In a groundbreaking study published in the 2025 volume of BMC Psychiatry, researchers closely examined the multifaceted factors influencing the methods of suicide among patients attended by mobile emergency medical services (EMS) in São Paulo state, Brazil. This comprehensive retrospective analysis, conducted over two years and encompassing 807 suicide attempts, offers critical insights into demographic, regional, and seasonal influences shaping the means by which individuals engage in self-harm. The findings emphasize the urgent need for rapid, targeted interventions in pre-hospital settings to mitigate fatalities and improve patient outcomes.
The study meticulously dissected data from EMS teams operating in the Botucatu and Ourinhos regions, regions chosen for their demographic diversity and representativeness of broader societal patterns in Brazil. Researchers employed multiple multinomial logistic regression techniques to parse the complex interplay of age, sex, region, seasonal timing, and chosen suicide methods. Their analysis reveals that exogenous intoxication—poisoning—constitutes the most prevalent method, accounting for over half of all cases, a statistic that aligns with global trends but with distinct regional characterizations in Brazil.
A notable finding highlights that individuals aged 24 years and older, comprising approximately two-thirds of the sample, predominantly engaged in poisoning as their method of suicide attempt. This age association (OR = 1.042) signals a gradual increase in the likelihood of poisoning with advancing age. Concurrently, female patients were disproportionately represented in the cohort, making up nearly 65% of cases, and showed a predilection toward poisoning over other methods. This sex-based disparity underscores the complex socio-psychological factors influencing method selection, with women more frequently choosing less immediately lethal means compared to men.
The study also provides compelling evidence that the probability of suicidal ideation culminating in specific methods fluctuates sharply with seasonal variation. Data indicate a significant association between suicide attempts in summer and suicidal ideation, reflected in an odds ratio of 3.00. This seasonal effect suggests underlying environmental and possibly neurobiological mechanisms modulating mental health exacerbations in warmer months, a phenomenon warranting further exploration and targeted preventive strategies.
Geographically, the Botucatu region emerged as a critical locus, with patients exhibiting greater odds of employing methods such as suicidal ideation and self-aggression compared to their counterparts in Ourinhos. The research indicates that residing in Botucatu dramatically increases the likelihood (OR = 28.143 for suicidal ideation and OR = 5.688 for self-aggression) of utilizing particular self-harm means, suggesting localized socio-economic, cultural, or healthcare access factors uniquely shaping suicide behaviors in this area.
A striking observation pertains to the protective factors identified through rigorous statistical modeling. Being female, residing specifically in the Botucatu region, and experiencing suicide attempts via exogenous intoxication all correlated inversely with mortality outcomes. The protective nature of these variables indicates that although these groups are more likely to attempt suicide, their chosen methods or regional characteristics may afford higher survival rates when treated promptly by EMS teams, highlighting the critical role of emergency response in life preservation.
In contrast, hanging as a method exhibited a negative association with female sex, with an odds ratio below 0.5, reinforcing previous literature that men are more prone to choose highly lethal methods. Such insights are essential for shaping gender-sensitive suicide prevention policies and intervention frameworks, acknowledging that method lethality and sex are intertwined determinants of both attempt and fatality rates.
The researchers underscore the indispensable role of mobile EMS teams who provide pre-hospital emergency care, often being the first point of contact for suicidal patients. The efficacy of rapid medical intervention, particularly in poisoning cases where antidotes and supportive measures exist, can significantly alter survival probabilities. Their data advocate for enhanced training, resource allocation, and strategic deployment of EMS services in high-risk regions like Botucatu.
Moreover, this analysis puts a spotlight on the necessity for integrated mental health strategies spanning acute emergency care and longer-term psychosocial support. Identifying individuals presenting with suicidal ideation or self-aggressive behaviors in predictable seasonal peaks or geographic clusters allows targeting interventions to mitigate both immediate risks and future suicide attempts.
Seasonal and regional nuances in suicide method prevalence suggest intricate relationships between environmental stressors, societal factors, and healthcare infrastructure. The summer peak in suicidal ideation might reflect seasonal affective patterns, heat-induced irritability, or sociocultural rhythms affecting mental health. Understanding these dynamics can inform temporal allocation of public health resources and community outreach programs.
The study’s multifactorial approach combining demographic, environmental, and clinical datasets lays a vital foundation for future research. By precisely characterizing suicide attempt methods through robust epidemiological methods, it paves the way for developing predictive models that can inform EMS prioritization and broader suicide prevention efforts in Brazil and similar socio-economic contexts globally.
In conclusion, this investigation elucidates how age, sex, regional residence, seasonality, and method intertwine to influence not only suicide attempt frequency but also survival outcomes among individuals served by mobile EMS in Brazil. The emergence of female sex, Botucatu residency, and poisoning as protective factors against death underscores complex behavioral and systemic interrelations. The research strongly advocates for tailored emergency response frameworks and continuous public health vigilance to confront the multifaceted epidemiology of suicide, ultimately aiming to reduce the tragic toll of this global public health issue.
Subject of Research: Factors influencing the means of suicide among patients attended by mobile emergency medical services in Brazil.
Article Title: Factors determining the means of suicide among suicidal patients treated by mobile emergency medical services in Brazil
Article References:
Meneguin, S., Afonso, M.G., de Almeida, P.M.V. et al. Factors determining the means of suicide among suicidal patients treated by mobile emergency medical services in Brazil. BMC Psychiatry 25, 1077 (2025). https://doi.org/10.1186/s12888-025-07444-5
Keywords: Suicide; Attempted Suicide; Emergency Medical Services; Death; Cause of Death
DOI: 11 November 2025
Image Credits: AI Generated
