Why this study matters

Firearm owners, and in particular the women who do not own firearms, must be made aware that the suicide rate increases 4-fold when a firearm is introduced into their previously firearm-free home.

Study design

A total of 9.5 million adult women residing in homes without firearms at the time the study was launched were followed for up to 12 years. During the study period, the number of women who subsequently resided in homes with firearms was noted. The number of firearm and non-firearm suicides were recorded.

Results and conclusion

Of the 9.5 million women enrolled in the study, 331,968 (3.5%) had a change in household firearm exposure.

During the study period, there were 2197 suicides, 337 of which (15%) involved firearms.

The all-cause suicide rate was higher among women residing in homes with firearms than women residing in homes without firearms (HR = 1.43). The increased suicide rate was due to firearms (HR = 4.32). There was no difference in non-firearm suicides between women living in homes with and without firearms (HR = 0.90).