Suicides Among American Indian/Alaska Natives — National Violent Death Reporting System, 18 States, 2003–2014

Suicide disproportionately affects American Indians/Alaska Natives (AI/AN). The suicide rate among AI/AN has been increasing since 2003 (1), and in 2015, AI/AN suicide rates in the 18 states participating in the National Violent Death Reporting System (NVDRS) were 21.5 per 100,000, more than 3.5 times higher than those among racial/ethnic groups with the lowest rates.* To study completed suicides across all ages of AI/AN, NVDRS data collected from 2003 to 2014 were analyzed by comparing differences in suicide characteristics and circumstances between AI/AN and white decedents. Group differences were assessed using chi-squared tests and logistic regression. Across multiple demographics, incident characteristics, and circumstances, AI/AN decedents were significantly different from white decedents. More than one third (35.7%) of AI/AN decedents were aged 10-24 years (versus 11.1% of whites). Compared with whites, AI/AN decedents had 6.6 times the odds of living in a nonmetropolitan area, 2.1 times the odds of a positive alcohol toxicology result, and 2.4 times the odds of a suicide of a friend or family member affecting their death. Suicide prevention efforts should incorporate evidence-based, culturally relevant strategies at individual, interpersonal, and community levels (2) and need to account for the heterogeneity among AI/AN communities (3,4).

identification. §, ¶ Non-Hispanic whites (whites) were used as a comparison group because they have the second-highest suicide rate, but concentrated among different age groups than AI/AN, allowing for comparisons that might reveal unique contributors to suicide above general risk factors. Rural-Urban Commuting Area codes were used to classify geographic areas into metropolitan and nonmetropolitan categories.** Demographics, incident characteristics, and precipitating circumstances were examined by race/ethnicity using chi-squared tests. Significant chi-squared results (p<0.05) were further examined using logistic regression, controlling for age and sex.
From 2003 to 2014, a total of 1,531 suicides among AI/ AN and 103,986 among whites were collected in NVDRS (Table 1). More than one third (35.7%) of AI/AN suicides § https://www.cdc.gov/violenceprevention/pdf/nvdrs_web_codingmanual.pdf. ¶ Information on race and ethnicity are recorded as separate items in NVDRS consistent with U.S. Department of Health and Human Services (HHS) and Office of Management and Budget standards for race/ethnicity categorization. HHS guidance on race/ethnicity is available at https://aspe.hhs.gov/datacncl/ standards/ACA/4302/index.shtml. ** ZIP Code Rural-Urban Commuting Area (RUCA) codes (2010) were used to determine whether decedents resided in nonmetropolitan versus metropolitan areas. RUCA codes measure daily commuting flows, population density, and urbanization levels to classify sub-county level geographic areas. Victim residential ZIP codes were dichotomized as "metro" (RUCA codes 1-3) and "nonmetro" (RUCA codes 4-10). Descriptions of the RUCA classification codes 1-10 are available at https://www.ers.usda.gov/dataproducts/rural-urban-commuting-area-codes/documentation/. Circumstance information, obtained primarily through information provided by persons who knew the decedent as indicated in coroner/medical examiner reports and law enforcement reports, was known for 87.5% of AI/AN and 89.8% of white suicides (Table 2). Although intimate partner problems were a common precipitating circumstance for both AI/AN (39.1%) and white decedents (29.4%), AI/AN had significantly higher odds of experiencing this circumstance (aOR = 1.2; 95% CI = 1.1-1.3). Approximately two in 10 AI/AN suicides were preceded by an argument, compared with one in 10 white suicides (aOR = 1.4; 95% CI = 1.2-1.7). Compared with white decedents, AI/AN decedents had 2.4 times the odds of the suicide of a friend or family member affecting their death (as ascertained through a note or interviews with persons who knew the decedent) (95% CI = 1.9-3.1) and 1.7 times the odds Island, South Carolina, Utah, Virginia, and Wisconsin. † Adjusted odds ratios measure the association between the decedent having the demographic or incident characteristic and the race of the decedent being AI/AN. Each adjusted odds ratio used white as the reference group and controlled for age group and sex. Therefore, odd ratios for age groups and sex are not presented. § Chi-squared test result for difference between AI/AN and white significant at p<0.05. ¶ ZIP Code Rural-Urban Commuting Area (RUCA) codes (2010) were used to determine whether a victim resided in a nonmetropolitan versus a metropolitan area. Victim residential ZIP codes were dichotomized as "metro" (RUCA codes 1-3) and "nonmetro" (RUCA codes 4-10). Descriptions of the RUCA classifications codes 1-10 are available at https://www.ers.usda.gov/ data-products/rural-urban-commuting-area-codes/documentation/. ** No significant difference was found between AI/AN and white for this incident characteristic, therefore no measure of association was calculated. † † Statistical reliability criteria for logistic regression not met because cell frequencies were less than the required minimum. § § Includes suicides that occurred in a motor vehicle, street, highway, parking lot/garage, public transport, railroad tracks, or bridge. ¶ ¶ Includes suicides that occurred in a beach, river, field, or woods. *** Includes suicides that occurred in jail, prison, or supervised residential facility.
† † † Includes suicides that occurred in industrial or construction sites or an abandoned house, building, or warehouse.

Discussion
Suicide rates among AI/AN are historically higher than those of the total U.S. population (1). The results of this study are consistent with previous research on risk factors for AI/AN suicidal behaviors (3,5) and provide additional information on important circumstances and characteristics that precede suicide among AI/AN. Across many demographics, incident characteristics, and circumstances, AI/AN decedents were significantly different from whites.
Approximately 70% of AI/AN decedents resided in nonmetropolitan areas, including rural settings, underscoring the importance of implementing suicide prevention strategies in rural AI/AN communities. Residential status can affect the circumstances surrounding suicide. For example, in this study AI/AN decedents had lower odds than did white decedents of having received a mental health diagnosis or mental health treatment, even when controlling for age and sex. Rural areas often have lower availability and use of mental health services because of provider shortages † † and social barriers, including stigma and lack of culturally competent care (6). To address provider shortages, financial incentives, such as loan forgiveness for mental health practitioners, represent one strategy that could be helpful in recruiting providers for rural and nonmetropolitan areas (2). The high rate of suicides among AI/AN youths highlights the need for early prevention. School-based programs are able to reach a large number of AI/AN youths at high risk and could increase the availability of services for AI/AN in isolated nonmetropolitan areas (4). In addition, school-based programs that focus on individual life skills development and interpersonal social emotional learning programs to promote healthy relationships and conflict resolution might address the higher occurrence of intimate partner problems and arguments preceding AI/AN suicides (2,4).
AI/AN decedents were more likely to have a friend's or family member's suicide contribute to their death. A previous study in one AI/AN tribe found that suicidal behavior occurred close in time and within tight social networks, suggesting suicide contagion (5). Given the observation that AI/AN had an elevated risk of their own suicide being linked to the suicide death of a loved one, community level prevention strategies, including programs that focus on postvention (e.g., survivor support groups) and safe reporting of suicides by the media (e.g., not using sensationalized headlines), should be considered (http://reportingonsuicide.org/wp-content/themes/ros2015/ assets/images/Recommendations-eng.pdf ) (2).
Substance use is a recognized risk factor for suicidal behavior (4). A larger proportion of AI/AN decedents used alcohol before their suicide and had reported alcohol abuse problems. Previous studies have found that AI/AN youths aged 12-17 years have the highest rates of alcohol use among all racial/ethnic groups (4). Community-based programs to reduce excessive alcohol use (e.g., enforcement of laws prohibiting sales to minors and increasing alcohol taxes) and individual-level programs for persons at various risk levels, such as improved access to substance abuse treatment and life skills development programs for youths are necessary (1,4,7). Differences in the prevalence of alcohol use, interpersonal problems, and access to mental health treatment among AI/AN might be symptoms of disproportionate exposure to poverty, historical trauma, and other contexts of inequity and should not be viewed as inherent to AI/AN culture (4,8).
The findings in this report are subject to at least five limitations. First, race of AI/AN decedents is often misclassified on death certificates resulting in underascertainment of AI/AN mortality, including suicide (9). Second, tribal affiliation is not collected in NVDRS. Thus, the heterogeneity of AI/AN tribes and the cultural differences between these communities could not be assessed, and results might not be generalizable across all AI/AN communities. Future studies are needed to identify

Summary
What is already known about this topic? American Indian/Alaska Natives (AI/AN) have the highest rates of suicide of any racial/ethnic group in the United States. The rates of suicide in this population have been increasing since 2003.
What is added by this report?
Analysis of National Violent Death Reporting System data from 18 states showed AI/AN suicide decedents were younger and had higher odds of living in a nonmetropolitan area than did non-Hispanic whites who died by suicide. Suicide and nonsuicide deaths of friends and family, as well as alcohol use preceding death were associated with AI/AN decedents more often than non-Hispanic white decedents.
What are the implications for public health practice?
The high prevalence of suicide among the AI/AN population and the comparative differences in suicide circumstances among AI/AN decedents illustrate some of the disparities this population faces. Focused, yet comprehensive, suicide prevention and intervention efforts are needed that incorporate culturally relevant, evidence-based strategies at the individual, interpersonal, and community levels.
risk and protective factors for suicide that might be unique to individual tribes or communities. Third, it was not possible to determine whether decedents resided on tribal reservations based on the available information. Fourth, mental health diagnoses and treatment status are based on informant reports and could be underreported for either or both groups. Finally, NVDRS data were available from 18 states as of the time of this report and are therefore not necessarily representative of suicides outside these areas.
Prior research suggests comprehensive suicide prevention strategies designed to address the specific needs of an AI/AN  community are associated with reductions in suicide (10). The high prevalence of suicide among AI/AN and the comparative differences in suicide circumstances among this group are illustrative of the inequities faced by this population. This study highlights the importance of focused suicide prevention and intervention efforts that incorporate culturally relevant, evidence-based strategies at the individual, interpersonal, and community levels (2).