Description

The Suicidal Ideation Scale (SIS-4) is a brief psychometric instrument designed to assess the frequency, intensity, and severity of suicidal thoughts and desires experienced by an individual. The primary purpose of the scale is to evaluate the extent to which suicidal ideation is present and to estimate the degree of psychological distress associated with these thoughts.

The development of the Suicidal Ideation Scale was carried out in the United States by Froyd and Perry (1985), based on the framework of the Los Angeles Suicide Prevention Center Assessment of Suicide Potentially. The instrument was subsequently adapted from English into Greek by Kleftaras.

The SIS-4 consists of four items designed to examine different aspects of suicidal ideation. The first three items assess the frequency with which suicidal thoughts occur, while the fourth item evaluates the seriousness and intensity of suicidal ideation, including the presence of a specific suicide plan.

The scale is intended for use in psychological and clinical assessment contexts, particularly when evaluating individuals who may experience suicidal thoughts. Its results should always be interpreted within a broader clinical assessment framework and not as an independent diagnostic measure.

Data Analysis and Use

Data obtained through the SIS-4 can be analyzed to estimate the severity of suicidal ideation and identify variations in the frequency and intensity of suicidal thoughts among individuals.

The scale allows researchers and clinicians to examine both the occurrence of suicidal thoughts and the degree of planning or seriousness associated with them. Statistical analysis may include descriptive procedures such as means, standard deviations, frequency distributions, and comparisons between different populations or clinical groups.

The instrument may be used in psychological research examining relationships between suicidal ideation and other psychological variables, including emotional distress, depression, psychiatric symptoms, and psychosocial functioning.

In clinical settings, the SIS-4 may contribute to the structured assessment of suicidal ideation and assist professionals in identifying individuals who may require further evaluation and appropriate psychological support.

Objective

The primary objective of the Suicidal Ideation Scale (SIS-4) is to measure the frequency and severity of suicidal thoughts and desires experienced by an individual.

More specifically, the scale aims to evaluate how often suicidal ideation occurs, how intense these thoughts are, and whether they involve more serious characteristics such as the development of a specific suicide plan.

The instrument provides a brief method for assessing suicidal ideation and may contribute to clinical decision-making, research studies, and the monitoring of changes in suicidal thoughts over time.

Structure and Content

The SIS-4 includes four questions that assess different components of suicidal ideation.

The first three questions focus on the frequency of suicidal thoughts. These items are evaluated using a five-point Likert scale, where a score of 1 corresponds to “Never” and a score of 5 corresponds to “All the time.”

The fourth question assesses the seriousness and intensity of suicidal thoughts. This item is evaluated using a four-point Likert scale, where a score of 1 indicates “Not serious at all” and a score of 4 indicates the existence of a specific suicide plan.

Through these four items, the scale evaluates both the presence of suicidal ideation and the level of risk associated with the reported thoughts.

Scoring

The total score of the SIS-4 is calculated by summing the responses to all four items. The total score ranges from 4 to 19 points.

Higher scores indicate a greater severity of suicidal ideation and a more critical level of suicidal thoughts.

The interpretation of scores should consider both the frequency of suicidal thoughts and the seriousness of the reported ideation, particularly the response to the item assessing the existence of a suicide plan.

Because suicidal ideation is a sensitive clinical construct, scores should always be interpreted by appropriately trained professionals and considered alongside other relevant clinical information.

Statistical Analysis

Statistical evaluation of the SIS-4 may include examination of internal consistency, relationships between suicidal ideation scores and other psychological variables, and comparisons between different clinical or community populations.

The reliability of the scale has been examined through Cronbach’s alpha coefficients. For the total sample, internal consistency was reported as α = 0.95, while reliability coefficients were α = 0.81 for the community sample and α = 0.95 for the outpatient sample.

The scale may also be examined through analyses of its individual components, particularly the dimensions related to active suicidal desire, preparation, and passive suicidal desire.

Validity

The SIS-4 demonstrates evidence of internal consistency and psychometric adequacy according to the reported findings.

For the first three components of suicidal ideation, Cronbach’s alpha coefficients were reported as α = 0.92 for active suicidal desire, α = 0.69 for preparation, and α = 0.79 for passive suicidal desire.

These findings indicate satisfactory internal coherence among the components assessed by the scale. Further evaluation of validity should consider the specific population, cultural adaptation, and clinical context in which the instrument is applied.

Reliability

The SIS-4 demonstrates high reliability based on reported internal consistency coefficients.

The overall Cronbach’s alpha coefficient was reported as α = 0.95, indicating excellent internal consistency. Reliability was also high among specific samples, with α = 0.81 in the community sample and α = 0.95 in the outpatient sample.

These findings support the use of the instrument as a reliable measure for assessing suicidal ideation intensity and frequency within the populations examined.

References

Holi, M. M., Pelkonen, M., Karlsson, L., Kiviruusu, O., Ruuttu, T., Heilä, H., … & Marttunen, M. (2005). Psychometric properties and clinical utility of the Scale for Suicidal Ideation (SSI) in adolescents. BMC Psychiatry, 5(1), 1–8.

Froyd, J. E., & Perry, C. (1985). Development of assessment procedures based on the Los Angeles Suicide Prevention Center Assessment of Suicide Potentially.