Addressing Nonsuicidal Self-injury in Schools

Change in self-reported life-time prevalence of nonsuicidal self-injury is measured with a single-item (yes/no) from the Self-Injurious Thoughts and Behaviors Interview Self-Report Short-Form (SITBI-SR-SF).

Change in self-reported frequency of nonsuicidal self-injury (NSSI) is measured with NSSI checklist from the Inventory of Statements About Self-injury (ISAS). Number of NSSI incidence is registered from 0 to the highest number that participants rate. High scores indicate more frequent NSSI.

Change in self-reported health-related quality of life (HRQOL) is measured with the 52-item version of the kid screen (KIDSCREEN 52), a self-report measure that measures the subjective HRQOL in children and adolescents between the ages of 8 and 18. KIDSCREEN 52 questionnaire consisted of 52 items assessing ten HRQOL dimensions. The KIDSCREEN-52 HRQOL questionnaire assesses the frequency of behavior/feelings or and use a 5-point Likert response scale. Scores are computed for each dimension and are transformed into T-values with a mean of 50 and a standard deviation of 10. Higher scores indicate higher HRQOL.

Change in self-reported nonsuicidal self-injury expectancy is measured with the Non-Suicidal Self-Injury Expectancy Questionnaire (NEQ), which is a self-report measure that measures attitudes and expectancy to own and others' NSSI. A shortened 10-item version was used with items scored on a 4-point Likert scale, ranging from 10 to 40, with higher scores indicating higher endorsement of NSSI expectancies.

Change in self-reported perceived social support was measured using the Multidimensional Scale of Perceived Social Support, which is a self-report scale that measures perceived social support. It contains 12 items and is scored on a 7-point Likert scale with total scores ranging from 12 to 84, with higher scores indicating higher levels of perceived social support.

Change in self-reported stigma is measures with the Mental Health Stigmatization Scale-Revised (PMHSS-R). PMHSS-R assess perceptions of stigma awareness and agreement related to mental-health in peers. The subscales include six and five items rated on a five-point Likert scale (1 = disagree completely, 5 = agree completely). An individual score is generated by adding up all items of each subscale, which ranges from 6 to 30 (awareness) and 5 to 25 (agreement). Higher scores indicate higher levels of stigma agreement and stigma awareness, that is, higher levels of mental health related stigmatizing attitudes.

Change in self-reported help-seeking is measured with Help-Seeking Acceptability at School, Adult Help for Suicidal Youth and Reject Codes of Silence, which is a self-report measure that assesses attitudes toward seeking help from adults in three domains: "Help seeking acceptability", "Adult help for suicidal youth" and "Reject Codes of Silence". The total score includes 11 items which are scored on a 4-point Likert scale. Scores range from 4 to 16 (help-seeking acceptability); 3 to 12 (Adult help), and 3 to 12 (rejecting codes of silence). Higher scores indicate better outcome and a more positive attitude to help-seeking.

Change in self-reported suicidal ideation is assessed with the Self-Injurious Thoughts and Behaviors Interview Self-Report Short-Form (SITBI-SR-SF) as single-item assessment of prevalence yes/no.

Changes in self-reported difficulties in emotion regulation is measures with the 16-item version of the Difficulties in Emotion Regulation Scale (DERS-16). Total scores range from 16 to 80 with higher scores indicating higher levels of difficulties in emotion regulation.

Change in self-reported self-criticism is measures using the Self-Rating Scale (SRS), which is a self-report measure to assess self-criticism. It contains of 8 items which are scored on a 7-point Likert scale. The total scale ranges from 8 to 56 with higher scores indicating higher levels of self-criticism.