Evaluating the predictive validity of suicidal intent and medical lethality in youth

To examine whether suicidal intent and medical lethality of past suicide attempts are predictive of future attempts, the association between intent and lethality, and the consistency of these characteristics across repeated attempts among youth.

Suicide attempts in a 15-year prospective study of 180 formerly psychiatrically hospitalized adolescents (M(age at hospitalization) = 14.83; 51% female; 80% Caucasian) were characterized with the Subjective Intent Rating Scale and Lethality of Attempt Rating Scale. Anderson-Gill recurrent events survival models and generalized estimating equations were used to assess predictive validity. Generalized linear models were used to examine stability of characteristics across attempts.

Neither intent nor lethality from the most recent attempt predicted future attempts. The highest level of intent and most severe lethality of attempts during the follow-up predicted subsequent attempts, but the degree to which highest intent and most severe lethality contributed to prediction after considering methods of suicide attempts, past number of attempts, or psychiatric diagnoses was mixed. Across successive attempts, there was little consistency in reported characteristics. Intent and lethality were related to each other only for attempts occurring in early adulthood.

Highest intent and lethality were better predictors of future attempts than intent and lethality of the most recent attempt. However, these characteristics should be considered as predictors only within the context of other factors. For youth, clinicians should not infer true intent from the lethality of attempts, nor assume that characteristics of future suicide attempts will be similar to those of previous attempts.