Person:

Connery, Hilary

Objective: A paucity of corroborative psychological and psychiatric evidence may be inhibiting detection of drug intoxication suicides in the United States. We evaluated the relative importance of suicide notes and psychiatric history in the classification of suicide by drug intoxication versus firearm (gunshot wound) plus hanging/suffocation—the other two major, but overtly violent methods. Methods: This observational multilevel (individual/county), multivariable study employed a generalized linear mixed model (GLMM) to analyze pooled suicides and undetermined intent deaths, as possible suicides, among the population aged 15 years and older in the 17 states participating in the National Violent Death Reporting System throughout 2011–2013. The outcome measure was relative odds of suicide versus undetermined classification, adjusted for demographics, precipitating circumstances, and investigation characteristics. Results: A suicide note, prior suicide attempt, or affective disorder was documented in less than one-third of suicides and one-quarter of undetermined deaths. The prevalence gaps were larger among drug intoxication cases than gunshot/hanging cases. The latter were more likely than intoxication cases to be classified as suicide versus undetermined manner of death (adjusted odds ratio [OR], 41.14; 95% CI, 34.43–49.15), as were cases documenting a suicide note (OR, 33.90; 95% CI, 26.11–44.05), prior suicide attempt (OR, 2.42; 95% CI, 2.11–2.77), or depression (OR, 1.61; 95% CI, 1.38 to 1.88), or bipolar disorder (OR, 1.41; 95% CI, 1.10–1.81). Stratification by mechanism/cause intensified the association between a note and suicide classification for intoxication cases (OR, 45.43; 95% CI, 31.06–66.58). Prior suicide attempt (OR, 2.64; 95% CI, 2.19–3.18) and depression (OR, 1.48; 95% CI, 1.17–1.87) were associated with suicide classification in intoxication but not gunshot/hanging cases. Conclusions: Without psychological/psychiatric evidence contributing to manner of death classification, suicide by drug intoxication in the US is likely profoundly under-reported. Findings harbor adverse implications for surveillance, etiologic understanding, and prevention of suicides and drug deaths.

Objective: Higher prevalence of suicide notes could signify more conservatism in accounting and greater proneness to undercounting of suicide by method. We tested two hypotheses: (1) an evidentiary suicide note is more likely to accompany suicides by drug-intoxication and by other poisoning, as less violent and less forensically overt methods, than suicides by firearm and hanging/suffocation; and (2) performance of a forensic autopsy attenuates any observed association between overtness of method and the reported presence of a note. Methods: This multilevel (individual/county), multivariable analysis employed a generalized linear mixed model (GLMM). Representing the 17 states participating in the United States National Violent Death Reporting System throughout 2011–2013, the study population comprised registered suicides, aged 15 years and older. Decedents totaled 32,151. The outcome measure was relative odds of an authenticated suicide note. Results: An authenticated suicide note was documented in 31% of the suicide cases. Inspection of the full multivariable model showed a suicide note was more likely to manifest among drug intoxication (adjusted odds ratio [OR], 1.70; 95% CI, 1.56, 1.85) and other poisoning suicides (OR, 2.12; 1.85, 2.42) than firearm suicides, the referent. Respective excesses were larger when there was no autopsy or autopsy status was unknown (OR, 1.86; 95% CI, 1.61, 2.14) and (OR, 2.25; 95% CI, 1.86, 2.72) relative to the comparisons with a forensic autopsy (OR, 1.62, 95% CI, 1.45, 1.82 and OR, 2.01; 95% CI, 1.66, 2.43). Hanging/suffocation suicides did not differ from the firearm referent given an autopsy. Conclusions: Suicide requires substantial affirmative evidence to establish manner of death, and affirmation of drug intoxication suicides appears to demand an especially high burden of proof. Findings and their implications argue for more stringent investigative standards, better training, and more resources to support comprehensive and accurate case ascertainment, as the foundation for developing evidence-based suicide prevention initiatives.