Evidence that access to firearms significantly increases odds of suicide and homicide
Having access to a gun in the home increases the inhabitants' risk of being the victim of suicide or homicide, suggests an article being published in Annals of Internal Medicine.
Researchers conducted a systematic review and meta-analysis of 15 published studies comparing the odds of being a victim of suicide or homicide between persons with and without access to firearms. All but one of the 15 studies reviewed reported significantly increased odds of suicide (odds ratio, 3.2) and homicide (odds ratio, 1.9) victimization associated with firearm access. The researchers limited their review to studies with individual-level data because their focus was individual effects of firearm accessibility. Population-level data was excluded due to concerns about ecological bias. For example, population-level data on household gun ownership may not reflect the accessibility of guns to a specific suicide or homicide victim within that population, while individual-level data does reflect this individual-level gun accessibility.
The author of an accompanying editorial asserts that the researchers' estimations are far too conservative and that exclusion of population-level data could display an equally misleading bias. The editorialist cites population-based studies showing that places with higher levels of household gun ownership are associated with higher rates of firearm-related and overall suicide and that there is no other association between gun ownership levels and suicide by means other than guns. As for homicide, the editorialist writes that population-level evidence indicates that a gun in the home increases the risk for homicide victimization for others in society, either due to someone in the family shooting others (for example, the Sandy Hook Elementary School shootings) or the gun being stolen by criminals. He concludes that "obtaining a firearm not only endangers those living in the home but also imposes substantial costs on the community."