Background/Objectives:

A fatal diagnostic error of suicidal intention, i.e., an error implying death or serious injuries (i.e., incapacitating, chronic injury) to the patient, may have civil liability (punishable error) for the clinician. The Scale for Suicidal Ideation (SSI) is the reference psychometric instrument used to measure suicidal intention. A meta-analytical review was designed with the aim of estimating the true reliability of the SSI in general and in different settings (moderators) with the aim of correcting unreliability raw scores.

Method:

A total of 90 primary studies reporting SSI's reliability (internal consistency) was found in the literature, yielding a total of 92 effect sizes. Bare-bones meta-analysis of correlation coefficients correcting effect by sampling error were run.

Results:

The results showed an overall mean true internal consistency of .8904, 95% CI [.8878, .8930], meaning that 42.6% of the population standard deviation is error and 18.11% of an individual's measure is error. Additional estimations (moderators) of SSI's reliability for gender (men: .8873, women: .8808) adaptation version (English: .9212, Korean: .9052, Chinese: .8402, Italian: .9163, Persian: .8612), and population (subclinical: .8769, general: .9230, mental illness: .9040) were obtained. All mean true estimations were under the desirable standard for applied settings where critical decisions are made, .95. Furthermore, for populations with risk of suicide, such as prison inmates and militaries, mean true reliability could not be computed as k was insufficient.

Conclusion:

Implications of true reliabilities obtained for the estimation of individuals' true scores and population standard deviations are discussed. Examples of computation of true scores to minimize fatal diagnosis errors were performed for both known reliability and unknown reliability settings (e.g., risk populations).