Owning a gun at home substantially increase the risk of death by firearm to everyone in the home. It turns out that suicide is the leading cause of death for Americans who have purchased a handgun within the previous year. (data published in the New England Journal of Medicine – Wintermute GJ. NEJM. 2008; 358:1421-4). Like cigarette smoke, owning a firearm has deleterious effects on everyone in the home, not just on the one who purchased the gun. Writing in the peer-reviewed journal Annals of Emergency Medicine, Dr. Wiebe reported on a case-controlled study in which household were matched on a number of demographic factors, and then incidences of gun violence were compared. They found that people who keep a gun in their home are almost twice as likely to die in a gun-related homicide, and that the risk wasespecially greater for women: women living in a home where there is a gun are almost three times more likely to die in a gun-related homicide than men similarly situated. The risk of killing oneself using a gun was almost 17 times greater for persons who live in a home where there is a gun, compared to those in homes without guns. (Wiebe D. Annals of Emergency Medicine. 2003; 41:771-82).
Gun enthusiasts like to claim that keeping a gun handy protects them and their family from violent intruders. The study by Wiebe shows that having a gun at home is associated with an increased risk of dying by gunfire, so gun ownership does not appear to be protective of violent firearms-related killings. But the Wiebe study was also able to compute the likelihood of dying by violence other than gunfire. They found there was no relationship between owning a gun and homicide by means other than a gun. In other words, having a gun around is not associated with a decreased risk of homicide of any sort. The study could find no empiric evidence that owning a gun confers some protection on a household from homicide. To my knowledge, there is no peer-reviewed study published anywhere that provides evidence that guns or gun ownership protects individuals from death or injury. If anyone reading this knows of such a study, I hope they will tell me so I can go read that study.