Interpersonal and intrapersonal functions of deliberate self-harm (DSH) : a psychometric examination of the inventory of statements about self-injury (ISAS) scale

Deliberate self-harm (DSH), commonly defined as the intentional, direct andnon-suicidal destruction of one's body, appears to be Common across both clinical and norK linical populations. A recently developed measure- of functions of DSH, the Inventory of Statements About Self-Injury (ISAS), was examined to test its two-factox model within a sample of members of online social networks. The approach adopted was to fit data from the scale to the Rasch measurement model, which is increasingly used to develop and/or assess scales. Two hundred and one (η = 201) participants aged over 18 yean- of age, who had engaged in DSH in the last 1 2 months, were recruited from online social networks' DSH peer support groups to complete an online survey. An exploratory factor analysis supported interpersonal and intrapersonal factors based on 13 function domains. Furthermore, both factors demonstrated satisfactory fit to the Rasch model. Some local dependency was detected, and when addressed, it impacted on the alpha Coefficient level tor intrapersonal tact or- Tins study is the first independent psychometric invest tgation of ISAS, further supporting the scale authors' psychometric evaluations. Additional validation across different DSH samples is recommended.