Lethality of suicide attempt rating scale.

An 11-point (0-10) scale for measuring the degree of lethality of suicide attempts is presented. The scale has nine example "anchors" and uses the relative lethality of an extensive table of drugs. The psychometric studies show the scale to be of at least equal-interval, possibly even ratio measurement level. The equal-interval quality allows suicidal behaviors to be specified in numeric relationship to each other relieving us of the burden of using unquantified labels such as "mild," "moderate," and "serious." Having a standardized, commonly used reference scale should greatly facilitate our research and clinical efforts to communicate our findings. The scale can be used reliably by nonmedical personnel with no prior training.