Regional Variations in Suicide Rates -- United States, 1990-1994

In 1994, suicides were committed by 31,142 persons in the
United States (crude rate: 12.0 suicides per 100,000 population),
and suicide was the ninth leading cause of death (1). Although
rates of suicide have varied by geographic region (e.g., rates have
consistently been higher in western states {2}), reasons for these
regional variations are unknown but may reflect regional
differences in certain demographic variables. For example, suicide
rates have been higher for males, for the elderly, and for certain
racial/ethnic groups (e.g., non-Hispanic whites and American
Indians/Alaskan Natives) (2). CDC examined U.S. suicide rates from
1990 through 1994 to determine whether regional variations in
suicide rates are affected by differences in age,
race/Hispanic-ethnicity, and sex and to examine whether
method-specific rates varied by region. This report summarizes the
results of that analysis, which indicate that, despite adjustments
for certain demographic variables, regional differences persist.

Suicides in each state were identified using final mortality
data from CDC's underlying cause-of-death files for each year
during 1990-1994. Suicide and methods of fatal self-inflicted
injury were classified using the International Classification of
Diseases, Ninth Revision, (codes E950-E959). The three leading
methods of suicide (firearms {E955.0-E955.4}, strangulation {E953},
and overdose {E950}) and all other methods (inhalation {E951-E952},
cutting {E956}, drowning {E954}, falls {E957}, and others
{E958-E959})
combined were examined. Rates were calculated for 1990-1994
using population data from the 1990 Census enumerations and
postcensal year estimates compiled by the U.S. Bureau of the
Census. Crude suicide rates for each state were adjusted for age,
race/Hispanic-ethnicity, and sex. Overall- and method-specific
adjusted suicide rates were examined by region *.

During 1990-1994, a total of 154,444 persons committed suicide
in the United States; 23,734 (15%) suicides occurred in the
Northeast, 34,492 (22%) in the Midwest, 38,709 (25%) in the West,
and 57,509 (37%) in the South (Table_1). When state-specific
crude
suicide rates for the U.S. were ranked by quartiles, the rates from
10 of the 13 western states ranked in the highest quartile. This
pattern persisted after adjustments for age,
race/Hispanic-ethnicity, and sex (Figure_1).

Regional crude suicide rates were highest for persons residing
in the West (14.1 per 100,000 population), followed by the South
(13.1), Midwest (11.4), and Northeast (9.3). After adjusting for
age, race/Hispanic-ethnicity, and sex, rates remained highest in
the West (14.7), followed by the South (13.1), Midwest (10.9), and
Northeast (8.6). All regional rates were significantly different
from the total U.S. adjusted suicide rate (11.8 per 100,000
population) and from each other. Adjusted suicide rates were
approximately 70% higher in the West than in the Northeast (rate
ratio {RR}=1.7) (3).

When suicide rates in each region were stratified by method,
rates were highest in the West for all methods except firearms.
Firearms were the leading method in all regions, accounting for
69.8% of all suicides in the South, 58.3% in the West, 57.8% in the
Midwest, and 44.9% in the Northeast.

Regional variations were greatest for overdose- and
firearm-related suicide rates. For overdose, the adjusted suicide
rate in the West was approximately 100% higher than in the
Northeast, which had the lowest rate (RR=2.1). Adjusted firearm
suicide rates were highest in the South and were 130% higher than
in the Northeast (RR=2.3).

Editorial Note

Editorial Note: The findings in this report are consistent with
previous studies that documented regional differences in suicide
rates in the United States. In particular, during 1990-1994, both
crude and adjusted suicide rates were significantly higher in the
West than in the South, Midwest, and Northeast, and firearms were
the leading method employed in all regions. Factors that may
account for regional differences in suicide rates are varied and
complex. Regional differences in demographic patterns (i.e., age,
race/Hispanic-ethnicity, and sex) and in suicide methods do not
completely account for variations in suicide, and additional
analyses are required to clarify reasons for these differences and
to develop tailored prevention strategies.

The findings in this report are limited by the constraints
inherent in mortality data. Mortality files provide a limited
number of variables that may explain regional variations in suicide
rates, and reporting levels for some of these variables differ
among the states. For example, even though educational attainment
is contained in mortality files, this variable was not examined in
this analysis because of concerns about quality and completeness of
the data in some states. Marital status also is presented on death
certificates but was not examined for this report because it is not
consistently available in detailed state-level census data. Suicide
rates are inversely related to level of education, and are
substantially lower among married persons than among persons who
are single, separated, divorced, or widowed (2). However, available
census data reflect little variation in marital status and
educational attainment across regions, and it is unlikely that
these variables account for the differences in suicide rates.

Despite these limitations, this report documented important
region-specific differences in suicide rates both overall and when
stratified by method. For example, firearms were the leading method
in all regions, accounting for more than half the suicides
committed in every region except the Northeast (44.9%). The
availability of firearms in homes of suicidal or potentially
suicidal persons is associated with increased risk for suicide (4).
Although differences in firearm ownership or the availability of
firearms may account for some of the regional variation in suicide
rates, they do not explain the higher method-specific rates in the
West for strangulation, overdose, or other methods.

A spectrum of social and environmental factors have been
associated with suicidal behavior. For example, levels of
residential instability, unemployment, and other indicators of
limited economic opportunity may be higher in communities with
higher rates of suicide (5,6). Similarly, suicide rates are higher
in communities with low levels of social integration and unstable
social environments (5-7). Additional efforts are necessary to
determine the relation between these factors and variations in
regional suicide rates.

Arizona, Washington, and other states in the West have
initiated prevention strategies designed to reduce the impact of
injuries from suicidal behavior (8,9). For example, in Washington,
the suicide prevention plan includes multiple interventions such as
improving suicide surveillance efforts, public education campaigns,
crisis intervention services, and family support programs (10).
These strategies should be evaluated and, if documented effective,
adapted for use in other states, particularly those with the
highest suicide rates.

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