Social, environmental factors key to assessing rates of self-injury mortality and suicide

A variety of social and environmental factors are crucial to assess rates of self-injury mortality and suicide, according to results of a 2-decade-long U.S. cross-sectional study published in JAMA Network Open.

“This national study breaks new ground by identifying characteristics of states that are associated with high or low rates of self-injury mortality,” Ian R. H. Rockett, PhD, MPH, of the department of epidemiology and biostatistics in the School of Public Health at West Virginia University, told Healio. “These characteristics represent economic inequality, social isolation, demographics, barriers to health care, means or mechanisms of injury and system type as a surrogate for the variable quality of the medicolegal death investigations themselves.”

“Self-injury mortality (SIM) was conceived to transcend registered suicides by augmenting these known suicides, by any method, with most fatal opioid and other drug overdoses,” Rockett added. “Currently unknowable, some and perhaps many of these overdoses are misclassified suicides.”

Rockett and colleagues sought to examine any administrative and contextual factors associated with both state-level SIM as well as suicide rates, and to explore the differentials of regions and states to undercount suicides due to drug-death misclassification.

The researchers utilized a partial panel time series with underlying cause-of-death data in 101,325 SIMs from all 50 states and Washington, D.C., for the intervals of 1999 to 2000, 2007 to 2008, 2013 to 2014 and 2018 to 2019, which included all suicides, accidental and undetermined drug intoxication deaths and self-harm behaviors.

Ratios of basic SIM to suicide rates per 100,000 people were analyzed for potential misclassification. Data were analyzed from February 2021 to June 2021.

Results showed that SIM-to-suicide rate ratios sharply trended upwards over the course of the study intervals, with an attendant increase of overdose fatalities classified as unintentional or undetermined (1999-2000: 1.39; 95% CI, 1.38-1.41; 2018-2019: 2.12; 95% CI, 2.11-2.14). Rockett and colleagues also found that eight states posted a SIM-to-suicide rate ratio lower than 1.5 in 2018 to 2019 compared with 39 states in 1999 to 2000.

Eight factors were found to hold associations with the SIM rate by 2018 to 2019: centralized medical examiner system, labor underutilization rate, manufacturing employment, homelessness rate, percentage nonreligious, non-Hispanic white race and ethnicity, persons prescribed opioids for 30 days or more, and percentage of those lacking health insurance. Five additional factors associated with the suicide rate were percentage male, military veteran, rural location, gun ownership and misuse of pain relievers.

“This study suggests that reversal of the rising SIM trends in the 21st century, exacerbated by the COVID-19 pandemic, will require upstream preventive measures that target the economy, health care industry, schools and colleges, the military, jails and prisons, and other major institutions, as well as the need to scale treatment interventions with high-risk patients in hospital emergency department and psychiatric care settings,” Rockett said.