The effect of access to lethal methods of injury on suicide rates.

The relationship between the availability of lethal methods of injury and suicide rates is an important, but unresolved question. We investigated this relationship by prospectively classifying lethal methods according to their accessibility in the five counties of New York City. These counties have both similarities and differences in the proportion of their populations with access to specific lethal means. We then compared the age- and gender-adjusted method-specific suicide rates of these counties. There were marked differences in overall crude suicide rates among the five counties. The counties had similar suicide rates involving methods that were equally accessible to all persons in each county (eg, hanging, laceration, suffocation, and burns) as well as methods that were accessible to a smaller, but similar proportion of the population in each county (eg, firearms and drowning in waterways). Virtually all of the differences in overall suicide risk among counties were explained by differences in rates involving methods that were differentially available in the counties, principally fall from height, overdose of prescription medications, and carbon monoxide poisoning. We conclude that differences in suicide rates between communities are, in large part, due to differences in accessibility to lethal methods of injury. Therefore, systematic studies should evaluate the effect of reducing accessibility to specific lethal means on suicide rates.