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.