Identifying and Tracking Gas Suicides in the U.S. Using the National Violent Death Reporting System, 2005-2012

A serial analysis of hydrogen sulfide poisoning: three group accidents

Hydrogen sulfide (H2S) is a powerful toxic gas in workplace incidents, and it poses a threat to colleagues or family members involved in rescues, leading to a "domino effect" of multiple deaths. In this report, we describe three incidents in which 10 people died, and we present the results of the analyses performed in different incidents, including paper pulp pit, sewer, and sewage well. We provide the macroscopic and morphological findings of ten victims, which include conjunctival hemorrhage, corneal erosion, pulmonary edema, and pulmonary hemorrhage. Additionally, we observed large amounts of waste paper pulp or black sludge in the upper and lower respiratory tracts or upper and lower gastrointestinal tracts of six victims. Furthermore, we conducted a toxicological examination of the victims' blood sulfide using an alkylation extraction approach combined with gas chromatography/mass spectrometry. The sulfide concentrations in the 10 victims ranged from 0.06 to 6.72 mg/L.

Research utility and limitations of textual data in the National Violent Death Reporting System: a scoping review and recommendations

BACKGROUND

Many studies of injury deaths rely on mortality data that contain limited contextual information about decedents. The National Violent Death Reporting System (NVDRS) is unique among such data systems in that each observation includes both quantitative variables and qualitative texts (called "narratives") abstracted from original source documents. These narratives provide rich data regarding salient circumstances that can be used to inform prevention efforts. This review provides a comprehensive summary of peer-reviewed research using NVDRS narratives over the past 20 years, including the limitations of these texts and provides recommendations on utilizing and improving narrative quality for researchers and practitioners.

MAIN BODY

Studies that used narratives to examine deaths related to suicide, homicide, undetermined intent, accidental firearm, or legal intervention were identified by a title/abstract screening, followed by a full-text review. The search was conducted on English-language, peer-reviewed literature and government reports published from 2002 to 2022 in PubMed, PsycInfo, Scopus, and Google Scholar. Abstracted elements focused on the methodologies used to analyze the narratives, including approaches to explore potential biases in these texts. Articles were abstracted independently by two reviewers, with disagreements resolved through consensus discussion. During the 20-year period, 111 articles used narratives. Two-thirds studied suicide (n = 48, 43%) and homicides (n = 25, 23%). Most studies analyzed the narratives using manual review (n = 81, 73%) and keyword searches (n = 9, 8%), with only 6 (5%) using machine learning tools. Narratives were mainly used for case finding (n = 49, 44%) and characterization of circumstances around deaths (n = 38, 34%). Common challenges included variability in the narratives and lack of relevant circumstantial details for case characterization.

CONCLUSION

Although the use of narratives has increased over time, these efforts would be enhanced by detailed abstraction of circumstances with greater salience to injury research and prevention. Moreover, researchers and practitioners would benefit from guidance on integrating narratives with quantitative variables and standardized approaches to address variability in the completeness and length of narratives. Such efforts will increase the reliability of findings and set the stage for more widespread applications of data science methods to these texts.

An overview of suicides related to motor vehicles

Although vehicles may be used in a wide variety of suicides, this has not been a focus in the forensic literature. Thus, an analysis of coronial autopsy reports at Forensic Science SA, Adelaide, South Australia over a 16-year period from January 2005 to December 2020 was undertaken to provide an overview of cases in which it was considered that a vehicle had been integral to the successful completion of a suicide. De-identified details were collected from all cases in which a vehicle had facilitated or been used as a method of suicide. A number of different types of vehicle-related suicide methods were identified, including cases where vehicles had been used as secure places for suicide or where the vehicle had been used to cause significant blunt force trauma or to enter a lethal environment such as water. Specific examples were taken from the following categories: (1) inhalation of gas, (2) drug toxicity, (3) hanging or ligature strangulation, (4) self-immolation, (5) drowning, (6) vehicle collision, (7) driving off a cliff, (8) jumping or lying in front of a vehicle and (9) the use of more than one method (i.e. complex). This report is not intended to provide an epidemiological analysis of car-related suicides. Instead, the details of selected cases have been used to illustrate the spectrum of methods that may be used in vehicle-assisted suicides.

The evolution of charcoal-burning suicide: A systematic scoping review

INTRODUCTION

Suicide by charcoal burning has accounted for more than 100,000 deaths. It has become an increasingly common suicide method in Hong Kong since first reported in 1998, and it has spread into South Korea, Taiwan, Japan and other countries. This systematic scoping review aimed to explore current evidence on trends, risk factors, impact of media and prevention strategies for this suicide method, and to identify research gaps.

METHODS

A search for articles published from January 1998 to June 2021 was conducted through electronic databases (MEDLINE, EMBASE, SCOPUS and PsycINFO) with the keywords (suicide*) AND (charcoal). Articles describing prevalence, trends, characteristics, risk factors and prevention strategies of charcoal burning suicide deaths were included. Non-peer-reviewed articles, non-English articles, commentaries/editorials/letters, poster abstracts, reviews, meta-analyses and studies that documented only charcoal burning suicide attempters/survivors were excluded.

RESULTS

Eighty-eight studies were identified, most from East Asia. Charcoal burning suicide rates in Hong Kong, Taiwan and Japan has passed the peak, while continuing to increase in South Korea. Risk factors are changing and not static. Media appears to play an important role in triggering and spreading information. Restricting access to charcoal, and raising public awareness have been effective in the short term in preventing charcoal burning suicide, but there is little information on their long-term effectiveness or sustainability.

DISCUSSION

More research is required to update the development and dynamic changes of charcoal burning suicide and the contributing factors. The evidence from this review may assist in detecting and intervening early for future novel suicide methods.

Psychiatric diagnoses are associated with means selection in united states suicide deaths

PURPOSE

The purpose of this study was to examine whether the choice of means by persons who die by suicide is associated with a prior psychiatric diagnosis.

METHODS

In this cross-sectional study, we analyzed suicide surveillance data from 18 states reporting to the National Violent Death Reporting System (NVDRS) between 2003 and 2014. NVDRS compiled data from multiple sources (e.g., coroner's reports, police reports, death certificates) on every violent death within reporting jurisdictions, including information on indicated psychiatric disorders and suicide means. We assessed whether the selected suicide means were associated with diagnoses using multinomial logistic regression.

RESULTS

Adjusted models suggested that, compared to decedents using firearms, those using poisoning were more likely to have each psychiatric disorder examined, including bipolar disorder (aOR: 2.17 [95% CI 2.03-2.32]), schizophrenia (aOR: 1.81 [1.61-2.04]), depression (aOR: 1.64 [1.58-1.70]), anxiety disorder (aOR: 1.46 [1.35-1.57]), and PTSD (aOR: 1.41 [1.22-1.64]). A far greater proportion of individuals who died from less common means (other than firearms, suffocation, or poisoning) had schizophrenia (aOR: 4.52 [4.00-5.11]).

CONCLUSIONS

Many existing and proposed means restriction interventions have focused on firearms. Additional focus on access to potential agents of poisoning (e.g., the type and quantity of medication administered to patients) among individuals with psychiatric diagnoses may be warranted.

Surveillance of suicide deaths involving gases in Australia using the National Coronial Information System, 2006 to 2017

BACKGROUND

There have been concerns about the increased use of helium and nitrogen gas as a suicide mechanism in Australia.

METHODS

National Coronial Information System data were used to investigate gas-specific suicides in Australia over the period 2006-2017. Characteristics were compared between helium or nitrogen, carbon monoxide and seven other gases.

RESULTS

Gas inhalation accounted for 10% (3,103/31,002) of all suicide deaths in Australia between 2006 and 2017. The mean age of individuals who died by suicide was 47.6 years (SD 16.9, R 14-97) and 83.3% were male. The number of gas suicides declined over the study period (IRR=0.96). The fall was associated with a 47% decline in carbon monoxide suicides (IRR=0.93). There was an increase in deaths due to argon (IRR=1.60) and nitrogen (IRR=1.27). Compared to individuals using other non-carbon monoxide gases, individuals who died by suicide from helium or nitrogen were significantly more likely to be older, have a physical illness and/or disability, have contacted a euthanasia group and have accessed instructional material and purchased gas online.

CONCLUSIONS

Suicides by carbon monoxide decreased between 2006 and 2017 alongside an increase in argon and nitrogen gas use - particularly among older adults. The ease of access to these gases points to new targets for means restriction. Implications for public health: Identifying the types of gases used in suicide deaths and emerging trends may enable targeted interventions that could potentially reduce access.

Helium inhalation injuries managed at emergency departments

INTRODUCTION

Helium is a colorless, odorless, and tasteless inert gas. Inhaling helium can temporarily result in a high-pitched, squeaky voice. Individuals also may inhale helium to become intoxicated or commit suicide. The objective of this study was to characterize helium inhalations managed at emergency departments (EDs).

METHODS

Data were obtained from the National Electronic Injury Surveillance System (NEISS), a database of consumer product-related injuries collected from the EDs of approximately 100 United States hospitals. Helium inhalation-related injuries reported during 2000-2019 were identified by reviewing the record narratives for the term "helium." The distribution of the national estimate was determined for selected variables.

RESULTS

A total of 89 helium inhalation-related injuries were identified, resulting in a national estimate of 2,186 injuries. The estimated number of injuries was 99 during 2000-2004, 305 during 2005-2009, 864 during 2010-2014, and 918 during 2015-2019. The age distribution was 75 (3.4%) 0-5 years, 1,427 (65.3%) 6-12 years, 586 (26.8%) 13-19 years, and 98 (4.5%) 20 years or older; 1446 (66.1%) of the patients were male. The most commonly reported symptoms or injuries were 1500 (68.6%) syncope, 615 (28.1%) non-concussion head injury, 299 (13.7%) dizziness/lightheaded, 267 (12.2%) contusion/abrasion, and 236 (10.8%) concussion. The patient was treated or evaluated and released in 2149 (98.3%) estimated injuries.

CONCLUSION

The majority of patients with helium inhalation-related injuries treated at United States EDs were age 6-12 years and male. Most of the patients experienced either syncope or dizziness/lightheadedness and were released from the ED.

Prehospital characteristics, incidence trends, and outcome of emergency self-inflicted injury patients with gas substances: a population-based descriptive study in Osaka, Japan

Aim

Little is known about the detailed characteristics of patients using gas substances for self‐inflicted injury in prehospital settings. The aim of this study was to investigate the characteristics, incidence trends, and outcomes of patients who used gas substances for self‐inflicted injury in Osaka City, Japan, using ambulance records.

Methods

This was a retrospective observational study that used data from 2009 to 2015. We extracted details from ambulance records of self‐inflicted injury patients who used gas substances. The annual incidence of self‐inflicted injury by gas substance and age group and Poisson regression models were applied for calculating the annual incidence trend by type of gas substance. The main outcome was confirmed death at the scene, and we also calculated the crude odds ratios and 95% confidence intervals for each gas substance.

Results

During the study period, there were 324 self‐inflicted injury patients who used gas substances. The most commonly used gases were carbon monoxide (CO) (54.9%), followed by hydrogen sulfide (12.7%), helium (6.5%). The incidence of CO and hydrogen sulfide have subsequently decreased (P for trend = 0.023 and <0.001, respectively); however, the incidence of helium did not change during the study period (P for trend = 0.586). The mortality rate was highest in patients who used helium (66.7% [14/21]) and the crude odds ratio of helium was 3.857 (95% confidence interval, 1.267–11.745; P = 0.017) compared with hydrogen sulfide.

Conclusion

This study revealed that the incidence of self‐inflicted injury with helium did not change and its proportion of death at the scene was high in Osaka City.

How common are suicides using nitrous oxide?

Analysis of autopsy cases of suicide from Forensic Science South Australia files (2003–2017) where helium, nitrogen or nitrous oxide gas had been used revealed that only 2/58 (3.5%) cases utilised nitrous oxide; the remainder of cases had used helium or nitrogen. The two cases are presented here. In case 1, a 48-year-old man was found completely encased in a plastic bag with a hose connected to an opened cylinder of nitrous oxide. In case 2, a 27-year-old woman was found with a plastic bag over her head, tied around her neck, with a tube connected to a small canister of nitrous oxide. There were approximately 20 empty canisters of nitrous oxide nearby. Death in both cases was due to nitrous oxide augmentation of plastic bag asphyxia, manner suicide. The relative ease with which helium and nitrogen cylinders containing large amounts of gas can be obtained may explain the low numbers of suicides utilising nitrous oxide.

Suicide deaths by gas inhalation in Toronto: An observational study of emerging methods of suicide

BACKGROUND

Suicide death by gas inhalation has been the subject of global scientific interest due to a rapid increase in the use of helium and charcoal gas for suicide. These may be particularly amenable to means restriction strategies. There has been little scientific attention of this phenomenon in Canada.

METHODS

A review of coroner records was conducted for all suicide deaths in Toronto (1998-2015). Deaths were categorized as due to inhalational asphyxia by compressed gas (i.e. helium or nitrogen), charcoal burning or motor vehicle exhaust, with suicide deaths by other methods as a comparator. Demographic, clinical and suicide specific differences between decedents in these four categories were compared using chi-squared or ANOVA global test of significance with additional pairwise comparisons where appropriate. Secular trends were also examined.

RESULTS

Gas inhalational deaths accounted for 190 (4.7%) of all suicides in Toronto (n = 4062) over the study period and a higher proportion of males used compressed gas or motor vehicle exhaust gases than those who died by other methods (83.3% and 84.0% vs.69.7%, both p = 0.01). Comparing 1998-2003 to 2010-2015 there was a 1075% increase in deaths by helium (4 vs. 43 deaths) and a 533% increase in deaths by charcoal burning (3 vs. 16 deaths) although helium and charcoal burning deaths still accounted for only 4.2% of total suicides 2010-2015. Deaths by helium were more likely to be accompanied by the book "Final Exit" than those by non-inhalational methods (15% vs. 0.7%, p < 0.0001) while 13 of 14 people who died by charcoal burning whose ethnicity could be determined were Asian.

LIMITATIONS

Ethnicity and specific details of procurement of suicide methods were not systematically available in coroner records.

DISCUSSION

Suicide by inhalational asphyxia, particularly by compressed gases, has increased substantially over time in Toronto consistent with observations in other countries. Increased surveillance of these deaths, efforts to restrict access to these methods, and timely interventions including minimizing media reporting are all warranted.

Epidemiology of asphyxiation suicides in the United States, 2005-2014

BACKGROUND

From 2005 to 2014, the asphyxiation suicide rate in the United States (U.S.) increased by 45.7% from 2.45 to 3.57 per 100,000 population. The primary purpose of this cross-sectional study was to describe decedent and incident characteristics of asphyxiation suicides in the U.S. from 2005 to 2014. The secondary purpose of this study was to explore whether any demographic characteristics of asphyxia suicide decedents were associated with type of suicide incident.

METHODS

Data from the National Violent Death Reporting System (NVDRS) were used to describe asphyxiation suicide mechanisms and means in 16 states. Anchor points of hanging suicides were also described. Mechanisms, means, and anchor points were determined through a text search of cause of death, coroner/medical examiner narrative, and law enforcement narrative. Multivariable logistic regression was conducted separately for females and males to estimate beta coefficients to obtain adjusted odds ratios (AORs) and 95% confidence intervals (CIs) to compare hanging-related asphyxiation and other types of asphyxiation.

RESULTS

From 2005 to 2014, there were 25,270 asphyxiation suicides. Most decedents were male (79.9%) and white, non-Hispanic (76.8%). Most asphyxiation suicides involved hanging (90.7%, N = 22,931); 1717 (6.8%) involved smothering; 968 (3.8%) involved chemicals or gasses; and 145 (0.6%) involved strangulation. For hanging suicides, the three most commonly used means were power or extension cords (N = 1834), bedding (N = 873), and animal ropes (N = 578). The three most common anchor points for hanging suicides were trees (N = 2215), beams (N = 2014), and closets (N = 2009). Among females and males, odds of asphyxiation suicide were highest among those of Other, non-Hispanic race and black, non-Hispanic race, respectively [AOR (95% CI) = 3.73 (1.59, 8.79) and 2.72 (1.34, 5.50), respectively].

CONCLUSIONS

Commonly available objects are used in asphyxiation suicides. Modification of anchor points represents a potential solution for reducing hanging suicides. Changes in design and availability of grocery bags could help reduce smothering suicides. Strategies to reduce asphyxiation suicides need to be identified. Improving access to and utilization of mental health services can also reduce asphyxiation suicides. Future research should be conducted to better describe characteristics of asphyxiation suicide so that prevention efforts targeted by demographic subgroups can be implemented.

Has information on suicide methods provided via the Internet negatively impacted suicide rates?

Suicide rates in Germany consistently decreased from 1991 to 2006, but this trend was reversed in 2007. Underlying this reversal were large increases in suicides due to gassing in females and in being overrun in males. During a similar time period (2005-2013), Asian and some Western countries have also observed abrupt increases in suicides due to certain gasses, and the availability of "how-to" information on the Internet about these painless methods of suicide is thought to play a role in their increased use. This study used data from the Federal Statistics Office of Germany to examine current trends in overall suicide mortality in Germany (2007-2015) as well by age, gender, and suicide methods. Also assessed was whether suicides via newly emergent methods are associated with the frequency of corresponding Internet searches using data from Google Trends. Joinpoint regression analyses indicated significant increases in the overall suicide rate (Average Annual Percentage Change (AAPC) = 2.37%) for females, but not males. The largest annual increases were observed in gassing self-intoxication suicides (AAPC = 13.93%), the majority of which involved carbon monoxide. The increase in gassing suicides was larger in females (500%), compared to males (164%). The frequency of suicides by gassing was significantly associated with Internet searches for "carbon monoxide poisoning" for both male and female subgroups, independent of age group. This study provides the updated suicide surveillance data that are necessary for suicide prevention activities. Results are congruent with the recent abrupt rises in carbon monoxide suicides in other countries.