Trauma measures for use with psychosis populations: a systematic review of psychometric properties using COSMIN

Traumatic events play a key role in the development and course of psychosis. Psychotic symptoms themselves and coercive treatment practices can be inherently traumatic. Hence, reliable and valid methods of assessing trauma and its impact (i.e., Post-Traumatic Stress Disorder (PTSD) symptomology) are essential for use with people with psychosis. Many measures are available to select from, but this is the first review to appraise the psychometric properties of trauma measures to guide decision making regarding instrument use. The review was prospectively registered on Prospero (CRD42022306100). Evaluation of methodological and psychometric quality followed Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) guidance. Twenty-four articles were eligible, with sixteen trauma measures evaluated. Childhood Trauma Questionnaire- Short Form demonstrated the most robust evidence for assessing experience of trauma. The Trauma and Life Experience (TALE) checklist was the only measure to include specific psychosis and iatrogenic harm items. For PTSD measures, the Symptoms of Trauma Scale and PTSD Symptom Scale– Self Report had the highest quality evidence. Psychometric strengths and weaknesses of various trauma measures are comprehensively evaluated, highlighting future research directions to strengthen the evidence base with emphasis on further evaluation of the TALE, which integrates trauma specific to psychosis.

Key words: Instruments, Psychosis, Psychometric, Outcome Measure, Trauma, Schizophrenia