Impact of a High-resolution Program for the Prevention of Suicidal Behavior in At-risk Adults: a Quasi-experimental Ambispective Cohort Study

INTRODUCTION.

Epidemiological and Clinical Impact of Suicidal Behavior. Suicidal behavior is a phenomenon of increasing impact and one of the main public health concerns globally. According to the most recent data from the World Health Organization (WHO), published in 2025, more than 720,000 people die by suicide each year worldwide, a figure far exceeded by the number of attempts. It is estimated that for every completed suicide, there are approximately 20 attempts, and this is why these prior suicidal behaviors are consolidated as the individual risk factor with the greatest predictive value for future episodes. Suicidal behaviors generate extreme suffering with profound repercussions for both the individual and their socio-familial environment, thus generating a health and social impact of great magnitude. This is why suicide prevention has currently become a strategic priority on public health agendas.

In Spain, according to the latest data from the National Institute of Statistics (INE), there were 4,116 deaths by suicide in 2023, making it the second leading cause of death from external causes. The crude rate is 8.5 suicides per 100,000 inhabitants, with a notably asymmetrical distribution between sexes: 74% of cases correspond to men and 26% to women. These figures translate to an average of ten people committing suicide in Spain every day, highlighting the urgent need for effective clinical and preventative interventions.

Regulatory and strategic framework. The prevention of suicidal behavior is based on a solidly defined international and national strategic framework. Globally, the WHO's Action Plan for Suicide Prevention 2013-2030 establishes, in its third objective, the imperative need to implement mental health promotion and prevention strategies throughout the life cycle, with a commitment to reducing the suicide rate by one-third by 2030. In the Spanish context, the National Health System's (SNS) Mental Health Strategy 2022-2026 prioritizes, in its third strategic line, strengthening prevention, early detection, and optimizing the quality of care in this area. These guidelines are reinforced by the SNS's specific Action Plan for Suicide Prevention 2025-2027, which intensifies these measures with special emphasis on the most vulnerable groups and promotes intersectoral coordination as a response from the healthcare system.

Under this paradigm, the need arises to design effective and humanized intervention strategies as a comprehensive response, offering an effective response to the problem of suicide from a preventive, specialized, and community-based approach. Suicidal behavior is a preventable phenomenon through systematic and multidisciplinary actions.

Preventive interventions in suicidal behavior. Given the increase in deaths by suicide, there has been a proliferation of research focused on the development and evaluation of preventive strategies. In this area, it has become clear that preventive programs must be based on current, high-quality evidence. Previous studies have identified seven effective preventive interventions: case management, detection and therapeutic approach to depression, improvement of record systems, identification of local determinants, awareness campaigns, training of key agents or gatekeepers, and promotion of specific research.

Regarding the modality of interventions, evidence suggests that brief (six-twelve weeks) and ultra-brief (one-four weeks) programs are particularly promising due to their versatility and implementation in diverse clinical settings. Likewise, the importance of self-awareness in mental health has been highlighted in contrast to usual and conventional non-specific treatments, identifying key psychological factors for mitigating suicide risk. A key example in this field is the Zero Suicide model, based on the premise that "every suicide is potentially preventable." The application of this model in outpatient mental health settings by multidisciplinary teams has yielded statistically significant results. This model used the Columbia Suicide Severity Rating Scale (C-SSRS) as its primary assessment tool.

However, the implementation of intensive community programs still faces critical challenges. There remains a need for further research to determine the acceptability, treatment adherence, and clinical efficacy of these interventions in the community setting.

OBJECTIVES

1. Primary Objective:

• To evaluate the impact of a Suicide Prevention Program (SPP) on the incidence of suicidal behavior in adults at moderate-to-high risk, compared to usual care (UC), at three and twelve months of follow-up, at the Salamanca University Hospital Complex (CAUSA). Incidence will be measured by the occurrence of new episodes of suicidal ideation, suicide attempts, or completed suicide, assessed using the Columbia Suicide Severity Rating Scale (C-SSRS). 2. Secondary Objectives:

* To compare the number of emergency department visits for suicidal behavior between both groups during the follow-up period. (Hospital records) * To assess the reduction in emergency hospital admissions for suicidal behavior during the SPP and at twelve months of follow-up. (Hospital records) * To identify the clinical, sociodemographic, and psychosocial factors associated with suicidal behavior in the study population. • Monitor the evolution of suicide risk throughout the program and during follow-up, assessed using the Columbia Suicide Severity Rating Scale (C-SSRS) at three and twelve months of follow-up. * Evaluate program adherence and participant satisfaction (ad hoc scale).

HYPOTHESIS

The implementation of a specific, multidisciplinary, and high-resolution program focused on the prevention and management of suicidal behavior will result in a significantly greater reduction in the incidence of new episodes of suicidal behavior (suicidal ideation, suicide attempt, and completed suicide). This will be compared with those receiving usual care (TC) at two time points: three and twelve months of follow-up. The aim is to improve mental health indicators and increase adherence to therapeutic interventions in adults at moderate-to-high risk in the Salamanca health area.

METHODS AND ANALYSIS

1. Design.

A quasi-experimental, ambispective cohort study with two parallel groups was conducted: a control group (retrospective cohort) receiving usual treatment (HT) with data obtained from a review of medical records at the CAUSA (University Hospital of Salamanca), and an intervention group (prospective cohort) receiving the Suicide Prevention Program (PPS) with pre-intervention (baseline), post-intervention (3 months), and 12-month follow-up assessments. Group assignment was performed without randomization, in accordance with the TREND (Transparent Reporting of Evaluations with Non-Randomized Designs) declaration (13) and based on compliance with the previously established inclusion criteria.

The study setting was the University Hospital of Salamanca (psychiatric emergency department as the referral source) and two outpatient mental health centers within the Salamanca Specialized Care Management. 2. Study Population.

Study participants will be recruited from the CAUSA Emergency Department after an initial assessment and stabilization by psychiatry. Those subjects who meet the selection criteria specified below will be included in the intervention group (PPS). Conversely, patients with prior follow-up by the mental health team will form part of the control group (TH). 3. Sample Size.

The sample size was calculated based on the study by Goñi-Sarriés et al. (2022), which reported a recurrence rate of suicidal behavior of 31.4% at one year of follow-up in a population hospitalized for suicide attempts in Spain. Assuming a clinically relevant 50% reduction in the proportion of new episodes in the PPS group (from 31% to 15%), with 90% statistical power and a two-tailed significance level of 0.05, the minimum required sample size was 82 participants per group (Fleiss formula for comparing proportions). Estimating a 10% dropout rate, the adjusted sample size was 91 participants per group. Given the quasi-experimental design without randomization, a propensity score matching analysis will be performed to control for potential selection bias. 4. Recruitment and procedures.

Patients seen in the CAUSA Emergency Department who do not meet the inclusion criteria will be assigned to the control group and will receive standard treatment (ST) for suicide risk.

Patients who do meet the inclusion criteria will be referred from the CAUSA Emergency Department to the PPS to participate in the intervention group. A researcher, a mental health nurse specialist, will make initial telephone contact with each participant within 24 hours of referral to schedule the first in-person visit at the mental health center. During this initial visit, the first link in the therapeutic relationship will be established by welcoming the patient and their family and conducting a biopsychosocial assessment to identify the primary precipitating factor and associated risk and protective factors. A basic safety plan will then be developed. The study will be presented, any questions the participant may have will be answered, and the informed consent form and the program's therapeutic contract will be signed.

Data will be collected using a standardized data collection form, coded according to the previously defined primary and secondary variables. The recruitment period will last 12 months. For data processing, two separate databases will be maintained: one containing identifying information hosted on the SACYL network, and another anonymized database for statistical analysis, in accordance with current data protection regulations. The data will be anonymized using a numerical code that does not allow for direct identification of the participant.

Evaluations will be conducted at three points in time: at the initial visit (baseline), at the end of the program (at 3 months), and 12 months after the first contact. 5. Definition of the Intervention.

The Suicide Prevention Program (PPS) is a high-resolution, outpatient program carried out by a multidisciplinary team consisting of two mental health nurses, two psychiatrists, two psychologists, and two social workers. It is implemented in two community mental health centers in Salamanca, belonging to the Specialized Care Management, over a period of three months. It is applied to all patients referred from the psychiatric emergency department of the Salamanca University Hospital Complex who meet the inclusion criteria.

Referral to the program will be made via corporate email, accessible only to team members. The referral must include a suicide risk assessment based on the patient's history, psychopathological examination, and the application of the C-SSRS by the emergency psychiatry team. The patient will be evaluated and stabilized, both physically and behaviorally, prior to referral.

Initial Telephone Contact (\< 24 hours) The first contact with the patient will be made by telephone within 24 hours of referral and will be conducted by a mental health nurse. During this contact, the nurse will ensure that the patient and their family comply with the initial recommendations and safety measures provided in the emergency department until the first in-person appointment.

First Nursing Consultation (\< 72 hours) The first in-person contact will take place in a nursing consultation within 72 hours of referral. During this consultation, the patient and their family will be welcomed, the therapeutic relationship will be established, and a comprehensive biopsychosocial assessment will be conducted using Marjory Gordon's functional health patterns. Information will be provided about the development of the Personal Safety Plan (PSP), and informed consent and the therapeutic contract will be signed. The

• Type of Suicidal Behavior [Срок оценки: Baseline.]
• Suicidal Ideation Severity. [Срок оценки: Baseline, 3 months, 12 months.]
• Emergency Department Visits due to Suicidal Ideation [Срок оценки: 3 months, 12 months.]
• Global Clinical Impression of Suicidal Risk - Severity (CGI-SS-S) [Срок оценки: Baseline, 3 months, 12 months.]
• Global Clinical Impression of Suicidal Risk - Improvement (CGI-SS-I) [Срок оценки: 3 months, 12 months.]
• Anxiety and Depressive Symptomatology [Срок оценки: Baseline.]
• Impulsivity [Срок оценки: Baseline.]
• Patient Satisfaction with the Program [Срок оценки: End of program (3 months).]
• Adherence to the PPS Program [Срок оценки: 3 months (end of program).]
• Sociodemographic Characteristics [Срок оценки: Baseline.]
• Clinical Risk Factors for Suicidal Behavior [Срок оценки: Baseline.]
• Substance Use [Срок оценки: Baseline.]