How to improve testing when trying to predict inmate suicidal behavior

To measure the predictive power of the Suicide Probability Scale (SPS) in a male inmate population (federal penitentiary) with the added contribution of actuarial data.

SPS scores and data from the files of 518 inmates were analyzed in relation to their suicidal behaviors over the following 10 years.

During this period, 12 inmates committed suicide (2.32%), 43 engaged in non-lethal self-harm (8.3%) and 15 expressed serious suicidal intention (2.9%), for a total of 70 (13.51%) who manifested at least one form of suicidal behavior. The records of the 518 inmates allowed identifying seven actuarial variables (out of 24 documented) that distinguished the group that acted out. These variables were tested in combination with the SPS score to determine the best predictive models of suicidal behavior. Depending on type of suicidal behavior and on observation period, the following seven variables could prove useful in improving the predictive capacity of the SPS: age, prior suicidal behavior, borderline personality disorder, length of sentence, number of sentences, prior incarceration in a provincial prison, and juvenile priors. However, analyses did not allow developing a better predictive model for the specific subgroup of suicide completers.

SPS is improved when adding actuarial data.