Gun shows are an important source of firearms, but no adequately powered studies have examined whether they are associated with increases in firearm injuries.

To determine whether gun shows are associated with short-term increases in local firearm injuries and whether this association differs by the state in which the gun show is held.

Quasi-experimental.

California.

Persons in California within driving distance of gun shows.

Gun shows in California and Nevada between 2005 and 2013 (n = 915 shows) and rates of firearm-related deaths, emergency department visits, and inpatient hospitalizations in California.

Compared with the 2 weeks before, postshow firearm injury rates remained stable in regions near California gun shows but increased from 0.67 injuries (95% CI, 0.55 to 0.80 injuries) to 1.14 injuries (CI, 0.97 to 1.30 injuries) per 100 000 persons in regions near Nevada shows. After adjustment for seasonality and clustering, California shows were not associated with increases in local firearm injuries (rate ratio [RR], 0.99 [CI, 0.97 to 1.02]) but Nevada shows were associated with increased injuries in California (RR, 1.69 [CI, 1.16 to 2.45]). The pre–post difference was significantly higher for Nevada shows than California shows (ratio of RRs, 1.70 [CI, 1.17 to 2.47]). The Nevada association was driven by significant increases in firearm injuries from interpersonal violence (RR, 2.23 [CI, 1.01 to 4.89]) but corresponded to a small increase in absolute numbers. Nonfirearm injuries served as a negative control and were not associated with California or Nevada gun shows. Results were robust to sensitivity analyses.

Firearm injuries were examined only in California, and gun show occurrence was not randomized.

Gun shows in Nevada, but not California, were associated with local, short-term increases in firearm injuries in California. Differing associations for California versus Nevada gun shows may be due to California's stricter firearm regulations.

National Institutes of Health; University of California, Berkeley; and Heising-Simons Foundation.

枪支表演是枪支的重要来源，但没有足够有力的研究检查它们是否与枪支伤害的增加有关。

确定枪支表演是否与当地枪支伤害的短期增加有关，以及这种关联是否因举行枪支表演的州而异。

准实验。

加利福尼亚。

加利福尼亚州的人在枪展的车程范围内。

2005 年至 2013 年间加利福尼亚州和内华达州的枪支表演（n  = 915 场表演）以及加利福尼亚州与枪支相关的死亡率、急诊科就诊率和住院率。

与前 2 周相比，加州枪展附近地区的枪械伤害率保持稳定，但从每 10 万人中的 0.67 人受伤（95% CI，0.55 至 0.80 人受伤）增加到 1.14 人（CI，0.97 至 1.30 人受伤）。内华达州附近地区表演。在调整了季节性和聚类后，加利福尼亚州的表演与当地枪支伤害的增加无关（比率 [RR]，0.99 [CI，0.97 至 1.02]），但内华达州的表演与加利福尼亚的伤害增加有关（RR，1.69 [CI] , 1.16 至 2.45])。内华达州演出的前后差异显着高于加利福尼亚州演出（RR 比率，1.70 [CI，1.17 至 2.47]）。内华达州协会是由人际暴力造成的枪支伤害显着增加推动的（RR, 2.23 [CI, 1.01 to 4. 89]）但对应于绝对数量的小幅增加。非枪伤作为阴性对照，与加利福尼亚或内华达枪展无关。结果对敏感性分析是稳健的。

仅在加利福尼亚州检查了枪伤，枪展的发生不是随机的。

内华达州而非加利福尼亚州的枪支表演与加利福尼亚州当地的枪支伤害短期增加有关。加利福尼亚州与内华达州枪支表演的不同协会可能是由于加利福尼亚州更严格的枪支法规。

美国国立卫生研究院；加州大学伯克利分校；和海辛西蒙斯基金会。