Assessment of nonsuicidal self-injury: development and initial validation of the Non-Suicidal Self-Injury-Assessment Tool (NSSI-AT).

Research tools for assessing nonsuicidal self-injury (NSSI) epidemiology in community populations are few and are either limited in the scope of NSSI characteristics assessed or included as part of suicide assessment. Though these surveys have been immensely useful in establishing the presence of NSSI and in documenting basic epidemiological characteristics, they have been less useful in describing secondary NSSI features such as NSSI context, habituation, or perceived life impact. The aim of the current study was to examine the reliability of the test scores and validity of test score interpretations in a university population for the Non-Suicidal Self-Injury-Assessment Tool (NSSI-AT), a web-based measure of NSSI designed to assess primary (such as form, frequency, and function) and secondary (including but not limited to NSSI habituation; contexts in which NSSI is practiced; and NSSI perceived life interference, treatment, and impacts) NSSI characteristics for research purposes. Data for these analyses were drawn from 3 samples, all of which were originally part of a 2007 study of randomly selected students from 8 northeast and midwest public and private universities that participated in a web-based study entitled the Survey of Student Wellbeing. Overall, results provide support for the reliability of NSSI-AT test scores (as assessed by test-retest) and validity of NSSI-AT test score interpretations for the behavior and frequency modules (as assessed using concurrent, convergent, and discriminant evidence) in this population. Implications for research as well as next steps are discussed.