Risk of Suicide Among Recent Gun Purchasers

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Another way to clarify the causal relationship between suicidal intention

and gun ownership is to study the risk of suicide among recent gun

purchasers. Two record linkage studies have done this by using state gun

registration systems to compare the risk of suicide among gun purchasers

with the risk of suicide in a general population. Both of these studies

suggest that a small but significant fraction of gun suicides are committed

within days to weeks after the purchase of a handgun, and both also indicate

that gun purchasers have an elevated risk of suicide for many years

after the purchase of the gun. The first study, by Cummings et al. (1997a),

linked the membership list of a large health maintenance organization

(HMO) in Washington State with state handgun registration records and

state death certificates. Cases were HMO members who died of suicide or

homicide between 1980 and 1992; for each case subject, five control subjects

matched by age, sex, and zip code were randomly selected from the

HMO membership list. For each case and control subject, family members

were identified, and computerized records of handgun purchasers in Washington

State were searched for the first occurrence of a handgun purchase

from 1940 until the case’s date of death. About 52.7 percent of the suicides

were committed with a gun; 24.6 percent of persons who committed suicide

had a history of a handgun purchase by themselves or a family member,

compared with 15.1 percent of controls, with an adjusted relative risk of

1.9 (95 percent confidence interval 1.4 to 2.5). About 3.1 percent of suicide

victims or their family members had purchased a first handgun within a

year of the suicide, compared with 0.7 percent of controls. After the first

year, the relative risk of suicide persisted, but at a much lower level; the

median interval from first handgun purchase to suicide with a gun was 10.7

years.

The second study, by Wintemute et al. (1999), reported similar findings

in a population-based study of individuals purchasing handguns in California

in 1991. This study did not investigate the risk of suicide among the

family members of gun purchasers, but the changes in suicide risk over time

were presented in more detail. Age and sex-standardized mortality ratios

for handgun purchasers were compared with the mortality of the general

adult population of California. The risk of suicide in the first week after

purchase was 57 times the risk of suicide in the general population, and the

risk within the first year was 4.31 times the risk of suicide of the general

population. The rates of suicide by firearm within the first six years after

handgun purchase are presented graphically in Figure 7-2.

Taken together, these two studies provide strong evidence that some

guns are indeed purchased for the purpose of carrying out a planned suicide,

but this seems to represent only a small fraction of completed suicides:

handguns purchased within the past year were used in about 5 percent of

suicides in California, and about 3 percent of suicides in the Washington

HMO. However, the focus on legal handgun purchases provides only a

lower-bound estimate of the fraction of gun purchases that have occurred

0

25

50

75

100

1 2 3 4 5 6

Years

Suicides by Firearm (no./100,000

person-years)

FIGURE 7-2 Rates of suicide by firearm during the six years after purchase among

persons who purchased in California in 1991.

NOTE: The horizontal line indicates the age- sex-adjusted average annual rate of

suicide by firearms in California for 1991-1995 (10.7 per 100,000 persons per

year).

SOURCE: Adapted from Wintemute et al. (1999).

for the purpose of suicide, and both studies concern the purchase of handguns

in states with gun registration laws, so they do not indicate how many

guns might be purchased for the purpose of suicide if gun registration did

not occur. The most important limitation is that these studies do not indicate

whether handgun purchasers would have substituted other methods of

suicide if a gun were not available, and do not measure other factors, such

as history of substance abuse, psychiatric illness, criminal activity, or domestic

violence, which might explain or modify a link between gun ownership

and propensity for suicide.