Development of the post-traumatic stress disorder assessment scale for emergency services

This paper describes the development and validation of the Post-Traumatic Stress Disorder Assessment Scale for Emergency Services (PASES). The PASES was developed to address the needs of Australia’s first National Mental Health and Wellbeing Study of Police and Emergency Services, Answering the Call (AtC) which covered Police, Ambulance, Fire and Rescue and State Emergency Services personnel. PASES offers several advantages for use in the emergency services sector over other Post-Traumatic Stress Disorder (PTSD) screening scales, including assessment of functional impairment, a dimensional measure of severity which includes identification of sub-threshold cases experiencing distress and impairment, and allowing for experience of cumulative trauma. Analysis of Composite International Diagnostic Interview (CIDI) data from a large national sample identified PTSD symptoms that usually co-occur allowing streamlining of the scale with minimal information loss. In a large sample, PASES had high specificity and adequate sensitivity in comparison to self-reported PTSD diagnosis. Data from AtC supported there being a strong dimensional gradient in distress and associated harms, including suicidal behaviors, across the levels of severity of the PASES. In a subsample of 191 fire sector employees who completed both PASES and PCL-5, both scales had equivalent discrimination compared with self-reported diagnosis of PTSD by a mental health professional. The paper also presents population data for Australian volunteer and employed emergency services personnel collected in AtC.