Suicides, homicides, accidents, and other external causes of death among blacks and whites in the Southern Community Cohort Study.

Jennifer S Sonderman,William J Blot,Heather M Munro,Robert E Tarone,Joseph K Mclaughlin

doi:10.1371/journal.pone.0114852

Jennifer S Sonderman, William J Blot + Show 3 more

Open Access

https://doi.org/10.1371/journal.pone.0114852

Copy DOI

Abstract

Prior studies of risk factors associated with external causes of death have been limited in the number of covariates investigated and external causes examined. Herein, associations between numerous demographic, lifestyle, and health-related factors and the major causes of external mortality, such as suicide, homicide, and accident, were assessed prospectively among 73,422 black and white participants in the Southern Community Cohort Study (SCCS). Hazard ratios (HR) and 95% confidence intervals (CI) were calculated in multivariate regression analyses using the Cox proportional hazards model. Men compared with women (HR = 2.32; 95% CI: 1.87–2.89), current smokers (HR = 1.74; 95% CI: 1.40–2.17), and unemployed/never employed participants at the time of enrollment (HR = 1.67; 95% CI 1.38–2.02) had increased risk of dying from all external causes, with similarly elevated HRs for suicide, homicide, and accidental death among both blacks and whites. Blacks compared with whites had lower risk of accidental death (HR = 0.46; 95% CI: 0.38–0.57) and suicide (HR = 0.55; 95% CI: 0.31–0.99). Blacks and whites in the SCCS had comparable risks of homicide death (HR = 1.05; 95% CI: 0.63–1.76); however, whites in the SCCS had unusually high homicide rates compared with all whites who were resident in the 12 SCCS states, while black SCCS participants had homicide rates similar to those of all blacks residing in the SCCS states. Depression was the strongest risk factor for suicide, while being married was protective against death from homicide in both races. Being overweight/obese at enrollment was associated with reduced risks in all external causes of death, and the number of comorbid conditions was a risk factor for iatrogenic deaths. Most risk factors identified in earlier studies of external causes of death were confirmed in the SCCS cohort, in spite of the low SES of SCCS participants. Results from other epidemiologic cohorts are needed to confirm the novel findings identified in this study.

Highlights

External causes of death comprise a heterogeneous collection of events including the three major categories of suicide, homicide, and accidental death
Racial differences have persisted after adjustment for these factors in the United States (US) [19], and it has been suggested that risk factors for suicide among whites, for example, alcohol consumption, may not be a risk factor among blacks [8, 20]
Blacks in the Southern Community Cohort Study (SCCS) had 50% lower risks of suicides and accidental deaths compared with whites, consistent with expectation based on national mortality rates [1]

Summary

Introduction

External causes of death comprise a heterogeneous collection of events including the three major categories of suicide, homicide, and accidental death. These causes of death represent a significant proportion of potentially preventable mortality in the United States (US). In 2010, US whites had a much higher rate of death due to suicides (14.1 per 100,000) than US blacks (5.1 per 100,000) [1, 2]. The rate of death due to accidents was higher among whites (42.8 per 100,000) than among blacks (28.7 per 100,000). Blacks had a much higher death rate due to homicide (18.6 per 100,000) than whites (3.2 per 100,000) [1]. Religiosity has been suggested to reduce suicide risk among blacks in the US, but the evidence has been inconsistent [4, 16, 21]

Methods

Results

Conclusion