SUMMARY AND RECOMMENDATIONS
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67
68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84
85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101
102 103 104 105 106 107 108 109 110 111 112 113 114 115
The committee draws the following conclusions on the basis of the
present evidence:
1. States, regions, and countries with higher rates of household gun
ownership have higher rates of gun suicide. There is also cross-sectional,
ecological association between gun ownership and overall risk of suicide,
but this association is more modest than the association between gun ownership
and gun suicide; it is less consistently observed across time, place,
and persons; and the causal relation remains unclear.
2. The risk of suicide is highest immediately after the purchase of a
handgun, suggesting that some firearms are specifically purchased for the
purpose of committing suicide.
3. Some gun control policies may reduce the number of gun suicides,
but they have not yet been shown to reduce the overall risk of suicide in any
population.
TABLE 7-6 Quasi-Experimental Studies of Gun Laws and Suicide
Areas and
Time
Period
Source Compared Gun Law Population
Reuter and Australian 1996 gun buy- Whole population
Mouzos states, back
1979-1998
Ludwig and 50 states 1994 Brady act 21-54 years
Cook (2001) + DC
1985-1997 55+
Lott and 50 states Safe storage laws Children and
Whitley + DC adolescents 0-19
(2000) 1979-1996 Other gun laws
Cummings, 50 states Safe storage laws Children under 15
Grossman, + DC
Rivara, and 1979-1994
Koepsell
(1997a)
There are several substantive differences between the research literature
linking guns and crime and the research literature linking guns and suicide.
First, there is a cross-sectional association between rates of household gun
ownership and the number and fraction of suicides committed with a gun
that appears to be much more consistent than, for example, the crosssectional
association between gun ownership and gun homicide. There also
appears to be a cross-sectional association between rates of household gun
ownership and overall rates of suicide, reported by investigators on both
sides of the gun policy debate. However, the association is small, the findings
seem to vary by age and gender, and results have been sensitive to
model specifications, covariates, and measures used; furthermore, the association
is not found in comparisons across countries. In the absence of a
simple association between household gun ownership and crime rates within
the United States, the literature on guns and crime has been forced to attend
to some of the methodological problems of omitted variables and endogenous
relationships inherent in studying complex social processes. The presence
of a simple bivariate association between gun ownership and suicide
may have prevented suicide investigators from pursuing study designs hav-
Change in Change in Change in
Gun Suicide Nongun Suicide Overall Suicide
After Gun Law After Gun Law After Gun Law
Continuation of Continuation of Increase
of decreasing trend increasing trend
No significant No significant No significant
difference difference difference
Decrease No significant No significant
difference difference
Mixed: Not stated No significant
Decrease with difference
higher age limits
Not stated No significant
mixed differences
(see text)
No significant No significant No significant
difference difference difference
ing a better hope of justifying a causal inference. The issue of substitution
has been almost entirely ignored in the literature of guns and suicide.
Some of the problems in the suicide literature may also be attributable
to the intellectual traditions of the injury prevention field, which has been
strongly shaped by successes in the prevention of car crashes and other
unintentional injuries. An unintentional injury prevention model can lead
to misunderstandings when it is applied to the study of intentional injury;
the investigation of intentional injury should take account of the complexities
of preference, motivation, constraint, and social interaction among the
individuals involved.
In addition to better addressing these fundamental problems associated
with drawing causal inferences, this chapter has highlighted a number of
other data and methodological obstacles. What sort of data and what sort
of studies would be needed in order to improve the understanding of the
association between firearms and suicide? Although some knowledge may
be gained from further ecological studies, the most important priorities
appear, to the committee, to be improved data systems, improved individual-
level studies of the association between gun ownership and suicide,
and a more systematic analysis of the effect of firearms laws and related
interventions on the risk of suicide.
Proxy Measures of Gun Ownership
The association between gun ownership and gun suicide has led to
recommendations for the use of the fraction of suicides committed with a
firearm (FS/S) as a proxy for household gun ownership when direct measures
are unavailable. This means that a better understanding of the relationship
between firearms and suicide may also make a technical contribution
to the study of firearms and crime. However, investigators should be
aware of the biases that can be introduced by any proxy measures, and they
are warned that particularly serious artifacts can be introduced if FS/S is
used as a proxy for gun ownership when suicide is also the outcome of
interest.