To the Editor:

Despite high rates of unintentional firearm injuries,1-3 and recognition by the National Rifle Association (NRA) that firearm education is important,4 it is often said that firearm injuries occur primarily among inexperienced users and that firearm safety comes with experience and training. To investigate this contention, we conducted a study in which we hypothesized that firearm use would decline during the dates of NRA meetings — which attract tens of thousands of members from across the United States,5 including firearm owners and owners of venues where firearms are used (e.g., firing ranges and hunting grounds) — and that firearm injuries would also decline even among experienced users.

We identified emergency department visits and hospitalizations for firearm injuries during NRA convention dates and during identical days in the 3 weeks before and 3 weeks after NRA conventions in a national database of privately insured patients during 2007 through 2015. We estimated the rates of firearm injuries during convention dates versus control dates in a beneficiary-level multivariable linear regression of firearm injury (a binary variable) as a function of indicator variables for convention and control dates, patient age, sex, indicators for calendar week and year, and state fixed effects. We conducted subgroup analyses according to census region and state-level stratum of gun-ownership rates, hypothesizing that larger reductions in the rates of injury would occur in areas with more firearm use; according to patient sex, hypothesizing that larger reductions would occur among males, who disproportionately attend NRA meetings5; and according to whether a convention was held in a beneficiary’s state, hypothesizing that larger reductions would occur when conventions are easier to attend. In addition, we used the National Incident-Based Reporting System to analyze the proportion of crimes involving a firearm that occurred during convention versus control dates. Additional methods, results, and discussion are provided in the Supplementary Appendix, available with the full text of this letter at NEJM.org.

Figure 1. Figure 1. Firearm Injuries among Commercially Insured Persons That Occurred on Dates of National Rifle Association (NRA) Annual Conventions and Control Dates, 2007–2015. Shown are the adjusted rates of firearm injuries during convention dates versus control dates in a beneficiary-level multivariable linear regression of firearm injury as a function of indicator variables for convention and control dates, age, sex, indicators for calendar week and year (to adjust for seasonal trends), and state fixed effects. In Panel A, the adjusted estimates are from a model in which the key explanatory variable was a binary variable for NRA convention dates versus all control dates combined. In Panel B, the adjusted estimates are from a model in which the key explanatory variables were indicator variables for week relative to the NRA annual convention. In both panels, 𝙸 bars indicate 95% confidence intervals.

Among 75,567,650 beneficiary-period observations in the claims analysis, 14.3% occurred on NRA convention dates. The unadjusted rate of firearm injuries was lower during convention dates than during control dates (129 beneficiaries with a firearm injury among 10,883,304 persons [1.19 per 100,000] vs. 963 beneficiaries with a firearm injury among 64,683,254 persons [1.49 per 100,000]; P=0.004; relative difference, 20.1%; 95% confidence interval, 6.7 to 34.0). The findings were unaffected by adjustment for covariates (Figure 1).

Reductions in firearm injuries during convention dates were largest among men, in the South and West, in states in the highest third of gun-ownership rates, and among people who resided in the state hosting the convention. There was no difference in the proportion of crimes involving a firearm between convention and control dates.

These findings are consistent with reductions in firearm injuries occurring as a result of lower rates of firearm use during the brief period when many firearm owners and owners of places where firearms are used may be attending an NRA convention. Our results suggest that firearm-safety concerns and risks of injury are relevant even among experienced gun owners.

Anupam B. Jena, M.D., Ph.D.

Harvard Medical School, Boston, MA

Andrew R. Olenski, B.S.

Columbia University, New York, NY

Disclosure forms provided by the authors are available with the full text of this letter at NEJM.org.