. Over 60% of the patients were female (63.1%), with the highest prevalence observed among those aged 20–29 years (28.7%). The median age was 39.3 years. The most frequently reported method of SA was intentional drug overdose (IOD), accounting for 58.2% of cases, with 7.5% involving multiple methods. Other common methods included jumping from height (12.1%), self-cutting (11.2%), and hanging (10.8%). Notably, 66.4% of patients presented to the hospital outside regular working hours.

The types of care received and outcomes of the cases are shown in Table 3. Among all the cases, 8.3% were confirmed dead in the outpatient setting. A majority (68.4%) were admitted to the intensive care unit (ICU), while 11.9% returned home after receiving outpatient treatment alone. Among hospitalized patients, 70.5% were discharged within 1 month, and 4.4% died during their stay. Additionally, over 70% of patients received psychiatric consultation during hospitalization, and approximately 60% were referred to or informed about support organizations.

Table 4 presents the self-harm and/or SA history and social status of the cases. Nearly half of the cases had a prior history of SA. Among these, 28% were currently employed, and 10% were recipients of public financial assistance. It is worth noting that missing data rates for socioeconomic status items were relatively high, potentially limiting interpretations.

DISCUSSION

This study introduced the first nationwide prospective registry in Japan for patients with SA presenting to ECCCs. Our findings indicated that over half of the SA cases involved IOD, and nearly 70% of these patients required admission to the ICU. The proportions distribution among self-harm and suicide attempts enrolled in JA-RSA, particularly regarding sex and age, differed substantially from those observed among suicide deaths in national suicide statistics.

JA-RSA focuses on data collection from ECCCs where patients in critical condition are transported, which is unlikely to include patients with relatively mild symptoms. This specificity limits direct comparisons with data from other countries, where national registries often cover all types of emergency departments. Nevertheless, our findings, including the high prevalence of young individuals, women, and cases of overmedication in SA presentations, align with prior reports from Japan and abroad.^{6, 14-17} Furthermore, the significant disparities between the demographic and clinical profiles of SA patients and those of suicide death cases highlight the need for tailored prevention strategies targeting these at-risk populations and scenarios. JA-RSA data are accessible to researchers at participating institutions, fostering studies aimed at improving suicide prevention and support for suicide attempters.

Several limitations of this study must be acknowledged. First, the JA-RSA data cannot differentiate between repeat visits by the same patients due to technical constraints in personal information management. Addressing this issue is a key objective for the next stage of the registry, as not a few suicide attempters reattempt it.¹⁸ Second, the registry currently has an insufficient participation rate among ECCCs, potentially leading to the underrepresentation of cases in some regions. As the coverage of participating institutions increases in the future, it will be possible to analyze regional or inter-hospital differences in the number and characteristics of the patients. Third, the present study did not assess the severity of each case. In the future, it would be useful to identify, measure, and analyze items that can adequately assess the severity of SA, so that appropriate medical resources can be allocated to those who need them. Additionally, an uneven distribution of missing data was observed across the survey items, which could impact the analysis. To address these limitations, we are upgrading the data collection system to reduce the burden on registrars and developing incentives to encourage greater institutional participation. Expanding the registry to include all ECCCs in Japan remains a priority, as this would enable comprehensive data collection on SA presentations nationwide.

Despite these limitations, the JA-RSA offers a valuable dataset that provides critical insights into SA cases. This data will contribute to suicide prevention strategies and guide the allocation of emergency medical resources more effectively.

CONCLUSION

The initial findings from the JA-RSA have outlined key characteristics of SA cases in Japan. Expanding hospital participation and accumulating more case data are essential to enhance the registry's utility. Such efforts will provide invaluable information to support patients with SA and to prevent future reattempts.

CONFLICT OF INTEREST STATEMENT

The authors declare no conflicts of interest.

ETHICS STATEMENT

The protocol for this research project has been approved by a suitably constituted Ethics Committee of the institution, and it conforms to the provisions of the Declaration of Helsinki. Committee of the Japan Suicide Countermeasures Promotion Center, approval no. JSCP20221111-1.