Self-injury Mortality in the United States in the Early 21st Century: A Comparison With Proximally Ranked Diseases

Abstract

Importance: Fatal self-injury in the United States associated with deliberate behaviors is seriously underestimated owing to misclassification of poisoning suicides and mischaracterization of most drug poisoning deaths as “accidents” on death certificates. Objective: To compare national trends and patterns of self-injury mortality (SIM) with mortality from 3 proximally ranked top 10 causes of death: diabetes, influenza and pneumonia, and kidney disease. Data, Setting, and Participants: Underlying cause-of-death data from 1999 to 2014 were extracted for this observational study from death certificate data in the US Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research online databases. Linear time trends were compared by negative binomial regression with a log link function. Self-injury mortality was defined as a composite of suicides by any method and estimated deaths from drug self-intoxication whose manner was an “accident” or was undetermined. Main Outcomes and Measures: Mortality rates and ratios, cumulative mortality in individuals younger than 55 years, and years of life lost in 2014.Results: There were an estimated 40 289 self-injury deaths in 1999 and 76 227 in 2014. Females comprised 8923 (22.1%) of the deaths in 1999 and 21 950 (28.8%) of the 76 227 deaths in 2014. The estimated crude rate for SIM increased 65% between 1999 and 2014, from 14.4 to 23.9 deaths per 100 000 persons (rate ratio, 1.03; 95% CI, 1.03-1.04; P < .001). The SIM rate continuously exceeded the kidney disease mortality rate and surpassed the influenza and pneumonia mortality rate by 2006. By 2014, the SIM rate converged with the diabetes mortality rate. Additionally, the SIM rate was 1.8-fold higher than the suicide rate in 2014 vs 1.4-fold higher in 1999. The male-to-female ratio for SIM decreased from 3.7 in 1999 to 2.6 in 2014 (male by year: rate ratio, 0.98; 95% CI, 0.97-0.98; P < .001). By 2014, SIM accounted for 32.2 and 36.6 years of life lost for male and female decedents, respectively, compared with 15.8 and 17.3 years from diabetes, 15.0 and 16.6 years from influenza and pneumonia, and 14.5 and 16.2 years from kidney disease.Conclusions and Relevance: The burgeoning SIM rate has converged with the mortality rate for diabetes, but there is a 6-fold differential in the proportion of SIM vs diabetes deaths involving people younger than 55 years and SIM is increasingly affecting women relative to men. Accurately characterizing, measuring, and monitoring this major clinical and public health challenge will be essential for developing a comprehensive etiologic understanding and evaluating preventive and therapeutic interventions.