In total, 16 measures of either state-level firearm-control laws (Fig. 2), ATF-tracked firearm statistics, or gun ownership rates were collected for each state. In the unadjusted bivariate linear regression comparing these measures and firearm-related suicides for adults aged 18 years or older, 11 of 16 measures were significantly associated with fewer firearm-related suicides (Table 1). These included reduced gun ownership rates, lower Giffords Center ranking, handgun permit requirements, handgun magazine size restrictions, open carry restrictions, background check requirements for private gun sales, long gun magazine size restrictions, long gun registration requirements, child access prevention laws, safe storage requirements, and assault weapon bans (Table 1). In the same unadjusted bivariate analysis for children under 18 years of age, 11 of 16 measures were also associated with significantly fewer firearm-related suicides. These included fewer federal firearm licensees by state, lower gun ownership rates, lower Giffords Center ranking, handgun magazine size restrictions, handgun open carry restrictions, background check requirements on private gun sales, long gun magazine size restrictions, long gun registration requirements, child access prevention laws, safe storage requirements, and assault weapon bans (Fig. 3). The Beta value represents the slope of the relationship while the p value represents the strength of the statistical relationship between the two variables. For example, for gun ownership percentage in the adult population, the beta value of 0.22 notes that as the gun ownership percentage in a given state increases by 1 unit, there is 0.22 unit increase in the rate of firearm-related suicides in the adult population. This is significant at a p value of < 0.001. Therefore, states with higher gun ownership percentages are statistically associated with higher rates of adult firearm-related suicides, but no causal inference can be concluded.
Table 1
Unadjusted Analysis of 16 Firearm-Related Measures and Firearm-Related Suicides
Unadjusted Analysis |
| Adults | Children |
Statistical Measure | β (Slope) | P-Value | β (Slope) | P-Value |
ATF-Registered Weapons by State | -5.18E-06 | 0.52 | -3.24E-06 | 0.11 |
Federal Firearm Licensees by State | -4.24E-04 | 0.13 | -1.56E-04 | 0.03 |
Gun Ownership (% of adults) by State | 0.22 | < 0.001 | 0.052 | < 0.001 |
Gifford Ranking by State | 0.21 | < 0.001 | 0.047 | 0.001 |
Gun Law- Handgun Permit required | -2.68 | 0.01 | -0.53 | 0.06 |
Gun Law - Handgun Magazine Size restriction | -5.46 | < 0.001 | -1.11 | 0.002 |
Gun Law - Handgun Open Carry allowed | 3.42 | 0.03 | 0.83 | 0.04 |
Gun Law - Background Check on Private Gun Sales required | -4.6 | < 0.001 | -0.99 | 0.002 |
Gun Law - Long Gun Carry Permit required | -1.56 | 0.41 | -0.35 | 0.46 |
Gun Law - Long Gun Magazine Size restriction | -4.98 | < 0.001 | -1.02 | 0.007 |
Gun Law - Long Gun Open Carry allowed | 2.97 | 0.062 | 0.73 | 0.071 |
Gun Law - Long Gun Purchase Permit | -5.46 | 0.052 | -1. 19 | 0.097 |
Gun Law - Long Gun Registration required | -6.14 | 0.007 | -1.28 | 0.029 |
Gun Law - Child Access Prevention Firearm Law | -3.31 | 0.002 | -0.93 | < 0.001 |
Gun Law - Safe Storage or Gun Lock Requirement | -6.2 | < 0.001 | -1.22 | < 0.001 |
Gun Law - Assault Weapons Ban | -7.18 | < 0.001 | -1.38 | < 0.001 |
In the adjusted linear regression, controlling for poor mental health, percentage of nonwhite citizens, educational attainment, divorce rates, and poverty, 6 of 16 measures were still significantly associated with fewer firearm-related suicides among adults. These measures included lower gun ownership percentages, lower Giffords ranking, handgun permit requirements, handgun magazine size restriction, background checks on private gun sales, safe storage requirements, and assault weapon bans (Table 2). For example, in the adult population, holding divorce rates, poor mental health, the percentage of non-white citizens, educational attainment, and poverty the same across all states, for every increase in Gifford Center Ranking, there is a 0.17 unit increase in firearm-related suicides among adults for a given state. Since higher Gifford Center Ranking represent states with more relaxed gun laws, this can be interpreted as states with more relaxed gun laws are associated with increased firearm-related suicides, even after controlling for the aforementioned variables. In the adjusted multivariate analysis in the pediatric population, 5 of 16 measures were still significantly associated with fewer firearm-related suicides, including lower gun ownership rates, lower Giffords Center ranking, background checks on private gun sales, child access prevention laws, and safe storage requirements (Table 2), even after controlling for the aforementioned five potential confounding variables.
Table 2
Adjusted Analysis of 16 Firearm-Related Measures vs. Firearm-Related Suicides
Adjusted Analysis |
| Adults | Children |
Statistical Measure | β (Slope) | P-Value | β (Slope) | P-Value |
ATF-Registered Weapons by State | 4.55E-06 | 0.54 | 2.70E-07 | 0.9 |
Federal Firearm Licensees by State | -1.72E-04 | 0.49 | -5.87E-05 | 0.42 |
Gun Ownership (% of adults) by State | 0.19 | < 0.001 | 0.053 | < 0.001 |
Gifford Ranking by State | 0.17 | < 0.001 | 0.047 | < 0.001 |
Gun Law- Handgun Permit required | -1.85 | 0.03 | -0.44 | 0.08 |
Gun Law - Handgun Magazine Size restriction | -2.22 | 0.11 | -0.67 | 0.1 |
Gun Law - Handgun Open Carry allowed | 1.21 | 0.36 | 0.3 | 0.44 |
Gun Law - Background Check on Private Gun Sales required | -2.56 | 0.01 | -0.68 | 0.03 |
Gun Law - Long Gun Carry Permit required | -0.44 | 0.76 | -0.29 | 0.49 |
Gun Law - Long Gun Magazine Size restriction | -1.86 | 0.17 | -0.44 | 0.26 |
Gun Law - Long Gun Open Carry allowed | 0.93 | 0.47 | 0.2 | 0.6 |
Gun Law - Long Gun Purchase Permit | 0.13 | 0.96 | 0.11 | 0.88 |
Gun Law - Long Gun Registration required | -0.3 | 0.89 | -0.33 | 0.61 |
Gun Law - Child Access Prevention Firearm Law | -1.83 | 0.0594 | -0.58 | 0.04 |
Gun Law - Safe Storage or Gun Lock Requirement | -3.82 | 0.001 | -0.74 | 0.04 |
Gun Law - Assault Weapons Ban | -4.09 | 0.02 | -0.85 | 0.11 |
No measures relating to fewer guns in circulation or a more restrictive regulatory firearm environment were associated with an increase in firearm-related suicide among either juveniles or adults. Rather, of the associations that were statistically significant, all firearm-related restrictions or measures denoting fewer firearms in circulation resulted in diminished rates of firearm-related suicide among both the pediatric and adult populations.