[The validity and reliability of the Turkish version of the inventory of statements about self-injury]

Abstract

Objective: Non-suicidal self-injury (NSSI) is defined as the repetitive deliberate destruction of one's body tissue without suicidal intent and is frequently repetitive. The aim of this study was to examine the psychometric properties of the Inventory of Statements About Self-injury (ISAS), a measure designed to comprehensively assess non-suicidal self-injury (NSSI). The ISAS assesses 13 functions of NSSI, as well as the frequency of 12 NSSI behaviors.

Method: The ISAS was administered to 529 high school students who had performed at least one NSSI behavior. The internal consistency and test-retest reliability of the scale were examined; for construct validity, the relationship between the Turkish form of the ISAS and various criteria scales was examined, and confirmatory factor analysis (CFA) was conducted.

Results: Consistent with previous research, factor analysis of the functions scale confirmed the good-fit of the original's 2-dimension model (c²=243; s.d. = 59; NCI (c²/sd) = 4; RMSEA = 0.08 (.07-.09); CFI=0.97; NFI=0.97). In order to test the scale for construct validity, the Brief Symptom Inventory and Suicide Probability Scale were administered to participants, in addition to the ISAS, and the correlations with clinical constructs (e.g., suicidality, depression, anxiety) were in the expected direction. Also the reliability analysis revealed that the ISAS subscales demonstrated high internal consistency.

Conclusion: In the light of the findings, it was concluded that the Turkish version of ISAS could be used as a reliable and valid tool in assessing non-suicidal self-injury in research and treatment contexts.