Association between social and environmental determinants of health with suicide-related death among veterans
Authors: Wang Xiange , Tan Wenhuan , Martinez Katy (Kaitlyn) , McMahon Benjamin , Beckham Jean C. , Kimbrel Nathan A. , Crivelli Silvia 
Published: July 2024

Importance

Social and environmental determinants of health (SDOH and EDOH) may contribute significantly to suicide rates among U.S. veterans.

Objective

To identify key predictive variables for assessing suicide-related death rates (SRR), which include suicide deaths, suicide firearm deaths, and suicide non-firearm deaths and vulnerability areas.

Design, Setting, and Participants

This case-control study utilized Electronic Health Record (EHR) data, which included demographic and mental health information spanning from January 1, 2006, to December 31, 2016. The base cohort considered all veterans from the VHA outpatient database during the above period. Patients from the base cohort who died by suicide were identified through the National Death Index and considered as cases. Given the significantly larger number of alive patients compared to deceased patients, which caused the dataset to be extremely unbalanced and potentially biased, control participants were selected at a ratio of 4 controls to 1 case from those who were still alive. Cases of suicide-related death were matched with four controls based on birth year, cohort entry date, sex, and follow-up duration. Comprehensive data on social determinants (SDOH), geographic and gun-related factors, quality of access to healthcare, environmental determinants (EDOH), and food insecurity—were gathered from various sources at the midpoint of the study in 2011. Data analysis was carried out from January 2023 to January 2024.

Exposures

Suicide-related deaths associated with SDOH and EDOH.

Main Outcomes and Measures

A hierarchical clustering method was employed to down-select the large number of variables, while Cox regression models were used to identify key predictive variables for SRR and areas of vulnerability.

Results

Out of a total of 9,819,080 veterans, 28,302 were identified as having died by suicide. These cases were matched with 113,208 control participants. The majority of the cohort was male (137,264 [97%]) and White (101,533 [72%]), with a significant portion being Black veterans (18,450 [13.12%]). The average age (SD) was 64.77 (17.56) years. We found that Social Determinants of Health (SDOH) and Environmental Determinants of Health (EDOH) were significantly associated with an increased risk of suicide. By incorporating SDOH and EDOH into the model, the performance (AUC) improved from 0.70 to 0.73.

Conclusions and Relevance

In this study, veterans who died by suicide using firearms exhibited distinct characteristics based on SDOH and EDOH, particularly in gun-related variables, compared to those who died by non-firearm methods. Our analysis indicated that veterans living in areas with more social issues, higher temperatures, and higher altitudes are at a higher risk of all-means suicide. Furthermore, regions such as Montana, Wyoming, West Virgina and Arkansas, characterized by higher gun-owernship are predicted to have the highest vulnerability based on veteran suicide firearm rates. Gun ownership and gun laws grades showed as strong predictors rather than rurality.

Key points

Question

Are social and environmental determinants of health linked to a higher risk of suicide-related death rates (SRR) among US veterans, and can they help pinpoint areas of vulnerability for these individuals preemptively.

Findings

Cox models highlighted the significant social and environmental factors that contribute to suicide outcomes. Individuals who died by suicide using firearms have distinct characteristics compared to those who died by non-firearm methods, including higher rates of gun ownership, living in rural areas, greater distances to healthcare facilities. Both groups live in areas that exhibit higher altitudes, a higher percentage of veterans self-reported as white, reduced income and life quality. The model revealed clusters of high-risk firearm suicide individuals in Montana, Wyoming, West Virgina and Arkansas. These areas are characterized by high gun ownership and weaker gun laws. Conversely, clusters of high-risk non-firearm suicides were found in states like California, Washington, and the Eastern coastal area, including New York, where stricter gun control laws and better economic conditions are prevalent. This study shows that gun ownership and gun laws grade, rather than rurality, are the key factors that distinguish between firearm and non-firearm suicides.

Meaning

Results of this study suggest that social and environmental determinants of health are associated with higher risk of suicide-related death rates (SRR) among US veterans.