Lethality of Suicidal Methods and Suicide Risk: Two Distinct Concepts

Abstract

Two objective measures of the lethality of 11 suicidal methods were defined: Mean Seriousness of suicidal incidents involving the method, and Probability of Death resulting from use of the method. The measures were found to be essentially interchangeable. Fourteen judges were asked to rank the same 11 methods according to the “probability of death resulting from use of the method in a suicide attempt.” The judges' subjective estimates of lethality corresponded well with objective measures. The relationship between lethality and risk, or the probability of suicide at some future date, was examined. The two variables were clearly distinct. Rank correlation between lethality of, and risk associated with, the 11 suicidal methods was not significant Moreover, when all incidents within a given lethality category were collapsed, and then risk associated with each lethality category evaluated, the most lethal attempts had a significantly lower risk of future suicide than the least lethal attempts.